During sleep, there is alveolar hypoventilation and transient episodes of apnea that are accompanied by a fall in arterial oxygen saturation (hypoxia) and a rise in arterial carbon dioxide (hypercapnia). In some individuals, these factors lead to daytime sleepiness (hypersomnolence) with persistent hypoxia and hypercapnia accompanied by the development of
pulmonary hypertension, heart failure and eventually, respiratory failure.
Obesity is associated with cholelithiasis. In the Nurses’ Health Study, women with BMI <24 kg/m2 had an incidence of symptomatic gallstones of approximately 250 per 100 000 person-years of follow-up. Women with BMI >45 kg/m2 had a seven-fold increase in risk for gallstones