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Effect of hypohydration and altitude exposure on skin blood flow responses to local heating
Author(s) -
Castellani John,
Alinovi Martha,
Charkoudian Nisha
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1150.4
Subject(s) - plateau (mathematics) , effects of high altitude on humans , medicine , altitude (triangle) , skin temperature , blood flow , endocrinology , zoology , cardiology , biology , biomedical engineering , anatomy , mathematical analysis , geometry , mathematics
It is unknown whether hypohydration (HYPO) or hypobaric hypoxia alter skin blood flow (SkBF) responses to local heating. We hypothesized that HYPO (4% of body weight) and acute altitude (ALT, 3,048 m) would decrease forearm SkBF responses to local heating and that ALT‐HYPO together would result in a further decline. Four healthy young men (23 ± 6 years, 175 ± 5 cm, 74 ± 5 kg) completed 4 trials each: a) sea‐level–euhydrated (SL‐ EUH); b) SL‐HYPO; c) ALT‐EUH; and d) ALT‐HYPO. Local thermal control of cutaneous vascular conductance (CVC) was assessed by local heating to 42°C for 30 min. CVC was calculated as laser‐Doppler flow/mean arterial pressure and analyzed for initial peak (~2–4 min after onset of warming), and plateau (last 3–5 min of warming). Initial peak CVC values were 1107 ± 593, 673 ± 273, 619 ± 241 and 784 ± 440 % of baseline for SL‐EUH, SL‐HYPO, ALT‐EUH, and ALT‐HYPO, respectively. Plateau CVC values were 1585 ± 797, 1340 ± 609, 962 ± 396 and 1082 ± 869 % of baseline. There were no significant influences of HYPO or ALT (P > 0.05 for all), although HYPO and ALT reduced initial peak SkBF by 29–44% and plateau SkBF by 15–39%. Based on these pilot data, 14–18 subjects would be required to give 80% power to detect statistical differences in initial peak and plateau SkBF responses during local heating as a result of hypohydration and altitude exposure. The opinions contained herein are not official and do not reflect Army/DOD views