Postmenopausal Endogenous and Exogenous Hormones, Degree of Obesity, Thiazide Diuretics, and Risk of Osteoporosis

Publisher Summary This chapter reviews the relationship among thiazide diuretics, estrogen, both endogenous and exogenous, and the degree of obesity with bone mass and fractures among postmenopausal women. All of these factors may be interrelated to each other. Obese women have higher levels of circulating estrogens, reflecting the aromatization of androstenedione to estrone in fat tissue. When evaluating these relationships to bone mass and fracture risk, it is critical to consider the underlying factor of obesity. Thiazide diuretics may prevent hip fractures, but the underlying mechanisms for this effect are not known. More data are needed in normotensives before thiazide diuretics can be advocated for the prevention of osteoporotic fractures. Not only data on the efficacy of thiazide diuretics on fracture but also careful documentation of the risks and side effects of this therapy are needed. Obesity may be in the causal pathway among endogenous estrogens, bone mass, and fractures. In addition, there are other mechanisms for an effect of obesity on osteoporotic risk. Future research needs to identify this causal pathway to improve our understanding of the etiology of osteoporotic risk.