Nocturnal Intermittent Serious Hypoxia and Reoxygenation in Proliferative Diabetic Retinopathy Cases

Purpose To clarify the relationship between evaluation items of sleep-disordered breathing and diabetic retinopathy in detail. Design Cross-sectional comparative study. Methods Sixty-eight consecutive nonproliferative diabetic retinopathy and 151 proliferative diabetic retinopathy (PDR) cases who had undergone surgeries in our department were included in this study. Pulse oximetry was conducted overnight and mean oxygen saturation by pulse oximeter (SpO2 ; %), the sleeping 4% oxygen desaturation index (4% ODI times/hour), lowest SpO2 (%), and the cumulative percent time spent at SpO2 < 90% (CT 90%) were calculated. The results were evaluated and compared between the 2 groups. In addition, these results and preoperative patient background factors were analyzed using logistic regression analysis to clarify risk factor of PDR. Results 4% ODI and CT 90% in the PDR group were significantly higher than in the nonproliferative diabetic retinopathy group (4% ODI, 7.8 vs. 4.9; P = .007; CT 90%, 2.2 vs 0.8; P = .0006). Lowest SpO2 was significantly lower in the PDR group than in the nonproliferative diabetic retinopathy groups (82.4 vs 87.0; P = .0006). Logistic regression analysis identified being younger, having a lower value for the lowest SpO2 , and a high hemoglobin A1c value to be risk factors for PDR (age: odds ratio, 0.90; 95% confidence interval, −0.86 to −0.94; P < .0001; lowest SpO2 : odds ratio, 0.93; 95% confidence interval, 0.88 to 0.99; P = .02; hemoglobin A1c: odds ratio, 1.00 to 1.69; P = .047). Conclusions This study indicated that PDR cases had episodes of nocturnal intermittent hypoxia and reoxygenation as a result of sleep-disordered breathing and that low-value lowest SpO2 were the risk factors for PDR development.