Interventions
ADVERSE EFFECTS
Participants were asked to take 2000 mg extended-release metformin hydrochloride, dispensed in 500 mg tablets. Placebos were identical in shape, size and appearance. All trial drugs were provided by Merck Healthcare, Darmstadt, Germany. Participants were asked to take four tablets in the evening after food. They were provided information about possible adverse effects. Participants in both arms also received brief structured advice on diet and lifestyle and on medicine adherence at every visit. Adherence was measured using a visual adherence score and by pill counts.