Brown adipose tissue, whole-body energy expenditure, and thermogenesis in healthy adult men.
Brown adipose tissue (BAT) can be identified by (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in adult humans. Thirteen healthy male volunteers aged 20-28 years underwent FDG-PET after 2-h cold exposure at 19 °C with light-clothing and intermittently putting their legs on an ice block. When exposed to cold, 6 out of the 13 subjects showed marked FDG uptake into adipose tissue of the supraclavicular and paraspinal regions (BAT-positive group), whereas the remaining seven showed no detectable uptake (BAT-negative group). The BMI and body fat content were similar in the two groups. Under warm conditions at 27 °C, the energy expenditure of the BAT-positive group estimated by indirect calorimetry was 1,446 ± 97 kcal/day, being comparable with that of the BAT-negative group (1,434 ± 246 kcal/day). After cold exposure, the energy expenditure increased markedly by 410 ± 293 (P < 0.05) and slightly by 42 ± 114 kcal/day (P = 0.37) in the BAT-positive and -negative groups, respectively. A positive correlation (P < 0.05) was found between the cold-induced rise in energy expenditure and the BAT activity quantified from FDG uptake. After cold exposure, the skin temperature in the supraclavicular region close to BAT deposits dropped by 0.14 °C in the BAT-positive group, whereas it dropped more markedly (P < 0.01) by 0.60 °C in the BAT-negative group. The skin temperature drop in other regions apart from BAT deposits was similar in the two groups. These results suggest that BAT is involved in cold-induced increases in whole-body energy expenditure, and, thereby, the control of body temperature and adiposity in adult humans.
Yoneshiro
Takeshi
T
Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Sapporo, Japan.
Aita
Sayuri
S
Matsushita
Mami
M
Kameya
Toshimitsu
T
Nakada
Kunihiro
K
Kawai
Yuko
Y
Saito
Masayuki
M
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D001831:Body Temperature / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006262:Health; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D012881:Skin Temperature / Q000502:physiology; D022722:Thermogenesis / Q000502:physiology*; D055815:Young Adult
D019788:Fluorodeoxyglucose F18