Atherosclerosis Module 3 PDF

MODULE 3 6 DIETARY LIPIDS AND LIPOPROTEINS 7 OBESITY 8 ATHEROSCLEROSIS 1 8 ATHEROSCLEROSIS 2  8. ATHEROSCLEROSIS – CONTENTS – 1 Atherosclerosis Plaques or atheromas The role of LDL in plaque forma...

MODULE 3 6 DIETARY LIPIDS AND LIPOPROTEINS 7 OBESITY 8 ATHEROSCLEROSIS 1 8 ATHEROSCLEROSIS 2  8. ATHEROSCLEROSIS – CONTENTS – 1 Atherosclerosis Plaques or atheromas The role of LDL in plaque formation 2 LDL in atherosclerosis Normal subjects Familial hypercholesterolemia High cholesterol diet Familial hypertriglyceridemia 3 LDL receptors and LDL clearance 4 The atheroprotective role of HDL 5 Pharmacology of Atherosclerosis Statins Niacin CEPT inhibitors Omega-3 fatty acids 3  8. ATHEROSCLEROSIS – LEARNING OBJECTIVES – Describe the role of LDL in plaque or atheroma formation Discuss the role of LDL in familial hypercholesterolemia, high cholesterol diet, and familial hypertriglyceridemia. Draw your conclusions upon comparison with normal subjects Apply the knowledge on LDL receptors and LDL clearance as modulated by diet, genetic disorders, and age Explain the mechanism of action of statins at the target enzyme and transcriptional level. Discuss the role of HDL in reverse cholesterol transport Outline the mechanism of action of niacin and discuss whether or not it acts as an inhibitor of CEPT 4  1. ATHEROSCLEROSIS The process of atherosclerosis: Atherosclerosis is the leading cause of death in Western industrialized countries. Atherosclerosis is a systemic inflammatory disease characterized by the accumulation of lipid-rich lesions –plaques or atheromas– that can rupture leading to a reduction in blood flow and ischemia. Fatty material builds up on the intima of the arterial wall, thus narrowing the artery and restricting blood flow. The formation of an Normal artery atheroma takes years (though it can be accelerated Artery wall in different pathophysiological situations) to become a major occlusion. Normal foam fatty intermediate fibrous complicated blood flow cells streak lesion atheroma plaques lesion Abnormal rupture blood flow Plaque Narrowing Artery cross-section of artery endothelial dysfunction Narrowed Plaque From first decade From third decade From fourth decade artery smooth muscle thrombosis Growth mainly by lipid accumulation and collagen hematoma Stary classification of atherosclerotic plaques 5  1. ATHEROSCLEROSIS The role of LDL in plaque formation A major hypothesis for the pro- endothelial cells macrophages gression of atherosclerosis entails: smooth muscle cells macrophages A.LDL becomes entrapped in the redox active metal ions lipoxygenase myeloperoxidase sub-endothelial space where it is subject to oxidative modifications by resident vascular cells such as ox-LDL smooth muscle cells, endothelial cells, and macrophages. B.Oxidized LDL stimulates mono- cyte chemotaxis and prevents their egress, and C.supports foam cell formation. D.Once formed, oxidized LDL also results in endothelial dysfunction and injury, and E. Foam cells become necrotic due to the accumulation of oxidized LDL 6  2. LDL IN ATHEROSCLEROSIS In normal subjects, VLDL is secreted by the liver and converted to LDL in the capillaries of the peripheral tissues. Plasma LDL binds to the LDL receptor and is taken up by the liver. FAMILIAL NORMAL HYPERCHOLESTERO normal LDL Genetically defe receptor function LDL receptor LDL receptor synth LDL VLDL VLDL capillaries capillaries lipoprotein lipoprotein lipase fatty acids lipase 7 HIGH CHOLESTEROL DIET  2. LDL IN ATHEROSCLEROSIS In the genetic defect familial hypercholesterolemia, liver LDL