Impact of sleep-disordered breathing, visceral fat accumulation and adiponectin levels in patients with night-time onset of acute coronary syndrome.

Acute coronary syndrome (ACS) during sleep occurs at a relatively low frequency and the pathogenic background remains uncertain. The aim of the present study was to determine the significance of sleep-disordered breathing (SDB) and excess visceral fat with nocturnal dysregulation of adipocytokines in night-time onset of ACS. SDB, visceral fat area (VFA), and changes in circulating adipocytokine levels were assessed in 109 consecutive patients with ACS. SDB and VFA were assessed by cardiorespiratory monitoring and computed tomographic scan, respectively. Visceral fat accumulation was more common in patients with (12 to 7 a.m.) than without (7 to 12 a.m.) night-time onset of ACS (p <0.05). In patients with night-time onset of ACS, those with excess visceral fat were significantly more likely to have SDB and nocturnal dysregulation of adiponectin than those without such accumulation (p <0.05), but there was no difference between those with and without excess visceral fat (VFA cutoff 100 cm(2)) in patients with non-night-time onset of ACS. In conclusion, night-time onset of ACS is associated with excess visceral fat and SDB (referred as to "syndrome Z"). SDB and excess visceral fat are treatable risk factors. Decrease of excess visceral fat and treatment of SDB could be beneficial in in preventing nocturnal cardiac events.