Relation between heart rate recovery after exercise testing and body mass index

Area of Science:

• Cardiology
• Exercise Physiology
• Public Health

Background:

• Impaired heart rate (HR) recovery post-exercise is a recognized predictor of cardiovascular mortality.
• This phenomenon is associated with underlying vagus nerve dysfunction.

Purpose of the Study:

• To investigate the association between body mass index (BMI) and heart rate recovery following exercise testing.
• To determine if different BMI categories correlate with impaired HR recovery.

Main Methods:

• Analysis of 2443 patients (20-59 years) in sinus rhythm without contraindications for exercise testing.
• Categorization of BMI into normal (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), and obese (>30 kg/m²).
• Calculation of HR recovery as the difference between maximal and first-minute recovery HR; impairment defined as ≤12 bpm.

Main Results:

• Impaired HR recovery occurred in 3.6% of patients, being significantly more prevalent in obese (3x) and overweight (2x) groups.
• Obese individuals exhibited higher resting HR, lower maximal HR, and reduced chronotropic reserve.
• Multivariate analysis confirmed impaired HR recovery was associated with overweight (RR=1.8), obesity (RR=2), lower metabolic equivalents, and higher resting HR.

Conclusions:

• Higher body mass index is significantly associated with impaired heart rate recovery.
• Obesity is linked to vagus nerve dysfunction, as evidenced by reduced HR recovery post-exercise.