Effects of obstructive sleep apnoea-hypoapnoea syndrome on retinopathy processes in elderly patients with type 2 diabetes mellitus

Abstract

Objective To investigate the effect of obstructive sleep apnoea-hypoapnoea syndrome(OSAHS)on diabetic retinopathy(DR)in elderly patients with type 2 diabetes mellitus(T2DM)and analyze risk factors for DR process. Methods Data of elderly diabetic patients without DR admitted into our hospital from January 2012 to December 2014 were retrospectively analyzed.Based on whether or not to combine OSAHS, patients were divided into the OSAHS group(n=42)and the control group(n=85). After 36 months' follow-up, the incidence and progression of DR were compared, and the effect of different degree of OSAHS on DR was analyzed.Multivariate logistic regression analysis was used to analyze the risk factors for DR. Results The systolic pressure, diastolic pressure and Epworth sleepiness scores were higher in the OSAHS group than in the control group(P<0.05). At the(34.5±6.7)months of follow-up versus baseline, body mass index, renal function and cardiac function were markedly decreased in both groups(P<0.05). The systolic pressure, diastolic pressure, 2-h postprandial blood glucose and Epworth sleepiness scores were higher in the OSAHS group than in the control group; and the glomerular filtration rate(GFR)and left ventricular ejection fraction were lower in the OSAHS group than in the control group(P<0.05). The incidences of mild, moderate and severe non-proliferative DR were higher in the OSAHS group than in the control group(P<0.05). The results of subgroup analysis showed that the incidence of DR was higher in patients with moderate to severe OSAHS than in controls(OR=4.57, 95%CI: 1.24~13.78, P=0.002), while the incidence of DR in patients with mild OSAHS was similar to that in the controls(OR=2.33, 95%CI: 0.66~12.56, P=0.29). Multivariate logistic regression analysis showed that T2DM duration ≥7 years(OR=3.24, 95%CI: 1.80-9.59, P<0.05), haemoglobin A1c(HbA1c)≥7.5%(OR=2.07, 95%CI: 1.41-8.52, P<0.05), GFR<60 ml/min(OR=4.52, 95%CI: 1.75-14.26, P<0.05)and apnea/hyponea index ≥15/h(OR=2.03, 95%CI: 1.37-11.24, P<0.05)were independent risk factors for DR. Conclusions OSAHS patients tend to have hypertension and high glucose level, and are more prone to cardiac and renal dysfunction and DR.T2DM duration ≥7 years, HbA1c ≥7.5%, GFR<60 ml/min and AHI ≥15/h are independent risk factors for DR progression.And more studies are needed to confirm the independent risk factors. Key words: Diabetic retinopathy; Sleep hypoapnea, obstructive