Obstructive sleep apnea-hypopnea syndrome (OSAHS), the most common sleep disorder, negatively impacts different body system, cardiovascular system in particular. Continuous positive airway pressure is its most widely used and effective treatment, significantly improving night hypoxia and sleep fragments in OSAHS patients. The incidence, severity and prognosis of OSAHS are affected by such factors as age, gender and body mass index (BMI). OSAHS has historically been considered a male disease. However, recent studies have found that the clinical manifestations, prognosis and treatment options in women are different from men. Moreover, increased BMI will lead to different outcomes due to the gender differences. This paper reviews the effects of BMI and gender on OSAHS patients.