Pregnancy May Carry Higher Risk of Abnormal Glucose Metabolism vs PCOS

Although both conditions are known to carry a higher risk of abnormal findings on oral glucose tolerance tests (OGTTs), the authors of a new study from Serbia propose that pregnancy, vs polycystic ovary syndrome (PCOS), may be linked to a higher risk of adversely affecting glucose metabolism.

The 2 conditions carry this higher risk because of increased insulin resistance/altered immune tolerance to the fetus and placenta and an altered immune response to islet cells, respectively. In addition, women with PCOS have a greater risk of type 2 diabetes, which can increase their risk of gestational diabetes if pregnant.

The findings from their retrospective cross-sectional study were published recently in Medicine (Baltimore). All of the women included in the analysis received care at the Clinic for Gynaecology and Obstetrics, Clinical Centre of Serbia, between January 1, 2012, and December 31, 2019, with those with pathological OGTTs receiving additional care at the Clinic for Gynaecology and Obstetrics and Clinic for Endocrinology, Diabetes and Metabolic Diseases. They were divided into Group A (have PCOS; n = 3932) and Group B (are pregnant; n = 3479), and the following glycemia values applied:

• Fasting: 5.1 mmol/L
• 1 hour after oral glucose load: 10.0 mmol/L
• 2 hours after oral glucose load 8.6 mmol/L

“Despite recognized all-encompassing and profound physiological changes in pregnancy which may affect glucose metabolism,” the authors wrote, “we have an impression that the awareness of pregnancy as a challenging and risk-carrying condition is not at the appropriate level and that number of OGTT-tested women is decreasing.”

Whereas the total percentage of pregnant women taking an OGTT saw a large drop during the study period from 89.1% to 20.5%, the opposite was seen for women with PCOS taking an OGTT, among whom there was a leap from 10.9% to 79.5%. Differences were also apparent for the glycemia measurements evaluated. Among group A, fasting glycemia was higher, while the 1- and 2-hour totals were higher in group B.

The mean (SD) body mass index was similar, at 25.65 (7.31) and 24.02 (6.06) kg/m², respectively, as were the percentage in each group who were smokers: 31.12% and 29.28%.

Almost twice as many women in group B vs group A had pathological OGTT results, with apparent significant differences in results (χ², 45.288; P < .001). This finding correlated with a likelihood ratio of 45.427 (P < .001) in the pregnant women vs those with PCOS that there would be a higher prevalence of an abnormal result on an OGTT.

The study authors highlight that even though OGTT recommendations have not changed for women with PCOS and those who are pregnant in the past decade in Serbia, compliance with these guidelines has dropped for pregnant women. “The usage of OGTT is now moving with the times and trends in medicine, resulting in paying more attention to PCOS than to GDM,” they wrote.

They also noted that abnormal OGTT results among this patient group increased during the study period.

“To the best of our knowledge, our study is the first one to simultaneously investigate the trends in OGTT testing both in pregnant women and women with PCOS,” they added. “Against this background, we might conclude that pregnancy could have a more challenging influence on glucose metabolism and that might carry higher risks for abnormal glucose metabolism than PCOS.”

This area needs to be investigated in additional studies, they noted, with larger cohorts.

Reference

Gojnic-Dugalic M, Stefanovic K, Stefanovic S, et al. Distribution of normal and pathological OGTTs among pregnant population and non-pregnant women with PCOS – the cross-sectional study. Medicine (Baltimore). Published online September 17, 2021. doi:10.1097/MD.0000000000027232