Endocrine Abstracts

Back ground

Both pregnancy and polycystic ovary syndrome (PCOS) constitute insulin-resistant states, while gestational diabetes (GDM) is associated with adverse pregnancy outcomes. Though screening for GDM is typically performed later in pregnancy, some women demonstrate significant insulin resistance (IR) and develop GDM even in 1^st trimester. We have endeavoured to compare surrogate IR indices in 1^st trimester pregnant women and in women diagnosed with PCOS according to the Rotterdam consensus criteria.

Patients and methods

We performed 75 g Oral Glucose Tolerance Test (OGTT) with insulin measurements in 106 healthy 1^st trimester pregnant women at 9.9 ± 2.6 weeks of gestation and in 418 women with PCOS. We also assessed the prevalence of GDM according to the IADPSG and WHO (1999) criteria.

Results

Despite lower BMI (24.93 ± 5.43 kg/m² versus 26.53 ± 6.83 kg/m², P = 0.027) pregnant women had either similar (QUICKI, Belfiore index, Stumvoll_{0–120 min}) or greater IR than women with PCOS (e.g. HOMA-IR 3.85 ± 6.11 versus 2.64 ± 2.04, P = 0.002, and Stumvoll_demographics 0.1054 ± 0.045 versus 0.085 ± 0.58, P = 0.003), while only Matsuda index demonstrated less IR in pregnant women. Though correlation between IR indices in pregnant women was highly significant, it showed marked variability ranging from r = 0.334 (HOMA-IR versus Belfiore index) to r = 1.0 (HOMA-IR versus QUICKI). This was accompanied by high prevalence of GDM (14.2% and 9.4%, IADPSG and WHO criteria, respectively). Women with GDM diagnosed according to IADPSG criteria demonstrated greater IR than pregnant women without GDM. In women with GDM diagnosed according to WHO (1999) criteria these differences were visible only for OGTT-derived IR indices (Belfiore, Matsuda and Stumvoll0–120 index).

Conclusions:

Depending on the choice of IR indices healthy 1^st trimester pregnant women demonstrate either similar, or greater IR than women with PCOS and this is accompanied by high prevalence of early GDM. It remains to be established whether GDM screening should be performed in the 1^st trimester.