| 1. |
- Ahlqvist, Viktor H, et al.
(författare)
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Birth Weight and Cardiorespiratory Fitness Among Young Men Born at Term : The Role of Genetic and Environmental Factors
- 2020
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Ingår i: Journal of the American Heart Association. - : American Heart Association. - 2047-9980 .- 2047-9980. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Preterm delivery and low birth weight are prospectively associated with low cardiorespiratory fitness (CRF). However, whether birth weight, within the at-term range, is associated with later CRF is largely unknown. Thus, the aim of the current study was to examine this issue and whether such association, if any, is explained by shared and/or nonshared familial factors.Methods and Results: We conducted a prospective cohort study, including 286 761 young male adults and a subset of 52 544 siblings born at-term. Objectively measured data were retrieved from total population registers. CRF was tested at conscription and defined as the maximal load obtained on a cycle ergometer. We used linear and nonlinear and fixed-effects regression analyses to explore associations between birth weight and CRF. Higher birth weight, within the at-term range, was strongly associated with increasing CRF in a linear fashion. Each SD increase in birth weight was associated with an increase of 7.9 (95% CI, 7.8-8.1) and 6.6 (95% CI; 5.9-7.3) Wmax in the total and sibling cohorts, respectively. The association did not vary with young adulthood body mass index.Conclusions: Birth weight is strongly associated with increasing CRF in young adulthood among men born at-term, across all categories of body mass index. This association appears to be mainly driven by factors that are not shared between siblings. Hence, CRF may to some extent be determined already in utero. Prevention of low birth weight, also within the at-term-range, can be a feasible mean of increasing adult CRF and health.
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| 2. |
- Ahlqvist, Viktor H., et al.
(författare)
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Birth weight and grip strength in young Swedish males : a longitudinal matched sibling analysis and across all body mass index ranges
- 2019
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Low birth weight is associated with a lower grip strength later in life. However, associations between birth weight among infants born at-term and factors driving associations between birth weight and grip strength are largely unknown. A cohort of 144,369 young men born at-term, including 10,791 individuals who had at least one male sibling/s, were followed until conscription where they performed a grip strength test. We used linear and non-linear regression analyses in the full cohort, and fixed-effects regression analyses in the sibling cohort, to address confounding by factors that are shared between siblings. After adjustment, each unit increase in birth weight z-score was associated with increases of 17.7 (95% CI, 17.2-18.2) and 13.4 (10.1-16.6) newton grip strength, which converts to approximately 1.8 and 1.4 kilogram-force in the full and within-families cohorts, respectively. The associations did not vary with young adulthood BMI. Birth weight, within the at-term range, is robustly positively associated with grip strength in young adulthood among men across all BMI categories and associations appears to be mainly driven by factors that are not shared between siblings. These findings underline the importance of recognizing the influence of low birth weight, also within the at-termrange, on young adulthood muscle strength.
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| 3. |
- Ahlqvist, Viktor H., et al.
(författare)
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Caesarean section and its relationship to offspring general cognitive ability : a registry-based cohort study of half a million young male adults
- 2022
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Ingår i: Evidence-Based Mental Health. - : BMJ Publishing Group Ltd. - 1362-0347 .- 1468-960X. ; 25, s. 7-14
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Tidskriftsartikel (refereegranskat)abstract
- Background: A relationship between caesarean section and offspring cognitive ability has been described, but data are limited, and a large-scale study is needed.Objective: To determine the relationship between mode of delivery and general cognitive ability.Methods: A cohort of 579 244 singleton males, born between 1973 and 1987 who conscripted before 2006, were identified using the Swedish population-based registries. Their mode of delivery was obtained from the Swedish Medical Birth registry. The outcome measure was a normalised general cognitive test battery (mean 100, SD 15) performed at military conscription at around age 18.Findings: Males born by caesarean section performed poorer compared with those born vaginally (mean score 99.3 vs 100.1; adjusted mean difference -0.84; 95% CI -0.97 to -0.72; p<0.001). Both those born by elective (99.3 vs 100.2; -0.92; 95% CI -1.24 to -0.60; p<0.001) and non-elective caesarean section (99.2 vs 100.2; -1.03; 95% CI -1.34 to -0.72; p=0.001), performed poorer than those born vaginally. In sibling analyses, the association was attenuated to the null (100.9 vs 100.8; 0.07; 95% CI -0.31 to 0.45; p=0.712). Similarly, neither elective nor non-elective caesarean section were associated with general cognitive ability in sibling analyses.Conclusion: Birth by caesarean section is weakly associated with a lower general cognitive ability in young adult males. However, the magnitude of this association is not clinically relevant and seems to be largely explained by familial factors shared between siblings.Clinical implication: Clinicians and gravidas ought not to be concerned that the choice of mode of delivery will impact offspring cognitive ability.
