Cholesterol, total Lipoprotein

Patients with metabolic syndrome have an additional lipid parameter that needs to be assessed, namely non-high-density lipoprotein (non-HDL) cholesterol (total cholesterol minus HDL cholesterol). The target for non-HDL cholesterol is less than the patient s LDL cholesterol target plus 30 mg/dL (0.78 mmol/L). 

Increased low-density lipoprotein cholesterol, total cholesterol, triglycerides decreased high-density lipoprotein cholesterol. 

A variety of clinical studies have demonstrated that elevated levels of total cholesterol (total-C), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (apo B) are associated with... 

Gallbladder effect. Seed oil, administered orally to 11 young normocholesterolemic males at a dose of 100 g/day, was active. The subjects received 3 weeks of a low-fat diet followed by 3 weeks of a diet enriched with 100 g/daily of olive oil. Mean total cholesterol, total apolipoprotein (apo) B, low-density lipoprotein (LDL) cholesterol, and triglycerides decreased significantly after the olive oil diet. High-density lipoprotein (HDL) cholesterol, apo A-1, cholesterol saturation of bile, and gallbladder volumes were unchanged . 

Tibolone has combined estrogenic, progestogenic, and androgenic activity. Its effects depend on metabolism and activation in peripheral tissues. Tibolone has beneficial effects on mood and hbido and improves menopausal symptoms and vaginal atrophy. It protects against bone loss and reduces the risk of vertebral fractures. It reduces total cholesterol, triglyceride, lipoprotein (a), and, unfortunately, high-density lipoprotein concentrations. It may increase cardiovascular risk, breast cancer risk, and endometrial cancer risk. 

Appreciable research on the effect of canola oil on plasma cholesterol and lipoproteins has been reported. The primary impetus for this research was the finding that dietary monounsaturated fatty acids were as effective as polyunsaturated fatty acids in lowering plasma total and LDL cholesterol (100, 109). These findings also provided a possible explanation for the observation that canola oil was as effective as soybean oil in lowering plasma cholesterol in normolipidemic men (110). Prevailing theory had held that saturated fatty acids raised plasma cholesterol, polyunsaturated fatty acids lowered plasma cholesterol, and monounsaturated fatty acids were neutral, they neither raised nor lowered plasma cholesterol (111, 112). 

Reviews of the influence of diuretics on serum lipids (81-84) are in broad agreement as regards short-term effects. Thiazide and loop diuretics increase low-density lipoprotein (LDL) cholesterol, very-low-density lipoprotein (VLDL) cholesterol, total cholesterol, and triglycerides. The effect on high-density lipoprotein (HDL) cholesterol has been variable. The ratio of LDL/HDL or total cholesterol/HDL is generally increased, but not in all studies. Spironolactone 50 mg bd caused modest falls in... 

Despite inhibition of HMG-CoA reductase by statins, cells compensate by increasing enzyme expression several fold. However, the total body cholesterol is reduced by 20-40% due to increased expression of LDL-receptors after statin administration this enhances LDL (the major cholesterol carrying lipoprotein) clearance from serum with a net reduction of serum cholesterol (Chapter 20). Individuals who lack functional LDL-receptors (homozygous familial hypercholesterolemia. Chapter 20) do not benefit from statin therapy. However, statin therapy is useful in the treatment of heterozygous familial hypercholesterolemia. Since HMG-CoA reductase plays a pivotal role in the synthesis of many products vital for cellular metabolism, inhibitors of the enzyme may have toxic effects. Monitoring of liver and muscle function may be necessary to detect any toxicity of statin drug therapy. A decreased risk of bone fractures with statin therapy has been observed in subjects age 50 years or older, who are being treated for hypercholesterolemia. The mechanism of action of statins in bone metabolism may involve inhibition of prenylation... 

Dyslipidemia (elevated low-density lipoprotein [LDL] cholesterol, total cholesterol or triglycerides low high-density lipoprotein [HDL] cholesterol)... 

