Metformin plus oral contraceptives an alternative treatment for nonobese women with PCOS

In the treatment of polycystic ovary syndrome (PCOS), the combination of metformin plus oral contraceptives appears to benefit women without obesity, inducing favourable effects on glucose metabolism with no further harm on lipid metabolism, according to the results of a meta-analysis.

Researchers conducted a systematic review of studies in which the metabolic effects of metformin–oral contraceptives combination were compared with those of oral contraceptives alone in women with PCOS who had no obesity.

Multiple online databases were searched for relevant studies published in the English language and involving reproductive-age women with PCOS. The initial search yielded 396 studies, of which 14 were included in the meta-analysis.

With regard to oral contraceptives, nine studies used cyproterone acetate, three studies used drospirenone, one study used norgestimate, and one study used desogestrel. Meanwhile, metformin dose ranged from 0.5 to 2.0 g per day, and a regimen of 500 mg daily was used in one study. Five studies applied a gradual dose escalation to reduce gastrointestinal side effects.

The total number of participants was 707, and their mean body mass index was below the threshold used for obesity (<30 kg/m²).

Pooled data showed that compared with oral contraceptives alone, the addition of metformin led to a significant improvement in fasting glucose (mean difference [MD], –0.21, 95 percent confidence interval [CI], –0.31 to –0.12; p<0.00001) and fasting insulin (MD, –2.54, 95 percent CI, –4.04 to –1.04; p=0.0009) at study completion.

There was no significant between-group difference in the homeostasis model assessment of insulin resistance (HOMA-IR), high-density lipoprotein, low-density lipoprotein, total cholesterol, or triglycerides.