Plasma kinetics of a chylomicron-like emulsion in normolipidemic obese women after a short-period weight loss by energy-restricted diet

Oliveira, Maria Regina; Maranhão, Raul C.

doi:10.1053/meta.2002.34698

Cited by 12 publications

(11 citation statements)

References 48 publications

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“…Jensen et al 36 and Mekki et al 37 found increased triglyceride AUC in the chylomicron fraction, but in both studies the obese had higher fasting triglycerides than their controls. In our previous study, 9 the emulsion triglycerides were normally removed in normotriglyceridemic obese women and the lipolysis index was increased.…”

Section: Discussionmentioning

confidence: 82%

“…The emulsion was prepared as previously described, 22 with addition to the lipid mixtures of [1-14 C] cholesteryl-oleate (specific activity 2.07 Gbq/mmol) and [9, H] glyceroltrioleate (specific activity 518 GBq/mmol), supplied by Amersham International (UK). The emulsion was purified by two-step ultra centrifugation, as described previously, 23 sterilized by passage through a 0.2 mm filter and evaluated for sterility and pyrogenicity prior to injection into the patients.…”

Section: Emulsion Preparationmentioning

confidence: 99%

“…Plasma hydrolysis and removal of native chylomicrons, as well as chylomicron-like emulsions, displayed a rapid initial decay followed by a slow removal phase. 9,17,26 The k x,y constants represent the transfer or fractional catabolic rates (FCR) from compartment x to compartment y . Compartments 1-4 and 5-8 represent the kinetics of cholesterol and triglycerides metabolism, respectively.…”

Section: Kinetics Of the Emulsionmentioning

confidence: 99%

“…Both slow lipolysis and slow removal from the plasma of remnants have been found in CAD patients as compared with their controls without the disease. 17 In our recent study, 9 by using the method of chylomicronlike emulsions to assess this metabolism, it was shown that while the remnant removal was clearly diminished in obese patients comparatively with normal weight subjects, the lipolysis process was unexpectedly increased. In the current study, we evaluated the chylomicron catabolism in groups of normal weight, preobese, obese and morbid obese women, with body mass index (BMI) ranging from 22 to 50 kg/m 2 .…”

mentioning

confidence: 98%

“…2 The metabolism of chylomicrons, which is much less studied than that of the other lipoproteins due to methodological difficulties, is also altered in obesity. [9][10][11][12] Chylomicrons are produced in the intestine from the absorbed dietary fats and undergo two major catabolic events in the blood stream. Firstly, chylomicron particles undergo the action of lipoprotein lipase on the endothelial surface of capillaries.…”

mentioning

confidence: 99%

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

Oliveira

Maranhão

2004

Int J Obes

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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 (BMIo25 kg/m 2 ), preobese , obese and morbid obese (BMI440). 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 À1 ) 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 ¼ 0.310; P ¼ 0.05). On the other hand, FCR-CO progressively diminished from the normal to the morbid obese group (0.06970.01; 0.06470.01; 0.03170.003; 0.02970.005 min À1 , respectively, P ¼ 0.003) and there was a negative correlation between FCR-CO and BMI (r ¼ À0.388; P ¼ 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. The increased risk of developing coronary artery diseases in obese subjects may be related, among other causes, to disturbances in the plasma lipoproteins elicited by the weight gain. 1,2 Fasting hypertriglyceridemia is the main dyslipidemia found in obesity. It reflects the plasma accumulation of very-low-density lipoprotein (VLDL), the triglyceride-rich lipoprotein produced by the liver. 3 Low plasma HDL cholesterol may also be found in obese subjects due to the seesaw effect, whereby VLDL and HDL plasma concentration are inversely correlated. 4,5 Owing to the action of transfer proteins, the cholesterol net mass transfer from HDL to VLDL occurs when VLDL concentration increases by mass action law, thus decreasing HDL cholesterol. 5 Furthermore, hepatic lipase is increased in obesity 6 and as this enzyme promotes HDL degradation by the liver, the lipoprotein concentration decreases. 7 Hypertriglyceridemia and low HDL are established risk factors for coronary artery disease. The status in obesity of low-density lipoprotein (LDL) cholesterol is less clear: in some studies it was found increased, while in others it was normal. 1,8 On the other hand, small, dense LDL, which is the LDL subfraction considered as more atherogenic, may be enhanced in obesity. 2

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Section: Discussionmentioning

confidence: 82%