Hypertension and COVID-19 in conditions of desynchronizing factors when working in the Arctic

Aim. To study the effect of hypertension (HTN) on the course of coronavirus disease 2019 (COVID-19) and to evaluate the impairment of the chrono-structure of 24-hour blood pressure (BP) rhythm as a risk factor of infection in men working in the Arctic on a rotating basis. Material and methods. In the village of Yamburg (Nadymsky district), 517 medical records of inpatients treated at the medical unit of OOO GAZPROM DOBYCHA YAMBURG in 2020-2021 were retrospectively analyzed by random sampling. Of these, 233 patients with HTN and normal BP had a verified diagnosis of COVID-19. The diagnosis of COVID-19 was based on the detection of SARS-CoV-2 RNA by polymerase chain reaction. After matching the groups by age, 2 following groups were selected: group 1 — 88 patients with HTN; group 2 — 108 patients with normal blood pressure who had COVID-19, matched by shift work experience. All patients underwent general clinical examinations in the hospital, determination of blood oxygen saturation, chest computed tomography, and electrocardiography. In the group of patients with further COVID-19, before the disease, standard 24-hour BP monitoring and a chronobiological study using computer software to determine BP chronobiological types according to Cugini P. classification (1992). Results . Patients with HTN were significantly more likely to be diagnosed with severe COVID-19 due to the high frequency of hypoxemia, dyspnea at rest upon admission to hospital, prolonged hyperthermia, and lower blood oxygen saturation levels than those with normal BP. Patients with HTN and COVID-19 were more likely to have grade 2 respiratory failure, more often needed prone position, resuscitation, and more often had cardiac arrhythmias. Patients with HTN had significantly higher blood glucose and creatinine levels. Complaints of cough, headache, heart palpitations, heavy feeling in the chest also prevailed in patients with HTN. In patients, regardless of the BP level, normal 24-hour profile for systolic and diastolic BP was observed only in a third of those examined. In 64% of hypertensive patients and 60% of normotensive individuals who subsequently recovered from COVID-19, there was an impaired 24-hour BP profile of the non dipper and night peaker types. In 39,7% of men with HTN and 37,0% of normotensive individuals, there was no 24-hour BP periodicity with a predominance of the high-frequency component (3,4-8,0-hour oscillations) in 24-hour BP rhythm. The conducted correlation analysis revealed a fairly clear inverse correlation between COVID-19 and MESOR (r=-0,339, p=0,0001) and a direct relationship between COVID-19 and the aperiodic chronotype of HTN (r=0,244, p=0,002). In individuals with normal BP, correlation relationships between COVID-19 and the iso-normotension chronotype were revealed (r=0,240, p=0,052). Conclusion. Working in the Arctic conditions, patients with HTN had more severe clinical manifestations of COVID-19. At the same time, regardless of BP level, the risk of COVID-19 infection in men may increase with an impaired chrono-structure of BP 24-hour rhythm with a predominance of the high-frequency component.