OBJECTIVE: Hypoglycemia is a major concern in type 2 diabetes (T2DM), but little is known about its likelihood compared across common therapies. We compared the likelihood of hypoglycemia among metformin-treated patients with T2DM randomized to the addition of one of 4 common therapies.
RESEARCH DESIGN & METHODS: Randomized, controlled trial of 5,047 participants with T2DM of <10 years' duration, hemoglobin A1c (HbA1c) 6.8-8.5% (50.8-69.4 mmol/mol). Randomization to addition of glargine U100, glimepiride, liraglutide, or sitagliptin over 5.0 ± 1.3 (mean ± SD) years. HbA1c was measured quarterly; if a level >7.5% (>58.5 mmol/mol) was confirmed, rescue glargine and/or aspart insulin was added. We conducted a per-protocol analysis of 4,830, who attended at least one post-baseline visit and took at least one dose of assigned study medication. We assessed severe hypoglycemia events reported throughout the entire study. At quarterly visits, all participants were asked about hypoglycemic symptoms within the last 30 days, and those in the glargine and glimepiride groups were asked for any measured glucose <70 mg/dL (3.9 mmol/L) within this time period.
RESULTS: While participants were taking their assigned medications, severe hypoglycemia occurred in 10 (0.8%), 16 (1.3%), 6 (0.5%), and 4 (0.3%), (p<0.05) and hypoglycemic symptoms in 659 (54.2%), 833 (68.3%), 375 (32.4%), and 361 (29.1%) of participants following randomization to glargine, glimepiride, liraglutide, and sitagliptin, respectively (p<0.001).
CONCLUSIONS: In metformin-treated patients with T2DM who add a second medication, hypoglycemia is most likely with addition of glimepiride, less with glargine, and least likely with liraglutide and sitagliptin.
TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01794143.