Substantiation of the use of indices of the heart rate variability in predicting the development of polyneuropathies in workers of coal enterprises

Introduction. One of the most common forms of occupational diseases of the peripheral nervous system is autonomic-sensory polyneuropathy. For Kuzbass, which is one of the leaders in coal mining, the problem of early diagnosis and prevention of polyneuropathies is the most urgent.

The purpose of this study was to determine autonomic disorders and their role in the development of occupational polyneuropathy in workers of coal enterprises in Kuzbass.

Material and methods. 72 male miners aged from 40 to 64 years with working experience from 15 to 36 years were examined. The control group consisted of 18 subjects of the same age, engaged in light physical or mental work that had no occupational risk factors. To assess the degree of peripheral nerve damage electroneuromyography was performed in all cases; indices of spectral and nonlinear heart rate variability were used to determine the state of autonomic regulation.

Results. No signs of polyneuropathy were detected in 20 subjects of the examined workers of coal enterprises according to electroneuromyography data. The miners with diagnosed polyneuropathy were divided into 3 groups according to the severity of the lesion of the impulse conduction along the peripheral nerves. In the miners with no signs of polyneuropathy, who exposed to harmful production factors, a statistically significant decrease in the power of high-frequency oscillations of the heart rate variability spectrum was determined. The subjects with initial disorders of the impulse conduction showed a progressive decrease in high-frequency oscillations, with moderate signs of polyneuropathy, there were a sympathetic predominance and increased influence of suprasegmental autonomic centers. In the development of severe disorders of the impulse conduction along the peripheral nerves, depression of oscillations in all frequency ranges and rigidity of the heart rate are characteristic.

Conclusion. The obtained data confirm the influence of autonomic dysfunction on the development of occupational polyneuropathy. The analysis of heart rate variability is an important tool for evaluating autonomic regulation and can be used in mass medical examinations. A decrease in spectral and nonlinear parameters in coal-mining workers is an early sign of the disorder of autonomic regulation, which allows predicting the occurrence and development of peripheral nerve damage.