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| 4. |
- Ahlqvist, Viktor H., et al.
(författare)
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Elective and nonelective cesarean section and obesity among young adult male offspring : A Swedish population-based cohort study
- 2019
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Ingår i: PLoS Medicine. - : PUBLIC LIBRARY SCIENCE. - 1549-1277 .- 1549-1676. ; 16:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies have suggested that cesarean section (CS) is associated with offspring overweight and obesity. However, few studies have been able to differentiate between elective and nonelective CS, which may differ in their maternal risk profile and biological pathway. Therefore, we aimed to examine the association between differentiated forms of delivery with CS and risk of obesity in young adulthood.Methods and findings: Using Swedish population registers, a cohort of 97,291 males born between 1982 and 1987 were followed from birth until conscription (median 18 years of age) if they conscripted before 2006. At conscription, weight and height were measured and transformed to World Health Organization categories of body mass index (BMI). Maternal and infant data were obtained from the Medical Birth Register. Associations were evaluated using multinomial and linear regressions. Furthermore, a series of sensitivity analyses were conducted, including fixed-effects regressions to account for confounders shared between full brothers. The mothers of the conscripts were on average 28.5 (standard deviation 4.9) years old at delivery and had a prepregnancy BMI of 21.9 (standard deviation 3.0), and 41.5% of the conscripts had at least one parent with university-level education.Out of the 97,291 conscripts we observed, 4.9% were obese (BMI ≥ 30) at conscription. The prevalence of obesity varied slightly between vaginal delivery, elective CS, and nonelective CS (4.9%, 5.5%, and 5.6%, respectively), whereas BMI seemed to be consistent across modes of delivery. We found no evidence of an association between nonelective or elective CS and young adulthood obesity (relative risk ratio 0.96, confidence interval 95% 0.83–1.10, p = 0.532 and relative risk ratio 1.02, confidence interval 95% 0.88–1.18, p = 0.826, respectively) as compared with vaginal delivery after accounting for prepregnancy maternal BMI, maternal diabetes at delivery, maternal hypertension at delivery, maternal smoking, parity, parental education, maternal age at delivery, gestational age, birth weight standardized according to gestational age, and preeclampsia. We found no evidence of an association between any form of CS and overweight (BMI ≥ 25) as compared with vaginal delivery. Sibling analysis and several sensitivity analyses did not alter our findings. The main limitations of our study were that not all conscripts had available measures of anthropometry and/or important confounders (42% retained) and that our cohort only included a male population.Conclusions: We found no evidence of an association between elective or nonelective CS and young adulthood obesity in young male conscripts when accounting for maternal and prenatal factors. This suggests that there is no clinically relevant association between CS and the development of obesity. Further large-scale studies are warranted to examine the association between differentiated forms of CS and obesity in young adult offspring.Trial registration: Registered as observational study at ClinicalTrials.gov Identifier: NCT03918044.
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| 5. |
- Ahlqvist, Viktor H.
