Risk factors for benign prostatic hyperplasia.

This review summarizes recent findings regarding risk factors for benign prostatic hyperplasia (BPH), including new data on hormonal factors, growth factors, comorbid conditions and lifestyle, diet, and exercise as they relate to BPH. In addition, it addresses the design and measurement issues that influence the inference that can be drawn from those studies. Most of the population-based studies on BPH have provided only modest insight into risk factors for BPH. The relationships with circulating levels of steroid hormones and growth factors are still unclear, whereas the association between sexual function and BPH is fairly consistent. Whether this represents a cause and effect relationship or is due to some unobserved confounding factor remains uncertain. There are few data on lifestyle factors that may be amenable to intervention. As future studies aim to address these issues, they should be carried out with rigorous methods, bypassing as many of the methodologic shortcomings of past studies as possible.