receptors are diminished or absent. Patients have high cholesterol and they can die before the age of 20 unless managed carefully. The incidence of FH heterozygotes is 1/500 and they have twice the levels of LDL in plasma and that of FH homozygotes is much lower (1/106) and they have 6-10 times higher levels of plasma LDL from FAMILIAL HYPERCHOLESTEROLEMIA birth (heart attacks in childhood). LDL Genetically defective ction LDL receptor LDL receptor synthesis LDL LDL VLDL capillaries tein lipoprotein ase fatty acids lipase fatty acids 8  LDL LDL VLDL 2. LDL IN A THEROSCLEROSIS VLDL In normal individuals who ingest a high-cholesterol diet, the liver capillaries is filled with cholesterol, which represses the rate of LDL receptor capillaries lipoprotein lipoprotein production. lipase fatty acids lipase fatty acids HIGH CHOLESTEROL DIET dietary cholesterol cholesterol repression of LDL receptor synthesis LDL VLDL capillaries lipoprotein lipase fatty acids 9  2. LDL IN ATHEROSCLEROSIS In Familial hypertriglyceridemia VLDL levels are increased, whereas LDL levels are normal resulting in normal to elevated cholesterol and greatly elevated circulating triglyceride levels. Cause is overproduction and/or decreased removal of VLDL and triglycerides in serum. A relatively common disease treated FAMILIAL with diet. NORMAL HYPERCHOLESTER normal LDL Genetically defe receptor function LDL receptor LDL receptor synt LDL VLDL VLDL capillaries capillaries lipoprotein lipoprotein lipase fatty acids lipase 10 HIGH CHOLESTEROL DIET  receptor function LDL receptor LDL receptor synthesi ATHEROSCLEROSIS 3 LDL LEVELS AND ATHEROSCLEROSIS In normal subjects, VLDL is In familial hypercholesterolemia, In normal individuals who ingest LDL secreted by the liver and conver- liver LDL receptors VLDL are decreas- a high-cholesterol diet, VLDL the liver ted to LDL in the capillaries of ed or absent. Patients have high is filled with cholesterol, which the peripheral tissues. Plasma cholesterol and they can die represses the rate of LDL recep- LDL binds to the LDL receptor before the capillaries age of 20 unless tor production. capillaries and is taken up by the liver. managed carefully. The incidence lipoprotein lipoprotein lipase fatty acids lipase of FH heterozygotes is 1/500 and HIGH CHOLESTEROL they have twice the levels of LDL FAMILIAL DIET NORMAL HYPERCHOLESTEROLEMIA in plasma and that of FH dietary cholesterol repression homozygotes is much lower cholesterol of LDL receptor synthesis normal LDL Genetically defective receptor function LDL receptor (1/106) and they havesynthesis LDL receptor 6-10 times higher levels of plasma LDL FAMILIAL NORMAL HYPERCHOLESTEROLEMIA from birth normal LDL receptor function (heart attacks in LDLGenetically defective receptor synthesis LDL receptor childhood). LDL FAMILIAL VLDL LDL HYPER- LDL VLDL VLDL CHOLESTEROLEMIA capillaries LDL LDL VLDL VLDL lipoprotein capillaries capillaries lipase fatty acids lipoprotein lipoprotein lipase capillaries fatty acids capillarieslipase fatty acids HIGH CHOLESTEROL lipoprotein lipoprotein DIET fatty acids lipase lipase fatty acids HIGH CHOLESTEROL 11 dietary DIET  2. LDL IN ATHEROSCLEROSIS ______________________________________________________________________________________ Treatment ______________________________________________________________________________________ Familial Hypercholesterolemia LDL Diet, Statins, Niacin ______________________________________________________________________________________ High Cholesterol Diet LDL Diet, Statins ______________________________________________________________________________________ Familial Hypertriglyceridemia VLDL Diet, Niacin ______________________________________________________________________________________ 12  3. LDL RECEPTORS AND LDL CLEARANCE All LDL receptors (LDL-R) contain a single membrane-spanning domain, a relatively short cytosolic tail, and extracellular regions with 3 modules: ligand- binding repeats, epidermal growth factor (EGF) repeats, and b-propeller domains. ligand- —ligand-binding binding repeats ligand-binding repeats repeats extracellular region extracellular EGF region —EGF repeats EGF repeat repeats β-propeller β-propeller domaindomains β-propeller domains α-linked sugar o-linked sugar domain membrane- membrane-spanning domain spanning domain MEMBRANE region cytosolic cytosolic tail tail 13  3. LDL RECEPTORS AND LDL CLEARANCE Each circulating LDL particle contains both ApoB-100 and ApoE, which are recognized by LDL receptors on cells that need to take up cholesterol. The binding of LDL to an LDL receptor initiates endocytosis, which brings the LDL and its associated receptor into the cell within an endosome; lysosomal enzymes will hydrolyze the cholesteryl esters, releasing cholesterol and fatty acids into cytosol. ApoB100 and ApoE are degraded to amino acids, released to the cytosol; the LDL receptor escapes degradation and is recruited back to the cell surface, where it can again function in LDL uptake. CHOLESTERYL-ESTERS REGULATORY ACAT ACTIONS LDL receptors CHOLESTEROL HMG-CoA reductase E E E TG TG TG CE 100 100 100 CE CE C C C LDL LDL LDL receptor endosome aminoacids BINDING INTERNALIZATION LYSOSOMAL ENDOSOME FORMATION HYDROLYSIS 14  3. LDL RECEPTORS AND LDL CLEARANCE There are three isoforms of ApoE: ApoE-2, ApoE-3, and ApoE-4; these isoforms have slight amino acid variations but pronounced functional differences: __________________________________________________________________________________________________________ Isoform Amino Acid Binding to Associated Disorders Variation LDL receptor 112 158 _______________________________________________________________________________________________ ApoE2 Cys Cys Low Type III hyperlipoproteinemia ApoE3 Cys Arg High Unknown ApoE4 Arg Arg High Alzheimer’s disease Atherosclerosis __________________________________________________________________________________________________________ 15  3. LDL RECEPTORS AND LDL CLEARANCE Diet can modulate LDL receptor levels. Genetic disorders are associated with mutations in LDL receptor or ApoE, which binds to the LDL receptor. The LDL levels in plasma are inversely associated with the number of LDL receptors. In newborn humans, the levels of the LDL receptor are at their highest and LDL- cholesterol levels are low Threshold for Increased Coronary Risk In normal adults in Western societies 100 Relative Number of LDL Receptors (indicated by the bell-shaped curve), the levels of LDL-cholesterol range between 100 and 200 mg/dL 50 Higher levels are observed in familial hypercholesterolemia hetero- zygotes and even higher in homozy- NEWBORN HUMANS NORMAL ADULTS FH HETEROZYGOTES ↓ FH HOMOZYGOTES || ↓ gotes, where the relative number of 0 25 50 100 200 300 || 600 LDL-cholesterol (mg/dL) LDL receptors is at its lowest. 16  4. THE ATHEROPROTECTIVE ROLE OF HDL NATIONAL CHOLESTEROL EDUCATION PROGRAM The current NCEP guidelines published in 2001 and revised in 2004, recommend statins for heart disease patients with LDL (“bad”) cholesterol levels greater than 70 mg/dL of blood and for people who have a moderately elevated risk of heart disease as well as LDL levels above 100 mg/dL. An expected NCEP move to lower the treatment bar this year would follow a Food and Drug Administration advisory panel’s vote in December 2009 to broaden the prescription base of AstraZeneca’s drug Crestor (rosuvastatin) to an additional 6.5 million lower-risk Americans. The FDA usually accepts the panel’s recommendations. 