Exercise heart rate recovery assessment of the cardiac autonomic nervous system in workers occupationally exposed to lead

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). Exercisetest parameters– HRR in particular– were compared betweengroups, 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