Active Co-twins Research Articles

Long-Term Physical Activity May Modify Brain Structure and Function: Studies in Young Healthy Twins.

Physical activity (PA) is said to be beneficial to many bodily functions. However, the effects of PA in the brain are still inadequately known. The authors aimed to uncover possible brain modulation linked with PA. Here, they combine 4 of their studies with monozygotic twins, who were within-pair discordant in PA for a minimum of 1 year. The authors performed brain imaging, brain electrophysiology, and cardiovascular and body composition assessments, and collected questionnaire-based data. The present synopsis elucidates the differences associated with differing PA history in conditions without genetic variability. They present new structural and electrophysiological results. Participants, healthy, 45 male monozygotic twins (mean age 34.5 [1.5] y) differed in aerobic capacity and fat percentage (P < .001). More active co-twins showed larger gray matter volumes in striatal, prefrontal, and hippocampal regions, and smaller gray matter volumes in the anterior cingulate area than less active co-twins. Functionally, visual and somatosensory automatic change detection processes differed between more and less active co-twins. In monozygotic twins, who differed in their PA history, differences were observed in identifiable anatomic brain locations involved with motor control and memory functions, as well as in electrophysiological measures detecting brain's automatic processes. Better aerobic capacity may modify brain morphology and sensory function.

Leisure-time physical activity and intra-abdominal fat in young adulthood: A monozygotic co-twin control study.

To investigate differences in abdominal fat compartments between young adult monozygotic twin pairs discordant for leisure-time physical activity. Ten young adult male monozygotic twin pairs (age range 32-36 years) discordant for leisure-time physical activity during the past 3 years were systematically selected from a population-based Finnish twin cohort. Magnetic resonance image at the level of the L2-L3 intervertebral disc was used to predict intra-abdominal and subcutaneous abdominal fat masses. Dietary intake was assessed with a 4-day food diary. Inactive twins had 31% more intra-abdominal fat than their active co-twins (mean difference 0.52 kg, 95% CI 0.12 to 0.91, P = 0.016), whereas the difference in subcutaneous abdominal fat was only 13% (P = 0.21) and 3% in body mass index (P = 0.28). Intraperitoneal fat mass was 41% higher among inactive twins compared to their active co-twins (mean difference 0.41 kg, 95% CI 0.11 to 0.70, P = 0.012). Dietary intake did not differ between co-twins. A lower level of physical activity is related to greater accumulation of intra-abdominal fat among healthy adult males in their mid-30s. The findings highlight the importance of leisure-time physical activity independent of genes and diet in the prevention of intra-abdominal fat accumulation from early adulthood onward.

Persistent leisure-time physical activity in adulthood and use of antidepressants: A follow-up study among twins

BackgroundTo study whether persistent leisure-time physical activity (PA) during adulthood predicts use of antidepressants later in life. MethodsThe 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). ResultsAltogether 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). LimitationsSelf-reported physical activity and low number of discordant MZ pairs. DiscussionUse 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.

Physical activity, morbidity and mortality in twins: a 24-year prospective follow-up

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.

Leisure-time physical activity and nutrition: a twin study

To determine the association between long-term leisure-time physical activity/inactivity and eating behaviours in twin pairs discordant for physical activity for 30 years. Co-twin control design with cross-sectional data collection using questionnaire on eating habits and 5 d food diary. Differences in eating behaviours between physically active and inactive co-twins were analysed with pairwise tests. Finland. Sixteen same-sex twin pairs (seven monozygotic and nine dizygotic, mean age 60 years) discordant for physical activity, selected from the Finnish Twin Cohort on the basis of physical activity discordance for 30 years, blinded to their possible differences in eating behaviours. The eating habits questionnaire revealed that physically active co-twins more frequently reported that it is easy to eat according to need, whereas overeating and/or restrictive eating was more common among the inactive co-twins (P = 0·035). Avoiding calories was more common among the active than inactive co-twins (P = 0·034). Based on food diaries the physically active co-twins had daily energy intake on average 15·5 kJ/kg higher than their inactive co-twins (P = 0·030). The active co-twins also had a higher intake of vitamin C (P = 0·004), total water (P = 0·044), legumes and nuts (P = 0·015) and sweets (P = 0·036), as well as a lower energy-adjusted intake of meat (P = 0·013). The physically active persons seem to eat more but not necessarily healthier food. However, habitual physical activity may help in eating according to need and in reaching and maintaining a healthy body composition. Therefore, it is necessary to incorporate both dietary and physical activity advice into health counselling.

Effect of Physical Activity on Health in Twins

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. 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. 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. 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.

Leisure-time physical activity and high-risk fat: a longitudinal population-based twin study

Exercise is thought to reduce high-risk body fat, but intervention studies are frequently limited by short follow-ups and observational studies by genetic selection. Therefore, we studied the effects of a physically inactive vs active lifestyle on high-risk (visceral, liver and intramuscular) fat in twin pairs discordant for leisure-time physical activity habits for over 30 years. A longitudinal population-based twin study. Sixteen middle-aged (50-74 years) same-sex twin pairs (seven monozygotic (MZ), nine dizygotic (DZ)) with long-term discordance for physical activity habits were comprehensively identified from the Finnish Twin Cohort (TWINACTIVE study). Discordance was initially defined in 1975 and the same co-twin remained significantly more active during the 32-year-long follow-up. Magnetic resonance imaging-assessed visceral, liver and intramuscular fat. In within-pair analyses carried out after the adult life-long discordance in physical activity habits, the physically inactive co-twins had 50% greater visceral fat area compared with the active co-twins (mean difference 55.5 cm2, 95% confidence interval (CI) 7.0-104.1, P=0.010). The liver fat score was 170% higher (13.2, 95% CI 3.5-22.8, P=0.030) and the intramuscular fat area 54% higher (4.9 cm2, 95% CI 1.9-7.9, P=0.002) among the inactive co-twins. All the trends were similar for MZ and DZ pairs. Peak oxygen uptake was inversely associated with visceral (r=-0.46, P=0.012) and intramuscular fat area (r=-0.48, P=0.028), with similar trends in intrapair difference correlations (r=-0.57, P=0.021 and r=-0.50, P=0.056, respectively). The intrapair difference correlation between visceral and intramuscular fat was also high (r=0.65, P=0.009). Regular physical activity seems to be an important factor in preventing the accumulation of high-risk fat over time, even after controlling for genetic liability and childhood environment. Therefore, the prevention and treatment of obesity should emphasize the role of regular leisure-time physical activity.

