Arterial Hypertension Risk Prediction In Conditions Of Rotational Shiftwork In The Arctic

Objective: To study features and dynamics of chronostructure of circadian blood pressure (BP) rhythm in normotensive patients and define their prognostic value with respect to arterial hypertension (AH) within prospective observation in conditions of Arctic rotational shiftwork. Design and method: During the prospective one-year study, in conditions of rotational shiftwork in the Arctic, 173 men with normal BP and with negative history of AH (mean age 40.2 ± 4.1 years) were examined. Work experience in the Arctic was 16.5 ± 6.8 years; work experience in rotational shifts was 11.2 ± 3.8 years and office BP was 123.4 ± 7.5/80.5 ± 5.5. All patients underwent ambulatory blood pressure monitoring (ABPM) 1 time in 3 months; individual cosinor-data analysis was carried out to determine circadian rhythm chronotypes. Results: According to the classification of P. Cugini, true normotension (50%) and atypical chronotypes: allonormotension (22%) and isonormotonia (28%) were revealed in individuals with normal BP. The prognostic value of circadian BP rhythm disturbances was explained by high frequency of atypical normotensive chronotype transformation into hypertensive ones. During the year of observation, AH developed in 26% of normotonics with atypical chronotypes. Based on results of the study of chronobiological parameters in individuals with normal BP, the role of autonomic nervous system in the formation of chronotypes of circadian BP rhythm in normotensive patients was assessed. Moreover, atypical chronotypes of BP highlighted as main disturbances of circadian rhythm in the conditions of the Arctic region. Atypical normotensive chronotypes were characterized by more evident structural changes of the heart and vessels. In conditions of the Arctic, chronobiological approach in comparison with standard analysis of ABPM indicated higher diagnostic sensitivity, specificity and efficiency. Logistic regression revealed prognostic significance of normotensive atypical chronotypes compared to main risk factors (smoking, low physical activity, body mass index, dyslipidemia, age, duration of work in the Arctic and rotational shiftwork experience, the mode and type of rotational shiftwork). Conclusions: Using multivariant analysis, there was received the model for determining a diagnostic indicator showing risk for AH development during one-year observation in normotensive individuals in condition of rotational shiftwork in the Arctic.