TABLE 2

Prevalence of cold-activated BAT in adult humans

SummerAutumnWinter
Outdoor temperature (°C)21.3 (19.6–28.3)11.7 (7.6–16.1)−1.6(−5.2 to 1.8)
n883124
Age (years)23–3123–3223–3538–65
Prevalence
    Total2/8 (0/1)3/8 (0/3)16/31 (0/4)2/24
    Male subjects1/52/6 (0/2)8/19 (0/3)2/12
    Female subjects1/3 (0/1)1/2 (0/1)8/12 (0/1)0/12
  • Data are mean outdoor temperature (range) or n apparent FDG uptake into BAT (adipose tissue in the supraclavicular region)/total n. During a 7-month period from August of 2006 to the following March, a total of 71 FDG-PET/CT examinations were conducted under the 2-h cold condition for 56 healthy volunteer subjects as in Fig. 1A. Some (the number in parentheses) underwent the examination again under the warm condition as in Fig. 1B 2 weeks after that under the cold condition. Summer: 29 August to 28 September 2006. Autumn: 5 October to 19 October 2006. Winter: 29 January to 6 March 2007.