Physical activity, genes, and lifetime predisposition to chronic disease

Abstract This mini-review summarizes the main associations between physical activity and chronic diseases and discusses the basic concepts related to the role of genetic factors in studies evaluating the effects of physical activity/exercise therapy on chronic disease prevention/treatment during the life course. Many observational cohort studies have shown that high physical activity during young adulthood or middle age is associated with reduced later life morbidity, mobility limitations and mortality. Physical activity or exercise therapy has a positive effect on health via many disease-specific mechanisms. The most consistent finding of the various randomized controlled studies conducted to date is that aerobic/functional capacity and/or muscle strength can be improved by exercise training among patients with different chronic diseases. Genes are known to play a role in chronic disease predisposition and to contribute to physical fitness levels, physical activity participation and ageing. Physical fitness, physical activity and health outcomes may be partly due to underlying genetic factors that have a favourable effect on all these traits (genetic pleiotropy). This means that in observational studies, the relationship between baseline activity and the later occurrence of diseases may not be interpreted entirely as causal. Increased knowledge on the role of nuclear genome, mitochondrial genome, epigenetics, telomeres and regulation of gene expression will increase our understanding of their relationships with physical activity and morbidity.</jats:p

Factors behind Leisure-Time Physical Activity Behavior Based on Finnish Twin Studies : The Role of Genetic and Environmental Influences and the Role of Motives

Peer reviewe

Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History : Evidence from Monozygotic Twins

Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 +/- 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent electrical dipole sources of SMMR as well as gray matter (GM) voxel counts in regions of interest indicated by source analysis were evaluated. SMMR dipolar source strengths differed between active and inactive twins within twin pairs in postcentral gyrus, medial frontal gyrus and superior temporal gyrus and in anterior cingulate (AC) GM voxel counts differed similarly. Compared to active twins, their inactive twin brothers showed greater dipole strengths in short periods of the deviant-elicited SMMR and larger AC GM voxel counts. Stronger activation in early unattended cortical processing of the deviant sensory signals in inactive co-twins may imply less effective gating of somatosensory information in inactive twins compared to their active brothers. Present findings indicate that already in 30's long-term physical activity pattern is linked with specific brain indices, both in functional and structural domains.Peer reviewe

Mortality and health-related habits in 900 Finnish former elite athletes and their brothers

Background There is conflicting evidence on the associations between participation in vigorous sports, health habits, familial factors and subsequent mortality. We investigated all-cause mortality and health-related behaviour among former elite athletes and their brothers. Methods The mortality of Finnish male former elite athletes, who had represented Finland between 1920 and 1965 (n=900) and their age-matched brothers (n=900), was followed from the time when athlete started an elite athlete career until 31 December 2015. The age-adjusted HRs were calculated by a paired Cox proportional hazards model. In 2001, surviving participants (n=199 athletes and n=199 age-matched brothers) reported their self-rated health (SRH), physical activity, alcohol consumption and smoking habits in the questionnaire. Results During the total follow-up period, 1296 deaths (72% of the cohort) occurred. The age-adjusted HRs for all-cause mortality in former athletes was 0.75 (95% CI 0.65 to 0.87, P Conclusions Former elite athletes are more physically active, smoke less, have better self-rated health and live longer than their brothers. Genetic differences between athletes and brothers, aerobic training for endurance elite sports and a healthier lifestyle may all contribute to reduced mortality.Peer reviewe

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 (beta = -0.025 kg center dot m(-2) per one SD change in PA PRS, SE = 0.013, P = 1.87 x 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 x 10(-19)) and, for example, hypertension [OR = 0.93, P = 2.7 x 10(-44)), type 2 diabetes (OR = 0.91, P = 4.1 x 10(-42)), and coronary heart disease (OR = 0.95, P = 1.2 x 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.Peer reviewe

Leisure-time physical inactivity and association with body mass index : a Finnish Twin Study with a 35-year follow-up

Background: We investigated the stability and change of leisure-time physical inactivity in adult men and women during a 35-year follow-up. We also analysed the impact of long-term physical inactivity on the development of body mass index (BMI). Methods: In this population-based cohort study, 5254 Finnish twin individuals (59% women) participated in four surveys in 1975, 1981, 1990 and 2011. Mean age at baseline was 23.9 years. Individual long-term leisure-time physical activity (LTPA) was categorized into seven classes varying from 'persistently inactive' to 'persistently active'. We used the multivariate multilevel mixed-effects linear regression model and paired-sample t-test in the analyses. Co-twin control design was used for examining within-pair associations. Results: Of men 11%, and of women 8%, were persistently inactive. Among both sexes, the mean BMI slope trajectories were steeper among the persistently inactive and those who became inactive than among those who were persistently active. Overall, the inactive participants gained 1.4 kg/m(2) [95% confidence interval (CI) 1.2 to 1.7] more in weight than did the active participants from 1975 to 2011. Among twin pairs discordant for LTPA, the corresponding difference was 1.4 kg/m(2) (95% CI 0.83 to 2.0) in dizygotic pairs and 0.68 kg/m(2) (95% CI 0.05 to1.3) in monozygotic pairs. Conclusions: Over a 35-year time span from young adulthood, persistently inactive participants and those who had become inactive had greater weight increases than those who were persistently active. This association was also found in twin-pair analyses, although attenuated in monozygotic pairs. This may support the importance of LTPA in weight management, although further causal inference is required.Peer reviewe

