Purpose: Early predictors of diabetic complications may aid in the prevention and/or management of these complications. The aim of this cross-sectional study was to determine the predictive value of retinopathy for the presence of other diabetic complications.
Methods: The population studied comprised 648 patients with diabetes mellitus assessed by our service. There were 210 patients (32.4%) with insulin-dependent diabetes mellitus (IDDM), and 438 patients (67.6%) with non-insulin-dependent diabetes mellitus (NIDDM).
Results: Univariate analyses revealed that retinopathy significantly predicted the presence of neuropathy (odds ratio [OR] = 2.23; 95% confidence interval [CI] = 1.56-3.18; p < 0.001), nephropathy (OR = 5.68; 95% CI = 3.06-10.62; p < 0.001), and cerebrovascular disease (OR = 6.6; 95% CI = 1.16-67.21; p = 0.0239) in the total group. Similar associations were observed both in subjects with IDDM and NIDDM. The associations between retinopathy severity level and the prevalence rate of nephropathy were significant in the total group (p = 0.0001), in patients with IDDM (p = 0.0113), and in patients with NIDDM (p = 0.01). In patients with mild to moderate non-proliferative retinopathy (NPDR), nephropathy was present in 17.2% of patients with IDDM, and in 11.4% of patients with NIDDM. In patients with severe NPDR, nephropathy was present in 23.3% in patients with IDDM, and in 11.8% of patients with NIDDM. In patients with proliferative retinopathy (PDR), nephropathy was present in 50% in patients with IDDM, and in 45.5% in patients with NIDDM. In multivariate logistic regression analyses, nephropathy was the only significant complication to be independently associated with retinopathy in patients with IDDM (OR = 8.02; 95% CI = 1.95-33), and in patients with NIDDM (OR = 2.48; 95% CI = 1.02-6.03).
Conclusions: Retinopathy, especially the presence of PDR, is an independent predictor for nephropathy. The predictive value of retinopathy for nephropathy is stronger in patients with IDDM than in those with NIDDM. Ophthalmologists should refer patients with retinopathy for regular medical evaluations.