SESSION TITLE: Medical Student/Resident Sleep Disorders SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Obstructive sleep apnea (OSA) has been found to be an increasingly common disorder in the middle-aged men with reports suggesting about 15%-50% prevalence. The widely accepted definition of OSA is apnea hypopnea index (AHI) >5 events/hour as measured by a polysomnogram (PSG) with relevant symptomatology like snoring, fatigue and daytime somnolence. In this report, the relationship between OSA and pituitary-gonadal function manifesting as sexual dysfunction is discussed. CASE PRESENTATION: The patient is a 53-year-old non-smoking Caucasian male with history of asthma, type II diabetes mellitus, and testosterone deficiency, who presented to the with the chief complaint of shortness of breath. He was relatively asymptomatic until two months when he developed fatigue, insomnia, worsened snoring, gasping, and daytime sleepiness. Home medications included albuterol, fluticasone, salmeterol, tiotropium, montelukast, testosterone, ibesartan, glipizide, and pioglitazone. On physical examination, the patient had morbid obesity, a 19.5 cm neck circumference with Mallampati score of IV, and diminished breath sounds. Laboratory studies showed hemoglobin (Hb) of 19.1g/dL and hematocrit (Hct) of 61.3%. Secondary polycythemia was due to eight months of testosterone supplementation, which was subsequently stopped and required a total of six therapeutic phlebotomies. Repeat Hb was 14.7g/dL and Hct was 47.3%. His STOP-BANG score was 7 and diagnostic PSG showed mild obstructive sleep apnea with AHI of 48.9/hour during REM sleep and 14.5/hour overall. He was started on CPAP therapy at night and has continued to show symptomatic improvement. DISCUSSION: Our patient is characteristic of the demographic population being affected by these morbidities. He initially presented with sexual dysfunction due to low testosterone levels, but despite six months of bimonthly testosterone supplementation, his serum testosterone levels did not improve. It is well established that patients with low serum testosterone levels undergoing exogenous supplementation worsen or even precipitate OSA [1]. Interestingly, another school of thought implicates OSA as a potential cause of low serum testosterone levels [2] and that continuous positive airway pressure (CPAP) increases testosterone and sex hormone binding globulin levels. Recent studies have confirmed direct association between serum testosterone levels and sleep deprivation [3]. CONCLUSIONS: We propose that any patient who is found to have low testosterone should be evaluated for OSA before being considered for testosterone supplementation. CPAP should be considered as a first line therapy in patients with both OSA and testosterone deficiency. Albeit, given the complexity (Fig. 1), a causal relationship would be difficult to prove. To further explore this hypothesis, systematic investigations with randomized controlled trials should be performed. Reference #1: Matsumoto AM, Sandblom RE, Schoene RB, et al. Testosterone replacement in hypogonadal men: effects on obstructive sleep apnoea, respiratory drives, and sleep. Clin Endocrinol (Oxf) 1985; 22(6):713–21. Reference #2: Luboshitzky R, Lavie L, Shen-Orr Z, et al. Altered luteinizing hormone and testosterone secretion in middle-aged obese men with obstructive sleep apnea. Obes Res 2005;13(4):780–6. Reference #3: Abu-Samak MS, Mohammad BA, Abu-Taha MI, Hasoun LZ, Awwad SH. Am J Mens Health. 2018 Mar;12(2):411-419. https://doi.org/10.1177/1557988317735412. Epub2017 Oct 13.Associations Between Sleep Deprivation and Salivary Testosterone Levels in Male University Students: A Prospective Cohort Study. PMID: 29025356 DISCLOSURES: No relevant relationships by Ritha Kartan, source=Web Response No relevant relationships by Rohan Parikh, source=Web Response No relevant relationships by Krupa Solanki, source=Web Response