Search

BackgroundAn overall healthy lifestyle may mitigate the risk of all-cause and cardiovascular disease (CVD) mortality despite the inherited risk for CVD. We assessed if similar phenomenon is observed independently with physical activity (PA).MethodsIn a prospective older Finnish Twin Cohort, genetic liability for coronary heart disease, systolic and diastolic blood pressure was estimated with polygenic risk scores (PRSs) derived from the Pan UK Biobank (N≈400,000) and >1,000,000 genetic variants, and leisure-time PA longitudinally with validated and structured questionnaires three times during 1975–1990 among 4,897 participants aged 33–60-years (54.3% women). Interactions of PRSs and PA with mortality and the independent main effects of different PA metrics with mortality were evaluated with Cox proportional hazards models. A co-twin control design with 180 monozygotic twin pairs discordant for physical activity was used for causal inference.ResultsDuring the 17.4-y (mean) follow-up (85,136 person-years), 1,195 participants died with 389 CVD deaths. Although the favorable associations of an overall healthy lifestyle with mortality risk reduction replicated in the cohort, no interactions or significant independent main effects were observed with any of the assessed PA metrics. Adherence to World Health Organizations PA guidelines or vigorous PA during the 15-year observational period did not decrease mortality in more active twins compared to their less active identical twin brother or sister. The findings did not vary with genetic CVD risk.ConclusionsNo evidence was found that PA mitigates inherited CVD risk or is causally associated with mortality challenging some of our current understanding.

ObjectivePhysical activity (PA) is associated with a decreased incidence of dementia, but much of the evidence comes from short follow-ups prone to reverse causation. This meta-analysis investigates the effect of study length on the association.DesignA systematic review and meta-analysis. Pooled effect sizes, dose–response analysis and funnel plots were used to synthesise the results.Data sourcesCINAHL (last search 19 October 2021), PsycInfo, Scopus, PubMed, Web of Science (21 October 2021) and SPORTDiscus (26 October 2021).Eligibility criteriaStudies of adults with a prospective follow-up of at least 1 year, a valid cognitive measure or cohort in mid-life at baseline and an estimate of the association between baseline PA and follow-up all-cause dementia, Alzheimer’s disease or vascular dementia were included (n=58).ResultsPA was associated with a decreased risk of all-cause dementia (pooled relative risk 0.80, 95% CI 0.77 to 0.84, n=257 983), Alzheimer’s disease (0.86, 95% CI 0.80 to 0.93, n=128 261) and vascular dementia (0.79, 95% CI 0.66 to 0.95, n=33 870), even in longer follow-ups (≥20 years) for all-cause dementia and Alzheimer’s disease. Neither baseline age, follow-up length nor study quality significantly moderated the associations. Dose–response meta-analyses revealed significant linear, spline and quadratic trends within estimates for all-cause dementia incidence, but only a significant spline trend for Alzheimer’s disease. Funnel plots showed possible publication bias for all-cause dementia and Alzheimer’s disease.ConclusionPA was associated with lower incidence of all-cause dementia and Alzheimer’s disease, even in longer follow-ups, supporting PA as a modifiable protective lifestyle factor, even after reducing the effects of reverse causation.

BackgroundMeasures of biological aging range from DNA methylation (DNAm)-based estimates to measures of physical abilities. The purpose of this study was to compare DNAm- and physical functioning-based measures of biological aging in predicting mortality.MethodsWe studied 63- to 76-year-old women (N = 395) from the Finnish Twin Study on Aging (FITSA). Participants’ biological age (epigenetic clocks DNAm GrimAge and DunedinPACE) was estimated using blood DNAm data. Tests of physical functioning conducted under standardized laboratory conditions included the Timed Up and Go (TUG) test and 10-m walk test. Mortality hazard ratios were calculated per every 1 standard deviation (SD) increase in the predictor. Cox regression models were conducted for individuals and twin pairs, the latter controlling for underlying genetic effects. The models were adjusted for known lifestyle predictors of mortality.ResultsDuring the follow-up period (mean 17.0 years, range 0.2–20.3), 187 participants died. In both the individual-based and pairwise analyses, GrimAge and both functional biomarkers of aging were associated with mortality independent of family relatedness, chronological age, physical activity, body mass index, smoking, education, or chronic diseases. In a model including both the DNAm-based measures and functional biomarkers of aging, GrimAge and TUG remained predictive.ConclusionsThe findings suggest that DNAm GrimAge and the TUG test are strong predictors of mortality independent of each others and genetic influences. DNAm-based measures and functional tests capture different aspects of the aging process and thus complement each other as measures of biological aging in predicting mortality.

