| 1. |
- Fall, Tove, et al.
(författare)
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Age- and sex-specific causal effects of adiposity on cardiovascular risk factors
- 2015
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 64:5, s. 1841-1852
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Tidskriftsartikel (refereegranskat)abstract
- Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10(-107)) and stratified analyses (all P < 3.3 × 10(-30)). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors.
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| 2. |
- Howe, Laurence J., et al.
(författare)
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Educational attainment, health outcomes and mortality : a within-sibship Mendelian randomization study
- 2023
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Ingår i: International Journal of Epidemiology. - 0300-5771 .- 1464-3685. ; 52:5, s. 1579-1591
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Tidskriftsartikel (refereegranskat)abstract
- Background Previous Mendelian randomization (MR) studies using population samples (population MR) have provided evidence for beneficial effects of educational attainment on health outcomes in adulthood. However, estimates from these studies may have been susceptible to bias from population stratification, assortative mating and indirect genetic effects due to unadjusted parental genotypes. MR using genetic association estimates derived from within-sibship models (within-sibship MR) can avoid these potential biases because genetic differences between siblings are due to random segregation at meiosis. Methods Applying both population and within-sibship MR, we estimated the effects of genetic liability to educational attainment on body mass index (BMI), cigarette smoking, systolic blood pressure (SBP) and all-cause mortality. MR analyses used individual-level data on 72 932 siblings from UK Biobank and the Norwegian HUNT study, and summary-level data from a within-sibship Genome-wide Association Study including >140 000 individuals. Results Both population and within-sibship MR estimates provided evidence that educational attainment decreased BMI, cigarette smoking and SBP. Genetic variant-outcome associations attenuated in the within-sibship model, but genetic variant-educational attainment associations also attenuated to a similar extent. Thus, within-sibship and population MR estimates were largely consistent. The within-sibship MR estimate of education on mortality was imprecise but consistent with a putative effect. Conclusions These results provide evidence of beneficial individual-level effects of education (or liability to education) on adulthood health, independently of potential demographic and family-level confounders.
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| 3. |
- Jelenkovic, Aline, et al.
(författare)
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Associations between birth size and later height from infancy through adulthood : An individual based pooled analysis of 28 twin cohorts participating in the CODATwins project
- 2018
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Ingår i: Early Human Development. - : Elsevier BV. - 0378-3782 .- 1872-6232. ; 120, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is evidence that birth size is positively associated with height in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. Aim: To analyze the associations of birth weight, length and ponderal index with height from infancy through adulthood within mono- and dizygotic twin pairs, which provides insights into the role of genetic and environmental individual-specific factors. Methods: This study is based on the data from 28 twin cohorts in 17 countries. The pooled data included 41,852 complete twin pairs (55% monozygotic and 45% same-sex dizygotic) with information on birth weight and a total of 112,409 paired height measurements at ages ranging from 1 to 69 years. Birth length was available for 19,881 complete twin pairs, with a total of 72,692 paired height measurements. The association between birth size and later height was analyzed at both the individual and within-pair level by linear regression analyses. Results: Within twin pairs, regression coefficients showed that a 1-kg increase in birth weight and a 1-cm increase in birth length were associated with 1.14–4.25 cm and 0.18–0.90 cm taller height, respectively. The magnitude of the associations was generally greater within dizygotic than within monozygotic twin pairs, and this difference between zygosities was more pronounced for birth length. Conclusion: Both genetic and individual-specific environmental factors play a role in the association between birth size and later height from infancy to adulthood, with a larger role for genetics in the association with birth length than with birth weight.
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| 4. |
- Jelenkovic, Aline, et al.
(författare)
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Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age : A Study of the CODATwins Project
- 2015
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 18:5, s. 557-570
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Tidskriftsartikel (refereegranskat)abstract
- A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m(2) in childhood and adolescence and up to 0.2 kg/m(2) in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
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| 5. |
- Kilpi, Fanny, et al.
