Effect of Isotonic Exercise on Cardiovascular Parameters in Medical Students with Different Body Mass Indices: A Cross-sectional Study

Abstract

Introduction: Obesity is a known risk factor for hypertension. Baseline Heart Rate (HR) and blood pressure are known to scale linearly with Body Mass Index (BMI) values. Recent studies have reported an exaggerated acute response of blood pressure and HR to exercise. Aim: To assess the effect of isotonic exercise on cardiovascular parameters among individuals with different body mass indices in students at Osmania Medical College and look for any association between BMI and cardiovascular responses to isotonic exercise. Materials and Methods: A cross-sectional study was conducted in the Department of Physiology at Osmania Medical College, Hyderabad, Telangana, India, from January 2022 to December 2023, involving 100 healthy individuals with different body mass indices in the age group of 17 years-30 years. The subjects were divided into four groups based on their BMI. Baseline HR, Systolic Blood Pressure (SBP), and Diastolic Blood Pressure (DBP) were measured for all participants. Subsequently, the participants performed isotonic exercise for three minutes. Post-exercise HR, SBP, and DBP were measured immediately. One-way ANOVA was used to determine the significance of HR, SBP, DBP, Mean Arterial Pressure (MAP), and Pulse Pressure (PP) among the different BMI groups. A p-value of <0.05 was considered statistically significant. Results: A total of 100 subjects (28 males, 72 females) with a mean age of 18.64±0.92 years participated in the study. Significant differences were observed in pre-exercise HR (p=0.0002), SBP, DBP, and MAP (p<0.001), and post-exercise HR, SBP, DBP, and MAP (p<0.001) among the different BMI groups. Overweight and obese individuals showed an increased tendency for an exaggerated increase in HR. Changes in PP and MAP, affected by a combination of SBP and DBP, also showed statistical significance. Furthermore, there was an increased tendency for an exaggerated increase in blood pressure in the overweight and obese BMI groups. Conclusion: Individuals with higher BMI exhibit exaggerated increases in SBP, Mean and PP, as well as HR. Additionally, obese individuals demonstrated a significant elevation in DBP. The response of blood pressure and HR after exercise in overweight/obese individuals suggests a higher risk of developing hypertension and other cardiovascular diseases.