A study of post exercise hypotension in normotensive offspring of hypertensives after acute exercise.

Background & objectives: Post exercise hypotension (PEH) is a well-known entity in hypertensive and borderline hypertensive patients. Since the results are inconsistent in normotensives and there is a genetic predisposition of the individuals to hypertension, we hypothesized that PEH is expected to occur in those normotensives who are offspring of hypertensive parents. In this study, we therefore aimed to compare the magnitude of PEH after an acute bout of moderate intensity continuous exercise (MICE) in the offspring of hypertensives vs. offspring of normotensives. Methods: Sixty normotensive participants of both genders (male and female in equal proportion), aged 18-40 yr, were divided into two groups based on their family history of hypertension. The cases (Group 1, n=30) consisted of the normotensives who were offspring of hypertensive parents while the normotensives who were offspring of normotensive parents were taken as the controls (Group 2, n=30). The hypertensive patients were excluded from the study. The individuals underwent a control session (sitting at rest for 5-10 min), followed by a single acute bout of MICE based on the target heart rate (60-70% of maximum heart rate) on a treadmill at the same time of the day (in the morning). The pre- and post-exercise measurements (after 10 min post exercise) of systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) were taken in all the participants using mercury sphygmomanometer in sitting position on the left arm. The intergroup and intragroup net effects of exercise on BP were compared with P<0.05 considered significant. Results: The mean SBP was reduced by 5 mmHg than the baseline in the offspring of hypertensives (cases) as compared to the controls after exercise (P=0.01). The fall in mean DBP and MAP was insignificant across both the groups, but the magnitude of PEH measured as delta changes (BP before and after exercise) in SBP (~5 mmHg) and MAP (~4 mmHg) were significantly higher for the cases as compared to the controls (P=0.01). Interpretation & conclusions: PEH occurs in higher magnitude in normotensives who are genetically predisposed to hypertension, such as offspring of hypertensive parents, and may find regular exercise-induced PEH as an important primary preventive tool to prevent or delay the development of hypertension.