(författare)
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Disentangling the relative importance of different socioeconomic resources for myocardial infarction incidence and survival : a longitudinal study of over 300 000 Finnish adults
- 2016
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Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 26:2, s. 260-266
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lower socioeconomic position (SEP) is associated with an increased risk of myocardial infarction (MI) incidence and mortality, but the relative importance of different socioeconomic resources at different stages of the disease remains unclear. Methods: A nationally representative register-based sample of 40- to 60-year-old Finnish men and women in 1995 (n = 302 885) were followed up for MI incidence and mortality in 1996-2007. We compared the effects of education, occupation, income and wealth on first MI incidence, first-day and long-term fatality. Cox's proportional hazards regression and logistic regression models were estimated adjusting for SEP covariates simultaneously to assess independent effects. Results: Fully adjusted models showed greatest relative inequalities of MI incidence by wealth in both sexes, with an increased risk also associated with manual occupations. Education was a significant predictor of incidence in men. Low income was associated with a greater risk of death on the day of MI incidence [odds ratio (OR) = 1.40 in men and 1.95 in women when comparing lowest and highest income quintiles], and in men, with long-term fatality [hazard ratio (HR) = 1.74]. Wealth contributed to inequalities in first-day fatality in men and in long-term fatality in both sexes. Conclusion: The results show that different socioeconomic resources have diverse effects on the disease process and add new evidence on the significant association of wealth with heart disease onset and fatality. Targeting those with the least resources could improve survival in MI patients and help reduce social inequalities in coronary heart disease mortality.
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| 6. |
- Kilpi, Fanny, et al.
(författare)
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Early-life and adult socioeconomic determinants of myocardial infarction incidence and fatality
- 2017
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Ingår i: Social Science and Medicine. - : Elsevier BV. - 0277-9536 .- 1873-5347. ; 177, s. 100-109
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Tidskriftsartikel (refereegranskat)abstract
- Social inequalities in coronary heart disease mortality have roots in childhood conditions, but it is unknown whether they are associated both with the incidence of the disease and the following survival. We studied how several different early-life socioeconomic factors, together with later socioeconomic attainment, were associated with myocardial infarction (MI) incidence and fatality in Finland. The data was based on a register-based sample of households from a census in 1950 that also provided information on childhood circumstances. MI hospitalizations and mortality in 1988-2010 were studied in those who were up to 14 years of age at the time of the census and resident in Finland in 1987 (n = 94,501). Parental education, occupation, household crowding, home ownership, and family type were examined together with adulthood education and income. Hazard and odds ratios with 95% confidence intervals (CI) were calculated using Cox regression (incidence and long-term fatality) and logistic regression (short-term fatality) models. Lower parental education, occupational background and greater household crowding were associated with MI incidence. In models adjusted for adulthood variables, crowding increased the risk by 16% (95% CI 5-29%) in men and 25% (95% CI 3-50%) in women. Shortterm survival was more favourable in sons of white-collar parents and daughters of owner-occupied households, but most aspects of childhood circumstances did not strongly influence long-term fatality risk. Socioeconomic attainment in adulthood accounted for a substantial part of the effects of childhood conditions, but the measured childhood factors explained little of the disparities by adulthood education and income. Moreover, income and education remained associated with MI incidence when adjusted for unobserved shared family factors in siblings. Though social and economic development in society seems to have mitigated the disease burden associated with poor childhood living conditions in Finland, low adult socioeconomic resources have remained a strong determinant of MI incidence and fatality.
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| 7. |
- Kilpi, Fanny, et al.
(författare)
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Reply to Oude Groeniger and van Lenthe
- 2018
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 29:4, s. e37-e37
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Kilpi, Fanny, et al.
