OBJECTIVES
A previous study conducted in 2000 measuring the heart rate variability (HRV) of carbon disulfide (CS2)-poisoned subjects suggested that their HRV was reduced after exposure cessation. However, the study was limited by the following procedural limitations: (1) only 71 CS2-poisoned subjects participated, (2) no females participated, and (3) the CS2-poisoned subjects were older than the controls. This study was therefore conducted to overcome these limitations of the earlier study.
METHODS
The study subjects comprised 122 retired workers with CS2 poisoning and the same number of age- and sex-matched controls. Information on individual age, sex, height, weight, smoking history, alcohol drinking, regular exercise, medical and occupational history, chest x-ray, and ECG recording of the two groups was collected though a self-administered questionnaire and a medical examination. Standard Deviation of NN intervals (SDNN), Root-Mean-Square of Successive Differences (RMSSD), Total Power (TP), Low Frequency (LF), High Frequency (HF), and LF/HF ratio were measured as HRV indices for 5 minutes in the sitting position.
RESULTS
Univariate analysis revealed that all HRV indices of CS2-poisoned subjects were lower than those of the controls. Multiple linear regression analysis showed that CS2 poisoning had negative association with all HRV indices and that its association with RMSSD was statistically significant (P<0.05).
CONCLUSIONS
This study suggests that CS2-poisoned subjects continue to have reduced HRV, even though the exposure has ceased.