It is well known that many elderly individuals have difficulty sleeping, and it is also known that aging is associated with a decrease in growth hormone (GH) levels. Changes in sleep patterns drastically affect endocrine function, especially pituitary-dependent hormonal release, which may impact on nighttime levels of GH. An interesting question then, is whether the age-related decrease in the quality of sleep is responsible for the age-related decline in GH hormone secretion or, alternatively, whether the reverse is true and the age-related decline in GH secretion may be responsible for the age-related changes in sleep patterns. A recent study published in the Journal of American Medical Association has taken a step towards determining this relationship, by closely examining the correlation between various stages of sleep and levels of GH, in healthy men between 16 and 83 years of age. The association between the two is striking. Not only does it raise the possibility of using GH supplementation to conquer yet another marker of biological aging--reduced sleep--but it also presents sleep enhancement as a potential way of increasing GH levels.
Previous studies have shown that aging is associated with increases in the number and duration of awakenings during the night and decreases in the amount of slow-wave (SW) sleep. There is also a decrease in the amount of rapid eye movement sleep (REM) but this change is moderate by comparison. This earlier data was based on a comparison of two age groups young and aged persons.