(författare)
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The Spillover Influence of Partner’s Education on Myocardial Infarction Incidence and Survival
- 2018
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Ingår i: Epidemiology. - 1044-3983 .- 1531-5487. ; 29:2, s. 237-245
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Tidskriftsartikel (refereegranskat)abstract
- Background: Education is believed to have positive spillover effects across network connections. Partner’s education may be an important resource preventing the incidence of disease and helping patients cope with illness. We examined how partner’s education predicted myocardial infarction (MI) incidence and survival net of own education and other socioeconomic resources in Finland.Methods: A sample of adults aged 40–69 years at baseline in Finland in 1990 was followed up for MI incidence and mortality during the period 1991–2007 (n = 354,100).Results: Lower own and spousal education both contributed independently to a higher risk of MI incidence and fatality when mutually adjusted. Having a partner with basic education was particularly strongly associated with long-term fatality in women with a hazard ratio of 1.53 (95% confidence interval, 1.22–1.92) compared with women with tertiary level educated partners. There was some evidence that the incidence risk associated with basic spousal education was weaker in those with own basic education. The highest risks of MI incidence and fatality were consistently found in those without a partner, whereas the most favorable outcomes were in households where both partners had a tertiary level of education.Conclusions: Accounting for spousal education demonstrates how health-enhancing resources accumulate to some households. Marriage between people of similar educational levels may therefore contribute to the widening of educational differences in MI incidence and survival.
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| 9. |
- Martikainen, Pekka, et al.
(författare)
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Joint association between education and polygenic risk score for incident coronary heart disease events : a longitudinal population-based study of 26 203 men and women
- 2021
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 75:7, s. 651-657
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Tidskriftsartikel (refereegranskat)abstract
- Background Genetic vulnerability to coronary heart disease (CHD) is well established, but little is known whether these effects are mediated or modified by equally well-established social determinants of CHD. We estimate the joint associations of the polygenetic risk score (PRS) for CHD and education on CHD events.Methods The data are from the 1992, 1997, 2002, 2007 and 2012 surveys of the population-based FINRISK Study including measures of social, behavioural and metabolic factors and genome-wide genotypes (N=26 203). Follow-up of fatal and non-fatal incident CHD events (N=2063) was based on nationwide registers.Results Allowing for age, sex, study year, region of residence, study batch and principal components, those in the highest quartile of PRS for CHD had strongly increased risk of CHD events compared with the lowest quartile (HR=2.26; 95% CI: 1.97 to 2.59); associations were also observed for low education (HR=1.58; 95% CI: 1.32 to 1.89). These effects were largely independent of each other. Adjustment for baseline smoking, alcohol use, body mass index, igh-density lipoprotein (HDL) and total cholesterol, blood pressure and diabetes attenuated the PRS associations by 10% and the education associations by 50%. We do not find strong evidence of interactions between PRS and education.Conclusions PRS and education predict CHD events, and these associations are independent of each other. Both can improve CHD prediction beyond behavioural risks. The results imply that observational studies that do not have information on genetic risk factors for CHD do not provide confounded estimates for the association between education and CHD.
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| 10. |
- Narusyte, Jurgita, et al.
(författare)
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Genetic Liability to Disability Pension in Women and Men: A Prospective Population-Based Twin Study
- 2011
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies of risk factors for disability pension (DP) have mainly focused on psychosocial, or environmental, factors, while the relative importance of genetic effects has been less studied. Sex differences in biological mechanisms have not been investigated at all.Methods: The study sample included 46,454 Swedish twins, consisting of 23,227 complete twin pairs, born 1928–1958, who were followed during 1993–2008. Data on DP, including diagnoses, were obtained from the National Social Insurance Agency. Within-pair similarity in liability to DP was assessed by calculating intraclass correlations. Genetic and environmental influences on liability to DP were estimated by applying discrete-time frailty modeling.Results: During follow-up, 7,669 individuals were granted DP (18.8% women and 14.1% men). Intraclass correlations were generally higher in MZ pairs than DZ pairs, while DZ same-sexed pairs were more similar than opposite-sexed pairs. The best-fitting model indicated that genetic factors contributed 49% (95% CI: 39–59) to the variance in DP due to mental diagnoses, 35% (95% CI: 29–41) due to musculoskeletal diagnoses, and 27% (95% CI: 20–33) due to all other diagnoses. In both sexes, genetic effects common to all ages explained one-third, whereas age-specific factors almost two-thirds, of the total variance in liability to DP irrespective of diagnosis. Sex differences in liability to DP were indicated, in that partly different sets of genes were found to operate in women and men, even though the magnitude of genetic variance explained was equal for both sexes.Conclusions: The findings of the study suggest that genetic effects are important for liability to DP due to different diagnoses. Moreover, genetic contributions to liability to DP tend to differ between women and men, even though the overall relative contribution of genetic influences does not differ by sex. Hence, the pathways leading to DP might differ between women and men.
