Polygenic Risk Scores and Physical Activity

Hyperandrogenaemia, polycystic ovary syndrome, and physical fitness in women-a Northern Finland birth cohort study

OBJECTIVE

To investigate the independent associations of hyperandrogenaemia (HA) and polycystic ovary syndrome (PCOS) with physical fitness in women among the general population.

DESIGN

A population-based birth cohort study including 5889 women.

METHODS

Longitudinal associations of serum testosterone (T), free androgen index (FAI), and PCOS with cardiorespiratory fitness (CRF) (measured by heart rate after a submaximal exercise test) and grip strength over the 31 to 46 years of age timespan were examined using multivariable linear mixed models adjusted for time, body mass index, homeostatic model assessment of insulin resistance, physical activity and smoking. The results are reported as regression coefficients (β) with corresponding 95% confidence intervals [95% CI].

RESULTS

The third and fourth T and FAI quartiles were associated positively with higher heart rate after the submaximal exercise test in multivariable models indicating poorer CRF compared with women in Q1 of T and FAI (Q3: β of T = 1.58 [95% CI: 0.21 to 2.96], β of FAI = 1.97 [0.54 to 3.39]; Q4: β of T = 1.88 [0.46 to 3.30], β of FAI = 2.70 [1.15 to 4.25]). The second, third, and fourth quartiles of FAI were associated with higher grip strength in multivariable models compared with women in Q1 (Q2: β = 0.59 [0.04 to 1.14], Q3: β = 0.74 [0.16 to 1.30], Q4: β = 0.68 [0.06 to 1.27]). Excluding women with PCOS did not alter these results, while PCOS itself was not associated with CRF or grip strength.

CONCLUSION

Hyperandrogenaemia in premenopausal women was associated with poorer CRF but better grip strength, independently of PCOS, which suggests that HA, rather than PCOS, has an independent and complex association with physical fitness in premenopausal women.

Association Between Accelerometer-Measured Physical Activity and Mobility Limitations in Twins

BACKGROUND

The associations between mobility limitations and device-measured physical activity are sparsely studied. In this study, these associations are studied among community-dwelling older twins.

METHODS

This cross-sectional study utilized data gathered in 2014-2016 for the MOBILETWIN study. Participants were twins born in Finland between 1940 and 1944 (774 participants, mean age 73 years). Physical activity was measured with a hip-worn accelerometer. Mobility limitations were assessed with a questionnaire.

RESULTS

Individual-level analyses revealed that physical activity was associated with mobility limitations. Participants with severe mobility limitations took 2,637 (SD = 1,747) steps per day, those with some mobility limitations 4,437 (SD = 2,637) steps, and those without mobility limitations 7,074 (SD = 2,931) steps (p < .05). The within-twin pair analyses revealed the same pattern for the 144 dizygotic twin pairs, but no associations were seen for the 117 monozygotic twin pairs.

CONCLUSIONS

Accelerometer-measured physical activity and mobility limitations were associated in community-dwelling older adults. Genetic factors may explain some of the variations in physical activity.

SIGNIFICANCE

A personalized exercise program to promote increased physical activity should be provided for older adults who report mobility difficulties. Future research is needed to examine causality between physical activity and mobility limitations.

Genetic liability to sedentary behaviour and cardiovascular disease incidence in the FinnGen and HUNT cohorts

OBJECTIVE

Energy-saving sedentary behaviour may be an evolutionarily selected trait that is no longer advantageous. We investigated the associations between genetic liability to sedentary behaviour and the incidence of the most common cardiovascular disease (CVD).

METHODS

We constructed and validated a genome-wide polygenic score for leisure screen time (PGS LST) as a measure of genetic liability to sedentary behaviour. We performed survival analyses between higher PGS LST and register-based CVDs using the FinnGen cohort (N=293 250-333 012). Replication and exploratory analyses were conducted in an independent Norwegian Trøndelag Health Study (HUNT) cohort (N=35 289).

RESULTS

In FinnGen, each SD increase in PGS LST was associated with a higher risk of incident CVD (HR: 1.05 (95% CI 1.05 to 1.06)) (168 770 cases over 17 101 133 person-years). The magnitudes of association for the three most common CVDs were 1.09 ((95% CI 1.08 to 1.09), 1.06 ((95% CI 1.05 to 1.07) and 1.05 ((95% CI 1.04 to 1.06) for hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively. Those in the top decile of PGS LST had 21%, 35%, 26% and 19% higher risk of any CVD, hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively, than those in the bottom decile. Associations were replicated in HUNT and remained independent of covariates (socioeconomic status, body mass index and smoking) except for cerebrovascular disease. Besides direct effects, reduced physical activity served as a potential mediating pathway for the observed associations.

