Treatment intensification strategies after initial metformin therapy in adult patients with type-2 diabetes: results of the DPV and DIVE registries

Aims Our study aimed to analyse treatment strategies after failure of initial metformin mono-therapy in adult patients with type-2 diabetes (T2DM). Methods The DIVE and DPV databases were combined and 16,681 adult patients with T2DM and metformin mono-therapy identified. Patients were analysed depending on whether metformin was continued (MET), or whether it was combined with other oral antidiabetics (OAD), with GLP-1 antagonists (GLP-1) or with basal insulin (BOT/BOT plus). Metabolic control, body weight and hypoglycaemia, micro- and macro-vascular events were compared within 1 year. Results A total of 11,911 (71%) participants continued MET until the end of the observation period, 3334 (20.0%) were intensified using OAD, 579 (3%) started on GLP-1, and 857 (5%) were initiated on BOT/BOTplus. Predictors of OAD and BOT/BOTplus therapy were elevated HbA1c, longer diabetes duration and the presence of micro- and macro-vascular diseases, while GLP-1 therapy was predicted by younger age, female sex, higher body weight and shorter diabetes duration. Micro- and macro-vascular diseases were negative predictors of GLP-1 therapy. Effects on HbA1c were highest in the BOT/BOTplus and OAD group, while GLP-1 treatment had the best effect on body weight. Conclusions BOT/BOTplus and OAD show good HbA1c reduction even in patients with longer diabetes duration and in older patients. GLP-1 therapy is effective concerning weight loss in overweight patients and is more often used in females and patients with shorter diabetes duration. Interestingly, despite several studies showing positive effects on micro- and macro-vascular outcomes, prevalent macro-vascular diseases are no predictors of GLP-1 use.