Response to Comment on Kwon et al. The Long-term Effects of Metformin on Patients With Type 2 Diabetic Kidney Disease. Diabetes Care 2020;43:948-955.

We appreciate the comments by Fu and van Diepen (1) on our recent study (2) about the advantage of metformin use in patients with advanced chronic kidney disease in terms of decreasing the risk of all-cause mortality and incident end-stage renal disease. As metformin users had better baseline characteristics than nonmetformin users, we used propensity score matching for covariate balancing. Due to the limitations of randomized controlled trials, such as extensive resource requirements and difficulties in long-term follow-up, and introduction of electronic health record system, many observational studies based on real-world data have been conducted recently (3). The prevalence of diabetic kidney disease, one of the microvascular complications, increases …