Abstract

EFFECT OF YOGA ON SERUM CORTISOL, PLASMA MELATONIN AND CARDIOVASCULAR PARAMETERS IN HYPER-REACTIVITY TO COLD PRESSOR TEST IN YOUNG HEALTHY MEDICAL STUDENTS

Madhuri Agnihotri, Rahul Verma*, Chanda Rajak, Prateek Prabhaker Awasthi, Santosh Pathak

ABSTRACT

Background: The stress response is a complex emotion that produces physiological changes to prepare us for fight-or-flight, to defend ourselves from the threat or flee from it. Stress, anxiety and depression are known to be significant factors in the onset and progression of a wide spectrum of illness ranging from cardiovascular diseases, asthma, cancer, HIV-infection & affect multiple systems of body. The stress hormone cortisol, is public health enemy number one & elevated cortisol levels act as a potential trigger for mental illness and decreased resilience- especially in adolescence, affect multiple systems of body. Objective: To study the effect of yoga on serum Cortisol, Plasma melatonin and cardiovascular parameters in hyper-reactivity to cold pressor test in young healthy medical students. Material and method: Fourty apparently-healthy male undergraduate students (aged, 18-24 years) were taken. After recording the basal blood pressure and pulse rate, the cardiovascular reactivity of all the 25 male students was measured by application of cold pressor test devised by Hines & Brown.25 were found to be hyper reactor to this test. These 25 hyper reactors underwent yogic exercises, pranayama and meditation 60 minutes, twice a day for six months. Before and After the yogic training period the serum cortisol, mean systolic and diastolic blood pressure and mean pulse rate was measured which was found to be significantly reduced, whereas, plasma melatonin was significantly increased, statistically by using student„ t‟ test. Result: Regular practice of yoga for six months significantly reduced the cardiovascular reactivity to cold pressor test, serum cortisol, basal blood pressure and pulse rate., whereas plasma melatonin was significantly increased Conclusion: We concluded that regular practice of yoga for six months reduced the serum Cortisol level and cardiovascular parameters whereas plasma melatonin was significantly increased and possibly by inducing parasympathetic predominance and cortico- hypothalamo-medullary inhibition.

Keywords: Stress, Yoga, Cold pressor test, Serum Cortisol, Plasma Melatonin, Blood Pressure, Pulse rate.