Depression and bone mineral density: Is there a relationship in elderly Asian men? Results from Mr. Os (Hong Kong)

Previous epidemiological study has suggested that depression might be associated with low bone mass in Caucasian women. This has not been studied in Asian men. Mr. Os (Hong Kong) is the first, large, cohort study on osteoporosis in Asian men, and the current analysis deals with the association between depression and bone mass in this group. Data from the baseline examination of Mr. Os (Hong Kong) were used. Two thousand Hong Kong men aged 65 to 92 years were recruited from the community. Depression was diagnosed by face-to-face interview, using a validated Chinese version of the Geriatric Depression Scale (GDS), with depression being defined as a cut-off score of 8 or more. Bone mineral density (BMD) of the lumbar spine, total hip and total body was measured by dual X-ray densitometry (DEXA) using the Hologic QDR-4500 W densitometer. Multiple regression was used to compare BMD in depressed and non-depressed subjects, controlling for confounding variables. In the study sample 8.5% of men were found to be depressed, and the BMD at the total hip in these subjects was 2.1% lower than in non-depressed subjects (95% CI -0.13 to -4.1), after adjustment for age, body weight, medical history, alcohol consumption, cigarette smoking, calcium intake, physical activity and antidepressant use. Depression was associated with a 1.4-fold (95% CI 1.00 to 2.08) relative risk (RR) of being diagnosed with a T-score equal to or less than -1.0 (low bone mass). We conclude that depression is associated with lower BMD; however, to determine whether depression causes lower BMD or vice versa, we will need to await findings from future prospective studies.