Genetic and early environmental differences including early health habits associate with future health. To provide insight on the causal nature of these associations, monozygotic (MZ) twin pairs discordant for health habits provide an interesting natural experiment. Twin pairs discordant for leisure-time physical activity (LTPA) in early adult life are thus a powerful study design to investigate the associations between long-term LTPA and indicators of health and wellbeing. We have identified 17 LTPA discordant twin pairs from two Finnish twin cohorts and summarize key findings of these studies in this paper. The carefully characterized rare long-term LTPA discordant MZ twin pairs have participated in multi-dimensional clinical examinations. Key findings highlight that, compared to less active twins in such MZ twin pairs, the twins with higher long-term LTPA have higher physical fitness, reduced body fat, reduced visceral fat, reduced liver fat, increased lumen diameters of conduit arteries to the lower limbs, increased bone mineral density in loaded bone areas and an increased number of large high-density lipoprotein particles. The findings increase our understanding on the possible site-specific and system-level effects of long-term LTPA. peerReviewed

Genetic and early environmental differences including early health habits associate with future health. To provide insight on the causal nature of these associations, monozygotic (MZ) twin pairs discordant for health habits provide an interesting natural experiment. Twin pairs discordant for leisure-time physical activity (LTPA) in early adult life are thus a powerful study design to investigate the associations between long-term LTPA and indicators of health and wellbeing. We have used this study design by identifying 17 LTPA discordant twin pairs from two Finnish twin cohorts and summarize key findings of these studies in this paper. The carefully characterized rare long-term LTPA discordant MZ twin pairs have participated in multi-dimensional clinical examinations. The occurrence of type 2 diabetes and death has been evaluated on the basis of prospective questionnaire data and register follow-up among a larger number of twin pairs. Key findings highlight that, compared to less active twins in such MZ twin pairs, the twins with higher long-term LTPA have higher physical fitness, reduced body fat, reduced visceral fat, reduced liver fat, increased lumen diameters of conduit arteries to the lower limbs, increased bone mineral density in loaded bone areas, increased high-density lipoprotein cholesterol levels and reduced occurrence of type 2 diabetes. However, we have not been able to document differences in the life expectancy between the less and more active twin siblings of the LTPA discordant MZ twin pairs. The findings are in agreement with intervention studies but not with all observational studies in which genetic factors are not controlled for.

Introduction: High physical activity (PA) at old age indicates good functional capacity enabling independent living. We investigated how different disease conditions are associated with measured PA indicators in old women and men, and whether they recognize this association. Materials and methods: This cross-sectional twin cohort study in Finland comprised 779 individuals (276 complete twin pairs, including 117 monozygotic pairs), who participated in hip-worn accelerometer monitoring of PA and responded to questions on diseases and mobility limitations at mean age of 73 (range 71 to 75). Results: Of the participants, 23.2% reported having a disease restricting mobility. With sex and age in the regression model, the reported disease restricting mobility explained 11.8% of the variation in moderate-to-vigorous PA and 10.4% of the variation in daily steps. Adding stepwise other self-reported diseases and body-mass index to the model increased the explanatory power for moderate-to-vigorous PA up to 18.5% and 25.5%, and for daily steps up to 16.0% and 20.7%, respectively. In the co-twin control analysis the PA differences were smaller in disease-discordant monozygotic than dizygotic pairs. Conclusions: Chronic disease conditions are associated with low PA, which individuals may not always recognize. Shared genetic factors may explain part of the associations. Among community dwelling older men and women one fourth of the variation in objectively measured moderate-to-vigorous physical activity is accounted for by age, sex, body-mass index and self-reported diseases. Occurrence of chronic diseases is associated with low physical activity and individuals do not always recognize this. Healthcare professionals should pay attention to the low physical activity and mobility of individuals with chronic disease conditions before these result in limitations in independent living. peerReviewed

This study assessed the associations of maximal isometric strength and movement economy in 126 recreationally active men and women. Oxygen consumption was assessed through a graded treadmill test with 4-minute increments (4-12 km∙h

