Many factors can alter sleeping patterns including stress, work, environment, and lifestyle. In the older population, sleep problems may actually be caused not by external factors, but rather by a natural decline in testosterone levels. Around the age of 40, men and women may begin to experience sleep disturbances which may ultimately affect their quality of life. This chronological pattern has led researchers into conducting clinical trials assessing the link between the onset of sleep disturbances and low testosterone levels.
Insufficient testosterone level has been shown to affect sleep quality. In a cohort study of men aged 65 years and over, Barrett-Connor et al. observed that those with lower testosterone levels experienced reduced sleep efficiency, increased nocturnal awakenings, and less time in slow wave sleep (one of the deepest phases of sleep). 
More recently, it has become clear that testosterone production is dependent on sleep. Luboshitzky et al. has shown that there is a decrease in testosterone levels in sleep-deprived individuals, especially in the older subjects, suggesting that the age-related decline in testosterone levels may trigger sleep disturbances.  Moreover, a recent study by Schmid et al. has also shown that restriction of sleep time to 4.5 hours was associated with a lower morning testosterone level. 
One of the major internal factors associated with sleep disturbances is disruption in the circadian rhythm, a roughly 24 hour cycle in the physiological processes of humans. In a study by Axelsson et al. involving night shift workers, it was found that disturbed sleep and wakefulness is associated with lower testosterone levels, suggesting that circadian rhythm disruption does have an impact on testosterone levels. 
On the other hand, Reynolds et al. found that healthy young men with higher blood testosterone levels have greater cognitive functioning and increased subjective sleepiness after 5 days of sleep restriction as compared to those with low blood testosterone levels. This result suggests that blood testosterone levels do have an effect on sleep quality.
Because of the inverse relationship of testosterone levels and sleep quality, a number of studies have looked into the therapeutic benefits of testosterone replacement therapy on patients with sleeping difficulties. For instance, a study by Matsomoto et al. reported that intramuscular injections of testosterone enanthate 200 mg every 2 weeks in hypogonadal men with sleeping problems resulted in longer sleep time. 
In another study, Shigehara et al. evaluated the effects of testosterone replacement therapy on sleep and quality of life in men with hypogonadism and nocturia (increased urination at night).  After 6 months of treatment, researchers observed that the participants had significant improvements in sleeping time, nocturia symptoms, and quality of life.
Call 800-277-4041 for a Free Consultation
Genemedics® Health Institute is a global premier institute dedicated to revolutionizing health and medicine through healthy lifestyle education, guidance and accountability in harmony with functional medicine. Our physician-supervised health programs are personally customized to help you reach your health and fitness goals while looking and feeling better than ever.