Efficacy of isometric exercise full knee extension horizontally (FKEH)--a new and simple maneuver to predict early onset of hypertension.

ABSTRACT

Hypertension is recognized as one of the risk factors for cardiovascular mortality and morbidity. Early identification of persons at increased risk for developing hypertension is a priority, which help them, to live a healthy life by altering lifestyle. Persons having predisposing factors of hypertension (e.g., family history of hypertension) show blood pressure hyper-responsiveness to stress. Elevated blood pressure due to sympathetic stimulation prevailed longer time in susceptible persons. In previous studies some instruments (e.g., hand immersion in cold (4 degrees C) water or isometric exercise by handgrip dynamometer) were required to elicit sympathetic stimulation. In the present study a simple maneuver Full Knee Extension Horizontally (FKEH) has been introduced--a stressor that caused full isometric contraction of quadriceps femoris muscles of both sides. The test was conducted in normotensive, non-smoker males (n = 150) of age group 18-25 years. Among them some (n = 100) were from families having no history of familial hypertension and others (n = 50) were from the families with history of hypertension. The causal blood pressure and heart rate of the participants were recorded. Then the volunteers were requested to perform FKEH maneuver for one minute. Both blood pressure and heart rate were recorded immediately after and 3 minutes following FKEH. The data analyzed using t-test showed that, diastolic blood pressure didn't return and stabilized to pre-exercise level even after 3 minutes following FKEH in volunteers who were mostly from hypertensive family (P< 0.05) i.e., having predisposing factors of hypertension. This indicated those people are prone to early onset of hypertension as their Autonomic Nervous System (ANS) is not competent enough to stabilize their blood pressure to pre-exercise level. Hence, stress in the form of FKEH for one minute may be used as a bedside test to assess the competence of ANS and the proneness of developing early hypertension.