Background Epigenetic clocks are based on DNA methylation (DNAm). It has been suggested that these clocks are useable markers of biological aging and premature mortality. Because genetic factors explain variations in both epigenetic aging and mortality, this association could also be explained by shared genetic factors. We investigated the influence of genetic and lifestyle factors (smoking, alcohol consumption, physical activity, chronic diseases, body mass index) and education on the association of accelerated epigenetic aging with mortality using a longitudinal twin design. Utilizing a publicly available online tool, we calculated the epigenetic age using two epigenetic clocks, Horvath DNAmAge and DNAm GrimAge, in 413 Finnish twin sisters, aged 63–76 years, at the beginning of the 18-year mortality follow-up. Epigenetic age acceleration was calculated as the residuals from a linear regression model of epigenetic age estimated on chronological age (AAHorvath, AAGrimAge, respectively). Cox proportional hazard models were conducted for individuals and twin pairs. Results The results of the individual-based analyses showed an increased mortality hazard ratio (HR) of 1.31 (CI95: 1.13–1.53) per one standard deviation (SD) increase in AAGrimAge. The results indicated no significant associations of AAHorvath with mortality. Pairwise mortality analyses showed an HR of 1.50 (CI95: 1.02–2.20) per 1 SD increase in AAGrimAge. However, after adjusting for smoking, the HR attenuated substantially and was statistically non-significant (1.29; CI95: 0.84–1.99). Similarly, in multivariable adjusted models the HR (1.42–1.49) was non-significant. In AAHorvath, the non-significant HRs were lower among monozygotic pairs in comparison to dizygotic pairs, while in AAGrimAge there were no systematic differences by zygosity. Further, the pairwise analysis in quartiles showed that the increased within pair difference in AAGrimAge was associated with a higher all-cause mortality risk. Conclusions In conclusion, the findings suggest that DNAm GrimAge is a strong predictor of mortality independent of genetic influences. Smoking, which is known to alter DNAm levels and is built into the DNAm GrimAge algorithm, attenuated the association between epigenetic aging and mortality risk. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-021-01112-7.

Additional file 1. Prevalence of chronic diseases at baseline in DNAm GrimAge age acceleration (AAGrimAge) tertiles.

Motives for physical activity may vary considerably by age, sex, and the level of physical activity. We aimed to examine motives for physical activity in older men and women with different physical activity levels as well as whether genetic and/or environmental factors explain those motives. Finnish twins (mean age 72.9 years, 262 full twin pairs) self-reported their motives for physical activity. Time spent on moderate-to-vigorous physical activity was monitored using a hip-worn accelerometer. Comparisons between the different physical activity groups of older twins (n = 764-791/motive dimension) were analyzed using the Wald test, and effect sizes were calculated as Cohen's d. Quantitative genetic modeling was used to estimate genetic and environmental contributions. For both sexes, the most frequently reported motives for physical activity were physical fitness, health maintenance, and psychological well-being. Conforming to others' expectations was more important for men than for women (P

IMPORTANCEModerate-to-vigorous physical activity (MVPA) in old age is an important indicator of good health and functional capacity enabling independent living.OBJECTIVETo investigate whether physical activity and other health habits at ages 31-48 years predict objectively measured MVPA decades later.DESIGN, SETTING, AND PARTICIPANTSThis prospective twin cohort study in Finland comprised 616 individuals (197 complete twin pairs, including 91 monozygotic pairs, born 1940-1944), who responded to baseline questionnaires in 1975, 1981, and 1990, and participated in accelerometer monitoring at follow-up (mean age, 73 years).EXPOSURESPrimary exposure was long-term leisure-time physical activity, 1975-1990 (LT-mMET index). Covariates were body mass index (BMI), work-related physical activity, smoking, heavy alcohol use and health status in 1990, and socioeconomic status.MAIN OUTCOMES AND MEASURESPhysical activity was measured with a waist-worn triaxial accelerometer (at least 10 hours per day for at least 4 days) to obtain daily mean MVPA values.RESULTSHigh baseline LT-mMET index predicted higher amounts of MVPA (increase in R2 of 6.9% after age and sex adjustment, P2 value of the whole multivariate model was 17.2%, and with further addition of baseline smoking, socioeconomic status, and health status, the R2 increased to 20.3%. In pairwise analyses, differences in MVPA amount were seen only among twin pairs who were discordant at baseline for smoking (n=40 pairs, median follow-up MVPA 25 vs. 35 min, P=.037) or for health status (n=69 pairs, 30 vs. 44 min, P=.014). For smoking, the difference in MVPA also was seen for monozygotic pairs, but for health status, it was seen only for dizygotic pairs. Mediation analysis showed that shared genetic factors explained 82% of the correlation between LT-mMET and MVPA.CONCLUSIONS AND RELEVANCELow leisure-time physical activity at younger age, overweight, smoking, low socioeconomic status, and health problems predicted low MVPA in old age in individual-based analyses. However, based on the pairwise analyses and quantitative trait modeling, genetic factors and smoking seem to be important determinants of later-life MVPA.

