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Decreased Testosterone Levels Linked To Sleep Disorder
July 25, 2002
 

Sleep apnea is a respiratory disorder that affects 4%-9% of adult males. Its most common manifestation is loud snoring and it may occur several hundred times throughout the night, resulting in sleep fragmentation and excessive daytime sleepiness. The current study, reported in the July issue of The Journal of Clinical Endocrinology & Metabolism, found that nearly half the subjects who suffered from severe sleep apnea also secreted abnormally low levels of testosterone throughout the night.

HAIFA, ISRAEL and NEW YORK, NY, July 25, 2002-Male patients who suffer from obstructive sleep apnea (OSA) -- the inability to breathe properly during sleep -- produce lower levels of testosterone, resulting in decreased libido and sexual activity, according to researchers at the Technion-Israel Institute of Technology. Previous studies had indicated that male sleep apnea patients had reported decreased libidos but the studies were unable to establish a scientific link. The current study, reported in the July issue of The Journal of Clinical Endocrinology & Metabolism, found that nearly half the subjects who suffered from severe sleep apnea also secreted abnormally low levels of testosterone throughout the night.

"For years we have seen sleep-disorder patients complain of decreased libido but we had no explanation for this phenomenon until now," said Professor Peretz Lavie, head of the Technion Sleep Laboratory and study leader.

Sleep apnea is a respiratory disorder that affects 4%-9% of adult males. Its most common manifestation is loud snoring and it may occur several hundred times throughout the night, resulting in sleep fragmentation and excessive daytime sleepiness. For many years sleep apnea sufferers have complained of decreased libidos, yet previous studies reported that patients' testosterone levels, although low, were within the normal adult male range.

The current study adopted a different methodology. Earlier studies had only measured participants' testosterone levels once after awakening. In this study, subjects were admitted to the Technion Sleep Center for an entire night and were fitted with electrodes and catheters. They were monitored between 7 p.m. and 7 a.m. with blood samples collected every 20 minutes. At 10 p.m., lights were turned off and the participants retired to sleep. Two groups -- one of sleep apnea patients and another of normal controls of similar body weight and age -- were investigated.

The study found that nearly half the sleep apnea patients secreted abnormally low testosterone levels throughout the night.

"Should follow-up studies confirm these findings, then therapeutic intervention of sleep apnea could become a recommended remedy for certain forms of male sexual dysfunction," said Prof. Rephael Luboshitzky, an endocrinologist on the research team. "It is our hope that in the future, by correcting nighttime breathing patterns we will be able to stimulate hormone production and thereby raise libidos."

The Technion-Israel Institute of Technology is Israel's leading scientific and technological center for applied research and education. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni.

Based in New York City, the American Technion Society is the leading American organization supporting higher education in Israel with more than 20,000 supporters and 17 offices around the country.

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Neuroendocrine dysfunction in sleep apnea: reversal by continuous positive airways pressure therapy
RR Grunstein, DJ Handelsman, SJ Lawrence, C Blackwell, ID Caterson and CE Sullivan
Sleep Unit, Royal Prince Alfred Hospital, Sydney, Australia.

We studied the effects of sleep apnea on neuroendocrine function in a cross-sectional study of 225 consecutive men undergoing sleep studies and in a longitudinal study of 43 men with severe obstructive sleep apnea before and after 3 months of successful treatment with nasal continuous positive airways pressure to eliminate upper airways obstruction. Blood samples were collected at 0600-0630 h on awakening for measurement of plasma insulin-like growth factor I (IGF-I), total and free testosterone, sex hormone-binding globulin (SHBG), LH, FSH, PRL, T4, T4-binding globulin, and cortisol. The plasma hormone levels were analyzed in relation to the severity of sleep apnea, as indicated by the desaturation index (the hourly rate of episodes of arterial oxygen desaturation greater than 4% of the stable baseline) and the mean minimal oxygen saturation during the desaturation episodes. In the cross-sectional study plasma IGF-I, free and total testosterone, and SHBG levels were significantly lower in relation to the severity of sleep apnea, whereas plasma LH, FSH, PRL, T4, T4-binding globulin, and cortisol were not. The decreases in plasma IGF-I and total and free testosterone were independent of the effects of aging and adiposity by covariance analysis. In the longitudinal study plasma IGF-I, total testosterone, and SHBG, but not free testosterone, significantly increased after 3 months of nasal continuous positive airways pressure treatment. We conclude that sleep apnea causes reversible neuroendocrine dysfunction in men, which is manifested by decreased plasma. IGF-I, testosterone, and SHBG levels. This neuroendocrine dysfunction is related to the severity of the sleep apnea, as indicated by the nadir levels of arterial oxygen desaturation and the rate of desaturation episodes. These hormonal measurements may provide biochemical markers for both the severity of sleep apnea and its response to therapeutic intervention. In addition, sleep apnea may be a previously unrecognized confounder of the neuroendocrine correlates of aging.

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Obstructive sleep apnea due to endogenous testosterone production in a woman.

Dexter DD, Dovre EJ.

Department of Neurology, Midelfort Clinic, Eau Claire, Wisconsin 54701, USA.

Obstructive sleep apnea (OSA) is a common condition characterized by snoring, recurrent episodes of cessation of breathing (obstructive apneas), disrupted sleep, and excessive daytime somnolence. Associated serious complications are hypertension, increased risk of heart disease, stroke, and increased susceptibility to industrial and motor vehicle accidents. OSA is considerably more common in men than in women. In postmenopausal women, the incidence of OSA increases. These factors suggest that reproductive hormones have a role in the cause of OSA. Treatment with testosterone has been reported to cause OSA in men, and exogenous androgen administration has been reported to cause OSA in one woman. In a review of the English literature, we found no previous reports of OSA that was induced by endogenous testosterone in women. Herein we describe a nonobese 70-year old woman with clinically significant OSA and a benign testosterone-producing ovarian tumor. After successful removal of the tumor, her OSA resolved, and her testosterone level normalized. This unique case supports the theory of male hormonal (testosterone) influence in the OSA syndrome.

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Increased prevalence of obstructive sleep apnea syndrome in obese women with polycystic ovary syndrome.

Fogel RB, Malhotra A, Pillar G, Pittman SD, Dunaif A, White DP.

Sleep Disorders Section, Divisions of Endocrinology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.

Obstructive Sleep Apnea (OSA) is considerably more common in men than women. Preliminary data suggest that androgens may play a role in the male predominance of apnea. Polycystic Ovary Syndrome (PCOS) is characterized by menstrual disturbances, androgen excess, and frequently obesity. These features suggest that women with PCOS may be at increased risk for OSA. To determine whether obese women with PCOS have an increased prevalence of sleep apnea compared with age and weight-matched reproductively normal women, we performed overnight polysomnography for determination of the apnea-hypopnea index (AHI) in 18 obese women with PCOS and age and weight-matched control women. Additional measurements included waist, hip, and neck circumferences, serum total testosterone, unbound testosterone, and DHEAS. Women with PCOS had a higher AHI than controls (22.5 +/- 6.0, vs. 6.7 +/- 1.0, P = 0.008). Women with PCOS were also more likely to suffer from symptomatic OSA syndrome (44.4% vs. 5.5%, P = 0.008). AHI correlated with waist-hip ratio (r = 0.51, P < 0.03), serum testosterone (r = 0.52, P < 0.03) and unbound testosterone (r = 0.50, P < 0.05) in women with PCOS. We conclude that obese women with PCOS are at increased risk of OSA when compared with matched reproductively normal women. Women with PCOS should be carefully questioned regarding symptoms of sleep apnea.