| 31. |
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| 32. |
- Sennerby, Ulf, et al.
(författare)
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Cardiovascular diseases and risk of hip fracture
- 2009
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 302:15, s. 1666-1673
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Recent studies indicate common etiologies for cardiovascular disease (CVD) and osteoporotic fractures. OBJECTIVES: To examine the relation between CVD and risk of hip fracture in twins and evaluate the relative importance of genetics and lifestyle factors in this association. DESIGN, SETTING, AND PARTICIPANTS: A cohort of all 31,936 Swedish twins born from 1914-1944 was followed up from the age of 50 years. The National Patient Registry identified twins with CVDs and fractures from 1964 through 2005. Time-dependent exposures using Cox proportional hazard regression models were evaluated. MAIN OUTCOME MEASURE: Time to hip fracture after diagnosis of CVD. RESULTS: The crude absolute rate of hip fractures was 12.6 per 1000 person-years after a diagnosis of heart failure, 12.6 per 1000 person-years after a stroke, 6.6 per 1000 person-years after a diagnosis of peripheral atherosclerosis, and 5.2 per 1000 person-years after a diagnosis of ischemic heart disease compared with 1.2 per 1000 person-years for those without a CVD diagnosis. The multivariable-adjusted hazard ratio (HR) of hip fracture after a diagnosis of heart failure was 4.40 (95% confidence interval [CI], 3.43-5.63); after a stroke, the HR was 5.09 (95% CI, 4.18-6.20); after a diagnosis of peripheral atherosclerosis, the HR was 3.20 (95% CI, 2.28-4.50); and after an ischemic heart disease event, the HR was 2.32 (95% CI, 1.91-2.84). Identical twins without heart failure and stroke also had, after their co-twins had been exposed to these respective diseases, an increased rate of hip fracture. These sibling twins pseudoexposed for heart failure had a multivariable-adjusted HR of 3.74 (95% CI, 1.97-7.10) for hip fracture, whereas pseudoexposure for stroke had an HR of 2.29 (95% CI, 1.20-4.35). CONCLUSIONS: A diagnosis of CVD was significantly associated with risk of subsequent hip fracture. Increased risks in co-twins without an index diagnosis suggest genetic factors in the association between CVD and osteoporotic fractures.
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| 33. |
- Snellman, Greta, et al.
(författare)
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Seasonal genetic influence on serum 25-hydroxyvitamin D levels : a twin study
- 2009
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:11, s. e7747-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although environmental factors, mainly nutrition and UV-B radiation, have been considered major determinants of vitamin D status, they have only explained a modest proportion of the variation in serum 25-hydroxyvitamin D. We aimed to study the seasonal impact of genetic factors on serum 25-hydroxyvitamin D concentrations. METHODOLOGY/PRINCIPAL FINDINGS: 204 same-sex twins, aged 39-85 years and living at northern latitude 60 degrees, were recruited from the Swedish Twin Registry. Serum 25-hydroxyvitamin D was analysed by high-pressure liquid chromatography and mass spectrometry. Genetic modelling techniques estimated the relative contributions of genetic, shared and individual-specific environmental factors to the variation in serum vitamin D. The average serum 25-hydroxyvitamin D concentration was 84.8 nmol/l (95% CI 81.0-88.6) but the seasonal variation was substantial, with 24.2 nmol/l (95% CI 16.3-32.2) lower values during the winter as compared to the summer season. Half of the variability in 25-hydroxyvitamin D during the summer season was attributed to genetic factors. In contrast, the winter season variation was largely attributable to shared environmental influences (72%; 95% CI 48-86%), i.e., solar altitude. Individual-specific environmental influences were found to explain one fourth of the variation in serum 25-hydroxyvitamin D independent of season. CONCLUSIONS/SIGNIFICANCE: There exists a moderate genetic impact on serum vitamin D status during the summer season, probably through the skin synthesis of vitamin D. Further studies are warranted to identify the genes impacting on vitamin D status.
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| 34. |
- Sullivan, Patrick F, et al.