17  4. THE AHEROPROTECTIVE ROLE OF HDL Epidemiological studies show a strong inverse correlation between HDL- cholesterol levels and the risk of coronary heart disease. Even in patients treated aggressively with statins to lower levels of LDL cholesterol, low levels of HDL- cholesterol remain a significant predictor of major cardiovascular disease. The proposed atheroprotective properties of HDL are multifaceted: the most popular hypothesis revolves around the role of HDL in macrophage reverse cholesterol transport, in which excess cholesterol is effluxed to HDL and ultimately returned to the liver for breakdown. HDL has also been shown to inhibit endothelial inflammation, LDL oxidation, platelet aggregation and coagulation, and to maintain endothelial integrity through antiapoptotic effects. These multiple actions of HDL make it a complex therapeutic agent, albeit one with an abundance of antiatherogenic potential. Duffy, D. and Rader, D.J. (2009) Nature Reviews Cardiology 6, 455-4763 Khera, A.V. and Rader D.J. (2010) Curr Atheroscler Rep 12, 73-81 18  4. THE ATHEROPROTECTIVE ROLE OF HDL The role of HDL in reverse chole- HEPATOCYTE HEPATOCYTE BLOOD BLOOD MACROPHAGE MACROPHAGE sterol transport involves liver, HEPATOCYTE BLOOD MACROPHAGE blood, and peripheral tissues 11 1 ApoA-1 ApoA-1 ApoA-1 (macrophages) and can established 22 (PL (PL 2Lipidation Lipidation Lipidation + +cholesterol) cholesterol) (PL + cholesterol) ABCA1 ABCA1 ABCA1 with the following sequence of ABCA1 ABCA1 ABCA1 33 events: free free free cholesterol cholesterol cholesterol nascent nascent HDL nascentHDL HDL 1 Liver synthesizes apolipoprotein LCAT LCATLCAT 44 4 A1 (ApoA1) that is secreted in its lipid-free form. cholesteryl cholesteryl cholesteryl ester ester ester 5a 5a 5a 6 6 6 5b5b 5b ABCG1 ABCG1 2 Lipidation of ApoA1 occurs with ABCG1 BileBile Bile the acquisition of free cholesterol SR-B1 SR-B1 SR-B1 matureHDL mature mature HDL HDL and phospholipids by the hepato- CEPTCEPT 5c CEPT CETP 5c5c cyte ATP-Binding Cassette A1 LDL-R LDL-R LDL-R ApoB100 ApoB100 ApoB100 triglyceride triglyceride triglyceride (ABCA1), thus forming nascent cholesteryl ester cholesteryl cholesteryl esters ester ester HDL. ABCA1 is also known as LDL the cholesterol efflux regulatory LDL LDL protein and is a regulator of cholesterol homeostasis. 19  4. THE ATHEROPROTECTIVE ROLE OF HDL HEPATOCYTE HEPATOCYTE HEPATOCYTE BLOOD BLOOD BLOOD MACROPHAGE MACROPHAGE MACROPHAGE 3 Nascent HDL acquires addi- 11 1 ApoA-1 ApoA-1 ApoA-1 22 2Lipidation Lipidation Lipidation tional free cholesterol from (PL (PL + +cholesterol) ABCA1 ABCA1 ABCA1 cholesterol) (PL + cholesterol) macrophages (or other peripher- ABCA1 ABCA1 ABCA1 free free free 33 cholesterol cholesterol cholesterol al tissues), via ABCA1 LCAT LCAT nascent nascent LCAT HDL nascentHDL HDL 44 4 4 The action of LCAT on nascent 5a 5a 5a HDL generates mature HDL cholesteryl cholesteryl cholesteryl ester ester ester 6 6 6 5b5b 5b ABCG1 ABCG1 ABCG1 BileBile Bile (i.e., conversion of free chole- SR-B1 SR-B1 SR-B1 matureHDL mature mature HDL HDL sterol to cholesteryl esters). CEPT CETP CEPT 5c CEPT 5c 5c LDL-R LDL-R LDL-R triglyceride ApoB100 ApoB100 ApoB100 triglyceride triglyceride cholesteryl cholesteryl cholesteryl esters cholesteryl ester ester ester LDL LDL