Attenuation of baroreflex sensitivity and heart rate variability is linked to reduced levels of nitric oxide in pregnant women having risks of developing gestational hypertension.

Purpose: Decreased baroreflex sensitivity (BRS) and sympathovagal imbalance (SVI) have been reported as a cardiovascular (CV) risk in gestational hypertension (GH). Nitric oxide (NO) has been implicated in pathophysiology of GH. In the present study, we assessed the link of CV risks (decreased BRS and SVI) to the plasma levels of NO in women having risk of developing GH. Materials and Methods: A total of 96 pregnant women having risk factors for GH were recruited for the study. The blood pressure variability (BPV), heart rate variability (HRV), plasma NO, marker of insulin resistance (HOMA-IR), lipid risk factors, inflammatory markers (hsCRP, interleukin-6), and malondialdehyde (MDA), the marker of oxidative stress (OS) were measured at 16th and 36th week. Link of various parameters to NO was assessed by correlation and multiple regression analysis. Results: Of HRV indices, parasympathetic components were decreased and sympathetic components were increased, BRS was decreased, NO was decreased, HOMA-IR, lipid risk factors, hsCRP, interleukin-6, and MDA were increased significantly at 36th week compared to 16th week of pregnancy. Most of the markers of cardiometabolic risk were correlated with NO. However, only the markers of CV risk (SVI and reduced BRS) were independently associated with decreased level of NO, but not the metabolic markers except interleukin-6. The independent contribution of BRS (ß = 0.334, P < .001) to NO was found to be most significant. Conclusion: It was concluded that decreased BRS, SVI, and increased interleukin-6 are associated with reduction in NO in GH, which may possibly be linked to the development of CV risks in GH.

Effects of yoga on cardiometabolic risks and fetomaternal outcomes are associated with serum nitric oxide in gestational hypertension: a randomized control trial.

Gestational hypertension (GH) is associated with adverse cardiometabolic and pregnancy outcomes. Though yoga is known to be beneficial in pregnancy, the effects of yoga rendered for twenty weeks starting from 16th week of gestation in pregnant women having risk of GH on the incidence of hypertension, cardiometabolic risks and fetomaternal outcomes have not been studied. A randomized control trial was conducted on 234 pregnant women having risk of GH receiving standard antenatal care (Control group, n = 113), and receiving standard care + yoga (Study group, n = 121). Interventions were given for twenty weeks starting at 16th week of gestation. Baroreflex sensitivity (BRS), heart rate variability (HRV), insulin resistance, lipid-risk factors, and markers of inflammation, oxidative stress and vascular endothelial dysfunction (VED) were assessed before and after intervention. Incidence of new-onset hypertension, level of cardiometabolic risks at 36th week, and fetomaternal-neonatal outcomes in the perinatal period, were noted. The link of hypertension, pregnancy outcomes and cardiometabolic risks with nitric oxide (NO), the marker of VED was assessed by analysis of covariance, Pearson's correlations, and multilinear and logistic regressions. In study group, 6.61% women developed hypertension compared to 38.1% in the control group following 20-week intervention and there was significant decrease in risk of developing GH (RR, 2.65; CI 1.42-4.95). There was less-painful delivery, decreased duration of labor, increased neonatal birthweight and Apgar score in study group. Increase in total power of HRV (ß = 0.187, p = 0.024), BRS (ß = 0.305, p < 0.001), and decrease in interleukin-6 (ß = - 0.194, p = 0.022) had significant association with increased NO. Twenty weeks of practice of yoga during pregnancy decreases the incidence of hypertension, improves fetomaternal outcomes, and reduces cardiometabolic risks in pregnant women having risk of GH. Decreased blood pressure, increased HRV, BRS and birth weight and decreased inflammation were associated with improved endothelial function. Trial registration: Clinical Trials Registry of India (CTRI), registration number: CTRI/2017/11/010608, on 23.11.2017.