Controlled Study of Metabolic Syndrome among Offspring of Parents with Bipolar Disorder

Objectives: Bipolar disorder (BD) is highly heritable and associated with increased rates of metabolic syndrome (MetS). However, little is known about MetS in offspring of parents with BD. We therefore examined this topic in the Pittsburgh Bipolar Offspring Study cohort. Methods: Participants included 199 parents (n = 116 BD, diagnosed using DSM-IV; n = 83 non-BD) and 330 offspring (mean age 19.9 ± 5.3 years), including 198 high-risk offspring of parents with BD (n = 80 affected with a mood disorder) and 132 control offspring. We defined MetS and its components using International Diabetes Federation (IDF) guidelines (primary) and National Cholesterol Education Program (NCEP) guidelines (secondary). Multivariable analyses controlled for age and socioeconomic status in offspring. Sensitivity analyses controlled for psychotropic medications. Results: There was higher prevalence of MetS in parents with BD as compared to controls. NCEP-defined MetS was significantly more prevalent among affected high-risk offspring (16.3%) and controls (15.2%) vs unaffected high-risk offspring (6.0%; χ2 = 6.54, P = .04). There was greater mean number of MetS components (IDF: 1.7 ± 1.1; NCEP: 1.4 ± 1.0) among affected high-risk offspring vs unaffected high-risk offspring (IDF: 1.2 ± 1.0; NCEP: 1.0 ± 1.0) and controls (IDF: 1.3 ± 1.2; NCEP: 1.1 ± 1.1; IDF: H[2] = 10.26, P = .006; NCEP: H[2] = 9.18, P = .01). Most findings became nonsignificant in multivariable analyses. Some between-group results became nonsignificant after controlling for second-generation antipsychotics. Conclusions: This preliminary study found increased risk of MetS among affected high-risk offspring, which may be attributable to socioeconomic status. Prospective studies may determine timing of MetS onset in relation to mood disorder onset, and the role of socioeconomic status in moderating this association.