Aim: To evaluate the glycaemic efficacy of metformin in people with type 2 diabetes (T2D) and stage 3 chronic kidney disease (CKD3).
Participants and methods: This was a retrospective study including 145980 US veterans with T2D and an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2 who initiated metformin monotherapy between November 1999 and July 2017. Propensity-score-matched cohorts were generated based on baseline variables associated with CKD3 (eGFR 30-59 mL/min/1.73 m2 ) to evaluate the independent association between CKD3 and metformin discontinuation, the addition of a second hypoglycaemic agent, and changes in glycated haemoglobin (HbA1c) from baseline in those with and without CKD3. Associations were examined using the Kaplan-Meier method and multivariable regression models, adjusted for baseline and 12-month average metformin dose.
Results: The mean age of the entire cohort was 60.7 years, and 95% of the cohort were men, 21% were African American and 9% had CKD3. In the adjusted analyses, patients with CKD3 had a higher risk of metformin discontinuation or addition of a second hypoglycaemic agent, as compared with patients without CKD (hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.19-1.26, and HR 1.26, 95% CI 1.13-1.40, respectively). Among metformin monotherapy users, there were no differences in the average HbA1c reduction from baseline to 12 or 24 months between patients with and without CKD3.
Conclusions: Individuals with CKD3 and T2D were at increased risk of metformin monotherapy failure. However, the HbA1c-lowering efficacy of metformin was similar in patients with and without CKD3, highlighting that metformin is a valuable treatment option for newly treated individuals with T2D and CKD3.
Keywords: HbA1c; chronic kidney disease; metformin; second-line hypoglycaemic agents.
Published 2021. This article is a U.S. Government work and is in the public domain in the USA.