Plasma lipid concentrations

Flavell DM, Pineda Torra I, Jamshidi Y, Evans D, Diamond JR, Elkeles RS, et al. Variation in the PPARalpha gene is associated with altered function in vitro and plasma lipid concentrations in Type 2 diabetic subjects. Diabetologia 2000 43 673-680. 

In summary, results from several studies in to the effects of impaired insulin action can now be linked to CVD. Because of the numbers of people exhibiting sings of insulin resistance, there has been a lot of research effort has gone in to finding suitable therapeutic interventions. One group of drugs in particular, the thiazolidinediones (also known as glitazones) has attracted attention because they both increase insulin sensitivity and help to normalize plasma lipid concentrations. 

FIGURE 4.6 Effect of solid-state enzyme treatment on hypolipidemic activities of psyllium. Plasma lipid concentrations in hamsters were measured at day 35. Values are mean SEM (vertical bars) for nine animals per group. Within each response parameter, values not sharing common letters are significantly different, P<0.05. Modified Psy-1 and modified Psy-2 represent the two modified psyllium preparations using the Viscozyme L and the Shearzyme 500 L, respectively, under the solid-state reaction conditions (re-drawn from Allen et al., 2004). 

Gardner C et al Effect of raw garlic vs commercial garlic supplements on plasma lipid concentrations in adults with moderate hypercholesterolemia. Arch Intern Med 2007 167 346. [PMID 17325296]... 

The effects of wine and its polyphenol constituents on early indicators of coronary heart disease such as elevated levels of plasma lipids, platelets and serum antioxidant activity were discussed in a review by Cooper et al. (2004). This review also addressed whether the polyphenols or alcohol are responsible for the beneficial effects of wine on cardio-vascular health. The authors conclude that red wine polyphenols have little effect on plasma lipid concentrations, but that wine consumption reduces the susceptibility of low-density lipoprotein (LDL) cholesterol to oxidation and increase serum antioxidant capacity. These effects, however, do depend on the amount of wine that is consumed and the period of supplementation. It was suggested that specific polyphenols appear to have endothelium-dependent vaso-relaxing abilities. Red wine phenolics also have an inhibitory effect on platelet aggregation. Evidence suggests that alcohol has a positive synergistic effect with wine polyphenols on some atherosclerosis risk factors. Thus, evidence that wine drinking is beneficial for cardiac health appears positive. 

A similar mechanistic basis was proposed for the increased Vss and CL with increased plasma lipid concentrations demonstrated for amphotericin B (which associates with HDL and LDL [158] in a diabetic hyperlipidemic rat model [159]). The increased lipid concentrations in the diabetic compared with the nondiabetic rats were characterized by increased LDL concentrations. It was therefore suggested that increased association of amphotericin B with LDL in the diabetic rats increased LDL-associated uptake in peripheral tissues and in the liver, resulting in the increased Vss and CL. 

In a well-controlled study designed to assess the influence of the type and amount of dietary lipid on plasma lipid concentrations in endurance athletes, Lukaskl et al. (46) reported that the plasma response to dietary lipid was not attenuated in men who were physically very active. In contrast, Qulg and associates (47) reported that plasma total cholesterol concentration was lower in subjects who exercised and who ate a diet containing 0.4 or 1.4 gm of cholesterol dally. Thus, the influence of diet on the relationship between exercise and plasma lipids remains equivocal. 

B. Effect of Apolipoprotein E Heterogeneity on Plasma Lipid Concentrations... 

The function of apoE in lipoprotein metabolism is reviewed in the sixth chapter by Karl Weisgraber. The three-dimensional structure of a 22-kDa fragment of human apoE (34.2 kDa) has been solved by X-ray crystallography the relation of this structure to the role of apoE in lipoprotein metabolism is discussed in detail, together with a critical and extensive examination of the chemistry and biology of this apolipoprotein which plays such a central role in lipoprotein metabolism. Apolipoprotein E has three major isoforms in the human population which affect lipoprotein metabolism differently, resulting in different levels of the plasma lipoproteins. The impact of structure on function and how plasma lipid concentrations are affected by the different apoE isoforms are the themes of this important chapter. 

Flavell, D. M., Pineda Torra, I., Jamshidi, Y., Evans, D., Diamond, J. R., Elkeles, R. S., Bujac, S. R., Miller, G., Talmud, P. J., Staels, B., and Humphries, S. E. (2000). Variation in the PPARalpha gene is associated with altered function in vitro and plasma lipid concentrations in Type II diabetic subjects. Diabetologia 43, 673-680. 

Montoya, M.T., Porres, A., Serrano, S., J.C. Fruchart, Mata, P., Gerique, J.A. and Castro, G.R. (2002) Fatty Acid Saturation of the Diet and Plasma Lipid Concentrations, Lipoprotein Particle Concentrations, and Cholesterol Efflux Capacity, Am. J. Clin. Nutr. 75,484- 91. 

Of the epidemiologically recognized risk factors, plasma lipid concentrations, and particularly plasma cholesterol concentrations cause the most debate. That an association exists between plasma lipids and cardiovascular disease is based on extensive epidemiological and clinical evidence however, the exact nature of the interaction is only slowly becoming apparent. 

Metabolism In a systematic review of nine randomized controlled studies of atazanavir or atazanavir-I-ritonavir in 3346 patients, there were changes in plasma lipid concentrations, which were lower after 48 weeks of therapy with atazanavir-I-ritonavir than with other ritonavir-boosted protease inhibitor regimens [104 ]. Total and non-HDL cholesterol were higher with atazanavir-I-ritonavir than with atazanavir alone. 

A negative correlation between deficient biotin status and blood lipid concentrations was found in rats (Marshall et al. 1976) as well as in humans (Marshall et al. 1980). A decrease in plasma lipids was observed in human healthy volunteers within 30 min of absorption of 100 mg of biotin infusion. It was shown that oral biotin supplementation affected plasma lipid concentrations. The administration of 5 mg/day of biotin decreased hypercholesterolemia in atherosclerosis and hyperlipidemia patients (Dukusova and Krivoruchenko 1972). A 15 mg/day treatment by biotin for 28 days decreased hypertriglyceridemia of subjects whose triacylglycerol concentrations were more than 25% above the normal of 1.8mmol/L (Baez-Saldana 2004). 

An additional difficulty in defining normal plasma lipid values results from the influence of various factors on plasma lipid concentrations. Cholesterol and phospholipid concentrations vary with age and show an increase from the third to the sixth decade followed by a slight decrease thereafter (Adlersberg et al. 1956, Lewis et al. 1957, Schaefer et al. 1958). In higher decades values may be influenced by the inclusion of persons with clinically silent disease. Furthermore, alimentary influences result from the total amount of ingested fat and the composition of dietary fatty acids. Therefore, blood samples should not only be taken in the fasting state, but in many instances after a period of controlled dietary intake. 

Table 2. Normal ranges of plasma lipid concentrations (mean values i 2 standard deviations)...

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