Kobayashi J, Tashiro J, Murano S, Morisaki N, Saito Y
Second Department of Internal Medicine, School of Medicine, Chiba University, Japan.
Clin Endocrinol (Oxf). 1998 Apr;48(4):515-20. doi: 10.1046/j.1365-2265.1998.00485.x.
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).
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.
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 < 0.01). Body mass index (BMI) was not correlated with LPL mass or activity in the PHP. Multi-regressional analysis showed that abdominal visceral fat could be correlated with LPL mass in the PHP, independently of fasting serum insulin. The HL activity from PHP of the patients did not show significant correlation with visceral fat area, subcutaneous fat area or body mass index.
Fat distribution affects LPL mass and activity, either directly or via another metabolic abnormality such as insulin resistance, leading to impaired hydrolysis of triglycerides in chylomicrons and very low density lipoproteins (VLDL) in these subjects.
本研究旨在通过评估血浆中两种主要的脂解酶，即脂蛋白脂肪酶（LPL）和肝脂肪酶（HL），来调查腹部内脏脂肪堆积患者中富含甘油三酯脂蛋白脂解受损的可能性。
共分析了31例患者[20名男性，11名女性，年龄50±7岁，体重指数（BMI）26±2kg/m²（均值±标准差）]。使用计算机断层扫描（CT）方法在脐水平评估内脏脂肪和皮下脂肪面积。使用Triton X-100乳化的三油酸甘油酯测量肝素后血浆（PHP）中的总脂解活性，并将LPL活性计算为被LPL的5D2单克隆抗体抑制的全血浆中的活性。通过夹心酶免疫测定法测定LPL酶质量。
发现内脏脂肪面积与PHP中的LPL质量呈负相关（V与LPL质量，r = -0.37，P = 0.04），并且与PHP中的LPL活性有负相关趋势（V与LPL活性，r = -0.29，P = 0.12）。另一方面，皮下脂肪面积与PHP中的LPL活性（r = 0.13，P = 0.49）或质量（r = 0.22，P = 0.25）没有显示出任何相关性。发现内脏脂肪面积与空腹血清胰岛素水平呈正相关（r = 0.67，P <0.01）。体重指数（BMI）与PHP中的LPL质量或活性无关。多元回归分析表明，腹部内脏脂肪可能与PHP中的LPL质量相关，独立于空腹血清胰岛素。患者PHP中的HL活性与内脏脂肪面积、皮下脂肪面积或体重指数没有显示出显著相关性。
脂肪分布直接或通过另一种代谢异常（如胰岛素抵抗）影响LPL质量和活性，导致这些受试者中乳糜微粒和极低密度脂蛋白（VLDL）中甘油三酯的水解受损。