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| 11. |
- Nisen, Jessica, et al.
(författare)
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Education, Other Socioeconomic Characteristics Across the Life Course, and Fertility Among Finnish Men
- 2018
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Ingår i: European Journal of Population. - : Springer Science and Business Media LLC. - 0168-6577 .- 1572-9885. ; 34:3, s. 337-366
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Tidskriftsartikel (refereegranskat)abstract
- The level of education and other adult socioeconomic characteristics of men are known to associate with their fertility, but early-life socioeconomic characteristics may also be related. We studied how men's adult and early-life socioeconomic characteristics are associated with their eventual fertility and whether the differences therein by educational level are explained or mediated by other socioeconomic characteristics. The data on men born in 1940-1950 (N = 37,082) were derived from the 1950 Finnish census, which is linked to later registers. Standard and sibling fixed-effects Poisson and logistic regression models were used. Education and other characteristics were positively associated with the number of children, largely stemming from a higher likelihood of a first birth among the more socioeconomically advantaged men. The educational gradient in the number of children was not explained by early socioeconomic or other characteristics shared by brothers, but occupational position and income in adulthood mediated approximately half of the association. Parity-specific differences existed: education and many other socioeconomic characteristics predicted the likelihood of a first birth more strongly than that of a second birth, and the mediating role of occupational position and income was also strongest for first births. Relatively small differences were found in the likelihood of a third birth. In men, education is positively associated with eventual fertility after controlling for early socioeconomic and other characteristics shared by brothers. Selective entry into fatherhood based on economic provider potential may contribute considerably to educational differentials in the number of children among men.
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| 12. |
- Scheers Andersson, Elina, et al.
(författare)
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Heritability of gestational weight gain--a Swedish register-based twin study
- 2015
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 18:4, s. 410-8
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Tidskriftsartikel (refereegranskat)abstract
- Gestational weight gain (GWG) is a complex trait involving intrauterine environmental, maternal environmental, and genetic factors. However, the extent to which these factors contribute to the total variation in GWG is unclear. We therefore examined the genetic and environmental influences on the variation in GWG in the first and second pregnancy in monozygotic (MZ) and dizygotic (DZ) twin mother-pairs. Further, we explored if any co-variance existed between factors influencing the variation in GWG of the mothers’ first and second pregnancies. By using Swedish nationwide record-linkage data, we identified 694 twin mother-pairs with complete data on their first pregnancy and 465 twin mother-pairs with complete data on their second pregnancy during 1982–2010. For a subanalysis, 143 twin mother-pairs had complete data on two consecutive pregnancies during the study period. We used structural equation modeling (SEM) to assess the contribution of genetic, shared, and unique environmental factors to the variation in GWG. A bivariate Cholesky decomposition model was used for the subanalysis. We found that genetic factors explained 43% (95% CI: 36–51%) of the variation in GWG in the first pregnancy and 26% (95% CI: 16–36%) in the second pregnancy. The remaining variance was explained by unique environmental factors. Both overlapping and distinct genetic and unique environmental factors influenced GWG in the first and the second pregnancy. This study showed that GWG has a moderate heritability, suggesting that a large part of the variation in the trait can be explained by unique environmental factors.
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| 13. |
- Scheers Andersson, Elina, et al.
