A meta-analysis of currently available non-insulin antihyperglycaemic agents added to metformin revealed that, while reductions in glycosylated haemoglobin (HbA1c) were similar across several drug classes (including sulphonylureas, thiazolinediones and alpha-glucosidase inhibitors; reduction range: 0.64–0.97%), treatment side effects (such as weight gain and/or hypoglycaemia) varied considerably (3). This evidence concerns the gene INS and Hypoglycemia.