Metformin has no major effects on glucose homeostasis in pregnant women with PCOS: results of a randomized double-blind study.
OBJECTIVE
Previous non-randomized and uncontrolled studies indicate major metformin effects on glucose homeostasis in pregnant women with polycystic ovary syndrome (PCOS). We investigated metformin effects on glucose homeostasis in a prospective controlled study.


METHODS
Forty pregnant women with PCOS and without known diabetes mellitus were included in the first trimester and randomized to either metformin 850 mg twice daily or placebo. Outcome measures were fasting glucose and insulin at inclusion and changes to pregnancy weeks 19, 32 and 36 and 2 h glucose levels during a 75 g oral glucose tolerance test (OGTT) carried out at inclusion and pregnancy weeks 19 and 32. Insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta) were calculated using the homeostasis assessment model.


RESULTS
At inclusion, 2 h glucose levels during OGTT were higher in the placebo group (7.14 versus 6.03 mmol/L; p = 0.012). Accordingly, 6 out of 22 in the metformin group versus 2 out of 18 women in the placebo group (p = 0.21) had gestational diabetes mellitus at inclusion. At gestational weeks 19 and 32, 2-h plasma glucose levels were equal between the groups. The total proportion of women with gestational diabetes did not differ between the groups, nor did any of the other indices of glucose metabolism and insulin resistance.


CONCLUSIONS
Metformin seems to be without major effects on glucose homeostasis in pregnant women with PCOS.
Fougner
K J
KJ
Department of Endocrinology, St Olav's Hospital, Trondheim University Hospital, Trondheim, Norway.
Vanky
E
E
Carlsen
S M
SM
D000293:Adolescent; D000328:Adult; D016640:Diabetes, Gestational / Q000175:diagnosis / Q000188:drug therapy; D004311:Double-Blind Method; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D008687:Metformin / Q000494:pharmacology* / Q000627:therapeutic use*; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy*; D011247:Pregnancy; D013997:Time Factors
D008687:Metformin; D005947:Glucose