Subcutaneous Adipose Tissue
Fat stored beneath the skin, distributed across the body. Subcutaneous fat is less metabolically harmful than visceral fat and serves important functions including insulation and energy storage. It is also the tissue layer into which most peptide drugs are injected.
Technical Context
SAT is distributed beneath the skin throughout the body, with gender-specific patterns: gluteofemoral predominance in women (estrogen-mediated), abdominal predominance in men. SAT serves important physiological functions: energy storage, thermal insulation, mechanical protection, and endocrine function (producing leptin, adiponectin, and other adipokines). SAT is generally considered less metabolically harmful than VAT — the 'metabolically healthy obese' phenotype is characterised by SAT-predominant fat distribution with normal insulin sensitivity and inflammatory markers. However, SAT can become dysfunctional in obesity, with hypertrophic adipocytes, inflammatory infiltration, and fibrosis. For peptide drug administration, SAT is the tissue layer into which subcutaneous injections are deposited — its thickness varies by body region and individual, affecting needle length selection and injection technique.