Decreased baroreflex sensitivity is linked to sympathovagal imbalance, low-grade inflammation, and oxidative stress in pregnancy-induced hypertension

Abstract

Pregnancy-induced hypertension (PIH) has been reported as a cardiovascular (CV) risk. We assessed the sympathovagal imbalance (SVI) and the association of inflammation and oxidative stress (OS) with CV risks in PIH. A total of 125 pregnant women having a risk factor for PIH were followed till term and the incidence of PIH was observed. Retrospectively, they were divided into two groups: Group I (those who did not develop PIH, n = 82) and Group II (those who developed PIH, n = 43). Blood pressure variability (BPV) parameters including baroreflex sensitivity (BRS), spectral heart rate variability (HRV), autonomic function tests (AFTs), inflammatory markers (interleukin-6, TNF-α, interferon-γ), and OS markers were measured in both the groups. Alterations in parasympathetic and sympathetic components of AFTs were analyzed. Link of various parameters to BRS was assessed by correlation and multiple regression analysis. Parasympathetic components of AFTs were decreased from the early part of pregnancy and sympathetic components were increased toward the later part of pregnancy. Decreased BRS, the marker of CV risk, was more prominent in Group II subjects. Independent contribution of interleukin-6 (β = 0.276, P = 0.020), TNF-α (β = 0.408, P = 0.002), interferon-γ (β = 0.355, P = 0.008), and thiobarbituric-acid reactive substance (β = 0.287, P = 0.015) to BRS was found to be significant. It was concluded that sympathetic overactivity that develops more in the later part (third trimester) of pregnancy contributes to SVI and genesis of PIH. In PIH women, CV risks are present from the beginning of pregnancy that intensifies in the later part of pregnancy. Retrograde inflammation and oxidative stress contribute to the decreased BRS in PIH.

Baroreflex stimulation attenuates central but not peripheral inflammation in conscious endotoxemic rats

“…Baroreflex activation is considered a promising therapeutic approach for patients with resistant hypertension (Alnima et al, 2014; Bisognano et al, 2011; Halbach et al, 2015; Hoppe et al, 2012). Clinical studies showed that hypertensive patients have attenuated baroreflex function (Ding et al, 2011; Huang et al, 2017; Subha et al, 2016) associated with a high inflammatory profile (Harrison et al, 2011; Mattace-Raso et al, 2010; Sesso et al, 2007; Solak et al, 2016). These results suggest that baroreflex dysfunction may facilitate inflammation in hypertensive subjects.…”

Interleukin-6 contributes to myocardial damage in pregnant rats with reduced uterine perfusion pressure

“…Pregnancy-induced hypertension, especially preeclampsia, is one of the most frequent and difficult illnesses in pregnancy, which jeopardizes both mother and fetus ( 1 ). The International Society for the Study of Hypertension in Pregnancy has provided the following parameters for diagnosing preeclampsia: blood pressure at least 140/90 mmHg on two separate occasions, 4–6 hours apart, coupled to the appearance of protein in the urine corresponding to 300 mg/dL in 24-h collection ( 2 ). Preeclampsia is estimated to complicate 2–8% of all pregnancies ( 3 ), and it causes maternal morbidity and mortality primarily through cardiovascular complications ( 4 , 5 ).…”

“…Numerous studies have shown that preeclampsia is associated with chronic immune activation. The increased production of inflammatory cytokines and decreased expression of regulatory and anti-inflammatory cytokines further promote an inflammatory state ( 2 ). During preeclampsia, increased levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 are present in the circulation and in the trophoblast cells of the placenta, whereas the content of IL-10 and IL-4 is decreased ( 8 ).…”

Magnesium Lithospermate B Downregulates the Levels of Blood Pressure, Inflammation, and Oxidative Stress in Pregnant Rats with Hypertension

“…All the inflammatory markers were significantly increased in PIH, indicating that women who developed PIH later had an inflammatory milieu from the beginning of pregnancy [ 26 ]. Inhibition of inflammatory response has been suggested to relieve PIH [ 27 ]. Our results suggested that MLB may prevent the occurrence of PIH via inhibiting the inflammatory response.…”