LDL 20  4. THE ATHEROPROTECTIVE ROLE OF HDL 5 Fates of mature HDL: a it can serve as acceptor of chole- HEPATOCYTE HEPATOCYTE HEPATOCYTE BLOOD BLOOD BLOOD MACROPHAGE MACROPHAGE MACROPHAGE sterol efflux via the ABCG1 path- way. ABCG1 (ATP-Binding Cassette 11 1 ApoA-1 ApoA-1 ApoA-1 22 2Lipidation G1) is involved in cholesterol trans- (PL (PL Lipidation Lipidation + +cholesterol) cholesterol) (PL + cholesterol) ABCA1 ABCA1 ABCA1 port in macrophages. ABCA1 ABCA1 ABCA1 free free free 33 b it can be transported back to liver cholesterol cholesterol cholesterol nascent nascent HDL nascentHDL HDL where it binds the SRB1. Choles- LCAT LCATLCAT 44 4 teryl esters in liver are metabolized 5a 5a 5a to bile acids that are released into cholesteryl cholesteryl cholesteryl ester ester ester 6 6 6 5b5b 5b ABCG1 ABCG1 ABCG1 the intestine (6). BileBile Bile c it can transfer the cholesteryl esters SR-B1 SR-B1 SR-B1 matureHDL mature mature HDL HDL CEPT 5c CEPT CEPT to ApoB-containing lipoproteins (i.e. CETP 5c 5c LDL) by the action of CETP (Chole- LDL-R LDL-R LDL-R ApoB100 ApoB100 ApoB100 triglyceride triglyceride triglyceride steryl Ester Transfer Protein). LDL cholesteryl esters cholesteryl ester cholesteryl ester ester binds to the LDL-receptor in liver. LDL LDL LDL 21  5. PHARMACOLOGY OF ATHEROSCLEROSIS OH OH N O 5 Drug targeting of cholesterol synthesis – Statins N OH O Akira Endo, a Japanese biochemist, identified mevastatin (ML-236B), a molecule produced by F the fungus Penicillium citrinum, as an inhibitor of ATORVASTATIN - LIPITOR HMG-CoA reductase. The new generation of HO O statins H Inhibit HMG-CoA reductase and reduce H3C O H intracellular cholesterol CH3 CH3 Decrease intracellular cholesterol results in an H3C increase of SREBP-mediated transcription of LOVASTATIN HMG-CoA reductase and the LDL receptor H3C CH3 OH OH O Increase expression of LDL receptors in the N OH liver leads to an increase of LDL uptake and H3C N N consequently a decrease of serum LDL levels O S CH3 F O ROSUVASTATIN - CRESTOR 22  REGULATION OF CHOLESTEROL BIOSYNTHESIS a. Hormonal regulation of HMG-CoA reductase acetyl-CoA INSULIN In humans, cholesterol production is regulated by the intracellular cholesterol concentration phosphatase β-hydroxymethyl- glutaryl-CoA and by the hormones glucagon and insulin. Glucagon stimulates the phosphorylation (inac- HMG-CoA HMG-CoA reductase reductase tivation) of HMG-CoA reductase. Insulin P inactive active stimulates the dephosphorylation (activation) of mevalonate HMG-CoA reductase by activating the protein kinase phosphatase 1, thus favoring the synthesis of GLUCAGON cholesterol. cholesteryl cholesterol HMG-CoA reductase is allosterically inhibited esters ACAT (intracellular) by the intracellular levels of cholesterol, which also activate acyl-cholesterol-acyl-transferase LDL-cholesterol (ACAT), thus increasing the concentration of (extracellular) cholesterol esters. 23  5. PHARMACOLOGY OF ATHEROSCLEROSIS Statins HMG-CoA reductase is the rate-limiting step in cholesterol biosynthesis. Lovastatin is a cholesterol-lowering drug that results in reductions of serum cholesterol (at doses of 20-80 mg/day). Lovastatin is administered as an inactive lactone. After oral ingestion, it is hydrolyzed to the active mevinolinic acid, a competitive inhibitor of HMG-CoA reductase. Mevinolinic acid is thought to behave as a transition-state analog of the tetrahedral intermediate formed in the HMG-CoA reductase action. HMG-CoA OH O HO HO O | || COO– HOOC—CH2—C—CH2—C—SCoA | OH CH3 HO H H COO– H3C H3C H3C O O OH H H CH3 CH3 CH3 CH3 |—H SCoA tetrahedral intermediate