Metformin and -cell function in insulin-treated patients with type 2 diabetes: A randomized placebo-controlled 4.3-year trial

Wiebe Top, Coen Stehouwer, Philippe Lehert, Adriaan Kooy*

*Corresponding author for this work

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6 Citations (Web of Science)


In this trial, 390 insulin-treated patients with type 2 diabetes were randomized to either placebo or metformin. Fasting levels of glucose, insulin and C peptide were determined at baseline, after 4 months and yearly thereafter for 4 years to assess fasting estimates of beta cell function. The primary endpoint was the fasting C peptide-to-glucose ratio (FCPGR) and secondary measures were the disposition index (DI) and the fasting C peptide (FCP). We analysed the results with a general linear mixed model. Baseline FCPGR was 5.27 (95% CI, 4.83 - 5.71). Compared to placebo, FCPGR increased in the metformin group with 1.48 (95% CI, 1.09 - 1.87, P<0.001). The DI showed comparable results with a treatment effect of 1.50 (95% CI, 1.17 - 1.83; P<0.001). FCP also increased in the metformin group but did not reach statistical significance vs placebo (0.034 nmol, 95% CI, -0.005 - 0.072; P=0.085). Treatment with metformin vs placebo, added to insulin in patients with type 2 diabetes, improves long-term estimates of beta cell function in the fasting state.
Original languageEnglish
Pages (from-to)730-733
Number of pages4
JournalDiabetes Obesity & Metabolism
Issue number3
Publication statusPublished - 1 Mar 2018


  • beta cell function
  • HOME study
  • metformin
  • RCT
  • type 2 diabetes
  • BETA

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