Relationships Between Regional and Ectopic Adiposity and Insulin Sensitivity in Early and Late Pregnancy

OBJECTIVE: To determine relationships between measurements of total body, visceral, and ectopic (liver, skeletal muscle) fat with insulin sensitivity in pregnancy. RESEARCH DESIGN AND METHODS: Pregnant women of varying prepregnancy weights were prospectively studied in early (n = 59) and late (n = 47) gestation. At each visit, participants underwent body composition measurements including fat mass (FM), fat-free mass (FFM), abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT), ectopic lipid amounts in liver (intrahepatic lipid [IHL]) and calf skeletal muscle (intramyocellular lipid [IMCL] and extramyocellular lipid), and hyperinsulinemia-euglycemic clamp to determine insulin sensitivity (Rd), endogenous glucose production (EGP), hepatic insulin sensitivity index (HISI), and free fatty acid (FFA) levels. RESULTS: In early pregnancy, Rd ([mg/kg FFM/min]/µIU/mL) inversely correlated (P values