406: Association between the new ACC/AHA stage 1 hypertension and insulin resistance in nulliparous women

Abstract

The recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines introduced stage 1 hypertension (HTN), defined as blood pressure (BP) of 130-139 mmHg systolic or 80-89 mmHg diastolic. The significance of this lower threshold in pregnancy is understudied. Given the association between maternal insulin resistance and adverse pregnancy outcomes, including preeclampsia, we aimed to determine whether stage 1 HTN before 20 weeks is associated with mid-trimester insulin resistance. Secondary analysis of a multicenter randomized trial of vitamin C/E vs placebo to prevent preeclampsia in nulliparous women. Women with two BPs≥135/85 or with a history or current use of anti-hypertensives were excluded from the trial. Women were randomized < 17 weeks and a subset had fasting plasma glucose and insulin tested at 22-26 weeks. Insulin resistance was calculated using indirect indices of homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check (QUICKI). Women with stage 1 HTN before 20 weeks were compared with women without HTN using univariate and multivariate analyses controlling for BMI, race, treatment group, and gestational age at testing. Of the 1,178 women who had testing,142 (12%) hadstage 1 HTN before 20 weeks. Women with stage 1 HTN were older, more likely to be obese (BMI ≥30 kg/m2) and less likely to be Hispanic. Fasting maternal glucose, insulin, HOMA-IR, and QUICKI results did not differ between women with and without stage 1 hypertension (all p > 0.05). Results remained consistent in multivariate analyses. Compared with women without HTN, women with stage 1 HTN were not more likely to have HOMA-IR results ≥ 75thpercentile (adjusted odds ratio, 0.95; 95% confidence interval, 0.61-1.5) or QUICKI results ≤ 25thpercentile (adjusted odds ratio 0.98; 95% confidence interval 0.63 – 1.5). Stage 1 HTN before 20 weeks of gestation as defined by the new ACC/AHA guidelines is not significantly associated with mid-trimester insulin resistance.