Cholesterol esters are considerably more hydrophobic than cholesterol itself. The amounts of cholesterol and cholesterol esters associated in blood lipoprotein complexes called LDL are typically about two-thirds of the total plasma cholesterol (total plasma cholesterol ranges from 130 to 260 mg/100 mL of human plasma, with the most desirable levels between 160 and 200). More than 40% of the weight of the LDL particle is cholesterol esters, and the total of esterified and free cholesterol amounts to well over half the total weight. 

Upon obtaining CVN of their patients, physicians may be able to differentiate between cardio-vascular health states of two individuals who may have the same or very similar levels of total cholesterol and lipoprotein cholesterols. 

Effects of dietary fiber on plasma lipids have been most pronounced and most consistent in studies using purified, viscous types of fiber, such as pectin and guar gum. The decrease in total and LDL cholesterol when feeding these fibers is accompanied by an increased fecal bile-acid excretion. Increased bile-acid loss with increased de novo synthesis from cholesterol is usually considered the main mechanism by which dietary fiber may alter plasma cholesterol. However, decreased absorption of dietary cholesterol or altered cholesterol and lipoprotein metabolism by other mechanisms may also be important (for review see for instance. ... 

The standard lipoproteins or the total lipoprotein fraction containing 20-100 pg of protein are applied onto the HPLC apparatus for monitoring by A gg. The loaded volume of normolipidemic human serum for monitoring of total cholesterol (TC), choline-containing phospholipids (PL) and triglycerides (TG) in a post column effluent are 10 pi, 20 pi and 50 pi, respectively, according to detection limit of each lipid in this HPLC technique as described in Section 6. In the case of the hyperlipidemic subjects, the loaded volume of serum decreases with an increase in serum lipid concentration. 

The total lipoprotein fraction (d<1.210) prepared from serum by the ultracentrifugation was analyzed in the same HPLC conditions as in Fig. 7. As presented in Fig. 8, well separated peaks corresponding to chylomicrons+VLDL, LDL, HDL2 and HDLj are observed by monitoring at A2gQ. The elution volume of each lipoprotein peak in Fig. 8 is consistent with that of the reference standards in Fig. 7. The concentration of total cholesterol, triglycerides and phospholipids in each ml of eluate are plotted in the same figure. For all lipoprotein classes, the peak position of protein is consistent with those of the three lipid components. 

Recovery of the standard lipoproteins and the total lipoprotein fraction was examined on the basis of total cholesterol concentration, and was found to be satisfactory as follows 85.3 6.0 % for chylomicrons+VLDL, 94 5 % for LDL,... 

Fig. 10. Elution patterns of protein (A280) and total cholesterol (A550) for human serum. Column G5000PW+G3000SW+G3000SW+G3000SW. Sample (A), 20 pi of whole serum (B), 20 pi of the total lipoprotein fraction (d<1.210). Flow rate 1.0 ml/min for eluent 0.15 M NaCl), 0.35 ml/min for enzyme solution (Determiner TC"555"). Reaction temperature 40°C. Peaks 1, LDL 2, HDLg 3, HDL3 4, human serum albumin.

Table V. Twenty-Four-Hour Time-Averaged Mean (+SD) Plasma Total Cholesterol and Cholesterol in Lipoprotein Fractions of NIDDM Patients During LC and HL Profiles...

Mercer, N. H., 1985, Cholesterol-enriched semipurified diets containing two levels of either casein or soy protein Effect on plasma total cholesterol and lipoprotein cholesterol in Mongolian gerbils. Fed. Proc. (Abstr.) 44 1497. 

Coronary heart disease. The role of fatty acids in coronary heart disease is related to their effects on blood total cholesterol and lipoprotein cholesterol levels. It has been well documented that saturated fatty acids in our diets (mainly palmitic acid) are responsible for raising blood total cholesterol and LDL cholesterol levels and that decreases in total and LDL cholesterol can be achieved by reducing the content of saturated fat in the diet (for review, see Grundy, 1986a McNamara, 1987b). This saturated fatty acid effect is due partly to alterations in cholesterol synthesis and also to changes in lipoprotein synthesis... 

Age Number of subjects Total cholesterol (mg./lOO cc.) Total lipoproteins (mg./lOO cc.) a-Lipo- proteins (mg./lOO cc.) -Lipo- protein (mg./lOO cc.) Ratio jSlot lipoproteins... 

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