1. Hypertension Does Not Alter the Increase in Cardiac Baroreflex Sensitivity Caused by Moderate Cold Exposure
- Author
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Heidi Elisa Hintsala, Antti M Kiviniemi, Mikko P Tulppo, Heta eHelakari, Hannu eRintamäki, Matti eMäntysaari, Karl-Heinz eHerzig, Sirkka eKeinänen-Kiukaanniemi, Jouni J K Jaakkola, and Tiina Maria Ikäheimo
- Subjects
hypertension ,cold temperature ,Physiology ,Population ,Cold exposure ,030204 cardiovascular system & hematology ,Baroreflex ,lcsh:Physiology ,Tonic (physiology) ,03 medical and health sciences ,0302 clinical medicine ,Interquartile range ,Physiology (medical) ,Medicine ,Heart rate variability ,baroreflex ,education ,Original Research ,education.field_of_study ,lcsh:QP1-981 ,variability ,business.industry ,blood pressure ,Peripheral ,Blood pressure ,Anesthesia ,business ,030217 neurology & neurosurgery - Abstract
Exposure to cold increases blood pressure and may contribute to higher wintertime cardiovascular morbidity and mortality in hypertensive people, but the mechanisms are not well established. While hypertension does not alter responses of vagally-mediated heart rate variability to cold, it is not known how hypertension modifies baroreflex sensitivity and blood pressure variability during cold exposure. Our study assessed this among untreated hypertensive men during short-term exposure comparable to habitual winter time circumstances in subarctic areas. We conducted a population-based recruitment of 24 untreated hypertensive and 17 men without hypertension (age 55-65 years) who underwent a whole-body cold exposure (-10°C, wind 3m/s, winter clothes, 15 min, standing). Electrocardiogram and continuous blood pressure were measured to compute spectral powers of systolic blood pressure and heart rate variability at low (0.04-0.15 Hz) and high frequency (0.15-0.4 Hz) and spontaneous baroreflex sensitivity at low frequency. Comparable increases in baroreflex sensitivity were detected in hypertensive men, from 2.6 (2.0, 4.2) to 3.8 (2.5, 5.1) ms/mmHg (median (interquartile range)), and in control group, from 4.3 (2.7, 5.0) to 4.4 (3.1, 7.1) ms/mmHg. Instead, larger increase (p
- Published
- 2016