Sleep, Testosterone and Overall Health

Testosterone in men controls energy, libido, concentration and fatigue. Testosterone is also critical in building strength, muscle mass and bone density, and plays an important role in not only reproductive health but in insulin sensitivity, mood and general vigor. As we age, testosterone levels begin to drop, which can lead to declines in overall sense of well-being and other signs of good health. Essentially, testosterone deficiency can affect everything from fertility to weight gain and diabetes.

Another factor that drives testosterone levels into the ground is sleep deprivation. In fact, Eve Van Cauter, University of Chicago professor in medicine, and her colleagues found in a new study that lack of sleep (less than five hours a night) reduces a young man’s testosterone levels by the same amount as aging 10 to 15 years.

Cauter adds that growing research continues to recognize poor sleep quality and low sleep duration as endocrine disruptors, which gives us a great explanation for the testosterone deficiency commonly associated with sleep deprivation.

In their study, published in the June 1 issue of the Journal of American Medical Association, Cauter and her colleagues followed a small group of just ten subjects limited to lean and healthy young men with an average age of 24. To screen for endocrine or psychiatric disorders, researchers put the subjects under a series of psychological and physical tests.

The subjects slept for 10 hours a night for the first three nights, and then slept for less than five hours for the remaining eight nights. Researchers then took blood samples every 15 to 30 minutes for 24 hours on the last day of each of the two experiments.

The blood sample results found that after just one week of short sleep, testosterone levels dropped significantly, as much as 10 to 15 percent.

The subjects also reported a decline in mood, vigor and sense of well-being every day as the sleep restriction part of the study progressed and as their blood testosterone levels declined.

These findings add growing evidence that sleep deprivation has significant effects on hormone levels and thus many aspects of good health.