No association between bone mass and prolactin levels among patients with schizophrenia

Objective Decreased bone mineral density has been implicated in schizophrenic patients for long years. The purpose of this study was to assess the relationship between bone mass and prolactin levels in schizophrenic patients. Methods In this study, bone mass was measured using quantitative ultrasound densitometry of the calcaneus in 114 patients (49 males and 65 females). The osteosono-assessment index (OSI) was calculated as a function of the speed of sound and transmission index. Estradiol, testosterone, and prolactin levels were also measured. Factors that influenced prolactin levels and bone mass were determined via multiple linear regression analysis. Results Among the female patients, body mass index and estradiol levels were independently and significantly associated with the OSI. Neither prolactin levels nor duration of antipsychotic treatment was associated with bone mass for either gender. Conclusions These findings suggest that prolactin levels do not contribute to poor bone mass, as assessed using the OSI among schizophrenic patients. However, the interpretation of our results was hampered by lack of data including differences in lifestyle and type of antipsychotic medications used in schizophrenic patients. Association between prolactin levels and low bone mineral density was not completely ruled out. Future research exploring prolactin levels and bone mineral density is warranted. Copyright (C) 2011 John Wiley & Sons, Ltd.