title: Genetic and environmental influences on blood pressure variability: a study in twins.
abstract: OBJECTIVE
  Blood pressure variability (BPV) and its reduction in response to antihypertensive treatment are predictors of clinical outcomes; however, little is known about its heritability. In this study, we examined the relative influence of genetic and environmental sources of variance of BPV and the extent to which it may depend on race or sex in young twins.
  
  
  METHODS
  Twins were enrolled from two studies. One study included 703 white twins (308 pairs and 87 singletons) aged 18-34 years, whereas another study included 242 white twins (108 pairs and 26 singletons) and 188 black twins (79 pairs and 30 singletons) aged 12-30 years. BPV was calculated from 24-h ambulatory blood pressure recording.
  
  
  RESULTS
  Twin modeling showed similar results in the separate analysis in both twin studies and in the meta-analysis. Familial aggregation was identified for SBP variability (SBPV) and DBP variability (DBPV) with genetic factors and common environmental factors together accounting for 18-40% and 23-31% of the total variance of SBPV and DBPV, respectively. Unique environmental factors were the largest contributor explaining up to 82-77% of the total variance of SBPV and DBPV. No sex or race difference in BPV variance components was observed. The results remained the same after adjustment for 24-h blood pressure levels.
  
  
  CONCLUSIONS
  The variance in BPV is predominantly determined by unique environment in youth and young adults, although familial aggregation due to additive genetic and/or common environment influences was also identified explaining about 25% of the variance in BPV.
authors.affiliation: Department of Pediatrics, Georgia Prevention Institute, Georgia Health Sciences University, Augusta, Georgia 30912, USA.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Xu
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Ding
authors.forename: Xinyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Shaoyong
authors.initials: S
authors.lastname: Su
authors.forename: Frank A
authors.initials: FA
authors.lastname: Treiber
authors.forename: Robert
authors.initials: R
authors.lastname: Vlietinck
authors.forename: Robert
authors.initials: R
authors.lastname: Fagard
authors.forename: Catherine
authors.initials: C
authors.lastname: Derom
authors.forename: Marij
authors.initials: M
authors.lastname: Gielen
authors.forename: Ruth J F
authors.initials: RJ
authors.lastname: Loos
authors.forename: Harold
authors.initials: H
authors.lastname: Snieder
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000235:genetics*; D002648:Child; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008297:Male; D008957:Models, Genetic; D044469:Racial Groups; D012737:Sex Factors; D055815:Young Adult