Metabolism of a lipid nanoemulsion resembling low-density lipoprotein in patients with grade III obesity

Introduction: Obesity increases triglyceride levels and decreases high-density lipoprotein concentrations in plasma. Artificial emulsions resembling lipidic plasma lipoprotein structures have been used to evaluate low-density lipoprotein metabolism. In grade III obesity, low density lipoprotein metabolism is poorly understood. Objective: To evaluate the kinetics with which a cholesterol-rich emulsion (called a low-density emulsion) binds to low-density lipoprotein receptors in a group of patients with grade III obesity by the fractional clearance rate. Methods: A low-density emulsion was labeled with [14C]-cholesterol ester and [³H]-triglycerides and injected intravenously into ten normolipidemic non-diabetic patients with grade III obesity [body mass index higher than 40 kg/m²] and into ten non-obese healthy controls. Blood samples were collected over 24 hours to determine the plasma decay curve and to calculate the fractional clearance rate. Results: There was no difference regarding plasma levels of total cholesterol or low-density lipoprotein cholesterol between the two groups. The fractional clearance rate of triglycerides was 0.086 ± 0.044 in the obese group and 0.122 ± 0.026 in the controls (p = 0.040), and the fractional clearance rate of cholesterol ester (h-1) was 0.052 ± 0.021 in the obese subjects and 0.058 ± 0.015 (p = 0.971) in the controls. Conclusion: Grade III obese subjects exhibited normal low-density lipoprotein removal from plasma as tested by the nanoemulsion method, but triglyceride removal was slower.

Níveis plasmáticos de lipoproteína (a) em indivíduos normais e portadores de doença coronariana confirmada por cinecoronariografia / Lipoprotein (a) plasma levels in normal subjects and patients with coronary disease carriers subjects confirmed by coronary cineangiography

Avaliar a concentraçäo plasmática da lipoproteína (a) - Lp(a) - em indivíduos com cinecoronariografia normal ou com sinais de aterosclerose. Trinta e um indivíduos com cinecoronariografia normal e 131 com alteraçöes compatíveis com aterosclerose, de ambos os sexos. Foram medidos os níveis plasmáticos de Lp(a) por radioimunoensaio e também os de colesterol, triglicérides, apolipoproteínas A, A1 e B e avaliados fatores de risco como hipertensäo arterial sistêmica, tabagismo, diabetes, além de atividade física. Os indivíuduos com doença coronariana apresentaram Lp(a) plasmática média de 41,9 mg/dl, em comparaçäo com 23,9 mg/dl no grupo normal. O risco de desenvolvimento de doença coronariana entre os com Lp(a) igual ou acima de 25 mg/dl foi de 2,3 vezes, em comparaçäo com os indivíduos com valores abaixo. Houve correlaçäo entre tabagismo e doença coronariana, o que näo foi confirmado estatísticamente no tocante aos outros fatores de risco avaliados. Confirma-se a importância da Lp(a) como fator de risco da doença coronariana