A randomized trial of cold-exposure on energy expenditure and supraclavicular brown adipose tissue volume in humans

• Published in: Metabolism, clinical and experimental clinical and experimental, 2016-06, Vol.65 (6), p.926-934
• Main Authors: Romu, Thobias, Vavruch, Camilla Håkansson, Dahlqvist-Leinhard, Olof, Tallberg, Joakim, Dahlström, Nils, Persson, Anders, Heglind, Mikael, Lidell, Martin E, Enerbäck, Sven, Borga, Magnus, Nystrom, Fredrik H
• Format: Article
• Language: English
• Subjects: Adipose Tissue, Brown - diagnostic imaging; Adipose Tissue, Brown - metabolism; Adult; adult humans; Brown adipose tissue; Calorimetry, Indirect; Clinical Medicine; Cold exposure; Cold Temperature; Endocrinology & Metabolism; Energy Metabolism - physiology; Female; healthy humans; Humans; identification; Klinisk medicin; Magnetic Resonance Imaging; Male; Metabolic rate; metabolism; Organ Size - physiology; Thermogenesis - physiology; water-fat mri; Young Adult
• ISSN: 0026-0495; 1532-8600; 1532-8600
• DOI: 10.1016/j.metabol.2016.03.012

Abstract Objective To study if repeated cold-exposure increases metabolic rate and/or brown adipose tissue (BAT) volume in humans when compared with avoiding to freeze. Design Randomized, open, parallel-group trial. Methods Healthy non-selected participants were randomized to achieve cold-exposure 1 hour/day, or to avoid any sense of feeling cold, for 6 weeks. Metabolic rate (MR) was measured by indirect calorimetry before and after acute cold-exposure with cold vests and ingestion of cold water. The BAT volumes in the supraclavicular region were measured with magnetic resonance imaging (MRI). Results Twenty-eight participants were recruited, 12 were allocated to controls and 16 to cold-exposure. Two participants in the cold group dropped out and one was excluded. Both the non-stimulated and the cold-stimulated MR were lowered within the group randomized to avoid cold (MR at room temperature from 1841 ± 199 kCal/24 h to 1795 ± 213 kCal/24 h, p = 0.047 cold-activated MR from 1900 ± 150 kCal/24 h to 1793 ± 215 kCal/24 h, p = 0.028). There was a trend towards increased MR at room temperature following the intervention in the cold-group (p = 0.052). The difference between MR changes by the interventions between groups was statistically significant (p = 0.008 at room temperature, p = 0.032 after cold-activation). In an on-treatment analysis after exclusion of two participants that reported ≥ 8 days without cold-exposure, supraclavicular BAT volume had increased in the cold-exposure group (from 0.0175 ± 0.015 l to 0.0216 ± 0.014 l, p = 0.049). Conclusions We found evidence for plasticity in metabolic rate by avoiding to freeze compared with cold-exposure in a randomized setting in non-selected humans.