Lipoprotein lipase mass and activity in post-heparin plasma from subjects with intra-abdominal visceral fat accumulation

OBJECTIVES The purpose of this study was to investigate the possibility of impaired lipolysis of triglyceride-rich lipoproteins in patients with abdominal visceral fat accumulation by assessing two major lipolytic enzymes in the plasma, lipoprotein lipase (LPL) and hepatic lipase (HL). DESIGN AND PATIENTS A total of 31 patients [20 men, 11 women, age 50 ± 7 years old, body mass index (BMI) 26 ± 2 kg/m2 (mean ± sd)] were analyzed. Visceral fat and subcutaneous fat areas were evaluated using a computerized tomographic (CT) method at the level of the umbilicus. Total lipolytic activity in the postheparin plasma (PHP) was measured using Triton X-100-emulsified triolein and LPL activity was calculated as the activity in whole plasma inhibited by the 5D2 monoclonal antibody for LPL. LPL enzyme mass was determined by a sandwich enzyme immunoassay. RESULTS The visceral fat area was found to be negatively correlated with LPL mass (V vs LPL mass, r = − 0.37, P = 0.04) in PHP and had a tendency toward negative correlation with the LPL activity in the PHP (V vs LPL activity, r = − 0.29, P = 0.12). Subcutaneous fat area, on the other hand, did not show any correlation with LPL activity (r = 0.13, P = 0.49) or mass (r = 0.22, P = 0.25) in the PHP. The visceral fat area was found to be positively correlated with fasting serum insulin levels (r = 0.67, P