Associations of physical activity, fitness, and body composition with heart rate variability-based indicators of stress and recovery on workdays : a cross-sectional study

BACKGROUND: The purpose of this study was to investigate how physical activity (PA), cardiorespiratory fitness (CRF), and body composition are associated with heart rate variability (HRV)-based indicators of stress and recovery on workdays. Additionally, we evaluated the association of objectively measured stress with self-reported burnout symptoms. METHODS: Participants of this cross-sectional study were 81 healthy males (age range 26-40 y). Stress and recovery on workdays were measured objectively based on HRV recordings. CRF and anthropometry were assessed in laboratory conditions. The level of PA was based on a detailed PA interview (MET index [MET-h/d]) and self-reported activity class. RESULTS: PA, CRF, and body composition were significantly associated with levels of stress and recovery on workdays. MET index (P < 0.001), activity class (P = 0.001), and CRF (P = 0.019) were negatively associated with stress during working hours whereas body fat percentage (P = 0.005) was positively associated. Overall, 27.5% of the variance of total stress on workdays (P = 0.001) was accounted for by PA, CRF, and body composition. Body fat percentage and body mass index were negatively associated with night-time recovery whereas CRF was positively associated. Objective work stress was associated (P = 0.003) with subjective burnout symptoms. CONCLUSIONS: PA, CRF, and body composition are associated with HRV-based stress and recovery levels, which needs to be taken into account in the measurement, prevention, and treatment of work-related stress. The HRV-based method used to determine work-related stress and recovery was associated with self-reported burnout symptoms, but more research on the clinical importance of the methodology is needed.Peer reviewe

Cross-sectional associations between the diversity of sport activities and the type of low back pain in adulthood

Leisure-time physical activity has a complex relationship with low back pain (LBP). Thus, we aimed to investigate whether the diversity of sport activities is associated with the type of LBP. In the FinnTwin16 study, 4246 (55% females) Finnish twins at mean age 34.1 years replied to a health behaviour survey in 2010-2012. Based on the participation in different sport activities, we created two measures of diversity: quantity (i.e. the number of sport activities: 1, 2, 3, 4 and >= 5) and quality (i.e. the type of sport activity: endurance, strength, body care, etc.). Based on the frequency, duration and type of LBP, we created three groups: no history of LBP lasting more than one day, radiating LBP and non-radiating LBP. The associations between the quantity and quality of sport activities and the type of LBP were investigated with logistic regression analyses. Participation in >= 5 sport activities associated with less radiating and non-radiating LBP in analyses pooled across sex (odds ratio 0.46, 95% CI 0.30-0.69 and 0.66, 0.44-0.99, respectively). However, the associations attenuated after adjusting for several confounders. Participation in endurance sports was associated with less radiating (0.58, 0.43-0.76) and non-radiating (0.60, 0.44-0.81) LBP, whereas strength sports and body care only with less radiating LBP (0.76, 0.58-1.00 and 0.26, 0.09-0.74, respectively) adjusted for all sport types. On a sport-specific level, running and cycling were associated with less radiating and non-radiating LBP. In adulthood, the diversity of sport activities, particularly participation in endurance sports, may be associated with less radiating and non-radiating LBP.Peer reviewe

Twin studies on the association of physical activity with cognitive and cerebral outcomes

Regular physical activity (PA) offers positive effects on the human body. However, the effects of PA on cognition and in the brain are less clear. In this paper, we narratively review the relationship of PA with cognition and dementia, first from general perspective and then through genetically informed studies on the topic. Then we move on to imaging studies on exercise and brain anatomy first by presenting an overall picture of the topic and then discussing brain imaging studies addressing PA and brain structure in twins in more detailed way. Regarding PA and cognition or dementia, genetically informed studies are uncommon, even though the relationship between PA and cognitive ageing has been extensively studied. It is challenging to find twin pairs discordant for PA and dementia. Concerning brain imaging studies, among PA discordant young adult twin pairs, the more active co-twins showed larger gray matter volumes in striatal, prefrontal, and hippocampal regions and in electrophysiological studies automatic deviance-detection processes differed in brain regions involved with sensorimotor, visual and memory functions.Peer reviewe

Sport disciplines, types of sports, and waist circumference in young adulthood - a population-based twin study

Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32-37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The number of sport disciplines participated in was inversely associated with WC, the linear decrease averaging 1.38cm (95% CI 1.10-1.65) per each additional sport discipline. The result persisted after adjustment for the main covariates, such as volume of PA and diet quality. Among dizygotic twin pairs discordant for sports participation (0-2 vs. 5 or more disciplines), the mean within-pair difference in WC was 4.8cm (95% CI 0.4-9.1) for men and 11.2cm (95% CI 4.4-18.0) for women; among discordant monozygotic pairs, no differences were observed. In men, all three types of sports were individually associated with smaller WC, while in women, only mixed and power sports showed this association. Conclusions: Participation in several sport disciplines and sport types was associated with smaller WC among young adults in their mid-30s. Shared genetic background may explain some of the associations.Peer reviewe