LAUSR

PURPOSE Trimethylamine N-oxide serum levels have been associated with type 2 diabetes mellitus and its complications. The current study aimed to find out if plasma trimethylamine N-oxide level may be a novel marker in the diagnosis of diabetic retinopathy and if it can be used in the differential diagnosis of diabetic and nondiabetic retinopathy. METHODS The study included 30 patients with diabetic retinopathy, 30 patients with nondiabetic retinopathy, 30 patients with type 2 diabetes mellitus without retinopathy, and 30 healthy control participants. Biochemical parameters, serum IL-6, TNF-α, and trimethylamine N-oxide levels were measured in all participants. RESULTS Trimethylamine N-oxide level was significantly higher in diabetic retinopathy than in the other groups (p<0.001). There was no significant difference in trimethylamine N-oxide levels between nondiabetic retinopathy and control or type 2 diabetes mellitus Groups. There was a significant positive correlation between trimethylamine N-oxide level and elevated FPG, BMI, HOMA-IR score, BUN, IL-6, and TNF-α levels. CONCLUSION The current study showed that the trimethylamine N-oxide level is elevated in diabetic retinopathy. These findings suggest that serum trimethylamine N-oxide level might be a novel marker for diabetic retinopathy, and it might be used in the differential diagnosis of diabetic and nondiabetic retinopathy.