CONCLUSIONS

We found that genetic liability to sedentary behaviour is associated with incident CVD, although effect sizes with current PGS remained small. These findings suggest that genetic liability to sedentary behaviour is an under-recognised driver of common CVDs.

Nuclear regulatory disturbances precede and predict the development of Type-2 diabetes in Asian populations

To identify biomarkers and pathways to Type-2 diabetes (T2D), a major global disease, we completed array-based epigenome-wide association in whole blood in 5,709 Asian people. We found 323 Sentinel CpGs (from 314 genetic loci) that predict future T2D. The CpGs reveal coherent, nuclear regulatory disturbances in canonical immune activation pathways, as well as metabolic networks involved in insulin signalling, fatty acid metabolism and lipid transport, which are causally linked to development of T2D. The CpGs have potential clinical utility as biomarkers. An array-based composite Methylation Risk Score (MRS) is predictive for future T2D (RR: 5.2 in Q4 vs Q1; P=7x10 -25 ), and is additive to genetic risk. Targeted methylation sequencing revealed multiple additional CpGs predicting T2D, and synthesis of a sequencing-based MRS that is strongly predictive for T2D (RR: 8.3 in Q4 vs Q1; P=1.0x10 -11 ). Importantly, MRS varies between Asian ethnic groups, in a way that explains a large fraction of the difference in T2D risk between populations. We thus provide new insights into the nuclear regulatory disturbances that precede development of T2D, and reveal the potential for sequence-based DNA methylation markers to inform risk stratification in diabetes prevention.

Genetic contributions to body mass index over adolescence and its associations with adult weight gain: a 25-year follow-up study of Finnish twins

INTRODUCTION

High body mass index (BMI) in adolescence is a strong predictor of adult obesity. However, the nature of this association is unclear. We investigated how adolescent BMI is associated with adult weight change using longitudinal data from ages 11.5 to 37 years and examined the genetic factors behind these associations.

DATA AND METHODS

The study cohort consisted of 1400 Finnish twin individuals (40% males) with 494 complete twin pairs who reported their body mass index (BMI) at five ages: 11.5, 14, 17.5, 24, and 37 years. BMI trajectories (defined as BMI changes (i.e., slope) and BMI at baseline age (i.e., intercept)) were calculated in adulthood (from 17.5 to 37 years of age) using linear mixed-effects models. Polygenic Risk Scores of BMI (PRSBMI) and genetic twin models were utilised to analyse the role of genetic factors underlying BMI trajectories and their associations with BMI at 11.5 and 14 years of age.

RESULTS

Mean BMI increased in adulthood (4.06 kg/m2 in men and 3.39 kg/m2 in women). The BMI changes correlated with BMI at the baseline age of 17.5 years (i.e. intercept) (r = 0.24 in men and r = 0.35 in women) as well as with BMI in adolescence (11.5 and 14 years of age). Genetic factors contributed to the BMI changes during adulthood (correlation with PRSBMI r = 0.25 in men and r = 0.27 in women; heritability estimates 0.63 and 0.64 respectively) as well as to their correlations with BMI at the baseline age (rA = 0.5 in men and 0.54 in women) and BMI during adolescence (at 11.5 and 14 years of age) (rA = 0.63-0.64).

CONCLUSION

We found that genetic factors play a role in BMI change in adulthood, and part of this genetic component overlaps with the genetics of BMI in adolescence. Genetic predisposition to high BMI in adolescence is also related to adult weight gain.

Proteomic associations with fluctuation and long-term changes in BMI: A 40-year follow-up study

Introduction

While some studies have explored associations between weight change and blood proteins, most have been intervention-based, offering limited insight into proteomic associations with long-term weight gain. It remains unclear whether plasma proteins are related to BMI fluctuation over time. This study investigates associations of long-term BMI changes and fluctuations with over 1,000 plasma proteins involved in cardiometabolic and inflammation functions.

