Assessment of Cardiac Autonomic Nervous System in Workers Occupationally Exposed to Lead via Exercise Heart Rate Recovery

OBJECTIVE The aim of the present study was to assess cardiac autonomic function via indices of exercise heart rate recovery (HRR) in workers occupationally exposed to lead. METHODS A total of 98 lead-exposed workers and 98 healthy controls were enrolled. All underwent exercise testing and transthoracic echocardiography. HRR indices were calculated by subtracting 1st- (HRR1), 2nd- (HRR2), and 3rd-minute (HRR3) heart rates from maximal heart rate (HR). Exercise test parameters- HRR in particular- were compared between groups, and correlation analysis of blood, 24-hour urine lead levels, and test parameters was performed. RESULTS Baseline demographic and clinical characteristics were found to be similar between groups. Mean HRR1 (26.2±3.6 vs 29.0±4.1 bpm, p