Associations between kidney function with all-cause and cause-specific mortality in type 2 diabetes mellitus patients: a prospective cohort study in China.

BACKGROUND

Abnormal kidney function is associated with adverse outcomes in patients with type 2 diabetes mellitus (T2DM). However, the evidence between kidney function and mortality among Chinese patients with T2DM were still limited.

METHODS

This cohort study included 19,919 participants with baseline T2DM from 2013 to 2014 in Jiangsu, China. Serum estimated glomerular filtration rate (eGFR), urea, and uric acid were measured at baseline, and Cox regression models were used to evaluate hazard ratios (HRs) and 95% confidential intervals (95%CIs) of all-cause and cause-specific mortality. Restricted cubic splines were used to analyze dose-response relationships, and we explored the best cut-off values by receiver operating characteristic (ROC) curves.

RESULTS

During a median follow-up of 9.77 years, 4,428 deaths occurred, including 1,542 (34.8%) due to cardiovascular disease (CVD), and 1,074 (24.3%) due to cancer. Compared to lowest quintile level (Q1), the highest quintile (Q5) of eGFR was negatively associated with all-cause (HR = 0.67, 95%CI: 0.58-0.77) and CVD mortality (HR = 0.57, 95%CI = 0.44-0.75). The higher levels of urea and uric acid were positively associated with all-cause mortality (Q5 vs. Q1: HR = 1.27, 95%CI: 1.16-1.39; HR = 1.21, 95%CI: 1.10-1.34), with an overall "U-shaped" dose-response relationships. Moreover, higher urea was negatively associated with cancer mortality (Q5 vs. Q1: HR = 0.79, 95%CI: 0.66-0.95). The best cut-off values with all-cause mortality were 88.50 ml/min/1.73m, 6.95 mmol/L and 342.50 µmol/L for eGFR, urea, and uric acid, respectively.

CONCLUSION

We found abnormal kidney function was associated with mortality among people with T2DM. More clinical researches are needed to validate the effects and cut-off values of kidney function on mortality risk for T2DM prevention and management.