Relationship between retinol and risk of diabetic retinopathy: a case-control study.

ABSTRACT

BACKGROUND AND OBJECTIVES: The aim of the present study was to evaluate the relationship between retinol and risk of diabetic retinopathy in Chinese adults. METHODS AND STUDY DESIGN: Eighty-six subjects with type 2 diabetes mellitus (T2DM) and 40 healthy subjects (healthy comparison group, HCG) were recruited in Beijing Luhe Hospital. Of the 86 T2DM subjects, 43 subjects were diagnosed with diabetic retinopathy (DRG), and 43 subjects had no retinopathy (DNRG). RESULTS: Dietary intake of retinol (p<0.001) and retinol equivalent (p<0.05) was significantly higher but serum retinol and (p<0.001) retinol binding protein 4 (RBP4) (p<0.05) were significantly lower in DNRG compared with HCG. Dietary intake of retinol (p<0.05) and retinol equivalent (p<0.05) was significantly lower, and serum retinol and (p<0.01) retinol binding protein 4 (RBP4) (p<0.01) were significantly higher in DRG compared with DNRG. In T2DM subjects, per 100 µg/day higher dietary retinol intake was associated with 17% lower risk of diabetic retinopathy (odds ratio (OR), 0.83; 95% CI, 0.70 to 0.98; p=0.032), and after adjusting for potential confounding factors, the OR was 0.82 (95% CI, 0.69 to 0.99; p=0.036); per 100 µg/day higher in dietary retinol equivalent intake was associated with 12% lower risk of diabetic retinopathy (OR, 0.88; 95% CI, 0.79 to 0.97; p=0.010), and after adjusting for potential confounding factors, the OR was 0.88 (95% CI, 0.79 to 0.98; p=0.025). CONCLUSIONS: Higher dietary intake of retinol or retinol equivalent is associated with lower risk of diabetic retinopathy.