Effect of obesity on cardiovascular responses to submaximal treadmill exercise in adult males

CONTEXT: Obesity is a major risk factor for chronic diseases. Abnormal changes in cardiovascular responses to exercise indicate the alteration in autonomic activity in obese. AIMS: To assess and compare the cardiovascular parameters before and after exercise among obese and nonobese adult males. SUBJECTS AND METHODS: Thirty each obese and normal-weight males between the age group 18-45 years were selected as cases and controls, respectively. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), corrected QT intervals were measured before and after submaximal treadmill exercise (QT and QTc) were done according to Bruce protocol. HR, SBP, DBP, MAP, QT, and QTc were also measured during passive recovery at 1 min and 5 min after exercise. STATISTICAL ANALYSIS USED: One-way analysis of variance and t-test were used to assess changes before and after exercise. RESULTS: Resting HR was significantly higher in obese when compared to nonobese (P < 0.05). SBP, DBP, MAP, QT, and QTc were significantly higher in obese when compared to nonobese (P < 0.001). Immediately after exercise HR, SBP, DBP, MAP, QT, and QTc were significantly higher in obese when compared to nonobese (P < 0.001) 1 min after exercise. CONCLUSIONS: Obese individuals had elevated resting cardiovascular parameters and showed increased responses to steady exercise which could be due to alteration in autonomic functions with sympathetic hyperactivity. Delayed rate of decrease in HR and BP after exercise was also observed in obese, which indicates that they are at risk of developing cardiovascular diseases.