title: Physical activity attenuates genetic effects on BMI: Results from a study of Chinese adult twins.
abstract: OBJECTIVE
  This study aimed to examine the gene-environment interaction of physical activity and body mass index (BMI) using the Chinese National Twin Registry (CNTR).
  
  
  METHODS
  A total of 19,308 same-sex adult twins from CNTR were included in the analysis. Twin zygosity was determined by self-reported questionnaire. Height and weight were measured using self-reported questionnaire. The vigorous physical activity was defined as greater or equal to five times a week of at least 30 min moderate- or high-intensity physical activity. A twin structural equation model was used to analyze the gene-environment interaction of vigorous exercise with BMI among 13,506 monozygotic twins and 5,802 dizygotic twins.
  
  
  RESULTS
  A structural equation model adjusting for age and sex found vigorous exercise significantly moderated the additive genetic effects (P < 0.001) and shared environmental effects (P < 0.001) on BMI. The genetic contributions to BMI were significantly lower for people who adopted a physically active lifestyle [h(2) = 40%, 95% confidence interval (CI): 35%-46%] than those who were relative sedentary (h(2) = 59%, 95% CI: 52%-66%). The observed gene-physical activity interaction was more pronounced in men than women.
  
  
  CONCLUSIONS
  Our results suggested that adopting a physically active lifestyle may help to reduce the genetic influence on BMI among the Chinese population.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Biqi
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Gao
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lv
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Canqing
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Shengfeng
authors.initials: S
authors.lastname: Wang
authors.affiliation: Qingdao Center for Diseases Control and Prevention, Qingdao, China.
authors.forename: Zengchang
authors.initials: Z
authors.lastname: Pang
authors.affiliation: Zhejiang Center for Disease Control and Prevention, Hangzhou, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Cong
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Shanghai Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.affiliation: Jiangsu Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.affiliation: Sichuan Center for Disease Control and Prevention, Chengdu, China.
authors.forename: Xianping
authors.initials: X
authors.lastname: Wu
authors.affiliation: Tianjin Center for Disease Control and Prevention, Tianjin, China.
authors.forename: Guohong
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Qinghai Center for Disease Control and Prevention, Xining, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Wang
authors.affiliation: Harbin Medical University, Harbin, China.
authors.forename: Binyou
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Cao
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics; D004200:Diseases in Twins / Q000235:genetics; D015444:Exercise; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000235:genetics; D012042:Registries; D011795:Surveys and Questionnaires; D014429:Twins, Dizygotic / Q000235:genetics / Q000706:statistics & numerical data*; D014430:Twins, Monozygotic / Q000235:genetics / Q000706:statistics & numerical data*