Section III: Special Conditions, Disorders, and Clinical Issues Gender Differences in Obstructive Sleep Apnea , ,
INTRODUCTION Obstructive sleep apnea (OSA), the clinical entity characterized by repetitive par tial a n d /o r complete collapse of the upper airway during sleep and symptoms of excessive daytime sleepiness, has been historically described as a disease of males. Charles Dickens is often credited with the first description of OSA. He described a character, fat boy Joe, who suffered from the classic symptoms of snoring, excessive daytime sleepiness, obesity, and "dropsy." Nearly 170 years later, our interest in the pathophysiology and clinical sequelae of OSA has height ened, partly due to the identified associations of the syndrome with cardiovascu lar disease (1-4), motor vehicle accidents, and decreased quality of life (5). Early clinical research in the field of OSA identified the disease as a male-predominant disorder, w ith estimated male:female ratio for disease prevalence from 10:1 to 60:1 (6). However, these prevalence estimates are based on clinical studies that often had a referral bias of more men than women. In contemporary epidemio logic studies, the reported male:female prevalence ratios are in the order of 3:1 to 2:1, suggesting that OSA is not as rare in women as previously thought. In addi tion, women w ith OSA have clinical presentations, therapeutic considerations and prognoses that differ from men, making an accurate diagnosis and initiation of therapy a challenge and a priority. This chapter focuses on the elements of OSA, including epidemiology, risk factors, and treatment, which contribute to gender differences, as well as gender-specific conditions that may affect the clini cal expression of OSA.