INS and diabetes mellitus: In addition, diabetes duration (OR 1.17, 95% CI 1.14-1.21, P < 0.001), HbA1c (OR 1.62, 95% CI 1.41-1.85, P < 0.001), insulin (OR 4.43, 95% CI 3.82-5.71, P < 0.001), and oral antidiabetic drugs (OR 3.11, 95% CI 2.00-4.83, P < 0.001) were associated with diagnosis of DR compared to the no DR group.