(författare)
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Total and Trimester-Specific Gestational Weight Gain and Offspring Birth and Early Childhood Weight : A Prospective Cohort Study on Monozygotic Twin Mothers and Their Offspring
- 2016
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 19:4, s. 367-76
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Tidskriftsartikel (refereegranskat)abstract
- Gestational weight gain (GWG) has in numerous studies been associated with offspring birth weight (BW) and childhood weight. However, these associations might be explained by genetic confounding as offspring inherit their mother's genetic potential to gain weight. Furthermore, little is known about whether particular periods of pregnancy could influence offspring body weight differently. We therefore aimed to explore total and trimester-specific effects of GWG in monozygotic (MZ) twin mother-pairs on their offspring's BW, weight at 1 year and body mass index (BMI) at 5 and 10 years. MZ twin mothers born 1962-1975 were identified in national Swedish registers, and data on exposure and outcome variables was collected from medical records. We analyzed associations within and between twin pairs. We had complete data on the mothers' GWG and offspring BW for 82 pairs. The results indicated that total, and possibly also second and third trimester GWG were associated with offspring BW within the twin pairs in the fully adjusted model (β = 0.08 z-score units, 95% CI: 0.001, 0.17; β = 1.32 z-score units, 95% CI: -0.29, 2.95; and β = 1.02 z-score units, 95% CI: -0.50, 2.54, respectively). Our findings, although statistically weak, suggested no associations between GWG and offspring weight or BMI during infancy or childhood. Our study suggests that total, and possibly also second and third trimester, GWG are associated with offspring BW when taking shared genetic and environmental factors within twin pairs into account. Larger family-based studies with long follow-up are needed to confirm our findings.
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| 14. |
- Silventoinen, Karri, et al.
(författare)
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Changing associations of coronary heart disease incidence with current partnership status and marital history over three decades
- 2022
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Ingår i: SSM - Population Health. - : Elsevier BV. - 2352-8273. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Married men and women have better health than non-married, but little is known about how cohabitation and marital history are associated with coronary heart disease (CHD) incidence and how these associations have changed over time. We analyzed these associations by fitting Cox regression models to register data covering the whole Finnish population aged 35 years or older (N = 4,415,590), who experienced 530,560 first time non-fatal or fatal CHD events during the years 1990–2018. Further, we used stratified Cox regression models to analyze CHD incidence within same-sex sibling pairs (N = 377,730 pairs). Married men and women without previous divorce had the lowest CHD incidence whereas cohabitation and a history of divorce were associated with higher CHD incidence. The associations were stronger in younger (35–64 years old) than older participants (65 years or older). These associations remained after adjusting for several indicators of social position, and the lower CHD incidence among those married without previous divorce was also observed within sibling pairs with a shared family background. The differences in CHD incidence between the categories generally widened over time; the largest and most systematic widening was observed among women in the younger age category. The long standing negative effect of divorce suggests that selection may partly explain the association between partnership status and CHD incidence. Partnership status is an increasingly important factor contributing to social inequalities in health.
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| 15. |
- Silventoinen, Karri, et al.
(författare)
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Does obesity modify the effect of blood pressure on the risk of cardiovascular disease? : A population-based cohort study of more than one million Swedish men
- 2008
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 118:16, s. 1637-42
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Some studies have suggested that increased blood pressure has a stronger effect on the risk of cardiovascular disease (CVD) in lean persons than in obese persons, although this is not a universal finding. Given the inconsistency of this result, we tested it using a large population-based cohort data set. METHODS AND RESULTS: Systolic and diastolic blood pressures (BPs) and body mass index were measured in 1 145 758 Swedish men born between 1951 and 1976 who were in young adulthood (median age 18.2 years). During the register-based follow-up, which lasted until the end of 2006, 65 611 new CVD events took place, including 6799 myocardial infarctions and 8827 strokes. Hazard ratios (HRs) per 1-SD increase in systolic and diastolic BP were computed within established body mass index categories (underweight, normal, overweight, or obese) with Cox proportional hazards models. The strongest associations of diastolic BP with CVD (HR 1.18), myocardial infarction (HR 1.22), and stroke (HR 1.13) were observed in the obese category. For systolic BP, the strongest associations were observed in the obese category with CVD (HR 1.16) and stroke (HR 1.29) but in the overweight category with myocardial infarction (HR 1.19). We observed statistically significant interactions (P<0.0001) with body mass index for diastolic BP in relation to CVD and for systolic BP in relation to CVD and stroke. CONCLUSIONS: In contrast to the findings of previous studies, we observed a general increase in the magnitude of the association between blood pressure and subsequent CVD with increasing body mass index. Hypertension should not be regarded as a less serious risk factor in obese than in lean or normal-weight persons.
