A new study of sleep patterns, published in the Journal of the American Medical Association, has implications for all adults, especially those with CFS.
Researchers found that deteriorating sleep as a result of aging occurs in at least two stages, and for men, the first stage occurs earlier than previously thought, between ages 25 and 45. They also found that changes in sleep were mirrored by changes in hormone secretion.
For CFS/FM sufferers in or entering mid-life where the two stages of deep sleep (stages three and four) are already illusive, the study sheds light on sleeping problems.
The study was performed by scientists at the University of Chicago and examined sleep quality as well as hormones influenced by sleep throughout adulthood. “Our study maps out the chronology of age-related changes in sleep duration and quality and suggests that altered levels of certain hormones may be a consequence of sleep decay,” said Eve Van Cauter, Ph.D., professor of medicine at the University of Chicago and director of the study.
The first stage of deterioration of sleep due to aging occurs between young adulthood (ages 16 to 25) and mid-life (35-50). Although the total amount of sleep remained constant as young adults moved into mid-life, the proportion of slow wave or deep sleep decreased from nearly 20% of a normal night’s sleep for those under 25 to less than five percent for those over 35. Growth hormone secretion, which occurs primarily during deep sleep, also declined by about 75%.
Growth hormone is responsible for many of the repair processes that go on in our muscles and in the rest of our body. It is theorized that this loss of repair function that normally occurs during deep sleep contributes to the pain experienced by those who suffer from CFS/FM.
The second stage of deterioration of sleep due to aging occurs after age 50. It includes decreased total sleep – which declines by about 27 minutes per decade – more frequent and longer night-time awakenings, and a significant reduction in REM or dream sleep, to about 50% of young-adult levels. The loss of REM sleep appears to be associated with elevated evening levels of the stress-related hormone cortisol – our ‘fight or flight’ hormone that heightens attention and alertness.
This study suggests that clinical trials of growth-hormone replacement therapy, which have previously been conducted in older men and women, might better target individuals in early mid-life. In addition, researchers are looking at an indirect form of hormonal therapy. This would involve using experimental drugs to stimulate increases in deep sleep to trigger a proportional increase in growth hormone secretion.
“It is a tantalizing concept,” said Van Cauter. “To develop medications that can, in part, restore the capacity for deep sleep.”