title: The influence of zygosity status on blood pressure and on lipid profiles in male and female twins.
abstract: OBJECTIVE
  To study the influence of zygosity on blood pressure and serum lipid concentrations among male and female twins.
  
  
  METHODS
  Department of Endocrinology, Odense University Hospital, Denmark.
  
  
  METHODS
  A total of 125 monozygotic and 178 dizygotic twin pairs aged 55-74 years of age, ascertained from The Danish Twin Register.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Blood pressure and serum lipid concentrations.
  
  
  RESULTS
  The prevalence of hypertriglyceridemia and hypercholesterolemia were higher among monozygotic compared with dizygotic twins, whereas the prevalence of hypertension was similar. The level of triglycerides [0.28 (0.44) versus 0.18 (0.41), P = 0.01] and total cholesterol [1.82 (0.17) versus 1.78 (0.19), P = 0.03] were significantly higher in monozygotic compared with dizygotic twins. Systolic blood pressure was non-significantly higher among monozygotic twins (136.8 (21.3) versus 134.1 (19.6), P = 0.10). When comparing monozygotic and dizygotic twins within each sex group, the difference in triglyceride level was only apparent among male twins and the differences in systolic blood pressure and total cholesterol were only seen among female twins. Birth weight as determined in a subgroup of the population was similar in monozygotic and dizygotic twins.
  
  
  CONCLUSIONS
  Zygosity status per se influences fasting serum triglycerides and total-cholesterol and to some extent systolic blood pressure in twins, supporting an influence of an intrauterine component on lipid profiles. The influence is independent of birth weight and seems to be sex-specific.
authors.affiliation: Department of Endocrinology, Odense University Hospital, DK-5000 Odense C, Denmark. p.poulsen@winsloew.ou.dk
authors.forename: Pernille
authors.initials: P
authors.lastname: Poulsen
authors.forename: Allan
authors.initials: A
authors.lastname: Vaag
authors.forename: Henning
authors.initials: H
authors.lastname: Beck-Nielsen
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000235:genetics*; D002784:Cholesterol / Q000097:blood; D003718:Denmark; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000235:genetics*; D006973:Hypertension / Q000235:genetics*; D015228:Hypertriglyceridemia / Q000235:genetics; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012727:Sex Characteristics; D014280:Triglycerides / Q000097:blood; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
chemical_list: D008055:Lipids; D014280:Triglycerides; D002784:Cholesterol