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.

The older Finnish Twin Cohort (FTC) was established in 1974. The baseline survey was in 1975, with two follow-up health surveys in 1981 and 1990. The fourth wave of assessments was done in three parts, with a questionnaire study of twins born during 1945–1957 in 2011–2012, while older twins were interviewed and screened for dementia in two time periods, between 1999 and 2007 for twins born before 1938 and between 2013 and 2017 for twins born in 1938–1944. The content of these wave 4 assessments is described and some initial results are described. In addition, we have invited twin-pairs, based on response to the cohortwide surveys, to participate in detailed in-person studies; these are described briefly together with key results. We also review other projects based on the older FTC and provide information on the biobanking of biosamples and related phenotypes.

Background Maintaining good fitness and good level of physical activity are important factors for maintaining physical independence later in life. The aim was to investigate the relationship between self-reported fitness and objectively measured physical activity and sedentary behavior in the elderly. Methods Same-sex twin pairs born 1940–1944 in Finland were invited to the study. Altogether 787 individuals (mean age 72.9 years), of whom 404 were female, used a hip-worn triaxial accelerometer for at least 4 days and answered a question on perceived fitness. First, individual differences were studied between four fitness categories. Second, pairwise differences were examined among twin pairs discordant for fitness. Results Self-reported fitness explained moderately the variation in objectively measured physical activity parameters: R2 for daily steps 26%, for daily mean metabolic equivalent 31%, for daily moderate-to-vigorous activity time 31%, and lower for sedentary behavior time 14% (all p < .001). Better self-reported fitness was associated with more steps taken on average (8,558 daily steps [very good fitness] vs 2,797 steps [poor fitness], p < .001) and with a higher amount of moderate-to-vigorous activity (61 min vs 12 min p < .001, respectively) in the adjusted multivariable model. Among 156 twin pairs discordant for self-reported fitness, co-twins with better fitness took more steps, did more moderate-to-vigorous activity, and had less sedentary behavior (all, p < .05) compared to their less fit co-twins; however, difference was smaller among monozygotic than dizygotic pairs. Conclusion One simple question on self-reported fitness is associated with daily activity profile among community-dwelling older people. However, genetic factors modulate this association to some extent.

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.

Introduction We studied whether objectively measured physical activity (PA) and sedentary behavior (SB) are associated with cognition in Finnish elderly twins. Methods This cross-sectional study comprised twins born in Finland from 1940 to 1944 in the Older Finnish Twin Cohort (mean age, 72.9 years; 726 persons). From 2014 to 2016, cognition was assessed with a validated telephonic interview, whereas PA was measured with a waist-worn accelerometer. Results In between-family models, SB and light physical activity had significant linear associations with cognition after adjusting for age, sex, wearing time, education level, body mass index, and living condition (SB: β-estimate, −0.21 [95% confidence intervals, −0.42 to −0.003]; light physical activity: β-estimate, 0.30 [95% confidence intervals, 0.02–0.58]). In within-family models, there were no significant linear associations between objectively measured PA and cognition. Discussion Objectively measured light physical activity and SB are associated with cognition in Finnish twins in their seventies, but the associations were attributable to genetic and environmental selection., Highlights • Objectively measured physical activity was associated with cognition in elderly. • Light physical activity was associated with better cognition in individuals. • Sedentary behavior was associated with worse cognition in individuals. • Twin analyses show similar genetics and environment contributing to the associations.

