Sleep apnea and daytime sleepiness and fatigue: relation to visceral obesity, insulin resistance, and hypercytokinemia. - Vgontzas,AN.; Papanicolou,DA.; Bixler,EO.; Hopper,K.; Lotsikas,A.; Lin,H.; Kales,A.; Chrousos,GP. (J Clin Endocrinol Metab, 2000)