A patient-level analysis of efficacy and hypoglycaemia outcomes across treat-to-target trials with insulin glargine added to oral antidiabetes agents in people with type 2 diabetes

Background: A better understanding of hypoglycaemia risk when insulin is used in combination with one or more oral antidiabetes agents may assist in the treatment decision-making process for the clinician and address concerns regarding hypoglycaemia when initiating or intensifying insulin therapy. The objective of this study was to analyse efficacy and hypoglycaemia outcomes in people with type 2 diabetes receiving insulin glargine (IG) with metformin (MET), sulphonylurea (SU) or MET+SU. Methods: Patient-level data were pooled from 15 randomised, treat-to-target trials (fasting plasma glucose [FPG] targets <5.6 mmol/l) with a duration ≥24 weeks. Efficacy outcomes included glycated haemoglobin (HbA_1c), FPG and HbA_1c target achievement. Overall hypoglycaemia events were assessed by a confirmed PG value of <3.9, <3.1 and <2.8 mmol/l or assistance required; daytime, nocturnal (00:01-05:59 AM); and severe (assistance required or with confirmed PG <2.0 mmol/l). Results: Overall, 2,837 IG patients were analysed, with either MET (634), SU (906) or MET+SU (1,297) as background oral antidiabetes agents. Endpoint HbA_1c in IG+MET and IG+MET+SU-treated patients was significantly lower than in IG+SU-treated patients (adjusted difference -0.32 %; p=0.0001 and -0.33 %; p=0.0002, respectively). Fewer patients achieved endpoint HbA_1c <7.0 % with IG+SU (32 %) versus IG+MET (57 %) or IG+MET+SU (49 %). IG+SU and IG+MET+SU led to significant increases in overall, daytime and nocturnal hypoglycaemia versus IG+MET; severe hypoglycaemia was rare. Weight gain was lowest in IG+MET patients (adjusted difference -1.51 kg versus IG+SU; p<0.0001; -0.78 kg versus IG+MET+SU; p=0.0037) despite higher insulin doses (0.51 U/kg versus 0.43 and 0.42 U/kg, respectively). Conclusions: Better glycaemic goal achievement and reduced risk of hypoglycaemia and weight gain were observed with IG+MET versus IG+SU and IG+MET+SU, albeit with an increased insulin dose requirement.