Blood concentrations of brain natriuretic peptide (Nt-pro-BNP) and the regulation of hemodynamic reactions in healthy adult Arctic residents

Abstract

BACKGROUND: In previous studies, we have observed that the levels of Nt-pro-BNP in healthy individuals are lower than among patients with coronary heart disease and hypertension. Additionally, Nt-pro-BNP concentration increases with age. Interestingly, Arctic residents have higher levels of Nt-pro-BNP compared to those living in other northern territories.
 AIM: To study the role of Nt-pro-BNP in the regulation of hemodynamic reactions in adults residing in the Arctic.
 MATERIALS AND METHODS: In total, 111 healthy adults (66 women and 45 men) aged 4655 years living and working on Svalbard, and in the Murmansk region comprised the study group. The comparison group included 118 healthy adults of the same age from the Arkhangelsk region (59 women and 59 men). Peripheral venous blood samples were taken. Hemogram and concentrations of CD3+, CD4+, CD8+, CD10+, CD16+, CD19+, CD23+, CD25+, CD71+ lymphocytes were studied by an indirect immunoperoxidase reaction and a flow cytometry. Blood concentrations of Nt-pro-BNP, endothelin-1, total NO, endogenous NO2, nitrate NO3, cortisol, norepinephrine, epinephrine were assessed using enzyme immunoassay. Data were presented as means and standard errors of the mean (Mm). Depending on the distribution, unpaired t-tests or MannWhitney U-tests were used for all comparisons.
 RESULTS: Blood concentration of Nt-pro-BNP was higher in the Arctic residents compared with those living in Arkhangelsk. Elevated concentrations of Nt-pro-BNP in the Arctic residents were associated with higher levels of norepinephrine and cortisol and lower concentrations of epinephrine and endothelin-1. Moreover, we observed a re-distribution of lymphocytes and monocytes from the circulating to the marginal pool. These features of the hemodynamic reaction were more pronounced among the Arctic residents and among women in all settings.
 CONCLUSION: The effect of natriuretic peptide is associated with simultaneous activation of the concurrent activation of norepinephrine and cortisol secretion, which poses a risk of disrupting the body's mechanisms for maintaining a narrow range of osmolarity in the internal environment.