(författare)
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Chronic fatigue in a population sample : definitions and heterogeneity
- 2005
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Ingår i: Psychological Medicine. - 0033-2917 .- 1469-8978. ; 35:9, s. 1337-1348
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Tidskriftsartikel (refereegranskat)abstract
- Our data are consistent with the 'existence' of CFS-like illness although the dominant nosological approach captures population-level variation poorly. We suggest that studying a more parsimonious case definition - impairing chronic fatigue not due to a known cause - would represent a way forward.
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| 35. |
- Sullivan, Patrick F, et al.
(författare)
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Twin analyses of chronic fatigue in a Swedish national sample
- 2005
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Ingår i: Psychological Medicine. - 0033-2917 .- 1469-8978. ; 35:9, s. 1327-1336
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Tidskriftsartikel (refereegranskat)abstract
- Current fatiguing illness appears to be a complex trait resulting from both environmental and genetic sources of variation without pronounced differences by gender.
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| 36. |
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| 37. |
- Svedberg, Pia, et al.
(författare)
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No evidence of sex differences in heritability of irritable bowel syndrome in Swedish twins.
- 2008
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Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 11:2, s. 197-203
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Tidskriftsartikel (refereegranskat)abstract
- Studies have shown that familial aggregation is of importance for abdominal symptoms including irritable bowel syndrome and there are a few reports of a moderate heritability for irritable bowel syndrome. Sex differences in prevalence and incidence of irritable bowel syndrome have been demonstrated however less is known about sex differences in heritability. The objective was to investigate whether there were sex differences in heritability of irritable bowel syndrome while accounting for different prevalences among women and men in different age groups. A sample of 45,750 Swedish twins, whereof 16,961 were complete twin pairs, participated in a telephone interview. The sample was divided into three age groups (40-54, 55-64 and 65 years and older) and the diagnosis of irritable bowel syndrome was operationally defined with a number of disorder specific symptoms. Standard biometrical model fitting analyses were conducted using raw ordinal data from same-sex and opposite-sex twins. The prevalence of irritable bowel syndrome was greater among women than men and more prevalent at younger ages (e.g., women 10.3%, men 6.3% at ages 40-54 years vs. women 6.1%, men 4% at ages over 65 years). The heritability of the disorder was approximately 25% in all age groups. We found no evidence for sex differences in heritability in any of the age groups, however, models allowing prevalences of irritable bowel syndrome to differ between sexes and age groups fitted best.
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| 38. |
- Tsuchiya, Takafumi, et al.
(författare)
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Association of the calpain-10 gene with type 2 diabetes in Europeans: Results of pooled and meta-analyses
- 2006
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192. ; 89:1-2, s. 174-184
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Tidskriftsartikel (refereegranskat)abstract
- We conducted pooled and meta-analyses of the association of the calpain-10 gene (CAPN10) polymorphisms SNP-43, Indel-19 and SNP-63 individually and as haplotypes with type 2 diabetes (T2D) in 3237 patients and 2935 controls of European ancestry. In the pooled analyses, the common SNP-43*G allele was associated with modest but statistically significant increased risk of T2D (odds ratio (OR) = 1.11 (95% confidence interval (0), 1.02-1.20), P = 0.01). Two haplotype combinations were associated with increased risk of T2D) (1-2-1/1-2-1, OR = 1.20 (1.03-1.41), P = 0.02; and 1-1-2/1-2-1, OR = 1.26 (1.01-1.59), P = 0.04) and one with decreased risk (1-1-1/2-2-1, OR = 0.86 (0.75-0.99), P = 0.03). The meta-analysis also showed a significant effect of the 1-2-1/1-2-1 haplogenotype on risk (OR = 1.25 (1.05-1.50), P = 0.01). However, there was evidence for heterogeneity with respect to this effect (P = 0.06). The heterogeneity appeared to be due to data sets in which the cases were selected from samples used in linkage studies of T2D. Using only the population-based case-control samples removed the heterogeneity (P = 0.89) and strengthened the evidence for association with T2D) in both the pooled (SNP-43*G, OR = 1.19 (1.07-1.32), P = 0.001; 1-2-1/1-2-1 haplogenotype, OR = 1.46 (1.19-1.78), P = 0.0003; 1-1-2/1-2-1 haplogenotype, OR = 1.52 (1.12-2.06), P = 0.007; and 1-1-1/2-2-1 haplogenotype, OR = 0.83 (0.70-0.99), P = 0.03) and the meta-analysis (SNP-43*G, OR = 1.18 (1.05-1.32), P = 0.005; 1-2-1/1-2-1 haplogenotype, OR = 1.68 (1.33-2.11), P = 0.00001). The pooled and meta-analyses as well as the linkage disequilibrium and haplotype diversity studies suggest a role for genetic variation in CAPN10 affecting risk of T2D in Europeans. (c) 2006 Elsevier Inc. All rights reserved.
