Abstracts for the 15th International Congress on Twin Studies and the 3rd World Congress on Twin Pregnancy

s for the 15th International Congress on Twin Studies and the 3rd World Congress on Twin Pregnancy CHILDHOOD MOTOR DEVELOPMENT AND LEISURE-TIME PHYSICAL ACTIVITY IN YOUNG ADULTHOOD: A DISCORDANT TWIN-PAIR ANALYSIS S. Aaltonen1,2, A. Latvala1, U. M. Kujala3, J. Kaprio1,4,5, K. Silventoinen2 1Department of Public Health, The Hjelt Institute, University of Helsinki, Helsinki, Finland 2Department of Social Research, University of Helsinki, Helsinki, Finland 3Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland 4Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland 5Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland Introduction: Previous longitudinal studies have shown that the motor proficiency in early life may act as a determinant of physical activity in later life. However, familial factors including genetic effects may explain the association, but long-term follow-up studies taking into account potential confounding by family background are still missing. The study design of discordant same-sex twin pairs enables adjustment for genetic, familial and other factors shared by co-twins. The aim of the present twin study was to investigate whether the parental reports of within-pair differences in childhood motor skill development are associated with self-reported leisure-time physical activity levels in young adulthood independently of familial background. Materials and Methods: Participants were identified from two ongoing Finnish twin studies, the FinnTwin12 and FinnTwin16 studies. 1,550 twin pairs (795 MZ, 755 same-sexed DZ) from the FinnTwin12 study and 1,752 twin pairs (882 MZ, same-sexed 871 DZ) from the FinnTwin16 study with the relevant variables were included in the analysis. Childhood motor development was assessed by questionnaire sent to the parents at baseline (age 11 for FinnTwin12 and age 16 for FinnTwin16). Parents reported whether one or the other of the co-twins had been ahead in motor skill development in infancy and childhood. The motor skill development indicators assessed were: (1) turning over from back to stomach, (2) standing unaided, (3) walking unaided, (4) climbing stairs unaided, (5) general motor skills at age 6 years, (6) agility in childhood and (7) physical strength in childhood. Leisure-time physical activity was assessed at wave 4 of each study, when the twins were young adults (mean age 24.4 years, SD 1.3 years, range 19–28). Leisure-time physical activity was based on questionnaire data, and the activity level was assessed as leisure-time MET hours/day. The associations between the pairwise differences in childhood motor development indicators and pairwise differences in leisure-time physical activity levels in young adulthood were analyzed using conditional linear regression analysis. Results: In both cohorts, learning to stand unaided earlier in infancy predicted higher leisure-time MET values in young adulthood (FinnTwin16 p = .001 and FinnTwin12 p = .02). In the FinnTwin16 study sample, having been ahead in climbing stairs unaided (p = .04), in agility (p = .02) and in general motor skills (p = .005) in childhood also predicted higher leisure-time MET values as young adults. A similar tendency was seen for childhood agility in the FinnTwin12 study sample but the difference was not statistically significant in this sample. The co-twins who had been ahead in walking unaided in infancy had statistically significantly higher leisure-time MET values in young adulthood according to the FinnTwin12 study sample (p = .05). However, this association was not seen in the FinnTwin16 study sample. The significance of the associations were robust to adjustment for birth weight and birth order with the exception of with the indicator ‘standing unaided’ in the FinnTwin12 cohort. Conclusion: More advanced childhood motor development is associated with higher leisure-time MET values in young adulthood at least partly independently of familial background. Motor skill interventions to improve movement skills of preschool children may be effective in promoting long-term physical activity. HERITABILITY OF LOWER URINARY TRACT SYMPTOMS IN MEN N. Afari1, M. Gasperi1, C. Forsberg2, J. Goldberg2, D. Buchwald3, J. Krieger3 1VA Center of Excellence for Stress and Mental Health & University of California, San Diego, USA 2Vietnam Era Twin Registry, Seattle, USA 3University of Washington, Seattle, USA Introduction: Urinary conditions such as urinary incontinence, overactive bladder, and chronic prostatitis/chronic pelvic pain syndrome are common, comorbid, disabling, and without clear etiology. Common to all of these conditions are non-specific urinary symptoms such as urgency and frequency, known as Lower Urinary Tract Symptoms (LUTS). LUTS are associated with significant negative impact on quality of life and economic burden, and increase with advancing age. However, little is known about the etiology of LUTS and the relative contribution of genetic and environmental factors to the phenotypic variance of LUTS. To date, only one study has examined the heritability of LUTS in women, finding robust evidence of a genetic influence for susceptibility to urinary incontinence, frequency and nocturia, but also that shared environmental factors seem important for the predisposition to develop overactive bladder. No similar studies have focused on heritability of LUTS in men. Materials and Methods: The aim of this study was to examine the relative contribution of genetic and environmental factors to the phenotypic variance of LUTS in men. Data from the Vietnam Era Twin Registry