Relationships in women between body mass index and the intravascular metabolism of chylomicron-like emulsions

• Published in: International Journal of Obesity 2004-11, Vol.28 (11), p.1471-1478
• Main Authors: Oliveira, M R M, Maranhão, R C
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Body mass index; Cardiology. Vascular system; Coronary heart disease; Emulsions; Epidemiology; Health Promotion and Disease Prevention; Heart; High density lipoprotein; Internal Medicine; Lipids; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Obesity; Public Health; Vein & artery diseases
• ISSN: 0307-0565; 1476-5497
• DOI: 10.1038/sj.ijo.0802780

OBJECTIVE: To investigate whether increasing body mass index (BMI) produces increasingly intense disturbances in the metabolism of chylomicrons, the lipoproteins that carry the dietary lipids absorbed by the intestine in the circulation. SUBJECTS: Four groups of 10 normolipidemic nondiabetic women at the normal (BMI40). METHODS: Chylomicron metabolism was studied using the method of triglyceride-rich emulsions that mimic chylomicrons. The chylomicron-like emulsion doubly labeled with 3 H-triolein (TO) and 14 C-cholesteryl-oleate (CO) was intravenously injected to calculate the plasma fractional clearance rates (FCR, in min −1 ) by a compartmental analysis model. FCR-TO mirrors both the lipolysis from lipoprotein lipase that the emulsion suffers while still in the circulation, and the triglycerides portion that is not broken down and is removed from the plasma together with the remnant particles. Lipolysis index is calculated subtracting CO from TO areas under the curve. RESULTS: FCR-TO did not differ among the four groups. The lipolysis index was positively correlated with BMI ( r =0.310; P =0.05). On the other hand, FCR-CO progressively diminished from the normal to the morbid obese group (0.069±0.01; 0.064±0.01; 0.031±0.003; 0.029±0.005 min −1 , respectively, P =0.003) and there was a negative correlation between FCR-CO and BMI ( r =−0.388; P =0.01). CONCLUSION: In obesity, the capacity to break down chylomicron triglycerides by lipoprotein lipase in vivo increases, but the ability of the organism to remove the resulting chylomicron remnants particles progressively diminishes as the BMI rises. Remnant accumulation most likely predisposes to coronary artery disease development.