Obstructive sleep apnea and retinopathy in patients with type 2 diabetes: a longitudinal study

Rationale: Obstructive sleep apnea (OSA) is associated with several pathophysiological deficits found in diabetic retinopathy (DR). Hence, it’s plausible that OSA could play a role in the pathogenesis of sight-threatening DR (STDR). Objectives: To assess the relationship between OSA and DR in patients with type 2 diabetes and to assess whether OSA is associated with its progression. Methods: A longitudinal study was conducted in diabetes clinics within two U.K. hospitals. Patients known to have any respiratory disorder (including OSA) were excluded. DR was assessed using two field 45-degree retinal images for each eye. OSA was assessed using home-based multichannel cardiorespiratory device. Measurements and Main Results: A total of 230 patients were included. STDR and OSA prevalence rates were 36.1% and 63.9%, respectively. STDR prevalence was higher in patients with OSA than in those without OSA (42.9% vs. 24.1%; P = 0.004). After adjustment for confounders, OSA remained independently associated with STDR (odds ratio, 2.3; 95% confidence interval, 1.1–4.9; P = 0.04). After a median (interquartile range) follow-up of 43.0 (37.0–51.0) months, patients with OSA were more likely than patients without OSA to develop preproliferative/proliferative DR (18.4% vs. 6.1%; P = 0.02). After adjustment for confounders, OSA remained an independent predictor of progression to preproliferative/proliferative DR (odds ratio, 5.2; 95% CI confidence interval, 1.2–23.0; P = 0.03). Patients who received continuous positive airway pressure treatment were significantly less likely to develop preproliferative/proliferative DR. Conclusions: OSA is associated with STDR in patients with type 2 diabetes. OSA is an independent predictor for the progression to preproliferative/proliferative DR. Continuous positive airway pressure treatment was associated with reduction in preproliferative/proliferative DR. Interventional studies are needed to assess the impact of OSA treatment on STDR.