Feasibility of Adipose Tissue Triglyceride (TG) Labelling in Familial Partial Lipodystrophy (FPLD)

Study Description: The feasibility of adipose tissue triglyceride labeling in patients with FPLD will be assessed in this non-interventional protocol. Specifically, subjects with FPLD (n=5) and control subjects without FPLD (n=5) will undergo isotope administration followed by abdominal and femoral subcutaneous fat biopsies. Objectives: Primary objective: (1) To establish the technique of subcutaneous femoral adipose tissue biopsy in patients with FPLD, and subsequently, (2) to establish the feasibility of detecting labeled TG/FA in these adipose tissue biopsy samples. Secondary objectives: (1) To determine metabolic fluxes in healthy volunteers and patients with FPLD. (2) To determine if peripheral subcutaneous adipocytes are capable of fatty acid uptake and retention in patients with FPLD. (3) To assess standard metabolic parameters impacted by adipose fat storage capacity. (4) To assess different forms of circulating fat. (5) To determine feasibility of measuring adipose tissue lipoprotein lipase (LPL) activity. Endpoints: Primary Endpoints: (1) Feasibility of performing subcutaneous femoral adipose tissue biopsy in patients with FPLD and (2) presence of detectable stable isotope labeling in adipose tissue specimens. Secondary Endpoints: (1) Blood labeling of glucose, glycerol, palmitate, and saponified fatty acids and other metabolites, as feasible; (2) quantity of stable isotope labeling in adipose tissue specimens; (3) blood glucose, insulin, NEFA, beta-OH-butyrate; (4) blood TG, VLDL, chylomicrons, NEFA and complete lipoprotein panel by NMR; (5) adipose tissue LPL activity and (6) adipose tissue histologic analysis.