Cholesterol high-density lipoprotein

Fig. 10.5 Apolipoprotein E (APOE)-relsled serum levels of APOE, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density hpoprotein (LDL) cholesterol, amyloid- 3 peptide (1 2), and histamine in Alzheimer s disease. (Adapted from refs. 12,59, and 289.)...

Hyperlipidemia is a condition characterized by the presence of elevated lipoprotein levels in the blood. The term hyperlipidemia encompasses a number of different conditions, but it most often refers to high levels of cholesterol in the form of low-density lipoprotein (LDL). LDL cholesterol is often called bad cholesterol. High-density lipoprotein (HDL) is the good form of cholesterol. High LDL and/or low HDL levels are widely believed to be linked to increased heart disease risk. Because of the prevalence of hyperlipidemia in developed nations, antihyperlipidemic drugs are in high demand. 

A lipid profile (cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides) and complete blood count were determined before and after four weeks of treatment for all patients. 

E683 Tetrault, G.A., Miller, W.G. and Chinchilli, V.M., et al. (1990). Regional interlaboratory standardization of determinations of cholesterol, high-density lipoprotein cholesterol, and triglycerides. Clin. Chem. 36, 145-149. 

Lipid sources - fatty acids, cholesterol, high-density lipoproteins and low-density lipoproteins, etc. 

Cholesterol, high-density lipoprotein Target value 30%... 

The liver is responsible for synthesis of cholesterol, high-density lipoproteins, and very-low-density lipoproteins. The enzymes lipoprotein lipase and lecithin-cholesterol acyltransferase also are synthesized in this organ. Increased serum triglyceride and FFA concentrations are encountered in patients with hepatic failure, primarily due to the increased lipolysis. The significant insulin resistance that can be seen in cirrhosis causes a shift to lipids as a fuel source. Whereas only 35% of total calories are derived from fat in normal patients after an overnight fast, this can increase to 75% in patients with cirrhosis. Incorporation of late evening snacks in patients with liver cirrhosis may correct abnormal substrate metabolism, increase carbohydrate, and decrease fat oxidation rates. ... 

Lipoproteins produced in the liver take one of two forms. Low-density lipoproteins (LDL) carry cholesterol directly to cells. Because this cholesterol serves a useful biological function, it is sometimes called good cholesterol. High-density lipoproteins (HDL), by contrast, bypass cells and remain in the blood stream. The cholesterol in HDL lipoproteins serves no useful function in the body and is often referred to as bad cholesterol. The role of cholesterol in the human body and dietary methods of maintaining the correct HDL LDL ratio in the blood has been the subject of some controversy and considerable educational programs in recent decades. 

Toth, P. P. (2005). The "Good Cholesterol" High-density lipoprotein. Circulation 111, e89-e91. 

Edwards et al. [22] conducted a controlled, randomized crossover trial in 10 subjects with mild hypercholesterolemia in which subjects served as their own controls. For 3 weeks, subjects either consumed their regular diet or substituted 20% of their daily calorie intake with pistachio nuts after the first 3-week period, those on the pistachio diet crossed over to consume their regular diet, and those on the regular diet crossed over into the pistachio diet. At the end of the study, subjects experienced significant decreases in total cholesterol and total cholesterol/high-density lipoprotein (HDL) cholesterol ratio, with significant increases in HDL cholesterol. 

A large-scale comparative study was undertaken over a 12-month period in groups of women taking tamoxifen alone, HRT alone, or tamoxifen with transdermal HRT to see whether the cardiovascular risk factors (low-density lipoprotein cholesterol, high-density lipoprotein-cholesterol levels, platelet eounts) were changed by concurrent use. It was found that the deerease in total and LDL-cholesterol levels due to the tamoxifen was un-ehanged in eurrent HRT users, but reduced by two-thirds in women taking tamoxifen who then started HRT. It would therefore seem important to eheek the outeome of concurrent use. More study is needed. 

Blood tests to assess heart disease focus on measuring your cholesterol levels. This includes low-density lipoproteins (LDLs, often called bad cholesterol), high-density lipoproteins (HDLs, often called good cholesterol), emd triglycerides (a type of fat). This test edso typically requires you to not eat for about half a day prior to having your blood taken, as your cholesterol levels can be easily influenced by what you have recently had to eat... 

Serum Lipid Analysis. Blood samples were withdrawn from the marginal ear-vein after overnight food deprivation every 2 wk until the termination of the experimental periods. Total cholesterol, high density lipoprotein cholesterol (HDL-C), and tri-acylglycerol (TG) concentrations were determined using enzymatic methods. Low density lipoprotein cholesterol (LDL-C) was calculated according to Friedewald et al. (14). 

A summary of risk factors associated with the development of CHD from atherosclerosis is summarized in Table 1. Those with the strongest relationship with CHD are low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), and the total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio (1). 

During the 1980s, research indicated that trans fatty acids have an effect on blood cholesterol similar to that of saturated fats, although study results vary. Several studies reported that trans fatty acids raise the levels of LDL-cholesterol, low-density lipoproteins containing cholesterol that can accumulate in the arteries. Some studies also report that trans fatty acids lower HDL-cholesterol, high-density lipoproteins that carry cholesterol to the liver to be excreted. 

Blood lipid profiles were measured during the studies and consisted of total cholesterol, high-density lipoprotein cholesterol (HDL), very low-density lipoprotein cholesterol (VLDL), low-density lipoprotein cholesterol (LDL), and triglycerides. In HMB-supplemented snbjects, HDL cholesterol showed no change, while in the placebo-supplemented subjects, a 4% increase in HDL cholesterol was seen (p < 0.04). Of particnlar interest is that supplemental HMB significantly (p < 0.03) lowered total cholesterol by 3.7% in all snbjects and by 5.8% in subjects with cholesterol levels over 200 mg/dl. The decrease in total cholesterol with HMB supplementation was mainly the result of a significant decrease in LDL cholesterol... 

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