Data and Methods

The study included 304 Finnish adult twins (117 men) born before 1958 from the Older Finnish Twin Cohort, with BMI data spanning five time points (1975, 1981, 1990, 2011, and 2012-2014). Proteomic data were derived from blood samples collected at the last BMI measurement. Linear mixed-effects models analyzed individual BMI trajectories, producing intercepts (baseline BMI) and slopes (BMI change rates). BMI fluctuation was calculated as the average squared deviation from expected BMI across time points. Associations between BMI changes/fluctuation and (i) 1,231 plasma proteins related to cardiometabolic and inflammatory functions and (ii) polygenic risk scores for BMI (PRSBMI), as well as interaction effects between PRSBMI and baseline BMI on protein-BMI relationships were studied. Within-pair analyses using monozygotic twins were conducted to account for shared confounding factors.

Results

A total of 135 proteins were associated with changes in BMI over 40 years, while 17 proteins were linked to fluctuation in BMI: 12 associations (10 with BMI changes and 2 with fluctuation) remained significant in within-twin pair analyses. PRSBMI associated with BMI changes but not with fluctuations. PRSBMI-protein interactions explaining BMI changes or fluctuation was found, though a single interaction between the CD72 protein and baseline BMI was observed.

Conclusion

This study highlights significant associations between plasma proteins and long-term BMI changes and fluctuations, with no evidence of PRSBMI-protein interactions influencing BMI trends. These findings underscore the substantial role of environmental factors in shaping proteome-BMI associations over adulthood.

Measurement invariance of the Center for Epidemiological Studies-Depression scale and associations with genetic risk in older adults

BACKGROUND

As populations are aging, it needs to be ensured that valid depression rating scales are available across old adulthood. Center for Epidemiological Studies-Depression scale (CES-D) is a common depression rating scale, however, few studies have assessed its validity in individuals with age over 90 and/or cognitive impairment. We examined the factor structures of 20-, 15-, and 8-item CES-D scales, their measurement invariance for age and cognition, and associations with genetic risk of depression.

METHODS

Participants were from a population-based older Finnish Twin Cohort study including 71-79-year-olds from the MEMTWIN II (n = 1034 for exploratory and n = 664 for confirmatory factor analyses) and 90+ year-olds from the NONAGINTA (n = 134, confirmatory factor analyses) sub-studies. Associations of polygenic risk score of major depressive disorder (MDD-PRS) with CES-D scales were examined in MEMTWIN II.

RESULTS

Exploratory factor analyses (n = 1034) suggested four- (CES-D 20) and three-factor (CES-D 8) structures and these models fit well in confirmatory analyses (n = 664). Unidimensional models had good (CES-D 15 & 20) or fair fit (CES-D 8). Results supported scalar invariance of all CES-D versions for age and cognitive status. Higher MDD-PRS was associated with more depressive symptoms in different CES-D versions.

CONCLUSIONS

Different CES-D versions are adequate for measuring depressive symptoms across age groups and cognitive spectrum in old age. Genetic risk of depression predicts depressive symptoms even in old age.

Intergenerational and genetic influences on physical activity: family data from the HUNT study, Norway

OBJECTIVES

The objectives of this study are to examine the association of physical activity in parents with physical activity in their adult offspring and explore if the offspring's genetic liability (ie, polygenic risk score) to physical activity influences this association.

METHODS

The Trøndelag Health Study cohort is a population-based longitudinal study with data collected in 1984-1986, 1995-1997, 2006-2008 and 2017-2019. We calculated the odds ratio for being physically active and mean difference in physical activity levels according to parental physical activity (device-measured and self-reported) and own polygenic risk score.

RESULTS

Compared with offspring with mothers in the lowest third of metabolic equivalent of task (MET)-min/day accumulated by vigorous physical activities, offspring with mothers in the upper third had an OR of 1.93 (95% CI 1.65 to 2.27) for accumulating ≥900 MET-min/week of vigorous physical activity. The OR for the corresponding father-offspring association was 1.78 (95% CI 1.48 to 2.14). Compared with offspring of parents not accumulating ≥900 MET-min/week, we found an OR of 1.89 (95% CI 1.45 to 2.44) for offspring to meet the same threshold if both parents accumulated ≥900 MET-min/week. Offspring with higher polygenic risk score to bephysically active and having physically active parents did more weekly physical activity, but we found no strong evidence of multiplicative synergistic effects between these two factors (all p values ≥0.01).

CONCLUSION

Both parental physical activity and offspring's polygenic risk score were positively associated with physical activity levels in the adult offspring, but there was no evidence of effect modification between these factors. A family-based approach to promote physical activity may be effective from a public health perspective.

