Alcohol, cytokines, and estrogen in the control of bone remodeling

Alcohol has been identified as a risk factor for the development of osteoporosis. Chronic alcohol abuse has been shown to decrease bone mass and increase the incidence of fractures. Although the exact mechanism by which alcohol influences bone metabolism is not clear, it is likely a combination of both direct and indirect effects on bone cells. Alcohol has the potential to alter bone metabolism indirectly through its effects on gonadal hormones and through the secretion of cytokines shown to be critical factors in postmenopausal osteoporosis. Data are summarized here demonstrating that interleukin-1 and tumor necrosis factor play a direct causal role in the bone loss due to estrogen deficiency. In addition, studies are cited showing that these same cytokines are produced in alcohol-induced liver disease with the potential to enhance bone loss in post-menopausal women and in male patients. Although there are not yet data directly supporting the role of cytokines in bone loss due to alcohol consumption, the studies presented herein are intended to stimulate further research on the role of alcohol, estrogen, and cytokines in osteoporotic bone loss.