Changes in Glucose Tolerance over Time in Women with Polycystic Ovary Syndrome: A Controlled Study

Abstract

We performed this study to access the changes in glucose tolerance over time in a group of women with polycystic ovary syndrome (PCOS) (n = 71) and control women (n = 23) with regular menstrual cycles and baseline normal glucose tolerance. Mean follow-up was between 2 and 3 yr for both groups (PCOS 2.5 ± 1.7 yr; controls 2.9 ± 2.1 yr). Based on World Health Organization glucose tolerance categories, there was no significant difference in the prevalence of glucose intolerance at follow-up in the PCOS group. In the PCOS group, 25 (37%) had impaired glucose tolerance (IGT) and seven (10%) had type 2 diabetes mellitus at baseline, compared with 30 (45%) and 10 (15%), respectively, at follow-up. There were also no differences within groups (PCOS or control) or between groups (PCOS vs. control) in the oral glucose tolerance test-derived measure of insulin sensitivity, but in the women with PCOS who converted to either IGT or type 2 diabetes mellitus, there was a significant decrease (P < 0.0001). At the follow-up visit, the mean glycohemoglobin level was 6.1 ± 0.9% in women with PCOS vs. 5.3 ± 0.7% in the control women (P < 0.001). Women with PCOS and baseline IGT had a low conversion risk of 6% to type 2 diabetes over approximately 3 yr, or 2% per year. The effect of PCOS, given normal glucose tolerance (NGT) at baseline, is more pronounced with 16% conversion to IGT per year. Our study supports that women with PCOS (especially with NGT) should be periodically rescreened for diabetes due to worsening glucose intolerance over time, but this interval may be over several years and not annually.

Prevalence of abnormalities of glucose metabolism in patients with polycystic ovary syndrome

“…It's possible that this increase in prevalence in the fourth decade of life can reflect the natural history of AGM in patients with PCOS. In fact, AGM, as categorized by WHO criteria, tends to worsen over time in women with PCOS, with a non-significant nearly 2-fold increase in the rates of conversion for subjects with PCOS and baseline normal glucose tolerance, without a concomitant change in BMI (16).…”

Retinol-binding protein 4 levels are elevated in polycystic ovary syndrome women with obesity and impaired glucose metabolism

“…Women with PCOS are known to be at an increased risk for the development of IGT and T2DM, which is thought to be a direct consequence of the high prevalence of obesity and insulin resistance. Furthermore, in PCOS women with normal glucose tolerance, a conversion rate to an IGT of 16% per year has been reported (24). In addition to obesity and a positive family history of type 2 diabetes, other risk factors are being discussed to contribute to the high prevalence of insulin resistance and abnormal glucose metabolism in PCOS women.…”

Diverse impacts of aging on insulin resistance in lean and obese women with polycystic ovary syndrome: evidence from 1345 women with the syndrome

“…Only one study reported progression of 2% from normal glucose tolerance to DM in lean patients with PCOS followed up for 15 years (26). Only one early study reported increase in insulin levels (11), a finding not corroborated by the other available reports (23,24,25,26,27,28). The existing prospective studies assessing progression to DM in women with PCOS are summarized in Table 2 and emphasize the role of BMI in DM development.…”