Physical, metabolic and endocrine correlates of male aging

There area number of physiological changes that occur with normal aging that may contribute significantly to decline in physical function and increased risk of frailty and are associated with considerable morbidity and reduced quality of life in many elderly men. These include age-related: changes in body composition, characterized by increased total and intra-abdominal fat mass which is associated insulin resistance and increased risk Of type 2 diabetes and coronary artery disease, decreased lean mass, reduced muscle mass (sarcopenia) and strength, decreased Done mineral density and increased risk of bone fractures (osteoporosis), and thinning of the skin and decrease in body hair; decline in sexual functioning (diminished libido and erectile dysfunction); changes in mood; decrease in cognitive function; and alterations in sleep quality with reduced deep and rapid-eye-movement sleep. Aging in men is also associated with a progressive decline in circulating levels of hormones that a known endocrine regulators of some these physiological functions. The most prominent age-related endocrine changes include: a gradual decline of serum testosterone levels beginning in middle; a decline in growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels; a marked decrease in the adrenal androgen, dehydroepiandrosterone (DHEA) beginning at a relatively young age; and a decline in the pineal hormone, melatonin. Because deficiencies of some of these hormones (e.g testosterone) in younger men may result in alterations in body function similar those associated with normal aging, it is possible that the age-related decline in these hormones may contribute to changes in physiological function with aging: Preliminary studies of testosterone treatment in elederly men suggest potential beneficial effects on body composition, muscle strength, bone mass and psychosexual well-being without significant short-term adverse effects. Although these studies are encouraging, the long term effects of testosterone on the prostate gland and risk of coronary artery disease are not known. Larger and longer-term randomized placebo-controlled studies are needed to determine the balance of potential benefits and risks of testosterone replacement therapy in elderly men.