Bipolar disorder and bone health: A case-control study

Abstract

BackgroundBipolar disorder (BD) is associated with significant psychological and physical comorbidity. Yet little is known about the bone health of individuals with BD. Thus, we aimed to investigate the association between BD and bone health in a population-based sample of women. MethodsWomen with a history of BD (cases; n = 117) were recruited from public and private health care settings and controls, without BD, were drawn from the Geelong Osteoporosis Study (n = 909). BD was identified using a semi-structured clinical interview (SCID-I/NP). Bone mineral density (BMD) was measured at the spine, femoral neck and total body using dual energy x-ray absorptiometry, and bone quality by quantitative heel ultrasound and included the following parameters: Speed of Sound (SOS), Broadband Ultrasound Attenuation (BUA) and Stiffness Index (SI). Weight and height were measured and information on medication use and lifestyle was obtained. ResultsAdjusted mean BMD among the cases was 4.3% lower at the hip and 1.6% lower at the total body compared to controls. Age was an effect modifier at the spine. Among women <50 years, mean spine BMD for cases was 3.5% lower than controls. No differences in spine BMD for those ≥50 years were detected. Cases also had a 1.0%, 3.2% and 7.8% lower adjusted mean SOS, BUA and SI compared to controls, respectively. LimitationsCourse, chronicity and recovery of BD were not explored in relation to bone health. ConclusionThese data suggest BD is associated with low bone quantity and quality in women. Replication and research into underlying mechanisms is warranted.