(författare)
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Methodological challenges in pregnancy pharmacoepidemiology : the case of antiseizure medication and offspring neurodevelopment
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is driven by the overarching aim of elucidating methodological challenges inherent in pharmacoepidemiology during pregnancy, with a particular focus on antiseizure medications. In Study I, a substantial surge in antiseizure medication use in the United Kingdom is observed, notably linked to increases in psychiatric indications. This shift in the medication landscape raises questions about the predominant contributors to this rise and underscores the necessity of understanding evolving patterns in drug utilization during pregnancy. In Study II, a large-scale examination of associations between specific antiseizure medications and neurodevelopmental conditions across Sweden and the United Kingdom emphasizes the importance of considering drug classes and shared confounders, providing valuable insights into the possible causal effect of these drugs. Study III explores the intricate interplay between epilepsy and psychiatric conditions, unveiling a heightened risk of neurodevelopmental conditions in individuals diagnosed with epilepsy. These findings shed light on the complex within-individual links between these conditions, potentially explaining the observed higher likelihood of neurodevelopmental diagnoses in children of women using antiseizure medications in pregnancy. In Study IV, a critical evaluation of drug safety studies warns against indication-based sampling, advocating for comprehensive regression adjustments to mitigate biases. Finally, Study V introduces the marginalized between-within model, a novel approach to derive absolute measures of occurrence in sibling analysis, enhancing the interpretability of findings. This thesis, collectively, calls for a concerted effort to improve the methodology of pharmacoepidemiology during pregnancy, fostering a more nuanced understanding of medication risks, and ultimately enhancing maternal and fetal health outcomes.
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| 6. |
- Ballin, Marcel, et al.
(författare)
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Genetic and Environmental Factors and Cardiovascular Disease Risk in Adolescents
- 2023
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Ingår i: JAMA Network Open. - : American Medical Association (AMA). - 2574-3805. ; 6:11
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Tidskriftsartikel (refereegranskat)abstract
- Importance Cardiovascular risk factors in youth have been associated with future cardiovascular disease (CVD), but conventional observational studies are vulnerable to genetic and environmental confounding.Objective To examine the role of genetic and environmental factors shared by full siblings in the association of adolescent cardiovascular risk factors with future CVD.Design, Setting, and Participants This is a nationwide cohort study with full sibling comparisons. All men who underwent mandatory military conscription examinations in Sweden between 1972 and 1995 were followed up until December 31, 2016. Data analysis was performed from May 1 to November 10, 2022.Exposures Body mass index (BMI), cardiorespiratory fitness, blood pressure, handgrip strength, and a combined risk z score in late adolescence.Main Outcomes and Measures The primary outcome was fatal or nonfatal CVD, as recorded in the National Inpatient Register or the Cause of Death Register before 2017.Results A total of 1 138 833 men (mean [SD] age, 18.3 [0.8] years), of whom 463 995 were full brothers, were followed up for a median (IQR) of 32.1 (26.7-37.7) years, during which 48 606 experienced a CVD outcome (18 598 among full brothers). All risk factors were associated with CVD, but the effect of controlling for unobserved genetic and environmental factors shared by full siblings varied. In the sibling analysis, hazard ratios for CVD (top vs bottom decile) were 2.10 (95% CI, 1.90-2.32) for BMI, 0.77 (95% CI, 0.68-0.88) for cardiorespiratory fitness, 1.45 (95% CI, 1.32-1.60) for systolic blood pressure, 0.90 (95% CI, 0.82-0.99) for handgrip strength, and 2.19 (95% CI, 1.96-2.46) for the combined z score. The percentage attenuation in these hazard ratios in the sibling vs total cohort analysis ranged from 1.1% for handgrip strength to 40.0% for cardiorespiratory fitness. Consequently, in the sibling analysis, the difference in cumulative CVD incidence at age 60 years (top vs bottom decile) was 7.2% (95% CI, 5.9%-8.6%) for BMI and 1.8% (95% CI, 1.0%-2.5%) for cardiorespiratory fitness. Similarly, in the sibling analysis, hypothetically shifting everyone in the worst deciles of BMI to the middle decile would prevent 14.9% of CVD at age 60 years, whereas the corresponding number for cardiorespiratory fitness was 5.3%.Conclusions and Relevance In this Swedish national cohort study, cardiovascular risk factors in late adolescence, especially a high BMI, were important targets for CVD prevention, independently of unobserved genetic and environmental factors shared by full siblings. However, the role of adolescent cardiorespiratory fitness in CVD may have been overstated by conventional observational studies.
