Visceral adipose tissue (VAT)

Visceral adipose tissue (VAT) is the metabolically active fat depot surrounding the intra-abdominal organs, distinct from subcutaneous adipose tissue. VAT adipocytes drain into the portal circulation and secrete pro-inflammatory adipokines including TNF-α, IL-6, and resistin while producing less adiponectin than subcutaneous fat, creating a systemic inflammatory and insulin-resistant milieu. High VAT is associated with increased risk of type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and all-cause mortality independently of total body fat or BMI. Gold-standard quantification uses abdominal CT or MRI; DEXA and waist circumference are practical surrogates. Aerobic exercise and weight loss preferentially reduce VAT relative to subcutaneous depots.