Background: Vascular alterations are present in pregnant women affected by preeclampsia. In this study, we assessed arterial compliance in women affected by hypertensive disorders of pregnancy. We hypothesized that arterial compliance is reduced in women affected by preeclampsia.
Methods: Forty-three hypertensive pregnant women undergoing evaluation for preeclampsia were studied. Clinical data about each patient and pregnancy were collected. Large (C1) and small (C2) artery compliance were assessed by radial tonometry, while the patients underwent laboratory tests to diagnose preeclampsia. At the time of delivery, gestational age and newborn data were recorded.
Results: Eighteen women were diagnosed with preeclampsia. C2 levels were lower among preeclamptic versus hypertensive aproteinuric women (mean ± SD, 4.5 ± 1.3 vs 5.9 ± 2.3 mL/mm Hg · 100, P = 0.013, 95% confidence interval [CI] of difference 0.32-2.55), whereas C1 levels did not differ. In the preeclampsia group, C2 levels correlated with urine total protein concentrations measured the same day (Spearman ρ = -0.49, P = 0.047, upper 95% CI -0.01) and with gestational age at first occurrence of hypertension (Spearman ρ = 0.59, P = 0.010, lower 95% CI 0.17). Among singleton gestations, C2 also correlated with newborn birth weight measured at delivery (Spearman ρ = 0.43, P = 0.009, lower 95% CI 0.11). Women who were hypertensive but aproteinuric at the time of compliance assessment, but who subsequently developed preeclampsia (n = 6), had C2 levels similar to those with an early diagnosis of preeclampsia (mean difference 0.37 mL/mm Hg · 100, 95% CI -2.42 to 1.67) and lower C2 levels than women diagnosed with gestational hypertension (P = 0.019, 95% CI 0.33-4.42 mL/mm Hg · 100).
Conclusions: The noninvasive assessment of arterial elasticity may contribute toward characterization of the nature of the pathophysiology in pregnancy-induced hypertensive disorders. The vascular alterations of the small arteries, as assessed by C2, may reflect the extent of vascular alterations present with preeclampsia.