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| 7. |
- Bergqvist, Rita, et al.
(författare)
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HMG-CoA reductase inhibitors and COVID-19 mortality in Stockholm, Sweden : A registry-based cohort study
- 2021
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Ingår i: PLoS Medicine. - : Public Library of Science (PLoS). - 1549-1277 .- 1549-1676. ; 18:10
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Tidskriftsartikel (refereegranskat)abstract
- Background: The relationship between statin treatment and Coronavirus Disease 2019 (COVID-19) mortality has been discussed due to the pleiotropic effects of statins on coagulation and immune mechanisms. However, available observational studies are hampered by study design flaws, resulting in substantial heterogeneity and ambiguities. Here, we aim to determine the relationship between statin treatment and COVID-19 mortality.Methods and findings: This cohort study included all Stockholm residents aged 45 or older (N = 963,876), followed up from 1 March 2020 until 11 November 2020. The exposure was statin treatment initiated before the COVID-19-pandemic, defined as recorded statin dispensation in the Swedish Prescribed Drug Register between 1 March 2019 and 29 February 2020. COVID-19-specific mortality was ascertained from the Swedish Cause of Death Registry. Hazard ratios (HRs) were calculated using multivariable Cox regression models. We further performed a target trial emulation restricted to initiators of statins.In the cohort (51.6% female), 169,642 individuals (17.6%) were statin users. Statin users were older (71.0 versus 58.0 years), more likely to be male (53.3% versus 46.7%), more often diagnosed with comorbidities (for example, ischemic heart disease 23.3% versus 1.6%), more frequently on anticoagulant and antihypertensive treatments, less likely to have a university-level education (34.5% versus 45.4%), and more likely to have a low disposable income (20.6% versus 25.2%), but less likely to reside in crowded housing (6.1% versus 10.3%).A total of 2,545 individuals died from COVID-19 during follow-up, including 765 (0.5%) of the statin users and 1,780 (0.2%) of the nonusers. Statin treatment was associated with a lowered COVID-19 mortality (adjusted HR, 0.88; 95% CI, 0.79 to 0.97, P = 0.01), and this association did not vary appreciably across age groups, sexes, or COVID-19 risk groups. The confounder adjusted HR for statin treatment initiators was 0.78 (95% CI, 0.59 to 1.05, P = 0.10) in the emulated target trial. Limitations of this study include the observational design, reliance on dispensation data, and the inability to study specific drug regimens.Conclusions: Statin treatment had a modest negative association with COVID-19 mortality. While this finding needs confirmation from randomized clinical trials, it supports the continued use of statin treatment for medical prevention according to current recommendations also during the COVID-19 pandemic.
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| 8. |
- Chen, Chu, et al.
(författare)
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Preschool environment and preschool teachers physical activity and their association with childrens activity levels at preschool
- 2020
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this study was to investigate the association between preschool playground size, formalized physical activity (PA) policies, time spent outdoors and preschool teachers levels of PA and childrens objectively assessed levels of PA and sedentary time (ST) during preschool hours. Methods In total, 369 children and 84 preschool teachers from 27 preschools in Sodermalm municipally, Stockholm Sweden wore an Actigraph GT3X+ accelerometer during 7 consecutive days. Preschool environmental and structural characteristics were measured via the Environment and Policy Evaluation Self-Report ( EPAO-SR) instrument and time in- and outdoors was recorded by preschool teachers during the PA measurements. Weight and height of children were measured via validated scales and parents filled out a questionnaire on demographical and descriptive variables. Linear mixed models, nested on preschool level, were used to assess the association between predictors and outcomes. Results The mean child age was 4.7 years (SD 0.8) and 45% were girls. We found that children were more active in preschools with a formalized PA policy, compared to preschools without such a policy, but not less sedentary. The association between policy and activity seemed to be more pronounced when accounting for other environmental factors. Similar associations were found in children spent most time outdoors (uppermost quartile) compared with children spent least time outdoors (Lowermost quartile). Preschool teachers light PA (LPA) (beta = 0.25, P = 0.004) and steps (beta = 0.52, P<0.001) were associated with childrens LPA and steps while the preschool playground size showed no association with PA in children, when accounting for other environmental factors. Conclusion The current study showed that preschool structural characteristics such as formalized PA policies and more time spent outdoors were positively associated with childrens PA. These findings suggest that formalized PA policies and time outdoors may be of importance for promoting childrens PA during preschool hours.
