Objectives: Previous research has demonstrated a relationship between adiposity and bipolar disorder, although data is derived predominantly from patient samples. This study investigated the association between bipolar disorder and indices of adiposity; including body fat mass as measured by DXA scans.
Methods: In this observational study, 21 women with bipolar disorder and 523 healthy controls were drawn from an age-stratified, random, community sample of women (20-93yr) participating in the Geelong Osteoporosis Study. Bipolar disorder was diagnosed utilising a semi-structured clinical interview (SCID-I/NP). Anthropometric measurements were recorded and fat mass was determined from whole body DXA scans (Lunar DPX-L). Results: There were no significant differences in any of the parameters measured either before or after adjusting for age. Age-adjusted mean (95% CI) values for bipolar vs controls according to adiposity indices were: weight 75.6 (68.9-82.3) vs 72.6 (71.3-74.0) kg, waist circumference 89.8 (84.1-95.6) vs 87.3 (86.1-88.5) cm, waist to hip ratio 0.85 (0.82-0.87) vs 0.84 (0.83-0.84), body mass index 27.6 (25.1-30.1) vs 27.5 (27.0-28.0) kg/m2, fat mass 31.4 (26.5-36.3) vs 28.6 (27.5-29.5) kg and percentage body fat 40.4 (36.9-43.9) vs 38.0 (37.3-38.7) %; all p>0.05. Further adjustment for psychotropic medication, energy intake or physical activity did not influence these patterns. Despite no significant relationships being detected between psychotropic medication use and adiposity, point estimates indicated greater adiposity amongst medication users.
Conclusions: Although the indices of adiposity were consistently greater among those with bipolar disorder, no significant differences were detected. Further research with a larger sample size may produce more conclusive results.