Jagdish Narayan1, Archana Ghildiyal2, Manish Goyal3, Dileep Verma2, Shraddha Singh4, Sunita Tiwari4. 1. Assistant Professor, Department of Physiology, King George's Medical University , Lucknow, Uttar Pradesh, India . 2. Associate Professor, Department of Physiology, King George's Medical University , Lucknow, Uttar Pradesh, India . 3. Assistant Professor, Department of Physiology, All India Institute of Medical Sciences , Bhubaneswar, Odisha, India . 4. Professor, Department of Physiology, King George's Medical University , Lucknow, Uttar Pradesh, India .
Abstract
BACKGROUND: Native high landers face two main environmental challenges i.e. hypobaric hypoxia and low ambient temperatures. Both factors contribute to increased sympathetic stimulation and increased blood pressure. Despite these challenges, subjects living at high altitude have lower systolic and diastolic pressures as compared to subjects living in plains. Present study investigated cold pressor test (CPT) which is a potential predictor of future hypertension in high landers and low landers Materials and Methods: Vascular reactivity in terms of changes in systolic and diastolic blood pressure and heart rate in response to cold pressor test has been compared in high lander (n=45) and low lander (n=46) population. RESULTS: Systolic and diastolic blood pressure changes and heart rate changes with cold pressor test are lower in high landers as compared to low landers. Females in both the groups in general exhibited greater cold pressor response than males. CONCLUSION: Hypo-reactive cold pressor test is due to higher parasympathetic tone and lower sympathetic tone. Decreased cold pressor response in high landers reflects another adaptive modulation of sympatho-vagal activity that enables them to stay in hypobaric atmosphere and lower temperatures without undue autonomic stress.
BACKGROUND: Native high landers face two main environmental challenges i.e. hypobaric hypoxia and low ambient temperatures. Both factors contribute to increased sympathetic stimulation and increased blood pressure. Despite these challenges, subjects living at high altitude have lower systolic and diastolic pressures as compared to subjects living in plains. Present study investigated cold pressor test (CPT) which is a potential predictor of future hypertension in high landers and low landers Materials and Methods: Vascular reactivity in terms of changes in systolic and diastolic blood pressure and heart rate in response to cold pressor test has been compared in high lander (n=45) and low lander (n=46) population. RESULTS: Systolic and diastolic blood pressure changes and heart rate changes with cold pressor test are lower in high landers as compared to low landers. Females in both the groups in general exhibited greater cold pressor response than males. CONCLUSION: Hypo-reactive cold pressor test is due to higher parasympathetic tone and lower sympathetic tone. Decreased cold pressor response in high landers reflects another adaptive modulation of sympatho-vagal activity that enables them to stay in hypobaric atmosphere and lower temperatures without undue autonomic stress.
Authors: L Bernardi; C Passino; G Spadacini; A Calciati; R Robergs; R Greene; E Martignoni; I Anand; O Appenzeller Journal: Clin Sci (Lond) Date: 1998-11 Impact factor: 6.124
Authors: C Passino; L Bernardi; G Spadacini; A Calciati; R Robergs; I Anand; R Greene; E Martignoni; O Appenzeller Journal: Clin Sci (Lond) Date: 1996 Impact factor: 6.124