Prevalence, Clinical Features And Analysis Of Related Factors In Type2Diabetic Patients Complicated With Obstructive Sleep Apnea Syndrome

Objective To investigate the prevalence of obstructive sleep apnea syndrome (OSAS)and analyze its possible correlation factors in hospitalized patients with type2diabetes mellitus(T2DM), and to explore the effect of OSAS to blood glucose control,chronic complications of T2DM and nocturnal glucose fluctuation among the samecohort.Method We continuously enrolled eligible T2DM patients in our hospital fromSeptember2011to July2012, recorded their sleep apnea information withApneaLinkTM screening device, and analyzed the prevalence, severity andcorrelation factors of OSAS. According to screening results mentioned above, patientswere then divided into two different groups as OSAS group and control group, whosefast blood glucose(FBG),2hours postprandial blood glucose(2hPBG), HbA1c level,HOMA-IR index and prevalence of diabetic retinopathy (DR), diabetic nephropathy(DN), diabetic peripheral neuropathy (DPN), hypertension and hyperlipidemia werealso recorded for further analysis in order to clarify the relationship between OSASseverity and foresaid factors. At the same time, we monitored patients’ nocturnalglucose level with continuous glucose monitoring system (CGMS). After thecomparison of differences between OSAS and control groups, we investigated thecorrelations between nocturnal glucose fluctuation and OSAS severity biomarkerssuch as apnea–hypopnea index (AHI).Result145eligible patients (109males and36females) completed the whole OSASsurvey. OSAS was diagnosed in114patients (78.6%). Patients complicated withOSAS had higher BMI, waist circumference and HbA1c level, as well as increasedincidence of hypertension and coronary disease（P＜0.05）. HbA1c was independentlyand positively correlated with patients’OSAS risks (OR=6.24,95%CI2.21-9.23). Theindepedent correlation factors of OSAS severity (AHI, Adjust R~2=46.1%) includedHbA1c level, BMI, complicated with hypertension, age and duration of diabetes, withHbA1c level as the predominant factor (Adjust R~2=33.1%). According to OSASscreening results, the same patient cohort was divided into OSAS group (114cases,87males and27females) and control group (31cases,22males and9females). Compared with control group, the average FBG,2hPBG, HbA1c level and HOMA-IRindex were significantly higher in OSAS patients (P<0.05). The AHI and BMI wereboth independently and positively correlated with patient’s FBG （AdjustR~2=37.1%,AHI31.1%）,2hPBG（Adjust R~2=31.2%, AHI26.2%） and HbA1c levels（Adjust R~2=38.7%, AHI33.1%）withAHI as the predominant risk factor of patient’spoor blood control. HbA1c level (OR5.86,95%CI4.64-7.08), suffering from OSAS(OR2.38,95%CI1.44-3.32), complicated hypertension(OR1.04,95%CI1.02-1.06)as well as patient’s diabetes duration (OR2.10,95%CI1.80-2.40) were alsoindependently and positively correlated with DR, and the independent and positivecorrelation factor of DPN included HbA1c level (OR8.56,95%CI5.86-10.64), OSAS(OR3.21,95%CI1.79-4.62) and hypertension (OR01.09,95%CI1.06-1.12). In thiscohort,57patients (43cases in OSAS group and14cases in control group) weremonitored by CGMS. The patients were similar in gender, age and duration of T2DMbetween2groups (P>0.05), but the average HbA1c level, BMI and waistcircumference in OSAS group were higher than control group. The average nocturnalglucose level (22：00-06：00,8.30±0.72mmol/L vs.7.38±0.43mmol/L，P＜0.05)andmean amplitude of glucose excursions (MAGE,3.19±0.29vs.2.86±0.09，P＜0.05)during night in OSAS group were both higher than that in control group as well.Using multiple stepwise linear regression analysis, we found that AHI was positivelycorrelated with nocturnal glucose level (y=7.619+0.020x, P＜0.05) and MAGE(y=2.819+0.012x, P＜0.05). Furthermore, BMI and waist circumference hadnon-independent correlation with nocturnal glucose level and MAGE.Conclusion Type2diabetes patients have significantly higher prevalence of OSAS.Patients with poor glucose control are more predisposed to OSAS which tended to bemore severe. OSAS is more serious in obese and aged patients with long diabetesduration or complicated with hypertension. Type2diabetes patients complicated withOSAS have poor blood glucose control and higher incidence of chronic complications.OSAS were the major risk factor of poor blood glucose control as well as theindependent risk factor of DR and DPN in these patients. Moreover, T2DM patientscomplicated with OSAS have poor control of nocturnal glucose, whose MAGE arealso bigger compared with control group. The severity of OSAS positively correlateswith patients’nocturnal glucose level and MAGE, which is independent of obesity.