Efficacy and safety of antihyperglycaemic drug regimens added to metformin and sulphonylurea therapy in Type 2 diabetes: a network meta-analysis

Aim: To assess the efficacy and safety of third-line adjuvant antihyperglycaemic agents in people with Type 2 diabetes mellitus failing metformin and sulphonylurea combination therapy.

Methods: We searched MEDLINE, CENTRAL, clinicaltrials.gov and regulatory websites, and conducted a manual search of references in the identified studies. Randomized trials evaluating antihyperglycaemic agents in adults with Type 2 diabetes experiencing poor glycaemic control despite optimized metformin and sulphonylurea therapy (≥ 1500 mg metformin or maximum tolerated dose; ≥ 50% of maximum sulphonylurea dose for ≥ 3 weeks) were included. Data extraction included: study characteristics; change in HbA1c concentration; weight; systolic blood pressure; and relative risk of hypoglycaemia, urinary tract infections; and genital tract infections. A network meta-analysis was performed.

Results: A total of 20 trials evaluating 13 antihyperglycaemic agents were included. Compared with placebo/control, all antihyperglycaemic agents reduced HbA1c levels, albeit by differing magnitudes [range 7 mmol/mol (0.6%) for acarbose to 13 mmol/mol (1.20%) for liraglutide]. Sodium glucose cotransporter-2 inhibitors reduced weight (1.43-2.07 kg) whereas thiazolidinediones, glargine and sitagliptin caused weight gain (1.48-3.62 kg) compared with placebo/control. Sodium glucose cotransporter-2 inhibitors, rosiglitazone and liraglutide decreased systolic blood pressure compared with placebo/control, pioglitazone, glargine and sitagliptin (2.41-8.88 mm Hg). Glargine, thiazolidinediones, liraglutide, sitagliptin and canagliflozin increased hypoglycaemia risk compared with placebo/control (relative risk 1.92-7.47), while glargine and rosiglitazone increased hypoglycaemia compared with most antihyperglycaemic agents (relative risk 2.81-7.47). No antihyperglycaemic agent increased the risk of urinary tract infection, but canagliflozin increased the risk of genital tract infection by 3.9-fold compared with placebo/control.

Conclusions: When added to metformin and a sulphonylurea, antihyperglycaemic agents had varying effects on efficacy and safety endpoints. These conclusions should be considered when clinicians choose between possible adjunctive agents.