Genetic Liability to Cardiovascular Disease, Physical Activity, and Mortality: Findings from the Finnish Twin Cohort

PURPOSE

We investigated whether longitudinally assessed physical activity (PA) and adherence specifically to World Health Organization PA guidelines mitigate or moderate mortality risk regardless of genetic liability to cardiovascular disease (CVD). We also estimated the causality of the PA-mortality association.

METHODS

The study used the older Finnish Twin Cohort with 4897 participants aged 33 to 60 yr (54.3% women). Genetic liability to coronary heart disease and systolic and diastolic blood pressure was estimated with polygenic risk scores (PRS) derived from the Pan-UK Biobank ( N ≈ 400,000; >1,000,000 genetic variants). Leisure-time PA was assessed with validated and structured questionnaires three times during 1975 to 1990. The main effects of adherence to PA guidelines and the PRS × PA interactions were evaluated with Cox proportional hazards models against all-cause and CVD mortality. A cotwin control design with 180 monozygotic twin pairs discordant for meeting the guidelines was used for causal inference.

RESULTS

During the 17.4-yr (mean) follow-up (85,136 person-years), 1195 participants died, with 389 CVD deaths. PRS (per 1 SD increase) were associated with a 17% to 24% higher CVD mortality risk but not with all-cause mortality except for the PRS for diastolic blood pressure. Adherence to PA guidelines did not show significant independent main effects or interactions with all-cause or CVD mortality. Twins whose activity levels adhered to PA guidelines over a 15-yr period did not have statistically significantly reduced mortality risk compared with their less active identical twin sibling. The findings were similar among high, intermediate, and low genetic risk levels for CVD.

CONCLUSIONS

The genetically informed Finnish Twin Cohort data could not confirm that adherence to PA guidelines either mitigates or moderates genetic CVD risk or causally reduces mortality risk.

Longitudinal multi-omics study reveals common etiology underlying association between plasma proteome and BMI trajectories in adolescent and young adult twins

BACKGROUND

The influence of genetics and environment on the association of the plasma proteome with body mass index (BMI) and changes in BMI remains underexplored, and the links to other omics in these associations remain to be investigated. We characterized protein-BMI trajectory associations in adolescents and adults and how these connect to other omics layers.

METHODS

Our study included two cohorts of longitudinally followed twins: FinnTwin12 (N = 651) and the Netherlands Twin Register (NTR) (N = 665). Follow-up comprised 4 BMI measurements over approximately 6 (NTR: 23-27 years old) to 10 years (FinnTwin12: 12-22 years old), with omics data collected at the last BMI measurement. BMI changes were calculated in latent growth curve models. Mixed-effects models were used to quantify the associations between the abundance of 439 plasma proteins with BMI at blood sampling and changes in BMI. In FinnTwin12, the sources of genetic and environmental variation underlying the protein abundances were quantified by twin models, as were the associations of proteins with BMI and BMI changes. In NTR, we investigated the association of gene expression of genes encoding proteins identified in FinnTwin12 with BMI and changes in BMI. We linked identified proteins and their coding genes to plasma metabolites and polygenic risk scores (PRS) applying mixed-effects models and correlation networks.

RESULTS

We identified 66 and 14 proteins associated with BMI at blood sampling and changes in BMI, respectively. The average heritability of these proteins was 35%. Of the 66 BMI-protein associations, 43 and 12 showed genetic and environmental correlations, respectively, including 8 proteins showing both. Similarly, we observed 7 and 3 genetic and environmental correlations between changes in BMI and protein abundance, respectively. S100A8 gene expression was associated with BMI at blood sampling, and the PRG4 and CFI genes were associated with BMI changes. Proteins showed strong connections with metabolites and PRSs, but we observed no multi-omics connections among gene expression and other omics layers.

CONCLUSIONS

Associations between the proteome and BMI trajectories are characterized by shared genetic, environmental, and metabolic etiologies. We observed few gene-protein pairs associated with BMI or changes in BMI at the proteome and transcriptome levels.