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| 16. |
- Silventoinen, Karri, et al.
(författare)
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Education in twins and their parents across birth cohorts over 100 years : an individual-level pooled analysis of 42 twin cohorts
- 2017
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Ingår i: Twin Research and Human Genetics. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1832-4274 .- 1839-2628.
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Tidskriftsartikel (refereegranskat)abstract
- Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990-1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
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| 17. |
- Silventoinen, Karri, et al.
(författare)
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Ethnic differences in blood pressure in young men living in similar environment : a study of international adoptees in Sweden
- 2010
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 28:7, s. 1393-1399
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Tidskriftsartikel (refereegranskat)abstract
- Objective To analyze differences in blood pressure in young men with different ethnic backgrounds but living in similar environment. Methods We utilized information on virtually the total Swedish male population born between 1951 and 1987 including 5388 international adoptees, 8834 Swedish adoptees and 1 469 196 Swedish nonadoptees. Systolic blood pressure (SBP), height and weight were measured during conscription examination at the average age of 18.2 years. Results SBP was lower in international adoptees than in native-born Swedes regardless of the geographic area of origin of the adoptees. BMI and height partly explained this difference, but additional adjustment for childhood social position only slightly modified the results. The largest difference was observed in adoptees from the Indian subcontinent when compared with native-born Swedes (-5.21 95% confidence intervals -6.16 to -4.27 when adjusted for height, BMI and childhood social position). Slightly lower SBP was also observed in Swedish adoptees when compared with Swedish nonadoptees. The association between BMI and SBP did not differ between international adoptees and native-born Swedes. Conclusion Our results suggest that international adoptees are not at higher risk for elevated blood pressure in young adulthood than native-born Swedes. Non-white genetic heritage or environmental exposures during pregnancy or in early life specific for adopted children may be associated with lower risk of hypertension. J Hypertens 28: 1393-1399 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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| 18. |
- Silventoinen, Karri, et al.
(författare)
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Genetic and environmental variation in educational attainment : an individual-based analysis of 28 twin cohorts
- 2020
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural–geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a2 = 0.43; 0.41–0.44), but also environmental variation shared by co-twins was substantial (c2 = 0.31; 0.30–0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900–1949 (a2 = 0.44; 0.41–0.46) than in the later cohorts born in 1950–1989 (a2 = 0.38; 0.36–0.40), with a corresponding lower influence of common environmental factors (c2 = 0.31; 0.29–0.33 and c2 = 0.34; 0.32–0.36, respectively). In conclusion, both genetic and environmental factors shared by co-twins have an important influence on individual differences in educational attainment. The effect of genetic factors on educational attainment has decreased from the cohorts born before to those born after the 1950s.
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| 19. |
- Silventoinen, Karri, et al.
