title: Genetic and Environmental Regulation on Longitudinal Change of Metabolic Phenotypes in Danish and Chinese Adult Twins.
abstract: OBJECTIVE
  The rate of change in metabolic phenotypes can be highly indicative of metabolic disorders and disorder-related modifications. We analyzed data from longitudinal twin studies on multiple metabolic phenotypes in Danish and Chinese twins representing two populations of distinct ethnic, cultural, social-economic backgrounds and geographical environments.
  
  
  METHODS
  The study covered a relatively large sample of 502 pairs of Danish adult twins followed up for a long period of 12 years with a mean age at intake of 38 years (range: 18-65) and a total of 181 Chinese adult twin pairs traced for about 7 years with a mean baseline age of 39.5 years (range: 23-64). The classical twin models were fitted to the longitudinal change in each phenotype (Δphenotype) to estimate the genetic and environmental contributions to the variation in Δphenotype.
  
  
  RESULTS
  Moderate to high contributions by the unique environment were estimated for all phenotypes in both Danish (from 0.51 for low density lipoprotein cholesterol up to 0.72 for triglycerides) and Chinese (from 0.41 for triglycerides up to 0.73 for diastolic blood pressure) twins; low to moderate genetic components were estimated for long-term change in most of the phenotypes in Danish twins except for triglycerides and hip circumference. Compared with Danish twins, the Chinese twins tended to have higher genetic control over the longitudinal changes in lipids (except high density lipoprotein cholesterol) and glucose, higher unique environmental contribution to blood pressure but no genetic contribution to longitudinal change in body mass traits.
  
  
  CONCLUSIONS
  Our results emphasize the major contribution of unique environment to the observed intra-individual variation in all metabolic phenotypes in both samples, and meanwhile reveal differential patterns of genetic and common environmental regulation on changes over time in metabolic phenotypes across the two samples.
authors: Unit of Human Genetics, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors: Shuxia
authors: S
authors: Li
authors: Department of Clinical Research, University of Southern Denmark, and Odense Patient data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark.
authors: Kirsten Ohm
authors: KO
authors: Kyvik
authors: Qingdao Center for Disease Control and Prevention, Qingdao, China.
authors: Zengchang
authors: Z
authors: Pang
authors: Department of Public Health, Qingdao University Medical College, Qingdao, China.
authors: Dongfeng
authors: D
authors: Zhang
authors: Qingdao Center for Disease Control and Prevention, Qingdao, China.
authors: Haiping
authors: H
authors: Duan
authors: Unit of Human Genetics, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.|Epidemiology, Biostatistics and Biodemography, Department of Public Health, University of Southern Denmark, Odense, Denmark.
authors: Qihua
authors: Q
authors: Tan
authors: Epidemiology, Biostatistics and Biodemography, Department of Public Health, University of Southern Denmark, Odense, Denmark.
authors: Jacob
authors: J
authors: Hjelmborg
authors: Unit of Human Genetics, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors: Torben
authors: T
authors: Kruse
authors: Environmental Medicine, Department of Public Health, University of Southern Denmark, Odense, Denmark.
authors: Christine
authors: C
authors: Dalgård
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000097:blood / Q000235:genetics; D002681:China; D003718:Denmark; D004200:Diseases in Twins; D004777:Environment; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D059647:Gene-Environment Interaction; D014644:Genetic Variation; D005843:Geography; D006801:Humans; D008055:Lipids / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008660:Metabolism / Q000235:genetics*; D008875:Middle Aged; D010641:Phenotype; D012923:Social Class; D014280:Triglycerides / Q000097:blood; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: D008055:Lipids; D014280:Triglycerides