ABSTRACT
BACKGROUND: This study was conducted to find out the relationship between autonomous function and fatigue rating. The subjects were patients with complaints of fatigue who visited the department of family medicine in a general hospital. METHODS: We conducted this study from April to December 2002 in patients complaining of fatigue. The subjects were categorized into low, intermediate, and high fatigue groups. Heart rate variability was measured for five minutes at rest, followed by a five minute mental arithmetic test. We analyzed the relationship between fatigue ratings and autonomous function with SPSS 10.0. RESULTS: There was a statistically significant increase in the mean heart rate variability in the all three groups at rest and with stress. There was a statistically significant increase in LF norm increase in the low and high fatigue groups. HF norm showed a statistically significant decrease in the intermediate and high fatigue group. The variation in LF norms was highest in the low fatigue group and lowest. With the mental arithmetic test, the low fatigue group showed decreased rMSSD, HF and HF norm values compared to the intermediate group. The above values showed decrease in the high fatigue group compared to the low group. CONCLUSIONS: Overactivity of the sympathetic nervous system was observed as fatigue ratings increased. The cadiovascular autonomic response tended to decrease as fatigue ratings increased.