(författare)
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Height, social position and coronary heart disease incidence : the contribution of genetic and environmental factors
- 2023
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 77:6, s. 384-390
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Tidskriftsartikel (refereegranskat)abstract
- Background The associations between height, socioeconomic position (SEP) and coronary heart disease (CHD) incidence are well established, but the contribution of genetic factors to these associations is still poorly understood. We used a polygenic score (PGS) for height to shed light on these associations.Methods Finnish population-based health surveys in 1992–2011 (response rates 65–93%) were linked to population registers providing information on SEP and CHD incidence up to 2019. The participants (N=29 996; 54% women) were aged 25–75 at baseline, and there were 1767 CHD incident cases (32% in women) during 472 973 person years of follow-up. PGS-height was calculated based on 33 938 single-nucleotide polymorphisms, and residual height was defined as the residual of height after adjusting for PGS-height in a linear regression model. HRs of CHD incidence were calculated using Cox regression.Results PGS-height and residual height showed clear gradients for education, social class and income, with a larger association for residual height. Residual height also showed larger associations with CHD incidence (HRs per 1 SD 0.94 in men and 0.87 in women) than PGS-height (HRs per 1 SD 0.99 and 0.97, respectively). Only a small proportion of the associations between SEP and CHD incidence was statistically explained by the height indicators (6% or less).Conclusions Residual height associations with SEP and CHD incidence were larger than for PGS-height. This supports the role of material and social living conditions in childhood as contributing factors to the association of height with both SEP and CHD risk.
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| 20. |
- Silventoinen, Karri, et al.
(författare)
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Joint associations of depression, genetic susceptibility and the area of residence for coronary heart disease incidence
- 2022
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 76:3, s. 281-284
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Tidskriftsartikel (refereegranskat)abstract
- Background Depression is a risk factor for coronary heart disease (CHD), but less is known whether genetic susceptibility to CHD or regional-level social indicators modify this association.Methods Risk factors of CHD including a Polygenic Risk Score (PRS) were measured for 19 999 individuals residing in Finland in 1997, 2002, 2007 and 2012 (response rates 60%–75%). During the register-based follow-up until 2015, there were 1381 fatal and non-fatal incident CHD events. Unemployment rate, degree of urbanisation and crime rate of the municipality of residence were used as regional level social indicators. HRs were calculated using register-based antidepressant purchases as a non-reversible time-dependent covariate.Results Those having depression and in the highest quartile of PRS had somewhat higher CHD risk than predicted only by the main effects of depression and PRS (HR for interaction 1.53, 95% CI 0.95 to 2.45). Depression was moderately associated with CHD in high crime (HR 1.51, 95% CI 1.20 to 1.90) and weakly in low crime regions (HR 1.07, 95% CI 0.86 to 1.33; p value of interaction=0.087). Otherwise, we did not found evidence for interactions.Conclusions Those having both depression and high genetic susceptibility need a special attention in healthcare for CHD.
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| 21. |
- Silventoinen, Karri, et al.
(författare)
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Marital status and genetic liability independently predict coronary heart disease incidence
- 2024
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 52:1, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Married individuals have a lower coronary heart disease (CHD) risk than non-married, but the mechanisms behind this are not fully understood. We analyzed whether genetic liability to CHD may affect these associations. Methods: Marital status, a polygenic score of CHD (PGS-CHD), and other risk factors for CHD were measured from 35,444 participants (53% female) in Finnish population-based surveys conducted between 1992 and 2012. During the register-based follow-up until 2020, there were 2439 fatal and non-fatal incident CHD cases. The data were analyzed using linear and Cox regression models. Results: Divorced and cohabiting men and women had a higher genetic risk of CHD than married individuals, but the difference was very small (0.023–0.058 standard deviation of PGS-CHD, p-values 0.011–0.429). Both marital status and PGS-CHD were associated with CHD incidence, but the associations were largely independent. Adjusting for behavioral and metabolic risk factors for CHD explained part of these associations (11–20%). No interaction was found between marital status and PGS-CHD for CHD incidence. Conclusions: We showed minor differences between the marital status categories in PGS-CHD and demonstrated that marital status and genetic liability predicted CHD incidence largely independently. This emphasizes the need to measure multiple risk factors when predicting CHD risk.
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| 22. |
- Silventoinen, Karri, et al.
