Relation of interleukin-17 and high-sensitivity C-reactive proteins with sympathetic reactivity in pre-hypertensive young adult

Abstract

Objectives: Recent studies have shown that both innate and adaptive immunity response contributes to vascular dysfunction by vascular remodelling and later hypertension. Furthermore, the sympathetic activity mediates the vascular dysfunction through pro-inflammatory activity of immune system. In context to insidious onset hypertension, the study was planned to observe the association of immunity with the increased sympathetic activity in pre-hypertensive adults. Materials and Methods: Thirty healthy pre-hypertensive (as per JNC VII) non-smokers, non-alcoholic and non-obese male adults volunteers were recruited from the study area. Equal numbers of normotensive controls were taken for comparison. On reporting day, they were subjected to the recording of demographic and anthropometric measurements, hand grip dynamometry and later investigated for serum levels of interleukin-17 (IL-17) and high-sensitivity C-reactive proteins (hsCRP) after written informed consent. The data collected were analysed for differences in mean and association of immune and inflammatory markers with sympathetic activity by statistical tests. Results: Significantly higher values of weight, BMI, % BF, visceral fat, resting heart rate and IL-17 and a lower sympathetic reactivity was observed in pre-hypertensive subjects. Values of hsCRP was higher in prehypertensive but was not statistically significant.. IL-17 was a positive significant predictor with 4.7 times (P = 0.02) increase in odds of being pre-hypertensive, whereas sympathetic reactivity was a significant negative predictor (OR = 0.75; P = 0.001). SBP and DBP are both related negatively and significantly (P < 0.05) to the sympathetic reactivity suggesting that blood pressure is related to sympathetic nervous system. Furthermore, the hsCRP is observed to be related positively to the % BF and to only SBP and RHR, complimenting link of adiposity as an inflammatory process to blood pressure. IL-17 levels in blood are observed to be positively and significantly related to DBP. Conclusion: Elevated IL-17 levels are significant predictor of pre-hypertension along with lower sympathetic reactivity. No direct association was observed between IL-17 and sympathetic system except with raised DBP. Immune mechanism is part of pathogenesis of increased blood pressure in pre-hypertensive with enhanced baseline sympathetic activity.