Approximately 30% of patients taking metformin experience gastrointestinal adverse events, with 5%–10% discontinuing the drug due to intolerance. The aim of our study is to develop and externally validate a prediction model for metformin intolerance in elderly patients with type 2 diabetes. This study utilized data from three independent cohorts of Chinese elderly metformin-naïve patients with type 2 diabetes. The derivation cohort consisted of 538 patients. External validation was performed using data from a separate cohort of 319 patients. Intolerance was assessed after patients initiated metformin and maintained treatment for over four weeks. Patients who were unable to complete at least four weeks of treatment due to gastrointestinal adverse effects were also classified as intolerance. In the derivation cohort, the median age was 67 years, median HbA1c was 8.1%, and 45% were female. The external validation cohort had a median age of 70 years, median HbA1c of 7.6%, and 54.5% were female. Metformin intolerance occurred in 75 patients (13.9%) in the derivation cohort and 63 patients (19.7%) in the external validation cohort. Multivariable analysis identified ten variables: gender, age, body mass index, fasting glucose, HbA1c, aspartate aminotransferase, gamma-glutamyl transferase, antidepressants, proton pump inhibitors and clopidogrel. In the derivation cohort, the model demonstrated an AUC of 0.889, with a sensitivity of 0.813 and a specificity of 0.773. Upon external validation, the model maintained good discriminative ability with an AUC of 0.883. We developed and validated a multivariable prediction model for metformin intolerance in Chinese elderly patients. This model may help physicians to be more confident when prescribing metformin, and reduce the intolerance of metformin. Not applicable.
Tan et al. (Tue,) studied this question.