[Sleep apnea-hypopnea syndrome without excessive daytime sleepiness].

Nowadays, sleepiness in patients with sleep apnea-hypopnea syndrome (SAHS) is understandable. It is somewhat more difficult to explain why most patients with SAHS enrolled in epidemiologic studies, even those with a high apnea-hypopnea index, do not experience excessive daytime sleepiness. The reasons for this discrepancy lie beyond mere polysomnographic events. This review examines data from the literature that may help us understand why these patients do not experience daytime sleepiness. It also analyzes studies that support and refute sleepiness as a marker of cardiovascular risk in patients with SAHS, and discusses the mechanisms that might increase this risk.