Nocturnal intermittent hypoxia as an associated risk factor for microalbuminuria in Japanese patients with type 2 diabetes mellitus

ObjectiveWe estimated the prevalence of nocturnal intermittent hypoxia, a surrogate marker of obstructive sleep apnoea, among type 2 diabetes mellitus (T2DM) patients and examined the association between nocturnal intermittent hypoxia and microvascular diseases.Design and methodsWe recruited 513 Japanese patients (292 men and 221 women) with T2DM. Nocturnal intermittent hypoxia was diagnosed using the 3% oxygen desaturation index, with less than five events per hour corresponding to normal and five events or more per hour corresponding to nocturnal intermittent hypoxia.ResultsThe prevalence of nocturnal intermittent hypoxia was 45.4% among T2DM patients. The nocturnal intermittent hypoxia group was older and had a higher BMI, greater weight change since the age of 20 years, higher smoking rate and increased prevalence of hypertension, hyperlipidaemia, microalbuminuria and macroalbuminuria. Microalbuminuria (model 1: odds ratio (OR), 3.41; 95% CI, 1.85–6.40; model 2: OR, 3.69; 95% CI, 1.85–7.59 and model 3: OR, 3.12; 95% CI, 1.45–6.95) and nephropathy (model 1: OR, 4.51; 95% CI, 1.58–15.1; model 2: OR, 7.31; 95% CI, 2.11–31.6 and model 3: OR, 5.23; 95% CI, 1.45–23.8) were derived as factors from all the three statistical models and constantly associated with nocturnal intermittent hypoxia only in women.ConclusionsNocturnal intermittent hypoxia was highly prevalent among T2DM patients and may be an independent associated risk factor for microalbuminuria in Japanese women with T2DM.