(författare)
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Smoking remains associated with education after controlling for social background and genetic factors in a study of 18 twin cohorts
- 2022
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Ingår i: Scientific Reports. - : Nature Portfolio. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs. Similarly, education levels were higher among former smoking than among currently smoking co-twins, and this difference was larger within DZ pairs. Our results support the hypothesis of a causal effect of education on both current smoking status and smoking cessation. However, the even greater intra-pair differences within DZ pairs, who share only 50% of their segregating genes, provide evidence that shared genetic factors also contribute to these associations.
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| 23. |
- Silventoinen, Karri, et al.
(författare)
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The CODATwins Project : The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits
- 2015
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 18:4
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Tidskriftsartikel (refereegranskat)abstract
- For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
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| 24. |
- Silventoinen, Karri, et al.
(författare)
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The genetic background of the associations between sense of coherence and mental health, self-esteem and personality
- 2022
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Ingår i: Social Psychiatry and Psychiatric Epidemiology. - : Springer. - 0933-7954 .- 1433-9285. ; 57:2, s. 423-433
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Sense of coherence (SOC) represents coping and can be considered an essential component of mental health. SOC correlates with mental health and personality, but the background of these associations is poorly understood. We analyzed the role of genetic factors behind the associations of SOC with mental health, self-esteem and personality using genetic twin modeling and polygenic scores (PGS).METHODS: Information on SOC (13-item Orientation of Life Questionnaire), four mental health indicators, self-esteem and personality (NEO Five Factor Inventory Questionnaire) was collected from 1295 Finnish twins at 20-27 years of age.RESULTS: In men and women, SOC correlated negatively with depression, alexithymia, schizotypal personality and overall mental health problems and positively with self-esteem. For personality factors, neuroticism was associated with weaker SOC and extraversion, agreeableness and conscientiousness with stronger SOC. All these psychological traits were influenced by genetic factors with heritability estimates ranging from 19 to 66%. Genetic and environmental factors explained these associations, but the genetic correlations were generally stronger. The PGS of major depressive disorder was associated with weaker, and the PGS of general risk tolerance with stronger SOC in men, whereas in women the PGS of subjective well-being was associated with stronger SOC and the PGSs of depression and neuroticism with weaker SOC.CONCLUSION: Our results indicate that a substantial proportion of genetic variation in SOC is shared with mental health, self-esteem and personality indicators. This suggests that the correlations between these traits reflect a common neurobiological background rather than merely the influence of external stressors.
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| 25. |
- Wennerstad, Karin Modig, et al.
(författare)
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Association between intelligence and type-specific stroke : a population-based cohort study of early fatal and non-fatal stroke in one million Swedish men
- 2010
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 64:10, s. 908-912
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Tidskriftsartikel (refereegranskat)abstract
- Background Inverse associations between IQ and stroke have been reported in a few studies, but none have investigated subtypes of stroke, nor have they studied fatal and non-fatal stroke separately. Stroke is a heterogenic disease and strength of associations with IQ and putative causal pathways cannot be assumed to be identical for different subtypes. Methods IQ was measured for 1.1 million Swedish men, born 1951 to 1976. Data from several national registers were linked and the cohort followed until the end of 2006 for non-fatal, and 2004 for fatal stroke. HRs with 95% CIs adjusted for age, body mass index, blood pressure and socioeconomic factors were estimated using Cox proportional hazards models. Results Inverse associations were found between IQ and all stroke subtypes. The strength of the associations differed by subtype, with the strongest RR found for haemorrhagic stroke. In adjusted models using IQ as a continuous variable over a standard nine point scale, HR for mortality in all stroke was 0.89 (95% CI 0.85 to 0.93), that is an 11% decrease in stroke risk per unit increase in IQ. For non-fatal stroke, the corresponding HR was 0.92 (95% CI 0.91 to 0.93). The results were based on a rather young cohort, and results should therefore be generalised to early stroke events rather than the general population. Conclusions Inverse associations were found between IQ and all stroke subtypes, fatal and non-fatal. For all types of non-fatal stroke, the inverse associations with IQ remained after adjustments for childhood and adult socioeconomic position.
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