Spotlight on metformin

The benefits of metformin treatment were highlighted by a few intriguing studies published in the past month.

In a Taiwanese cohort study, researchers assessed the development of affective disorder (AD) among about 60,000 patients with type 2 diabetes and 700,000 controls. Diabetic patients were categorized by their use of metformin, sulfonylureas, both, or neither. The study found that diabetics who took no oral antihyperglycemic agents had more than double the risk of depression as controls, whereas those taking either metformin or a sulfonylurea had similar risk as controls. Taking both kinds of medication was associated with an even lower risk of developing affective disorder than either drug alone (39.4 cases per 10,000 person-years). “These therapeutic regimens are feasible for most people with [type 2 diabetes] and may largely remove the risk of AD posed by diabetes,” the authors concluded in BMC Medicine on Nov. 29.

A trial in England randomized 151 children and adolescents with impaired fasting glucose or impaired glucose tolerance or hyperinsulinemia to 1500 mg of metformin or placebo daily. After six months, the metformin group had reduced their body mass by a mean of 3%. At three months in, they also showed significant improvements in fasting glucose, adiponectin to leptin ratio and alanine aminotransferase, although these differences were not sustained at six months. This largest-ever study of metformin in young people showed that “a short treatment course of metformin is clinically useful, safe, and well tolerated” and may be a “useful adjunct to support lifestyle modification,” the authors concluded in the Journal of Clinical Endocrinology on Nov. 21.

A case-control study at the Mayo Clinic followed 72 women with ovarian cancer who were taking metformin and compared their outcomes with 143 similar women with ovarian cancer who were not taking the drug. After multivariate analysis, women taking metformin were twice as likely to have survived ovarian cancer for five years. The survival difference was significant when the researchers looked specifically at epithelial ovarian cancer, too. Although the study couldn't prove causation, it does provide support for future trials of metformin in ovarian cancer, the authors concluded, in the journal Cancer on Dec. 3.