Associations of polygenic inheritance of physical activity with aerobic fitness, cardiometabolic risk factors and diseases: the HUNT study

Physical activity (PA), aerobic fitness, and cardiometabolic diseases (CMD) are highly heritable multifactorial phenotypes. Shared genetic factors may underlie the associations between higher levels of PA and better aerobic fitness and a lower risk for CMDs. We aimed to study how PA genotype associates with self-reported PA, aerobic fitness, cardiometabolic risk factors and diseases. PA genotype, which combined variation in over one million of gene variants, was composed using the SBayesR polygenic scoring methodology. First, we constructed a polygenic risk score for PA in the Trøndelag Health Study (N = 47,148) using UK Biobank single nucleotide polymorphism-specific weights (N = 400,124). The associations of the PA PRS and continuous variables were analysed using linear regression models and with CMD incidences using Cox proportional hazard models. The results showed that genotypes predisposing to higher amount of PA were associated with greater self-reported PA (Beta [B] = 0.282 MET-h/wk per SD of PRS for PA, 95% confidence interval [CI] = 0.211, 0.354) but not with aerobic fitness. These genotypes were also associated with healthier cardiometabolic profile (waist circumference [B = -0.003 cm, 95% CI = -0.004, -0.002], body mass index [B = -0.002 kg/m2, 95% CI = -0.004, -0.001], high-density lipoprotein cholesterol [B = 0.004 mmol/L, 95% CI = 0.002, 0.006]) and lower incidence of hypertensive diseases (Hazard Ratio [HR] = 0.97, 95% CI = 0.951, 0.990), stroke (HR = 0.94, 95% CI = 0.903, 0.978) and type 2 diabetes (HR = 0.94, 95 % CI = 0.902, 0.970). Observed associations were independent of self-reported PA. These results support earlier findings suggesting small pleiotropic effects between PA and CMDs and provide new evidence about associations of polygenic inheritance of PA and intermediate cardiometabolic risk factors.

Longitudinal multi-omics study reveals common etiology underlying association between plasma proteome and BMI trajectories in adolescent and young adult twins

Background

The influence of genetics and environment on the association of the plasma proteome with body mass index (BMI) and changes in BMI remain underexplored, and the links to other omics in these associations remain to be investigated. We characterized protein-BMI trajectory associations in adolescents and adults and how these connect to other omics layers.

Methods

Our study included two cohorts of longitudinally followed twins: FinnTwin12 (N=651) and the Netherlands Twin Register (NTR) (N=665). Follow-up comprised four BMI measurements over approximately 6 (NTR: 23-27 years old) to 10 years (FinnTwin12: 12-22 years old), with omics data collected at the last BMI measurement. BMI changes were calculated using latent growth curve models. Mixed-effects models were used to quantify the associations between the abundance of 439 plasma proteins with BMI at blood sampling and changes in BMI. The sources of genetic and environmental variation underlying the protein abundances were quantified using twin models, as were the associations of proteins with BMI and BMI changes. In NTR, we investigated the association of gene expression of genes encoding proteins identified in FinnTwin12 with BMI and changes in BMI. We linked identified proteins and their coding genes to plasma metabolites and polygenic risk scores (PRS) using mixed-effect models and correlation networks.

Results

We identified 66 and 14 proteins associated with BMI at blood sampling and changes in BMI, respectively. The average heritability of these proteins was 35%. Of the 66 BMI-protein associations, 43 and 12 showed genetic and environmental correlations, respectively, including 8 proteins showing both. Similarly, we observed 6 and 4 genetic and environmental correlations between changes in BMI and protein abundance, respectively. S100A8 gene expression was associated with BMI at blood sampling, and the PRG4 and CFI genes were associated with BMI changes. Proteins showed strong connections with many metabolites and PRSs, but we observed no multi-omics connections among gene expression and other omics layers.

Conclusions

Associations between the proteome and BMI trajectories are characterized by shared genetic, environmental, and metabolic etiologies. We observed few gene-protein pairs associated with BMI or changes in BMI at the proteome and transcriptome levels.

Genetic Pathways Underlying Individual Differences in Regular Physical Activity

Twin and family studies show a strong contribution of genetic factors to physical activity (PA) assessed by either self-report or accelerometers. PA heritability is around 43% across the lifespan. Genome-wide association studies have implied biological pathways related to exercise ability and enjoyment. A polygenic score based on genetic variants influencing PA could help improve the success of intervention programs.

A Polygenic Risk Score for Hand Grip Strength Predicts Muscle Strength and Proximal and Distal Functional Outcomes among Older Women

PURPOSE

Hand grip strength (HGS) is a widely used indicator of overall muscle strength and general health. We computed a polygenic risk score (PRS) for HGS and examined whether it predicted muscle strength, functional capacity, and disability outcomes.

