The incidence of mild and severe hypoglycaemia in patients with type 2 diabetes mellitus treated with sulfonylureas: a systematic review and meta-analysis

Patients with type 2 diabetes mellitus using sulfonylurea derivatives or insulin may experience hypoglycaemia. However, recent data regarding the incidence of hypoglycaemia are scarce. We conducted a systematic review and meta-analysis to determine the proportion of patients with type 2 diabetes mellitus that experience hypoglycaemia when treated with sulfonylurea or insulin. We searched MEDLINE and EMBASE for randomized controlled trials that compared incretin-based drugs to sulfonylureas or insulin and assessed hypoglycaemia incidence in the latter therapies. Subgroup and meta-regression analyses were performed to study possible associations with potential risk factors for hypoglycaemia. Data of 25 studies were extracted, 22 for sulfonylurea and 3 for insulin. Hypoglycaemia with glucose ≤3.1 mmol/L or ≤2.8 mmol/L was experienced by 10.1% [95% confidence interval (CI) 7.3-13.8%] and 5.9% (95% CI 2.5-13.4%) of patients with any sulfonylurea treatment. Severe hypoglycaemia was experienced by 0.8% (95% CI 0.5-1.3%) of patients. Hypoglycaemia with glucose ≤3.1 mmol/L and severe hypoglycaemia occurred least frequently with gliclazide: in 1.4% (95% CI 0.8-2.4%) and 0.1% (95% CI 0-0.7%) of patients, respectively. None of the risk factors were significant in a stepwise multivariate meta-regression analysis. Too few studies had insulin as comparator, so these data could not be meta-analysed. The majority of patients with type 2 diabetes mellitus on sulfonylurea therapy in clinical trials remain free of any relevant hypoglycaemia. Gliclazide was associated with the lowest risk of hypoglycaemia. Because participants in randomized controlled trials differ from the general population, care should be taken when translating these data into clinical practice