Growth Hormone and Aging: A Brief Review

As little as 10 years ago, the assertion that growth hormone (GH) was important for humans past the time of adolescence and closure of the bony epiphyses had little or no credence among endocrinologists. This was because the physiologic action of GH was “known” to be the growth of long bones, while its actions on other (soft) tissues was appreciated mainly as a pathological phenomenon in acromegaly. Also, it was widely accepted that adult patients with monomeric GH deficiency or panhypopituitarism treated with thyroid, adrenal, and sex hormones did relatively well. Nonetheless, physicians treating significant numbers of such patients noted that many of them complained of a lack of energy and strength, low levels of libido, and a “plump” physique with fat depots apparently resistant to exercise and dieting. The relationship of these problems to GH deficiency remained moot because the supply of human pituitary extract GH was only sufficient to treat short stature in children.