Association between obstructive sleep apnea hypopnea syndrome and type 2 diabetes mellitus

Abstract

Objective To investigate the association of obstructive sleep apnea hypopnea syndrome (OSAHS) and type 2 diabetes mellitus. Methods This study was conducted from May 2008 to December 2009 from the subjects diagnosed at the Sleep Center of the First Affiliated Hospital of Nanjing Medical University. Based on polysomnography examination, 104 habitual snorers were assigned to the simple snorer group (control group) and the OSAHS group which was further assigned to the mild OSAHS group and the moderate-to-severe OSAHS group according to the apnea hypopnea index (AHI) during sleep to compare the incidence of type 2 diabetes mellitus. Parameters among different groups were compared with Chi-square test and analysis of variance respectively. Spearman correlation analysis and Logistic regressive analysis were used to evaluate the correlation among AHI, minimal SaO2 (mini-SpO2), mean SaO2, fasting blood glucose, true insulin, proinsulin, HOMA index, body mass index (BMI), waist circumference (WC) and neck circumference (NC). Results Type 2 diabetes mellitus was found in 15.3%(13/85) of all the OSAHS patients. The incidence of type 2 diabetes mellitus in moderate-to-severe OSAHS group (25.7%(9/35)) was significantly higher than that in the control group (5.3%(1/19), χ2=4.942, P=0.026) and in the mild OSAHS group (8.0% (4/50), χ2=4.011, P=0.045). Spearman correlation analysis indicated that HOMA index and PI were negatively correlated with nocturnal mini-SpO2 and mean SpO2. There was no statistically significant correlation of HOMA index and PI with AHI. Mini-SpO2 and mean SpO2 were negatively correlated with BMI, WC, and NC. Univariate logistic regression analysis suggested that the HOMA index and PI were risk factors of severe OSAHS (odds ratio was 1.924 (1.302 to 2.847; P<0.01) or 1.714 (1.175 to 2.507; P<0.01)). Conclusion There is an association between OSAHS and type 2 diabetes mellitus. Insulin resistance may play an important role in the coexistence of OSAHS and type 2 diabetes mellitus. The OSAHS patients with a lower SpO2 can be more susceptible to type 2 diabetes mellitus. Key words: Type 2 diabetes mellitus; Obstructive sleep apnea hypopnea syndrome; Insulin resistance