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| 39. |
- Wagner, Helene, et al.
(författare)
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Simply ask them about their balance-future fracture risk in a nationwide cohort study of twins
- 2009
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 169:2, s. 143-149
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Tidskriftsartikel (refereegranskat)abstract
- The principal causal components of an osteoporotic fracture are a fall and weakened bone strength. While bone quality measures have been frequently studied, the ability of simple measures of impaired balance to predict fracture risk has received less attention. Computer-assisted telephone interviews were conducted between 1998 and 2000 among 24,598 Swedish twins aged 55 years or older. Impaired balance at the time of interview was reported by 2,890 (12%) of the twins. Twin pairs who were discordant with regard to impaired balance were selected for analysis and followed for fractures through 2005. In a pairwise analysis, the odds ratio for hip fracture was 3.13 (95% confidence interval (CI): 1.62, 6.05) among twins with impaired balance as compared with their co-twins with normal balance. When previously recognized clinical risk factors for osteoporotic fracture were considered in the model, the odds ratio for hip fracture with impaired balance was 3.88 (95% CI: 1.40, 10.72). Approximately 40% of all hip fractures were attributable to impaired balance. The odds ratios for any fracture and any osteoporotic fracture for twins with impaired balance were 2.00 (95% CI: 1.29, 3.11) and 2.39 (95% CI: 1.49, 3.82), respectively. These results imply that self-reported impaired balance is a novel and readily assessed risk factor for future fractures in the elderly.
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| 40. |
- Åberg, Maria A I, 1972, et al.
(författare)
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Cardiovascular fitness is associated with cognition in young adulthood.
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490.
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Tidskriftsartikel (refereegranskat)abstract
- During early adulthood, a phase in which the central nervous system displays considerable plasticity and in which important cognitive traits are shaped, the effects of exercise on cognition remain poorly understood. We performed a cohort study of all Swedish men born in 1950 through 1976 who were enlisted for military service at age 18 (N = 1,221,727). Of these, 268,496 were full-sibling pairs, 3,147 twin pairs, and 1,432 monozygotic twin pairs. Physical fitness and intelligence performance data were collected during conscription examinations and linked with other national databases for information on school achievement, socioeconomic status, and sibship. Relationships between cardiovascular fitness and intelligence at age 18 were evaluated by linear models in the total cohort and in subgroups of full-sibling pairs and twin pairs. Cardiovascular fitness, as measured by ergometer cycling, positively associated with intelligence after adjusting for relevant confounders (regression coefficient b = 0.172; 95% CI, 0.168-0.176). Similar results were obtained within monozygotic twin pairs. In contrast, muscle strength was not associated with cognitive performance. Cross-twin cross-trait analyses showed that the associations were primarily explained by individual specific, non-shared environmental influences (>/=80%), whereas heritability explained <15% of covariation. Cardiovascular fitness changes between age 15 and 18 y predicted cognitive performance at 18 y. Cox proportional-hazards models showed that cardiovascular fitness at age 18 y predicted educational achievements later in life. These data substantiate that physical exercise could be an important instrument for public health initiatives to optimize educational achievements, cognitive performance, as well as disease prevention at the society level.
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