Obstructive sleep apnea and testosterone

Testosterone Deficiency and Sleep Apnea

Obstructive sleep apnea (OSA) is a common condition among middle-aged men and is often associated with reduced testosterone (T) levels. OSA can contribute to fatigue and sexual dysfunction in men. There is suggestion that T supplementation alters ventilatory responses, possibly through effects on central chemoreceptors. Traditionally, it has been recommended that T replacement therapy (TRT) be avoided in the presence of untreated severe sleep apnea. With OSA treatment, however, TRT may not only improve hypogonadism, but may also alleviate erectile/sexual dysfunction.

Testosterone Deficiency and Sleep Apnea

Obstructive sleep apnea (OSA) is a common condition among middle-aged men and is often associated with reduced testosterone (T) levels. OSA can contribute to fatigue and sexual dysfunction in men. There is suggestion that T supplementation alters ventilatory responses, possibly through effects on central chemoreceptors. Traditionally, it has been recommended that T replacement therapy (TRT) be avoided in the presence of untreated severe sleep apnea. With OSA treatment, however, TRT may not only improve hypogonadism, but may also alleviate erectile/sexual dysfunction.

Efficacy of continuous positive airway pressure on testosterone in men with obstructive sleep apnea: a meta-analysis

OBJECTIVE

To evaluate the efficacy of continuous positive airway pressure (CPAP) on serum testosterone in men with obstructive sleep apnea (OSA).

METHODS

Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before June 2014. Information on characteristics of subjects, study design, pre- and post-CPAP treatment of serum total testosterone, free testosterone and sexual hormone blinding protein (SHBG) was extracted for analysis.

RESULTS

A total of 7 studies with 9 cohorts that included 232 men were pooled into meta-analysis. There was no change of total testosterone levels before and after CPAP treatment in OSA men (standardized mean difference (SMD) = -0.14, 95%CI: -0.63 to 0.34, z = 0.59, p = 0.558), even subdivided by CPAP therapeutic duration (>3 months). Meanwhile, no significant differences in free testosterone and SHBG were detected after CPAP treatment (SMD =  0.16, 95%CI: -0.09 to 0.40, z = 1.25, p = 0.211 and SMD = -0.58, 95%CI: -1.30 to 0.14, z = 1.59, p = 0.112, respectively).

CONCLUSION

CPAP has no influence on testosterone levels in men with OSA, further large-scale, well-design interventional investigation is needed.

Ventilatory sensitivity to carbon dioxide before and after episodic hypoxia in women treated with testosterone

We hypothesized that the ventilatory threshold and sensitivity to carbon dioxide in the presence of hypoxia and hyperoxia during wakefulness would be increased following testosterone administration in premenopausal women. Additionally, we hypothesized that the sensitivity to carbon dioxide increases following episodic hypoxia and that this increase is enhanced after testosterone administration. Eleven women completed four modified carbon dioxide rebreathing trials before and after episodic hypoxia. Two rebreathing trials before and after episodic hypoxia were completed with oxygen levels sustained at 150 Torr, the remaining trials were repeated while oxygen was maintained at 50 Torr. The protocol was completed following 8-10 days of treatment with testosterone or placebo skin patches. Resting minute ventilation was greater following treatment with testosterone compared with placebo (testosterone 11.38 +/- 0.43 vs. placebo 10.07 +/- 0.36 l/min; P < 0.01). This increase was accompanied by an increase in the ventilatory sensitivity to carbon dioxide in the presence of sustained hyperoxia (VSco(2)(hyperoxia)) compared with placebo (3.6 +/- 0.5 vs. 2.9 +/- 0.3; P < 0.03). No change in the ventilatory sensitivity to carbon dioxide in the presence of sustained hypoxia (VSco(2 hypoxia)) following treatment with testosterone was observed. However, the VSco(2 hypoxia) was increased after episodic hypoxia. This increase was similar following treatment with placebo or testosterone patches. We conclude that treatment with testosterone leads to increases in the VSco(2)(hyperoxia), indicative of increased central chemoreflex responsiveness. We also conclude that exposure to episodic hypoxia enhances the VSco(2 hypoxia), but that this enhancement is unaffected by treatment with testosterone.

Sleep-related erections: Clinical perspectives and neural mechanisms

Involuntary sleep-related erections (SREs) occur naturally during REM sleep in sexually potent men and other mammals. The regularity of their pattern and non-volitional nature made SREs useful clinically for differentiating psychogenic and organic erectile dysfunction (ED) in candidates for surgical intervention. Normative data available for different age groups added to the attractiveness of SRE measurement for clinical decision-making. Clinical SRE testing is less commonly applied today with the advent of minimally invasive medical therapies for ED. Nonetheless, as an objective measure of erectile function, SRE recording for research provides a precise technique for examining the mechanisms of erection and is still conducted to resolve legal disputes. SRE alterations provoked hormonally and pharmacologically are discussed. Different SRE patterns are associated with comorbid factors and some of these are illustrated, described, or both. Recording techniques developed for rats have proved extremely valuable for furthering our understanding of brain centers mediating erectile response. Data from lesion and stimulation studies are examined in the present review, moving us a step closer to understanding the underpinnings of erectile function.

