Elevated serum trimethylamine oxide levels as potential biomarker for diabetic kidney disease.

Background: Diabetic kidney disease (DKD) has become a major cause of chronic kidney disease. However, early diagnosis of DKD is challenging. Trimethylamine oxide (TMAO) is an intestinal microbial metabolite which might be associated with diabetes complications. The aim of this study was to investigate the correlation between TMAO and DKD. Methods: A cross-sectional study was conducted. A total of 108 T2DM patients and 33 healthy subjects were enrolled in this study. Multiple logistic regression analyses and area under receiver operating characteristic curves (AUROC) were performed to evaluate the correlation between serum TMAO and DKD. Results: Serum TMAO levels were significantly higher in DKD patients than healthy control group and the NDKD (T2DM without combined DKD) group (P < 0.05). TMAO levels were negatively correlated with eGFR and positively correlated with urea nitrogen, ACR and DKD (P < 0.05). Logistic regression analysis indicated that serum TMAO was one of the independent risk factors for DKD patients (P < 0.05). In the diagnostic model, the AUROC of TMAO for the diagnosis of DKD was 0.691. Conclusion: Elevated levels of serum TMAO levels were positively associated with the risk of DKD in T2DM patients, which might be a potential biomarker for DKD.