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| 9. |
- Christiansen, Filip, et al.
(författare)
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Physical activity through a classroom-based intervention : A pragmatic non-randomized trial among swedish adolescents in an upper secondary school
- 2021
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 18:21
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Tidskriftsartikel (refereegranskat)abstract
- Schools are an important arena to curb the decline in physical activity (PA) in youth. School-based interventions with accelerometer-measured PA are warranted. This study aimed to increase accelerometer-measured PA in adolescents following a 12-month school-based intervention. Two school-classes of 16–18-year-old Swedish students were allocated to intervention group and control group. Accelerometer-measured PA was gathered at baseline, 6-and 12-month follow-up. Mixed-effects linear regression was used to investigate between-group and within-group differences in mean minutes per day (min/day) of moderate to vigorous PA (MVPA), light PA (LPA) and sedentary time (ST). Fifty-seven students participated (intervention group = 31, control group = 26). At 12-month follow-up, the intervention group performed 5.9 (95% CI: −4.3, 16.2) min/day more in MVPA, 1.8 (95% CI: −17.9, 14.2) min/day less in LPA, and 4.1 (95% CI: −27.3, 19.2) min/day less in ST compared to the control group. Within the intervention group, there was no significant change in PA. Within the control group, LPA decreased (95% CI: −19.6, −0.2; p = 0.044) and ST increased (95% CI: 1.8, 30.8; p = 0.028). Although no between-group differences in PA were statistically significant, the within-group changes may suggest a preventive impact on the decline in PA during adolescence.
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| 10. |
- Ekström, Lucas, et al.
(författare)
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The association between birth by cesarean section and adolescent cardiorespiratory fitness in a cohort of 339,451 Swedish males
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Birth by cesarean section is increasing worldwide and associates with offspring morbidities capable of adversely impacting cardiorespiratory fitness later in life. Whether birth by cesarean section associates with lower levels of cardiorespiratory fitness later in life is unknown and is of interest to public health. Four Swedish national registers were linked to follow 339,451 singleton males, born between 1973–1987 until December 31 2005, for Watt-maximum achieved on a cycle ergometer test at conscription into the Swedish military. Main exposure was birth by cesarean section which was compared to vaginal birth. A sub-population of 45,999 males born between 1982–1987 was identified to explore differentiated associations between elective and non-elective cesarean section with Watt-maximum. Within-family analyses of 34,252 families with 70,632 biological male siblings, who conscripted during the study period, were performed to explore the role of familial confounding on Watt-maximum. Swedish males born by cesarean section achieved lower mean Watt-maximum (− 2.32 W, 95%C.I. − 2.90 to − 1.75) and displayed excess odds of low cardiorespiratory fitness (aOR = 1.08, 95%C.I. 1.05 to 1.11) at conscription in the eighteenth life-year compared to males born vaginally after adjusting for birth characteristics, maternal morbidities and parental socioeconomic position. In the sub-population, males born 1982–1987, there was a greater negative association of elective cesarean section with cardiorespiratory fitness (− 4.42 W, 95%C.I. − 6.27 to − 2.57, p < 0.001) than non-elective cesarean sections (− 1.96 W, 95%C.I. − 3.77 to − 0.16, p = 0.033) as compared to vaginal births. No associations between modes of cesarean delivery and cardiorespiratory fitness levels persisted in the within-family analyses where biological male siblings were compared whilst controlling for factors shared within families. Males born by cesarean section had lower levels of cardiorespiratory fitness eighteen years later compared to males born vaginally. These findings appear to be largely explained by factors of familial confounding.
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