Bone mineral density and osteoporosis risk in older patients with schizophrenia

People with schizophrenia are at a higher risk for osteoporosis. The authors investigated the prevalence of low bone density and its risk factors in older Korean patients with schizophrenia.

In cross-sectional study, 327 inpatients with schizophrenia were screened. Among them, 229 patients older than 50 years participated in this study. The control group consisted of healthy volunteers who were of similar ages (n = 125). Bone density was measured in the lumbar spine and the neck, trochanter, and ward regions of the right proximal femur by dual-energy x-ray absorptiometry. Clinical variables such as alcohol use, cigarette smoking, and fracture history were obtained. The Student t test, Pearson χ2 test, Wilcoxon rank sum test, and logistic regression analysis were used.

The prevalence of osteoporosis was significantly higher in patients with schizophrenia compared with healthy controls (34.9% vs 18.4%, P = 0.0043). Within the schizophrenia group, female subjects had a significantly higher prevalence of osteoporosis than male subjects (48.4% vs 25.7%, P = 0.0014); however, no sex differences were identified in the healthy control group. The actual bone density and t scores in patients with schizophrenia were significantly lower in all sites than in healthy controls. Among patients with schizophrenia, smokers and alcohol abuser showed lower bone density compared with those who did not smoke or drink. The lifetime prevalence of fracture was significantly higher in patients with schizophrenia (24.0%) compared with healthy controls (5.6%; P = 0.001).

Our results emphasize that older patients with schizophrenia are at risk for low bone density. Cigarette smoking and alcohol abuse are associated with low bone density in patients with schizophrenia.