Background: Physical activity has been associated with a reduced risk of cognitive decline but the nature of this association remains obscure. Objective: To study associations between midlife physical activity and cognition in old age for a prospective cohort of Finnish twins. Methods: Physical activity in the Finnish Twin Cohort was assessed using questionnaire responses collected in 1975 and 1981. After a mean follow-up of 25.1 years, the subjects' (n = 3050; mean age 74.2; range 66-97) cognition was evaluated with a validated telephone interview. Both participation in vigorous physical activity, and the volume of physical activity, divided into quintiles, were used as predictors of cognitive impairment. Metrics collected by TELE were used to categorize participants as: cognitively impaired, suffering mild cognitive impairment, or cognitively healthy. Results: Participation in vigorous physical activity compared to non-participation for both 1975 and 1981 was associated with a lower risk of cognitive impairment in individual-based analyses (fully adjusted OR 0.50, 95% CI 0.35-0.73). Pairwise analyses yielded similar but statistically non-significant associations. In terms of the volume of physical activity, the most active quintile of individuals (OR 0.69, 95% CI 0.46-1.04) had a reduced risk of cognitive decline compared with the most sedentary quintile in the fully adjusted model although no clear dose-response was found. Conclusion: Vigorous midlife physical activity was associated with less cognitive impairment but without a clear dose-response association between the volume of physical activity and cognition.

BACKGROUND: To study whether persistent leisure-time physical activity (PA) during adulthood predicts use of antidepressants later in life. METHODS: The Finnish Twin Cohort comprises same-sex twin pairs born before 1958, of whom 11 325 individuals answered PA questions in 1975, 1981 and 1990 at a mean age of 44 years (range 33-60). PA volume over 15-years was used as the predictor of subsequent use of antidepressants. Antidepressant use (measured as number of purchases) for 1995-2004 were collected from the Finnish Social Insurance Institution (KELA) prescription register. Conditional logistic regression was conducted to calculate odds ratios (OR) with 95% confidence intervals (CI) for the use of antidepressants in pairs discordant for PA (642, including 164 monozygotic (MZ) pairs). RESULTS: Altogether 229 persons had used at least one prescribed antidepressant during the study period. Active co-twins had a lower risk (unadjusted OR 0.80, 95%CI 0.67-0.95) for using any amount of antidepressants than their inactive co-twins; trends being similar for DZ (0.80, 0.67-0.97) and MZ pairs (0.78, 0.51-1.17). The lowest odds ratio (0.51, 0.26-0.98) was seen among MZ pairs after adjusting for BMI, smoking and binge drinking. The point estimates were similar but non-significant for long-term antidepressant use (4+purchases equivalent to 12 months use). LIMITATIONS: Self-reported physical activity and low number of discordant MZ pairs. DISCUSSION: Use of antidepressants was less common among physically active co-twins even when shared childhood experiences and genetic background were controlled for. Physical activity in midlife may therefore be important in preventing mild depression later in life.Copyright © 2016 Elsevier B.V. All rights reserved. Language: en

Observational studies report a strong inverse relationship between leisure-time physical activity and all-cause mortality. Despite suggestive evidence from population-based associations, scientists have not been able to show a beneficial effect of physical activity on the risk of death in controlled intervention studies among individuals who have been healthy at baseline. On the other hand, high cardiorespiratory fitness is known to be a strong predictor of reduced mortality, even more robust than physical activity level itself. Here, in both animals and/or human twins, we show that the same genetic factors influence physical activity levels, cardiorespiratory fitness and risk of death. Previous observational follow-up studies in humans suggest that increasing fitness through physical activity levels could prolong life; however, our controlled interventional study with laboratory rats bred for low and high intrinsic fitness contrast with these findings. Also, we find no evidence for the suggested association using pairwise analysis among monozygotic twin pairs who are discordant in their physical activity levels. Based on both our animal and human findings, we propose that genetic pleiotropy might partly explain the frequently observed associations between high baseline physical activity and later reduced mortality in humans.

