Association Between Heart Rate Recovery and Body Mass Index Among Non-Ischemic Patients in Sinus Rhythm Undergoing Treadmill Stress Test in a Tertiary Hospital

Introduction: Obesity is an independent risk factor for cardiovascular disease. It is hypothesized that the increased risk is due to its link to autonomic parasympathetic dysfunction. This fall in parasympathetic tone can be assessed by heart rate recovery measured during the first one minute after exercise. Objective: To determine the association between heart rate recovery and body mass index (BMI). Methods: This was a cross-sectional study that included all consecutive adult patients who underwent treadmill stress test in a tertiary hospital from March to October 2015. A total of 2,989 subjects were included in the final analysis. The main outcome measure was heart rate recovery (HRR). Results: Univariate analysis of BMI and HRR showed a significant association (P<0.001). Multivariate analysis adjusting for clinical and exercise variables showed that the association remained significant. Smoking history (P=0.021), family history of cardiovascular heart disease (P=0.015), the presence of hypertension (P<0.001), diabetes mellitus (P=0.009, age (P=0.005), baseline heart rate (P<0.001) and age (P=0.005) all showed a negative correlation with HRR. Maximum heart rate achieved (P<0.001) showed a positive correlation with HRR. Conclusion: Increasing BMI was significantly associated with a decrease in HRR, as well as smoking, family history of cardiovascular heart disease, hypertension, diabetes mellitus, age and higher baseline heart rate. Maximum heart rate achieved was positively correlated with HRR.