Hypertension in individuals working in the Arctic on a rotating basis: relationship of arterial stiffness with inflammatory markers and some metabolic risk factors

Abstract

Aim. To assess the relationship of arterial stiffness, inflammatory markers, some metabolic risk factors, including gender-specific aspects, in hypertensive (HTN) patients working in the Arctic on a rotating basis.Material and methods. In the polar settlement of Yamburg (68 21’ 40" northern latitude), on the basis of the medical unit of OOO YaGD, 99 men (M) and 81 women (F) with grade 1-2 HTN (61 M and 44 F) and normotensive individuals (HTN0) were examined. Patients with HTN were comparable in terms of age (p=0,68), number of rotation work years (p=0,7701), office systolic BP (p=0,473), diastolic BP (p=0,6992), and body mass index (p=0,465). We carried out 24-hour BP monitoring, common carotid artery ultrasound with the calculation of local stiffness parameters (distensibility coefficient, stiffness index, Peterson’s elastic modulus (Ep), Young’s elastic modulus (Eу)); pulse wave velocity (PWV) was studied. In addition, biochemical blood tests with the determination of high-sensitivity C-reactive protein, homocysteine, C-peptide, insulin, cortisol, atrial natriuretic peptide, interleukins (IL-1β, IL-6, IL-8, IL-10), tumor necrosis factor (TNF-α).Results. In groups M and F with HTN, in comparison with HTN0, higher values of following vascular stiffness parameters were revealed: group F — pulse pressure (p=0,018), intima-media thickness (p=0,0077), PWV (p<0,00001), Eу (p=0,0314); group M — PWV (p=0,0004), Eу (p=0,0024) and reduced common carotid artery strain (p=0,0131). In M with HTN, in comparison with F with HTN, intima-media thickness (p=0,0008), stiffness index (p=0,0368), Ep (p=0,051) were higher. PWV in M and F with HTN was determined significantly higher than in persons with normal BP (p=0,0007; p=0,0001). Correlation analysis revealed the relationship between PWV and 24-hour blood pressure monitoring in hypertensive men and women. An increase in PWV per unit of measurement in women increases the HTN probability by 1,7 times, in men — by 1,4 times. Compared with HTN0 group, the levels of C-peptide (p=0,032), insulin (p=0,035), IL-1β (p=0,025), cortisol (p=0,031) in M group were significantly higher, while significantly higher levels of C-peptide (p=0,015), insulin (p=0,012), IL-6 (p=0,021), TNF-α (p=0,047) were revealed in F group. Stepwise logistic regression analysis revealed following independent parameters affecting the HTN probability: M group — PWV (odds ratio (OR) 1,554 (95% confidence interval (CI): 1,058-2,281, p=0,025)), C-peptide (OR 1,186 (95% CI: 1,004-1,588, p=0,022)), IL-1β (OR 1,464 (95% CI: 0,936-2,291, p=0,099)); F group — PWV (OR 2,015 (95% CI: 1,319-3,078, p=0,001)), C-peptide (OR 2,133 (95% CI: 1,236-3,680, p=0,006)), IL-6 (OR 2,101 (95% CI: 1,003-4,400, p=0,049)) and reduced TNF-α level (OR 0,801 (95% CI: 0,668-0,959, p=0,016)).Conclusion. Under the rotation work conditions in the Arctic, high vascular stiffness values, regardless of sex, are associated with HTN. In men, regardless of BP level, vascular stiffness parameters were higher. However, a stronger association of vascular stiffness with the HTN risk was observed in women. In hyper­tensive patients in the Arctic, an association of vascular stiffness with nonspecific immune inflammation factors was found, which was more pronounced in women. In addition to vascular stiffness and pro-inflammatory cytokines, the "northern" HTN model includes C-peptide, which is an atherosclerosis modulator.