Leptin, obesity, and respiratory function

Leptin is a protein produced by adipose tissue that circulates to the brain and interacts with receptors in the hypothalamus to inhibit eating. The importance of this single peptide is vividly demonstrated by the profound obesity exhibited by the ob/ob mouse (C57BL/6J-Lep(ob)) which is unable to produce functional leptin. The measurement of respiratory function in the ob/ob mouse shows that the profound obesity is associated with impaired respiratory mechanics and depressed respiratory control, particularly during sleep. Longitudinal studies and leptin replacement studies in the ob/ob mouse indicate that leptin may act as both as a growth factor in the lung and as a neurohumoral modulator of central respiratory control mechanisms. Moreover, wildtype mice with diet-induced obesity have normal respiratory function associated with markedly elevated leptin levels. Human obesity, similar to obesity in wildtype mice, also causes an elevation in circulating leptin. However, unlike the tight relationship between obesity and elevated leptin present in an inbred strain of wildtype mice, human obesity is associated with more variable leptin levels for a given degree of adiposity. Thus, the possibility exists that a relative deficiency in leptin, or a leptin resistance, may play a role in obesity-related breathing disorders such as obesity hypoventilation syndrome (OHS) or obstructive sleep apnea (OSA).

Obstructive sleep apnea due to endogenous testosterone production in a woman

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.

Sleep-related erectile activity

Sleep-related erections occur in all healthy, potent men in close temporal association with REM sleep. These erections are naturally occurring and can be assessed quantitatively. The nocturnal tumescence cycle seems unaffected by behavioral factors. Furthermore, sleep-related erections are present across the life span with only a slight decline in older healthy people. Analogous phenomena are present in women. The function of sleep-related erections is not known; however, they clearly involve vascular, neurologic, and hormonal mechanisms. Sleep-related erection testing provides a physiologic, objective, diagnostically useful technique for evaluating erectile capacity. Laboratory-based studies with comprehensive polysomnography offer the most complete diagnostic picture of erectile function available. Nonlaboratory procedures require further validation. The sleep-related tumescence pattern contains a wealth of information about the physiology and pathophysiology of erection. The coordination between REM sleep and erection, the differential expansion at the penile base and upper shaft, and the rate of circumference increase and decrease are meaningful indicators for determining if erectile dysfunction exists. Sleep-related erection testing indexes the magnitude and nature of organic involvement and takes the differential diagnosis of impotence beyond a simplistic psychogenic-organic dichotomy.

Obesity and hormonal factors in sleep and sleep apnea

The presence of obesity, defined as weight 20 per cent or more above ideal body weight or increased body fat content, significantly increases risk of pulmonary, cardiovascular, metabolic, and gastrointestinal problems. Obesity is a major cause of shortened life expectancy. While obesity is not essential for the development of the obstructive sleep apnea syndrome, a significant percentage of patients with obstructive sleep apnea are obese. When evaluating these patients who have obstructive sleep apnea, it is important to search diligently for medical problems that are commonly found among the obese. While there is an increased incidence of obese patients among those who have obstructive sleep apnea, the exact reason for this is uncertain. The study of endorphins and enkephalins may expand our understanding of obesity, ventilatory regulation, and obstructive sleep apnea. This may, in fact, enable us to understand better the interrelationship between obesity and obstructive sleep apnea. The role that thyroid hormone, testosterone, and progesterone play in obstructive sleep apnea has also been reviewed. Patients who have obstructive sleep apnea should not be treated with testosterone. All patients given testosterone should be observed quite closely for the possible signs and symptoms of obstructive sleep apnea. Progesterone seems to be of some help in patients who have obesity hypoventilation syndrome. Its effectiveness in patients with obstructive sleep apnea is less clear. The obesity hypoventilation syndrome as described by Burwell is relatively uncommon. Many of the manifestations of the obesity hypoventilation syndrome, however, are found in patients with obstructive sleep apnea. The recognition that the symptoms stem from underlying obstructive sleep apnea offers great potential for therapy. Weight reduction is valuable therapy for patients with obesity and pulmonary dysfunction, obesity and obstructive sleep apnea, and obesity hypoventilation syndrome. Weight reduction and weight maintenance, while difficult, are essential in patients with obesity, obesity and obstructive sleep apnea, and the hypoventilation syndrome. Obesity should be viewed as a medical problem deserving medical attention and long-term medical follow-up.