Introduction. Physical activity is associated with a decreased occurrence of dementia. In twins, we investigated the effect of persistent physical activity in adulthood on mortality due to dementia. Materials and methods. Physical activity was queried in 1975 and 1981 from the members of the older Finnish Twin Cohort (n = 2 1,791), who were aged 24-60 years at the end of 1981. The subjects were divided into three categories according to the persistence of their vigorous physical activity. Dementia deaths were followed up to the end of 2011. Results. During the 29-year follow-up, 353 subjects died of dementia. In individual-based analyses the age-and sex-adjusted hazard ratio (HR) was 0.65 (95% CI 0.43-0.98) for subjects partaking in vigorous physical activities in both 1975 and 1981 compared to those who were inactive in both years. No significant change was observed after adjusting for potential confounding factors. The corresponding HR for within-pair comparisons of the less active twin versus the more active co-twin was 0.48 (95% CI 0.17-1.32). The results for analyses of the volume of physical activity were inconclusive. Conclusions. Persistent vigorous leisure-time physical activity protects from dementia, and the effect appears to remain after taking into account childhood environment.

Midlife self-rated health and fitness in relation to white matter lesions and grey matter volume 20 years later

The study aimed to investigate whether baseline physical activity protects against the occurrence of type 2 diabetes during a 28 year follow-up, after controlling for childhood environment and genetic predisposition.At baseline in 1975 same-sex twin pairs born in Finland before 1958 were sent a questionnaire including questions on physical activity. The participants (20,487 individuals, including 8,182 complete twin pairs) were divided into quintiles by leisure-time physical activity metabolic equivalent (MET) index (MET h/day). Type 2 diabetes was determined from nationwide registers for the follow-up period (1 January 1976-31 December 2004). Individual and pairwise Cox proportional hazard models were used.During follow-up, 1,082 type 2 diabetes cases were observed. Among all individuals, participants in MET quintiles (Q) III-V had significantly decreased risk for type 2 diabetes compared with sedentary individuals (QI). The pairwise analysis on pairs discordant for physical activity showed that participants in MET QII to V had significantly lower hazard ratios (0.61, 0.59, 0.61, 0.61) compared with sedentary participants. These findings from the pairwise analysis persisted after adjusting for BMI. In the pairwise analysis, the BMI-adjusted hazard ratio for type 2 diabetes was lower for physically active members of twin pairs (combined QII-V) than for inactive co-twins (HR 0.54; 95% CI 0.37-0.78). Similar results were obtained for both dizygotic and monozygotic pairs, as well as for the subgroup of twin pairs defined as free of co-morbidities in 1981 (HR 0.36; 95% CI 0.17-0.76).Leisure-time physical activity protects from type 2 diabetes after taking familial and genetic effects into account.

Purpose: The aim of this study was to investigate whether persistent leisure-time physical activity, adjusted for genetic liability and childhood experiences, protects against chronic diseases, early signs of disability, and loss of life satisfaction. Methods: From 5663 healthy adult twin pairs, we identified 146 pairs who were discordant for both intensity and volume of leisure physical activity in 1975 and 1981. Of them, both members of 95 pairs were alive and participated in our follow-up study in 2005 when chronic diseases (such as diabetes, cardiovascular disease, and osteoarthritis), life satisfaction, and disability were assessed by a structured telephone interview. The mean age of the participants was 58 yr (range = 47–79 yr) in 2005. Paired tests were used in the analyses. Results: At the end of follow-up, the active cotwins had a decreased risk of reporting at least one chronic diseases, whereas active monozygotic (MZ) twins had two or more chronic diseases significantly less often than their inactive cotwins (odds ratio [OR] = 0.14, P = 0.031). Overall, the risk for type 2 diabetes or glucose intolerance (OR = 0.09, P = 0.022) and elevated blood pressure (OR = 0.46, P = 0.039) was decreased among the active cotwins. These effects were seen clearly among dizygotic twins but not always among small number of monozygotic twins. The active cotwins reported greater life satisfaction (P = 0.047) and tended to be less likely to be hospitalized (P = 0.065), although active cotwins had somewhat more sports-related injuries (OR = 1.9, P = 0.051) than inactive cotwins. Studied disability variables did not differ between the active and the inactive cotwins. Conclusions: Physical activity reduces the risk for chronic diseases and helps in maintaining life satisfaction. However, genetic factors may play a role in this association because some findings emerged more clearly among dizygotic than monozygotic twins discordant for physical activity. peerReviewed

