Brown adipose tissue. VI. Amount, location, extent, and correlation with nutritional status in adult humans

Multilocular brown adipose tissue (BAT) is a versatile endocrine tissue involved in non-shivering thermogenesis, mitochondrial biogenesis, extracellular matrix homeostasis and signalling, and hibernation in hibernating animals. This study investigated the correlations between the amount and extent of BAT and nutritional status in adult humans. Samples of adipose tissue from nine body locations were taken from 107 consecutive autopsies in males and females, fixed in formalin, processed by routine methods and stained with hematoxylin-eosin. Based on the Quetelet index as a measure of nutritional status, the cases were divided into three groups: hypotrophic, eutrophic and hypertrophic (obese). We found significant sex and nutritional status differences in the frequencies of BAT positive cases. While no dependence on nutritional status was found in women, the frequencies of BAT positive cases in men were significantly different (41% in hypotrophy, 82% in eutrophy, and 64% in hypertrophy, P = 0.032). The distribution of BAT positive samples among sampled adipose tissue locations (positives for location and category/total positives for the category) were sex-independent, and showed that in hypertrophic cases, a large fraction of BAT is located in the periadrenal region, in agreement with a previous study by other authors. The present study also shows clear correlations between nutritional status and amount and extent of BAT in adult humans.