Niacin lipoproteins

Consider niacin or a fibrate for additional pharmacotherapy if high density lipoprotein (HDL) is <40 mg/dL... 

A fibrate derivative or niacin should be considered in select patients with a low high-density lipoprotein (HDL) cholesterol less than 40 mg/dL (1.04 mmol/L) and/or a high triglyceride level greater than 200 mg/dL (2.26 mmol/L). In a large randomized trial in men with established CAD and low levels of HDL cholesterol, the use of gemfibrozil (600 mg twice daily) significantly decreased the risk of non-fatal myocardial infarction or death from coronary causes.78... 

Niacin reduces plasma LDL cholesterol, lipoprotein (a), triglycerides and raises HDL cholesterol in all types of hyperlipoproteinemia [26]. Although available on the market for more than 40 years, the mechanisms of action of niacin are poorly understood. Putative mechanisms are the activation of adipose tissue LPL, diminished HTGL activity, a reduced hepatic production and release of VLDL, and composi-... 

Gemfibrozil reduces the synthesis of VLDL and, to a lesser extent, apolipoprotein B with a concurrent increase in the rate of removal of triglyceride-rich lipoproteins from plasma. Clofibrate is less effective than gemfibrozil or niacin in reducing VLDL production. 

High density extruded planks, 23 404 High density lipoproteins (HDLs), 5 135-137 10 829 niacin and, 25 798 High density polyethylene (HDPE), 10 596-595 11 225 16 21 17 724 20 149-179 24 267, 268. See also HDPE entries analysis of, 19 566 as barrier polymer, 3 377 bimodal reactor technology for, 20 170 blow molding of, 20 171-172 blown film applications, 20 173-174 catalysts used for, 20 152-155 chemical resistance of, 20 166 commercial applications of,... 

Primary chylomicronemia (familial lipoprotein lipase or cofactor deficiency) Chylomicrons, VLDL increased Dietary management (niacin, fibrate) Niacin plus fibrate... 

Sites of action of HMG-CoA reductase inhibitors, niacin, ezetimibe, and resins used in treating hyperlipidemias. Low-density lipoprotein (LDL) receptors are increased by treatment with resins and HMG-CoA reductase inhibitors. VLDL, very-low-density lipoproteins R, LDL receptor. 

Guyton JR. Extended-release niacin for modifying the lipoprotein profile. Expert Opin Pharmacother. 2004 5 1385-1398. 

This familial disorder, which is associated with increased atherogenesis, is determined chiefly by alleles that dictate increased production of the Lp(a) lipoprotein. Niacin reduces levels of Lp(a) in... 

Quantitative evidence of reversal of coronary disease was demonstrated with this regimen in three major clinical trials. Effects on lipoprotein levels are sustained, and no additional adverse effects have developed other than those encountered when the drugs are used singly. The drugs may be taken together, because niacin does not bind to the resins. LDL levels in patients with heterozygous familial hypercholesterolemia are usually normalized with daily doses of up to 6.5 g of niacin with 24-30 g of resin. 

In a small (81 patients) retrospective analysis, patients on lipidlowering medication (statins, fibrates, or niacin derivatives) at the time of PCI had a significantly lower incidence of adverse events during the procedure, such as emboli and dissections, as compared to those not taking such agents (57). A high-total cholesterol, low-density lipoprotein, or ratio of low to high-density lipoprotein were also associated with increased adverse events,... 

It is well established that HMG-CoA reductase inhibitors and bile acid sequestrants can be used together safely, with a greater reduction in LDL cholesterol than is obtainable when either drug is used alone. Unfortunately, bile acid sequestrants are often poorly tolerated, which limits the usefulness of this combination. Relatively low doses of niacin, when used in combination with statins, produce a very attractive effect on the lipoprotein profile (Gardner et al., 1996 Stein et al., 1996) the ability of niacin to substantially increase HDL cholesterol is additive, with the profound reduction in LDL cholesterol produced by the statin, and there is also a moderate reduction in triglycerides. However,... 

Correct answer = D. Clofibrate and gemfibrozil Increase the activity of lipoprotein lipase, thereby increasing the removal of VLDL from plasma. Niacin inhibits lipolysis in adipose tissue and thus eliminates the building blocks needed by the liver to produce triacylglycerol and there-... 

Only niacin offers benefits in regard to newly determined, independent risk factors for the development and progression of heart disease and the incidence of heart attacks and strokes. It lowers levels of a particularly nasty variant of LDL termed lipoprotein(a). The vitamin improves the balance of the hormonelike substances called prostaglandins, with the detrimental thromboxane falling and the protective prostacycline going up. Activity of blood platelets, cells involved in the clotting process, decrease, resulting in fewer clots that can lead to heart attacks. 

Finally, niacin lowers levels of inflammation in the arteries. As total and LDL cholesterol fall along with lipoprotein(a), HDL goes up, other benefits occur, and the measurements of inflammation decrease. 

F Before initiating statin therapy, it is recommended to have baseline measurements of the lipoprotein profile and LFTs. If the LFTs are more than three times the upper limit of normal (ULN), statins should be avoided. If the LFTs are less than three times the ULN, statin therapy can be initiated, but the patient should be monitored closely. If LFTs become elevated, reversal of the transaminase elevation is common upon discontinuation of the statin. Some experts also recommend obtaining a baseline creatine kinase (CK) level. If the CK level is more than 10 times the ULN while on a statin, the statin should be discontinued. The combination of a statin with niacin or a fibrate should be used cautiously because of an increased risk of myopathy. Although most statins are taken at dinner or bedtime, atorvastatin can be taken at any time of the day due to its longer T /i ( 14 hours). Lovastatin should be taken with food because this increases its bioavailabilty. 

The hypolipidemic effects of niacin may be due to its ability to inhibit lipolysis (i.e.. prevent the release of FFAs and glycerol from fatty tissues). As a consequence, there is a reduced reserve of FFA in the liver and diminution nf lipoprotein binsynthesis. which reduces the production nf VLDL. The decreased formation nf lipoproteins leads to a pool nf unused cholesterol normally incorporated in VLDL. This excess cholesterol is then excreted through the biliary tract. 

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