Nocturnal intermittent hypoxia and metabolic syndrome; the effect of being overweight: the CIRCS study

Aim: we investigated whether nocturnal intermittent hypoxia,a surrogate marker for obstructive sleep apnea,is associated with metabolic syndrome and its components among japanese. methods: we examined 1,710 male and 2,896 female community-dwelling japanese aged 40 to 69,who participated in annual cardiovascular examinations and investigations of sleep. nocturnal intermittent hypoxia was estimated based on a 3% oxygen desaturation index measured with pulse-oximetry during sleep. no,mild and moderate-to-severe nocturnal intermittent hypoxia were defined by <5,5 to <15 and ≥15 events/hour,respectively. metabolic syndrome was defined by modified criteria of the adult treatment panel iii guidelines. results: compared with no nocturnal intermittent hypoxia,the multivariable odds ratio of metabolic syndrome was 1.9 (95% confidence interval: 1.6 - 2.4) for mild and 3.2 (2.2 - 4.7) for moderate-to-severe nocturnal intermittent hypoxia among men; 2.6 (2.1 - 3.4) and 5.8 (3.4 - 9.8) among women,respectively. when stratified by overweight status (body mass index ≥25 kg/m2),the multivariable odds ratio of two or more metabolic risk factors (other than overweight) associated with moderateto-severe nocturnal intermittent hypoxia was 1.9 (1.2 - 3.1) among non-overweight subjects and 1.4 (0.9 - 2.1) among overweight subjects (p for interaction 0.002). conclusions: nocturnal intermittent hypoxia was associated with the accumulation of metabolic risk factors,especially among non-overweight individuals.