Description:
<jats:p>To assess the impact of hormonal treatment (a first‐line of treatment for polycystic ovary syndrome, PCOS) and insulin resistance on cardiovagal baroreflex sensitivity (CVBR), we suppressed endogenous estrogens and progesterone in obese PCOS women (n=3) for 10 days using a gonadotropin‐releasing hormone antagonist, and used an exogenous hormone add‐back design to isolate the effects of 0.2 mg/day transdermal estradiol (Trial 2) versus combined estradiol and 200 mg/day oral progesterone (Trial 3). CVBR was assessed during hormone suppression (Trial 1) and during the hormone add‐back conditions via intravenous administration of sodium nitroprusside and phenylephrine using the Modified Oxford technique, and was analyzed relating R‐R interval and systolic blood pressure. We also conducted an oral glucose tolerance test to assess insulin resistance across all subjects. CVBR was higher in the estradiol‐alone condition (21.85 ± 1.86, p=0.01), compared to the hormone suppression (12.32 ± 2.27) and combined hormone conditions (12.27 ± 1.56). Across all trials, CVBR was predicted by a linear combination of estrogen level (p=0.01) and level of insulin resistance (p=0.02), as determined by their HOMA score (R<jats:sup>2</jats:sup>=0.80). These data suggest that in obese PCOS women, who have higher levels of insulin resistance, estrogen administration may improve baroreflex sensitivity. Supported by NIH Grant HL081671.</jats:p>