Obesity and prostate diseases: the endocrine link

Obesity has increased steadily over the past decades in most of the developed countries, causing major health problems, such as cardiovascular diseases, metabolic dysregulation (diabetes mellitus, dyslipidemia), reproductive disorders, osteoarthritis and several types of cancer. Multiple alterations of the endocrine systems are present in obese subjects, both at hypothalamic-pituitary and peripheral level (e.g. gonadal and somatotroph axes, insulin, leptin and ghrelin circulating levels). It has been suggested that obesity might be an important risk factor for both benign prostate hyperplasia and prostate cancer, even though this relationship is still a matter of debate. Benign prostatic hyperplasia is one of the most common medical conditions in middleaged and older men, while prostate cancer constitutes about 11% of all male cancers in Europe. A large number of factors have been suggested to play a role in prostate cancer development, but the evidence is fragmentary or inconsistent. The association between obesity and prostate disease seems to be a consequence of numerous disturbances in hormones levels, including increased synthesis of estrogens by way of aromatization of testosterone in the adipose tissue, increased circulating concentrations of leptin, increased insulin resistance, and increased levels of bioavailable testosterone as a consequence of the reduction of sex hormone-binding globulin. Other circulating peptides, such as IGF-I, adiponectin and IL-6, are likely to be involved in normal and pathological prostatic tissue proliferation. Therapies for reducing weight in obese patients can significantly decrease the morbidity and mortality for cardiovascular, metabolic and neoplastic diseases secondary to obesity. Whether therapeutic interventions on obesity (behavioural, pharmacological or surgical) may have beneficial effects on prostate diseases, needs further clarification.