The linear association between pulse pressure and diabetic retinopathy: a cross-sectional study

Objective This study aimed to evaluate the relationship between pulse pressure (PP) and the prevalence of diabetic retinopathy (DR) in individuals diagnosed with type 2 diabetes mellitus. Methods This research is a secondary analysis of a cross-sectional study conducted between April 2002 and November 2004, which included 2,001 adults with diabetes mellitus (859 men and 1,142 women, mean age 64.1 ± 11.3 years) recruited from outpatient clinics in southern Taiwan. Comprehensive demographic and clinical data were collected, defining pulse pressure as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP) measured in mmHg. The association between PP and DR was assessed using multivariable logistic regression, adjusting for potential confounders, and a generalized additive model (GAM) was utilized to explore non-linear relationships. Results Elevated PP levels were consistently associated with higher odds of prevalent DR across progressively adjusted models. When PP was modeled per 10-mmHg increment, the association remained significant in Model 1 (OR 1.16; 95% CI 1.09–1.23; P < 0.0001), Model 2 (OR 1.13; 95% CI 1.06–1.21; P = 0.0002), and Model 3 (OR 1.09; 95% CI 1.02–1.17; P = 0.0136). When analyzed by tertiles, the middle tertile (50–61 mmHg) showed significant associations in the unadjusted model (OR 1.31; 95% CI 1.04–1.66; P = 0.0218) that diminished upon full adjustment (OR 1.19; 95% CI 0.92–1.52; P = 0.1828). In contrast, the high tertile (62–136 mmHg) maintained a significant association after adjustments (Model 1: OR 1.82; 95% CI 1.44–2.29; P < 0.0001; Model 3: OR 1.47; 95% CI 1.13–1.91; P = 0.0039). Conclusions This study indicates higher PP was associated with higher odds of prevalent DR in individuals with type 2 diabetes.