The physically active lifestyle is associated with low future morbidity and mortality, but the causality between physical activity and health is not always clear. As some inherited biological characteristics and childhood experiences may cause selection bias in observational studies, we sought to take them into account by identifying 16 twin pairs (7 MZ, 9 DZ, mean age 60 years) discordant for leisure time physical activity habits for thirty years. We conducted detailed health-related examinations among these twin pairs. Our main aims were to study the effects of physical activity and genes on fitness and body composition, with special reference to body fat compartments, metabolic syndrome components and related diseases and risk factor levels, status of arteries, structure and function of the heart, bone properties, and muscle and fat tissue-related mechanisms linked to physical activity and chronic disease development. Our physical activity assessments showed that inactive co-twins were on average 8.8 MET hours/day less active than their active co-twins through out their midlife (2.2 ± 2.3 vs. 11.0 ± 4.1 MET h/day, p < .001). Follow-up fitness tests showed that physically inactive co-twins were less fit than their active co-twins (estimated VO2peak 26.4 ± 4.9 vs. 32.5 ± 5.5 ml/kg/min, p < .001). Similar differences were found in both MZ and DZ pairs. On the basis of earlier epidemiological observations on nonrelated individuals, these physical activity and fitness differences are large enough to cause differences in many mechanisms and risk factors related to the development of chronic diseases and to permit future analyses.

The aim of this study was to find out whether persistent leisure-time physical activity, adjusted for genetic liability and childhood experiences, protect against occurrence of specific chronic diseases and all-cause mortality. Study design was a 24-year prospective follow-up after 6-year physical activity discordance in twin pairs. From 5,663 healthy adult twin pairs, 146 pairs (including 29 mozygotic) discordant for both intensity and volume of leisure physical activity at baseline in both 1975 and 1981 were systematically identified. Mortality and occurrence of chronic diseases (diabetes, hypertension, coronary heart disease defined according to reimbursable medication status) were followed for the period 1.1.1983–31.12.2006 for mortality and 1.1.1983–31.12.2004 for diseases. By end of follow-up, 19 inactive and 10 active co-twins had died. In the whole sample, HR of death adjusted for social class was 2.08 (95% CI 1.06–4.09) for inactive vs. active co-twins, the HR being 2.67 (95% CI 1.15–6.20) among DZ pairs with no mortality difference among the smaller number of discordant MZ pairs. The reimbursable medication analyses showed a tendency of higher risk for inactive vs. active co-twins. Among DZ pairs, HR of diabetes medication adjusted for social class was 2.73 (95% CI 0.62–12.00) and HR of hypertension medication was 2.14 (95% CI 0.94–4.89). This study supports the earlier findings that physical activity is associated with reduced mortality. However the difference was seen only in DZ pairs and therefore some residual genetic confounding effects on mortality cannot be excluded. peerReviewed

Background and objective: Physical activity level and obesity are both partly determined by genes and childhood environment. To determine the associations between long-term leisure-time physical activity, weight gain and waist circumference and whether these are independent of genes and childhood effects. Design and subjects: The study design is a 30-year follow-up twin study in Finland. For this study, 146 twin pairs were comprehensively identified from the large Finnish Twin Cohort. These twin pairs were discordant for both intensity and volume of leisure physical activity in 1975 and 1981 and were healthy in 1981. At follow-up in 2005, both members of 89 pairs were alive and participated in a structured telephone interview. In the interview self-measured weight and waist circumference, and physical activity level for the whole follow-up were assessed. Paired tests were used in the statistical analyses. Main outcome measures: Waist circumference at 30-year follow-up (2005) and change in weight from 1975 to 2005. Results: In the 42 twin pairs discordant for physical activity at all time points during the 30-year period, the mean weight gain from 1975 through 2005 was 5.4 kg (95% confidence interval (CI) 2.0–8.9) less in the active compared to inactive co-twins (paired t-test, P ¼ 0.003). In 2005, the mean waist circumference was 8.4 cm (95% CI 4.0–12.7) less in the active compared with inactive co-twins (Po0.001). These trends were similar for both monozygotic and dizygotic twin pairs. Pairwise differences in weight gain and waist circumference were not seen in the 47 twin pairs, who were not consistently discordant for physical activity. Conclusion: Persistent participation in leisure-time physical activity is associated with decreased rate of weight gain and with a smaller waist circumference to a clinically significant extent even after partially controlling for genetic liability and childhood environment. peerReviewed