Effect Of Long-term Physical Activity On Health In Twins: A 30-year Longitudinal Study

PURPOSE: Physical activity has many positive and some negative effects on health. The main aim of this study was to find out 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 146 pairs were identified 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 different chronic diseases, life-satisfaction, disability and physical activity level were assessed by a structured telephone interview. Mean age of the participants was 58 years (range from 47 to 79 years) in 2005. Paired tests were used in statistical analyses. RESULTS: Active co-twins had decreased risk of different chronic diseases with active MZ twins having significantly less often two or more chronic diseases than their inactive cotwins (OR=0.14, p=0.031). Overall, the risk of type 2 diabetes or glucose intolerance (OR= 0.09, p=0.022) and incident elevated blood pressure (OR=0.46, p=0.039) was decreased among active cotwins. Active cotwins were more satisfied with their life at follow-up (p=0.047), and tended to need less hospital care during the last three years of the follow-up (p=0.065). In contras, active co-twins showed a tendency of having more sports-related injuries (OR=1.9, p=0.051), but signs of disability did not differ according to activity. CONCLUSIONS: Physical activity may help in maintaining health and life satisfaction. However, genetic factors may play a role in explaining some of the association between disease occurrence and physical activity as some of the findings were more clear among physical activity discordant dizygotic than monozygotic twins.

Leisure Time Physical Activity And Body Fat: A Twin Study

Exercise is thought to reduce body fat, but intervention studies are frequently limited by short follow-ups and observational studies by genetic selection. To tackle these problems, we carried out within-pair analyses in twin pairs identified on the basis of their long-term physical activity discordance. By studying both monozygotic and dizygotic twin pairs, we were able to control for childhood environment and partially for genetic liability as monozygotic co-twins share all and dizygotic co-twins on average half of their segregating genes. PURPOSE: To study the effects of a physically inactive vs. active lifestyle on body fat in twin pairs discordant for physical activity for 32 years. METHODS: Sixteen middle-aged (50-74 yrs) same-sex twin pairs (seven monozygotic, nine dizygotic) discordant for physical activity habits were comprehensively identified from the Finnish Twin Cohort (N=5663 baseline healthy pairs). Discordance was initially defined in 1975 and the same co-twin remained significantly more active during most of the follow-up. At the end of the follow-up in 2007 a series of body composition measurements, including bioimpedance measurement of whole body fat and specific MR imaging, was carried out. RESULTS: At the end of the follow-up the inactive co-twins weighed 6.5 kg more (P=0.12) and had 6.0 kg more fat mass (P=0.015) than their active co-twins, but no differences in fat-free masses were found. Visceral fat area was 50 % (P=0.010), liver fat score 170 % (P=0.030) and midthigh intramuscular fat area 48 % (P=0.034) greater among the inactive co-twins. Similar trends were seen among both monozygotic and dizygotic pairs. The intrapair difference correlation between visceral and intramuscular fat was high (r=0.648, P=0.009). CONCLUSION: Long-term habitual physical activity seems to protect from the accumulation of total, visceral and ectopic fat, even after partly controlling for genetic liability and childhood environment. Therefore the prevention of obesity should emphasize the role of regular leisure time activity.

Effects of 32-Year Leisure Time Physical Activity Discordance in Twin Pairs on Health (TWINACTIVE Study): Aims, Design and Results for Physical Fitness

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 VO(2peak) 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.

MORTALITY IN TWINS DISCORDANT FOR LEISURE TIME SEDENTARY LIFESTYLE

36 In the past few years there has been increasing recognition of the importance of familial factors in longevity and mortality. Using the Finnish Twin Cohort, we investigated leisure time sedentary lifestyle and mortality with respect to familial factors which may cause a selection bias. In 1975 at baseline, 7775 healthy men and 7862 healthy women of the Finnish Twin Cohort aged 25 to 64 years responded to a questionnaire on physical activity habits and known predictors of mortality. We followed the cohort for deaths from 1977 to 1994. At baseline there were 710 same-sex twin-pairs discordant for leisure sedentariness (did not participate in leisure physical activity vs. participated in leisure physical activity at least corresponding to 7 MET-hours/wk) among whom there were 95 pairs (65 men and 30 women pairs) discordant for death during follow-up. The odds ratio (OR) for all-cause mortality was 2.07 (95% CI 1.34-3.17) in sedentary co-twins compared with non-sedentary co-twins (by conditional logistic regression analysis). After adjustment for baseline occupational group, BMI, smoking and use of alcohol the OR of death was 1.86 (95% CI 1.19-2.91) in sedentary co-twins compared with more active co-twins. Respectively, the adjusted OR in men pairs was 1.89 and in women pairs 1.69. Studying twins enabled us to adjust for familial factors, and we found further evidence that leisure physical activity helps prevent premature deaths