METHODS

Genomewide association study summary statistics for HGS from the Pan-UK Biobank was used. PRS were calculated in the Finnish Twin Study on Aging ( N = 429 women, 63-76 yr). Strength tests included HGS, isometric knee extension, and ankle plantarflexion strength. Functional capacity was examined with the Timed Up and Go, 6-min and 10-m walk tests, and dual-task tests. Disabilities in the basic activities of daily living (ADL) and instrumental ADL (IADL) were investigated with questionnaires. The proportion of variation in outcomes accounted for by PRS HGS was examined using linear mixed models and extended logistic regression.

RESULTS

The measured HGS increased linearly over increasing PRS ( β = 4.8, SE = 0.93, P < 0.001). PRS HGS independently accounted for 6.1% of the variation in the measured HGS ( β = 14.2, SE = 3.1, P < 0.001), 5.4% of the variation in knee extension strength ( β = 19.6, SE = 4.7, P < 0.001), 1.2% of the variation in ankle plantarflexion strength ( β = 9.4, SE = 4.2, P = 0.027), and 0.1%-1.5% of the variation in functional capacity tests ( P = 0.016-0.133). Further, participants with higher PRS HGS were less likely to have ADL/IADL disabilities (odds ratio = 0.74-0.76).

CONCLUSIONS

Older women with genetic risk for low muscle strength were significantly weaker than those with genetic susceptibility for high muscle strength. PRS HGS was also systematically associated with overall muscle strength and proximal and distal functional outcomes that require muscle strength.

The Association Between Puberty Timing and Body Mass Index in a Longitudinal Setting: The Contribution of Genetic Factors

We analyzed the contribution of genetic factors on the association between puberty timing and body mass index (BMI) using longitudinal data and two approaches: (i) genetic twin design and (ii) polygenic scores (PGS) of obesity indices. Our data were derived from Finnish cohorts: 9080 twins had information on puberty timing and BMI and 2468 twins also had genetic data. Early puberty timing was moderately associated with higher BMI in childhood in both boys and girls; in adulthood these correlations were weaker and largely disappeared after adjusting for childhood BMI. The largest proportion of these correlations was attributable to genetic factors. The higher PGSs of BMI and waist circumference were associated with earlier timing of puberty in girls, whereas weaker associations were found in boys. Early puberty is not an independent risk factor for adult obesity but rather reflects the association between puberty timing and childhood BMI contributed by genetic predisposition.

Gut Microbiota and Serum Metabolome in Elite Cross-Country Skiers: A Controlled Study

Exercise has been shown to affect gut the microbiome and metabolic health, with athletes typically displaying a higher microbial diversity. However, research on the gut microbiota and systemic metabolism in elite athletes remains scarce. In this study, we compared the gut microbiota profiles and serum metabolome of national team cross-country skiers at the end of an exhausting training and competitive season to those of normally physically-active controls. The gut microbiota were analyzed using 16S rRNA amplicon sequencing. Serum metabolites were analyzed using nuclear magnetic resonance. Phylogenetic diversity and the abundance of several mucin-degrading gut microbial taxa, including Akkermansia, were lower in the athletes. The athletes had a healthier serum lipid profile than the controls, which was only partly explained by body mass index. Butyricicoccus associated positively with HDL cholesterol, HDL2 cholesterol and HDL particle size. The Ruminococcus torques group was less abundant in the athlete group and positively associated with total cholesterol and VLDL and LDL particles. We found the healthier lipid profile of elite athletes to co-occur with known health-beneficial gut microbes. Further studies should elucidate these links and whether athletes are prone to mucin depletion related microbial changes during the competitive season.

Polygenic Score for Physical Activity Is Associated with Multiple Common Diseases

INTRODUCTION

Genetic pleiotropy, in which the same genes affect two or more traits, may partially explain the frequently observed associations between high physical activity (PA) and later reduced morbidity or mortality. This study investigated associations between PA polygenic risk scores (PRS) and cardiometabolic diseases among the Finnish population.

METHODS

PRS for device-measured overall PA were adapted to a FinnGen study cohort of 218,792 individuals with genomewide genotyping and extensive digital longitudinal health register data. Associations between PA PRS and body mass index, diseases, and mortality were analyzed with linear and logistic regression models.

