title: Trends in the association of parental history of obesity over 60 years.
abstract: OBJECTIVE
  The association of familial as compared to genetic factors in the current obesogenic environment, compared with earlier, leaner time periods, is uncertain.
  
  
  METHODS
  Participants from the Framingham Heart Study were classified according to parental obesity status in the Original, Offspring, and Third Generation cohorts; mean BMI levels were estimated and we compared the association of parental history across generations. Finally, a genetic risk score comprised of 32 well-replicated single nucleotide polymorphisms for BMI was examined in association with BMI levels in 1948, 1971, and 2002.
  
  
  RESULTS
  BMI was 1.49 kg/m2 higher per each affected parent among the Offspring, and increased to 2.09 kg/m2 higher among the Third Generation participants (P-value for the cohort comparison=0.007). Parental history of obesity was associated with increased weight gain (P < 0.0001) and incident obesity (P = 0.009). Despite a stronger association of parental obesity with offspring BMI in more contemporary time periods, we observed no change in the effect size of a BMI genetic risk score from 1948 to 2002 (P = 0.11 for test of trend across the time periods).
  
  
  CONCLUSIONS
  The association of parental obesity has become stronger in more contemporary time period, whereas the association of a BMI genetic risk score has not changed.
authors.affiliation: National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, USA; National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA; Department of Endocrinology, Hypertension, and Diabetes, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Fox
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pencina
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Heard-Costa
authors.forename: Peter
authors.initials: P
authors.lastname: Shrader
authors.forename: Cashell
authors.initials: C
authors.lastname: Jaquish
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: O'Donnell
authors.forename: Ramachandran S
authors.initials: RS
authors.lastname: Vasan
authors.forename: L Adrienne
authors.initials: LA
authors.lastname: Cupples
authors.forename: Ralph B
authors.initials: RB
authors.lastname: D'Agostino
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000235:genetics*; D010290:Parents; D015995:Prevalence; D012307:Risk Factors; D014481:United States; D015430:Weight Gain / Q000235:genetics