Background Sleep-related breathing disorders, such as obstructive sleep apnea (OSA), seems to have an important influence on the autonomic nervous function on the heart, and associated with cardiovascular mortality. Therefore, we assessed the relations of sleep apnea-related parameters with 5 min heart rate variability (HRV) in a large cohort of male commercial drivers.

Methods This cross-sectional study recruited 245 male bus drivers from one transportation company in Taiwan. Each participant was evaluated by a polysomnography (PSG) test and by blood lipids examination. Severity of OSA was categorized according to the apnea-hypopnea index (AHI). In addition, short-term HRV was tested.

Results Subjects were categorized into severe OSA group (n=44; 17.9%), moderate and mild OSA group (n=117; 47.8%), and non-OSA group (n=84; 34.3%). AHI had negative correlations with SDNN (β=−0.075, p=0.007) and RMSSD (β=−0.121, p<0.001), adjusting for age, body mass index, smoking, drinking, systolic blood pressure, HDL, and fasting blood glucose. RMSSD level was decreased with severe OSA (β=−0.266, p=0.042) even adjusting for confounders.

Conclusions The findings showed a low level of RMSSD in OSA among commercial drivers, especially in the severe group category. Decreased SDNN and RMSSD levels are associated with AHI level in commercial drivers, suggesting that they are tightly linked with autonomic dysfunction.