After 10 years of the DDPOS (DPP Outcomes Study), 2,029 participants, representing 74% of the cohort, were assessed at baseline and annually, and coronary calcium scans were done.  The scans were performed at a mean of 13.7 years after randomization, when the average ages of the participants were 67 years for men and 63 years for women. The mean duration of treatment was 9.6 years in the metformin group and 1.7 years and 1.3 years in the placebo and lifestyle groups, respectively. Diabetes developed in 54%, 59%, and 51% of the patients, respectively. The prevalence and severity of coronary artery calcium (CAC) after 14 years of metformin therapy were significantly lower in men, but not women, who started on the drug for prediabetes, in a longitudinal cohort study. Dr. Ronald Goldberg added that the metformin effect “occurred despite large numbers of individuals being on antihypertensive therapy and statin therapy.”  He also added that, “There is a background of information indicating that metformin might protect against heart disease in people with diabetes,” but this is the first time an effect has been seen in nondiabetic individuals. Metformin “seemed to be affecting the smallest lesions, and that might imply that the effect was on early atherosclerosis.” CAC was significantly less prevalent in males given metformin, at 75% vs 84% in the placebo group (P=0.02) and 84% in the lifestyle group (P<0.05). In contrast, no metformin effect on CAC was seen in women. The authors speculate that women may have less coronary calcification than men, making it harder to observe a benefit from metformin.  Published May 5, 2017 in Circulation.