Changes in autonomic regulation in workers under conditions of long-term fluoride intoxication

Abstract

Introduction. Long-term intake and accumulation of fluoride compounds in the body, in addition to pathological changes in the bronchopulmonary system, bone tissue, liver, leads to changes in the regulatory systems, primarily the autonomic ones, in the conditions of chronic fluoride intoxication. The aim of the study was to assess the nature and severity of the changes in autonomic regulation in workers of the main occupations in aluminum production under exposure to chronic fluoride intoxication. Material and methods. We examined fifty two male workers of aluminum production over the age range from 40 to 56 years; work experience was more than 15 years. Autonomic regulation was assessed using spectral analysis of the heart rate variability, highlighting oscillations in the ranges of very low frequency (0.004–0.08 Hz), low (0.09–0.16 Hz), and high frequencies (0.17–0.5 Hz). Results. Analysis of the heart rate variability made it possible to identify 4 groups of subjects: 16 individuals had a moderate decrease in variability and a predominance of low-frequency oscillations, 12 subjects examined cases had a pronounced decline in variability in all frequency ranges; a decrease in the capabilities of autonomic regulation was manifested during a test with hyperventilation by an increase in very low frequency oscillations frequency indicating the need for activation of suprasegmental autonomic centers. In 24 subjects, the stable predominance of low-frequency oscillations indicates an enhancement in sympathetic influence. In response to the hyperventilation test, most of them (18 subjects were included in the group 3) showed an increase in low and very low frequency oscillations as a sign of a violation of baroreceptor regulation. Limitations. The study was limited by the number of workers with long-term work experience in aluminum production who underwent an in-depth medical examination. Conclusion. Changes in autonomic regulation are observed in the majority of aluminum production workers with long-term work experience, which gives grounds to recommend a study of neurovegetative status using heart rate variability analysis during preventive examinations to identify individuals at high risk of developing comorbid diseases.