What Every Endocrinologist Needs to Know About Sleep Apnea

A recurring theme in this series of specialty-focused articles has been the causal presence, whether recognized or overlooked, of Obstructive Sleep Apnea (OSA) in the routine practice of just about every type of healthcare specialist: No matter your discipline or the focus of your practice, there is a good chance that the medical problems you treat are themselves useful screening criteria for OSA -- and in many cases, it is the causal mechanism.

This dynamic is well-known to primary care providers, and is of increasing awareness to cardiologists and anesthesiologists. But almost no specialty is untouched by the co-morbid and bi-directional pathophysiologies of OSA. Today's article looks to expand on that theme, and increase public health awareness within a community of increasingly holistic practitioners, by reviewing the clinical presentations of OSA that are commonly encountered by our colleagues in endocrinology.

Metabolic Syndrome, Hyperlipidemia and Type 2 Diabetes.  Depending upon how many risk factors the patient has, a co-morbidity with OSA may be present as much as 80% of the time.  Similar to the OSA-related hypertension encountered in primary care and cardiology, all of these conditions are likely to remain resistant to standard treatment until the OSA is successfully treated. The relationship between these clinical presentations and OSA is bi-directional: each puts the patient at greater risk of OSA, but OSA also puts an unaffected individual at greater risk of developing these chronic diseases.

PCOS and Infertility. Up to 70% of women with Polycystic Ovarian Syndrome (PCOS) have undiagnosed OSA, but the incidence of OSA is also elevated in women with unexplained infertility.  Successful treatment of underlying OSA will often regulate ovulation, but women (and their partners) who seek fertility care would likely be discouraged by the prolonged sleep apnea referral and evaluation process.  Nota bene: A woman who presents for an infertility work-up will of course benefit from a couples-based approach -- the male partner of a woman who struggles with fertility should also be evaluated for OSA, as sperm counts in untreated OSA in males are significantly lower.

Hypothyroidism.  As many as 74% of patients with hypothyroidism have OSA, and the relationship is causal: Among other pathophysiologic paths, patients with insufficient thyroid hormone tend to gain weight and have lower tone of pharyngeal muscles – both of which are strong predictors of OSA, which explains the high incidence of OSA in these patients.  As with OSA in general, male patients with hypothyroidism have a higher incidence of OSA, but the incidence is also significantly increased in females.

Low testosterone.  Serum testosterone levels are markedly decreased in men with OSA; this may account for some of the sexual dysfunction often observed in male OSA patients.  It is well-established that at least half of men with OSA suffer erectile dysfunction.  The expedient diagnosis and on-boarding to therapy of OSA patients could provide improvement in symptoms related to low testosterone, and offers an effective non-hormonal alternative to these patients. As mentioned, low testosterone could also be related to fertility problems, and a couples-based approach to infertility would reasonably include a screen for OSA in the male partner.

Osteoporosis.  Patients with OSA have higher rates of osteoporosis, lower lumbar bone mineral densities, and lower lumbar T-scores.  Complicating matters is that OSA is often overlooked in women, and the OSA symptoms they experience are often misattributed to menopause alone.  What is unusual in this population – concurrent OSA and osteoporosis –  is that these patients often have a lower BMI.

All doctors, particularly specialists, should be cognizant of our tendency to see clinical presentations through the prism of our specialty training.  Sleep is such an important pillar of health that all of us should consider its disturbance as a possible “upstream” cause of the medical problems we routinely and expertly handle.

If any of these clinical conditions are commonly present in your endocrinology practice, it’s worth considering the possibility of Obstructive Sleep Apnea (OSA) as their cause. Untreated OSA can have serious health implications, but the good news is that effective treatments are available. Refer your patients to Konk Sleep to explore their options and take the first step toward better sleep and improved health, all without leaving their homes.