title: Gender-assortative waist circumference in mother-daughter and father-son pairs, and its implications. An 11-year longitudinal study in children (EarlyBird 59).
abstract: OBJECTIVE
  Body mass index (BMI) is reportedly gender assortative (mother-daughter, father-son) in contemporary children. We investigated the corresponding transmission of waist circumference (WC) and its implications.
  
  
  METHODS
  We measured parental WC at baseline and WC, height, weight and para-umbilical skin-fold (USF) annually in their offspring from 5 to 15 years (n = 223 trios). Parents were deemed normal metabolic risk (NR) or high risk (HR) according to World Health Organization (WHO) cut-points for WC (mothers 80 cm, fathers 94 cm). The residual from WC adjusted for BMI (WC|BMI ) was used as a surrogate for excess intra-abdominal fat, and its association with insulin resistance (HOMA2-IR) was sought.
  
  
  RESULTS
  WC and USF were both gender assortative, while WC|BMI was not. WC was greater by 1.62 cm (P < 0.05, confidence interval [CI]: 0.09-3.16) and USF by 0.37 cm (P < 0.01, CI: 0.19-0.56) among the daughters (but not the sons) of HR compared with those of NR mothers, and by 1.32 cm (P < 0.05, CI: 0.09-2.55) and 0.18 cm (P < 0.05, CI: 0.04-0.32), respectively in the corresponding father-son (but not father-daughter) pairings. No such differences could be demonstrated for WC|BMI . A standard deviation score 1(SDS) change in WC|BMI , independent of BMI, was associated with a 7.14% change in IR in girls (P < 0.01, CI: 1.76-12.80) and 8.02% in boys (P < 0.001, CI: 2.93-13.36), but there was no relationship between IR and USF.
  
  
  CONCLUSIONS
  The relationship of offspring WC to metabolic health and to parental size is complex. Subcutaneous abdominal fat is gender assortative but harmless, while intra-abdominal fat (its surrogate in this analysis) is unrelated to parental waist circumference, but metabolically harmful.
authors.affiliation: Department of Endocrinology and Metabolism, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: M
authors.initials: M
authors.lastname: Mostazir
authors.forename: A
authors.initials: A
authors.lastname: Jeffery
authors.forename: L
authors.initials: L
authors.lastname: Voss
authors.forename: T
authors.initials: T
authors.lastname: Wilkin
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005220:Fathers; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D009035:Mothers; D009679:Nuclear Family; D012307:Risk Factors; D013997:Time Factors; D055105:Waist Circumference
keywords: Gender-assortative waist circumference; subcutaneous; visceral fat