The Importance of Brown Adipose Tissue

Abstract

In the April 9 issue, van Marken Lichtenbelt et al.,¹ Cypess et al.,² and Virtanen et al.³ report on functioning supraclavicular brown adipose tissue in adult humans. Van Marken Lichtenbelt et al. conclude that brown-adipose-tissue activity induced by exposure to cold is impaired in overweight healthy subjects, and Cypess et al., using epidemiologic-association techniques, conclude that older subjects and those with a higher body-mass index (BMI) have less brown adipose tissue. It is suggested that obesity is associated with reduced brown-adipose-tissue function or activity. However, disseminated brown adipocytes⁴ within the large subcutaneous adipose-tissue mass may cumulatively represent substantial brown-adipocyte activity that may not be detected with the use of integrated positron-emission tomography and computed tomography (PET–CT) or crude biochemical studies.