Previously, this site has advised the use of metformin as a first line therapy in all patients with type II diabetes.
This advice was based upon the reductions in risk of myocardial infarction seen in obese patients taking metformin in UKPDS1 however some recommendations suggest that sulphonylureas should be used in type II diabetics who are not obese.
A study in Diabetes Care has compared metformin therapy in normal, overweight and obese individuals. The abstract concludes that "metformin is at least as efficacious in normal and overweight individuals as it is in those who are obese" after the results demonstrated that HbA1c was not different in the three groups and that there were no statistically significant differences in diabetes-related complications.
Action: This study provides evidential support for metformin use in non-obese individuals with type II diabetes. Metformin is the first line agent for all patients with type II diabetes.