RESULTS

A high PA PRS predicted a lower body mass index (β = -0.025 kg·m-2 per one SD change in PA PRS, SE = 0.013, P = 1.87 × 10-80). The PA PRS also predicted a lower risk for diseases that typically develop later in life or not at all among highly active individuals. A lower disease risk was systematically observed for cardiovascular diseases (odds ratio [OR] per 1 SD change in PA PRS = 0.95, P = 9.5 × 10-19) and, for example, hypertension [OR = 0.93, P = 2.7 × 10-44), type 2 diabetes (OR = 0.91, P = 4.1 × 10-42), and coronary heart disease (OR = 0.95, P = 1.2 × 10-9). Participants with high PA PRS had also lower mortality risk (OR = 0.97, P = 0.0003).

CONCLUSIONS

Genetically less active persons are at a higher risk of developing cardiometabolic diseases, which may partly explain the previously observed associations between low PA and higher disease and mortality risk. The same inherited physical fitness and metabolism-related mechanisms may be associated both with PA levels and with cardiometabolic disease risk.

The genetic background of the associations between sense of coherence and mental health, self-esteem and personality

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.

Sex specific effect of gut microbiota on the risk of psychiatric disorders: A Mendelian randomisation study and PRS analysis using UK Biobank cohort

OBJECTIVE

The relationships between gut microbiota and brain-related diseases/traits remains not fully understood.

METHOD

A two-stage study was performed to investigate the relationships between gut microbiota and brain-related diseases/traits, and evaluate the potential sex specific effects of gut microbiota. In discovery stage, we systematically scanned the relationships between 515 brain-related diseases/traits and gut microbiota through two-sample Mendelian randomisation analysis. Using ∼500,000 individuals derived from the UK Biobank, polygenetic risk scoring (PRS) analysis was performed to validate the associations detected in discovery stage. To evaluate the potential sex-specific effect of gut microbiota on brain-related disorders, PRS analysis was conducted in female and male, respectively.

RESULTS

After systematically scanning diseases or traits, 41 of the 515 brain-related diseases/traits were identified to be associated with gut microbiota, such as Neuroticism score (P_2-MR = 0.0018), worrier/anxious feelings (P_2-MR = 0.0013), Suffer from 'nerves' (P_2-MR = 0.0062) and Nervous feelings (P_2-MR = 0.0158). 5 of 41 brain-related diseases or traits were successfully validated in UK Biobank, such as Neuroticism score (P_UK = 0.0024, P_UK-female = 0.0063, P_UK-male = 0.1142), Nervous feelings (P_UK = 0.0043, P_UK-female = 0.0115, P_UK-male = 0.1670) and Worrier/anxious feelings (P_UK = 0.0166, P_UK-female = 0.0196, P_UK-male = 0.2930).

CONCLUSION

Our results suggest that gut microbiota contributed more to brain-related diseases or traits in females than in males.Key pointsA two-stage study was performed to investigate the relationships between gut microbiota and brain-related diseases/traits.Using the individuals derived from the UK Biobank, polygenetic risk scoring analysis was performed to validate the associations detected in the discovery stage.Our results suggest that gut microbiota contributed more to brain-related diseases or traits in females than in males.

The Associations Between Leisure-Time Physical Activity and Academic Performance: A Twin Study

BACKGROUND

Both genetic and environmental influences have been shown to contribute to the association between physical activity and overall academic performance. The authors examined whether leisure-time physical activity (LTPA) shares genetic and environmental variances between spelling, essay writing, reading aloud, reading comprehension, and mathematics in early adolescence. Moreover, they investigated whether genetic polymorphisms associated with physical activity behavior affect these academic skills.

METHODS

Participants were 12-year-old Finnish twins (n = 4356-4370 twins/academic skill, 49% girls). Academic skills were assessed by teachers, and LTPA was self-reported. Polygenic scores for physical activity behavior were constructed from the UK Biobank. Quantitative genetic modeling and linear regression models were used to analyze the data.

RESULTS

The trait correlations between LTPA and academic skills were significant but weak (r = .05-.08). The highest trait correlation was found between LTPA and mathematics. A significant genetic correlation was revealed between LTPA and essay writing (rA = .14). Regarding polygenic scores of physical activity, the highest correlations were found with reading comprehension, spelling, and essay writing, but these results only approached statistical significance (P values = .09-.15).

CONCLUSIONS

The authors' results suggest that reading and writing are the academic skills that most likely share a common genetic background with LTPA.