Purpose: In this study, we explored the correlation between diabetic retinopathy (DR) and metabolic syndrome (MetS) among diabetes mellitus (DM) patients.
Methods: Logistic regression analysis was utilized to test the effects of MetS and its indicators on the incidence of DR and vision-related functional burden. The spline smoothing functions of continuous indicators of MetS were used to establish the logistic generalized additive model (GAM). The effective degree of freedom (EDF) =1 was served as a sign of linear relationship. EDF> 1 was a sign of a more complex association between MetS and DR.
Results: The proportion of difficulties of looking for objects on the crowded shelves in the DR group was higher than that in the non-DR group (19.40 vs 12.10, P < 0.05). Elevated fasting glucose (Glu) and blood pressure levels were related to the vision-related functional burden. The risk of DR development increased by 6% [95% confidence interval (CI): 1.03– 1.09, P < 0.001] and 1% (95% CI: 1.01– 1.02, P =0.004) per 1 unit increase in Glu and systolic blood pressure (SBP) of DM patients, respectively. In the univariate GAM, Glu had a linear effect on DR (EDF=1, P < 0.001) with a positive correlation after controlling SBP. And there was a nonlinear correlation between SBP and DR after controlling Glu (EDF=2.44, P =0.024).
Conclusion: Both Glu and blood pressure were associated with the occurrence of DR and vision-related functional burden. Controlling the levels of Glu and blood pressure may reduce the risk of DR and vision loss among DM patients.
Keywords: diabetic retinopathy, generalized additive model, glucose, blood pressure