Comparison of cystatin C- and creatinine-based estimated glomerular filtration rates for predicting all-cause mortality in Japanese patients with type 2 diabetes: the Fukuoka Diabetes Registry.

BACKGROUND

There is little information about the predictive ability of cystatin C-based estimated glomerular filtration rates (eGFR) for all-cause mortality in Asian populations. We compared the discriminatory ability of eGFR for all-cause mortality with that of creatinine-based estimated glomerular filtration rates (eGFR) in Japanese patients with type 2 diabetes.

METHODS

A total of 4869 participants were classified into four categories (eGFR ≤29, 30-59, 60-89, and ≥90 ml/min/1.73 m) by eGFR and eGFR, and followed up for a median of 3.3 years.

RESULTS

150 deaths were identified. The multivariable-adjusted risk of all-cause mortality was significantly increased in eGFR ≤29 ml/min/1.73 m compared with eGFR ≥90 ml/min/1.73 m [hazard ratio (HR) 2.4 (95 % confidence interval (95 % CI) 1.2-5.0)], whereas it was significantly increased in eGFR 59 ml/min/1.73 m or lower [30-59 ml/min/1.73 m, HR 1.9 (95 % CI 1.1-3.5); ≤29 ml/min/1.73 m, HR 5.8 (95 % CI 2.8-12.0)]. Comparing eGFR with eGFR, the proportions of participants reclassified to lower and higher eGFR stages were 6.3 and 28.8 %, respectively. The multivariable-adjusted HRs for all-cause mortality were 1.8 (95 % CI 1.1-2.9) and 0.7 (95 % CI 0.4-1.1), respectively. The C statistic of the model including eGFR and other risk factors was significantly increased compared with the model including eGFR. The net reclassification improvement and the integrated discrimination improvement were significantly positive.

CONCLUSIONS

Our findings suggest that eGFR has a stronger association with all-cause mortality and is superior to eGFR for predicting all-cause mortality in Japanese patients with type 2 diabetes.