Serum lutein is a promising biomarker for type 2 diabetes mellitus and diabetic kidney disease in the elderly

OBJECTIVE: To investigate the relationship between serum lutein and type 2 diabetes mellitus (T2DM) and diabetic kidney disease (DKD) in elderly individuals. METHODS: A total of 60 T2DM patients over 60 years were subgrouped into a DKD group and a non‐DKD group according to their urinary microalbumin‐to‐creatinine ratio (UACR), while 30 age‐matched non‐T2DM patients were recruited in the control group. Baseline characteristics, laboratory examination results, and serum lutein levels were compared, and their correlations were analyzed. Receiver operating characteristic (ROC) curves were plotted to identify the diagnostic potential of lutein in T2DM and DKD. RESULTS: The lutein level in the T2DM group was significantly lower than that in the control group and was also significantly lower in the DKD group than in the non‐DKD group (p < 0.001). Lutein levels were negatively correlated with body mass index, glycosylated hemoglobin, fasting blood glucose, triglyceride, and UACR and positively correlated with high‐density lipoprotein cholesterol (p < 0.05). T2DM patients were divided into four groups according to the quartile of their lutein level. The proportion of T2DM and DKD gradually decreased with increasing lutein levels (p < 0.001). The area under the ROC curve of serum lutein in diagnosing T2DM and DKD was 0.880 and 0.779, respectively, with corresponding cut‐off values of 0.433 μmol/L and 0.197 μmol/L (p < 0.001). CONCLUSION: The serum level of lutein is negatively correlated with the incidence of T2DM and DKD in the elderly and can serve as a diagnostic marker for T2DM and DKD.