Physiological Function of Adipose Tissue
In adults, subcutaneous fat consists almost entirely of white adipose tissue (WAT; adipocytes), which provides insulation and acts as an energy source.[10–13] Where energy intake exceeds its expenditure, this excess energy is stored in adipocytes, leading to obesity.[10–13] WAT also produces many peptide hormones, cytokines and paracrine transmitters.[10–13] These include leptin, tumour necrosis factor (TNF)-α, transforming growth factor-β, interleukin (IL)-1 and IL-6, acylation stimulating protein, adiponectin, resistin, visfatin, plasminogen activator inhibitor, androgens and nonesterified fatty acids.[6,10–13] WAT also acts as a source of functional mast cell progenitors. The hyperinsulinaemia associated with obesity augments the production of androgens from WAT and reduces circulating sex-hormone binding globulin (SHBG) levels, which further increases the supply of available free androgens.
In contrast, brown fat is most prominent in the newborn and its role appears to be physiologically distinct from that of white adipocytes. The role of brown fat in the older child and adult is a subject of much investigation and has been well reviewed recently.
The British Journal of Dermatology. 2011;165(4):743-750. © 2011 Blackwell Publishing
Cite this: Obesity and the Skin - Medscape - Oct 01, 2011.