K Pathak1, E K Calton1, M J Soares1, Y Zhao2, A P James1, K Keane3, P Newsholme3. 1. Faculty of Health Sciences, Department of Food, Nutrition and Health, School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia. 2. Department of Occupation and the Environment, School of Public Health, Curtin University, Perth, Western Australia, Australia. 3. School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.
Abstract
BACKGROUND: Resting metabolic rate (RMR) should be measured in the thermoneutral zone (TNZ). Forearm to fingertip skin temperature gradients (FFG) could serve as an objective measure of this pre-condition. SUBJECTS/ METHODS: Eighty-six adult Australians were studied at 25 °C in a temperature-controlled chamber. Measurements of overnight fasted RMR, respiratory quotient (RQ) and FFG were complemented by clinical biochemistry. McAuley's Index of insulin sensitivity (McA_ISI) and presence of metabolic syndrome was determined. Physical activity was estimated from the short version of the International Physical Activity Questionnaire. Fat mass (FM) and fat-free mass (FFM) were obtained from dual-energy x-ray absorptiometry. Twenty-nine participants were assessed for changes in RMR (ΔRMR), RQ (ΔRQ) and FFG (ΔFFG) following a 6-month free-living period. Multiple linear regression analyses of RMR and RQ on FFG, and of ΔRMR and ΔRQ on ΔFFG were conducted after controlling for 12 known determinants of energy metabolism. RESULTS: There were wide between-subject variations in unadjusted FFG ranging from -4.25 to +7.8 °C. The final parsimonious model for cross-sectional observations of RMR included age, FM, FFM, McA_ISI and FFG (β=63 kJ/d (95% confidence interval (CI): 14.2, 112.1, P=0.012)). However, FFG was unrelated to RQ.In the longitudinal cohort, adjusted ΔRMR significantly associated only with ΔFFG (β=100 kJ/d (95% CI: 10.3, 189.1; P=0.030)), and adjusted ΔRQ associated with ΔFFG (-0.003 (95% CI: -0.005, 0.0002, P=0.038)), age and McA_ISI. CONCLUSIONS: Sizeable between-subject variations in FFG at 25 °C were associated with RMR and RQ. Monitoring FFG may serve as an objective assessment of the TNZ during RMR measurements.
BACKGROUND: Resting metabolic rate (RMR) should be measured in the thermoneutral zone (TNZ). Forearm to fingertip skin temperature gradients (FFG) could serve as an objective measure of this pre-condition. SUBJECTS/ METHODS: Eighty-six adult Australians were studied at 25 °C in a temperature-controlled chamber. Measurements of overnight fasted RMR, respiratory quotient (RQ) and FFG were complemented by clinical biochemistry. McAuley's Index of insulin sensitivity (McA_ISI) and presence of metabolic syndrome was determined. Physical activity was estimated from the short version of the International Physical Activity Questionnaire. Fat mass (FM) and fat-free mass (FFM) were obtained from dual-energy x-ray absorptiometry. Twenty-nine participants were assessed for changes in RMR (ΔRMR), RQ (ΔRQ) and FFG (ΔFFG) following a 6-month free-living period. Multiple linear regression analyses of RMR and RQ on FFG, and of ΔRMR and ΔRQ on ΔFFG were conducted after controlling for 12 known determinants of energy metabolism. RESULTS: There were wide between-subject variations in unadjusted FFG ranging from -4.25 to +7.8 °C. The final parsimonious model for cross-sectional observations of RMR included age, FM, FFM, McA_ISI and FFG (β=63 kJ/d (95% confidence interval (CI): 14.2, 112.1, P=0.012)). However, FFG was unrelated to RQ.In the longitudinal cohort, adjusted ΔRMR significantly associated only with ΔFFG (β=100 kJ/d (95% CI: 10.3, 189.1; P=0.030)), and adjusted ΔRQ associated with ΔFFG (-0.003 (95% CI: -0.005, 0.0002, P=0.038)), age and McA_ISI. CONCLUSIONS: Sizeable between-subject variations in FFG at 25 °C were associated with RMR and RQ. Monitoring FFG may serve as an objective assessment of the TNZ during RMR measurements.
Authors: E K Calton; K Pathak; M J Soares; H Alfonso; K N Keane; P Newsholme; N K Cummings; W Chan She Ping-Delfos; A Hamidi Journal: Eur J Nutr Date: 2015-08-26 Impact factor: 5.614
Authors: Charmaine Childs; Jennifer Elliott; Khaled Khatab; Susan Hampshaw; Sally Fowler-Davis; Jon R Willmott; Ali Ali Journal: Int J Environ Res Public Health Date: 2020-09-22 Impact factor: 3.390