Changes in glucose tolerance with metformin treatment in polycystic ovary syndrome: a retrospective analysis.
OBJECTIVE
To determine whether treatment with metformin would prevent progression to glucose intolerance and type 2 diabetes in women with polycystic ovary syndrome (PCOS).


METHODS
We conducted a retrospective review of medical records of women treated for PCOS during a 5-year period. Eligibility criteria included exclusion of diabetes at baseline by an oral glucose tolerance test, treatment with metformin, and a repeated oral glucose tolerance test after at least 1 year of metformin therapy. Fifty women with PCOS fulfilled the eligibility criteria.


RESULTS
At baseline, 11 women (22%) had impaired glucose tolerance (IGT), and 39 (78%) had normal glucose tolerance (NGT). After treatment with metformin, IGT persisted in 5 (45%) of the 11 women who had IGT at baseline, whereas 6 (55%) had reversion to NGT. During a mean treatment period of 43.3 months, 2 (5%) of the 39 women with baseline NGT had conversion to IGT, resulting in an annual conversion rate from NGT to IGT of 1.4%. In comparison with the 16% to 19% annual conversion rate reported in the literature, metformin treatment in this study resulted in an 11-fold decrease in the annual conversion rate from NGT to IGT (P = 0.01). None of the 50 women developed diabetes.


CONCLUSIONS
The findings of this retrospective study suggest that long-term treatment with metformin delays or prevents the development of IGT and type 2 diabetes in women with PCOS.
The Division of Endocrinology and Metabolism, Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0111, USA.
Susmeeta T
ST
Sharma
Edmond P
EP
Wickham
John E
JE
Nestler
D000328:Adult; D003276:Contraceptives, Oral / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D007333:Insulin Resistance; D008687:Metformin / Q000008:administration & dosage* / Q000009:adverse effects; D011085:Polycystic Ovary Syndrome / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D003276:Contraceptives, Oral; D007004:Hypoglycemic Agents; D008687:Metformin