in HMG-CoA reductase H3C H3C mechanism mevinolinic acid (after oral ingestion, LOVASTATIN 2 NADPH lovastatin is hydrolyzed (cholesterol-lowering drug: to the active compound) administered as inactive lactone) 2 NADP+ OH | HOOC—CH2—C—CH2—CH2OH | CH3 24  5. PHARMACOLOGY OF ATHEROSCLEROSIS Statins at the transcriptional level + CHOLESTEROL – CHOLESTEROL § In the presence of cholesterol, the two proteins SREBP and SCAP are ER retained in the ER by binding to SREBP SCAP INSIG SREBP SCAP INSIG. PRESENCE OF ABSENCE OF CHOLESTEROL CHOLESTEROL § In the absence of cholesterol, INSIG no longer binds to SREBP- ✂ SCAP and SREBP-SCAP transloc- ✂ GOLGI ates to Golgi. § In Golgi, the transcription factor domain of SREBP (SRE) is released from the membrane by proteolytic cleavage catalyzed by proteases. SRE target genes HMG-CoA Reductase NUCLEUS LDL receptor § SRE translocates to the nucleus and activates target genes such as HMG-CoA reductase and the LDL receptor. 25  5. PHARMACOLOGY OF ATHEROSCLEROSIS TRIGLYCERIDES NIACIN Niacin – (Niaspan) Niacin inhibits lipolysis in adipose tissue, FATTY ACIDS resulting in decreased hepatic VLDL synthesis and production of LDLs in the plasma. FATTY ACIDS Niacin is the most effective agent for TRIGLYCERIDES increasing HDL-cholesterol. It also lowers VLDL triglycerides. Niacin can be used in combina- tion with statins. VLDL LDL 26  5. PHARMACOLOGY OF ATHEROSCLEROSIS Niacin – (Niaspan). Niacin acts on the nicotinic acid receptor (GPR109A) on adipocytes and inhibits adenylate cyclase (AC) resulting in a decrease of cAMP levels, PKA activation, lipolysis (lack of activation of HSL). The decrease in free fatty acids (FFA) induced by nicotinic acid results in substrate shortage for hepatic triglyceride synthesis and VLDL. As a result, VLDL as well as LDL plasma levels drop. The mechanism by which Niacin raises HDL-cholesterol levels is not well understood though some in vitro studies support the notion that niacin decreases ApoA1 degradation. Niacin was also shown to inhibit CETP expression. β-adrenergic nicotinic Nicotinic Acid receptor acid receptor glucagon AC ATP ↓TG synthesis ↓ cAMP ↓VLDL formation TG PKA HSL x HSL P ↓VLDL inactive active FFA ↓FFA CETP? ↓ HDL ↓LDL-C CETP? 27  5. PHARMACOLOGY OF ATHEROSCLEROSIS HDL and cholesterol-reverse transfer HEPATOCYTE HEPATOCYTE HEPATOCYTE BLOOD BLOOD BLOOD MACROPHAGE MACROPHAGE MACROPHAGE HDL and its major protein, ApoA1, 11 1 ApoA-1 ApoA-1 have been shown to prevent and 22 (PL 2Lipidation Lipidation Lipidation + +cholesterol) ApoA-1 ABCA1 (PL cholesterol) (PL + cholesterol) ABCA1 ABCA1 reverse atherosclerosis in animal ABCA1 ABCA1 ABCA1 free free free 333 models. One of the major functions cholesterol cholesterol cholesterol nascent nascentHDL nascent HDL HDL LCAT of HDL is to promote efflux of LCAT 44 4 LCAT cholesterol from macrophages in the 5a cholesteryl ester 5a 5a cholesteryl cholesteryl ester ester artery wall (3 and 5a). Hence, drugs 6 6 BileBile 6 5b5b 5b ABCG1 ABCG1 ABCG1 Bile have been developed to increase the SR-B1 SR-B1 SR-B1 mature matureHDL mature HDL HDL levels of HDL or inhibit the chole- CEPTCEPT CEPT 5c 5c 5c CETP steryl ester transfer protein (CETP) LDL-R LDL-R LDL-R ApoB100ApoB100 ApoB100 triglyceride triglyceride triglyceride (5c). cholesteryl ester esters cholesteryl ester cholesteryl ester LDLLDL LDL 28  5. PHARMACOLOGY OF ATHEROSCLEROSIS CEPT inhibitors – Several CETP inhibitors have been developed to determine whether or not raising HDL-cholesterol by inhibiting CEPT would result in improved cardiovascular outcomes and reduced cardiovascular disease risk. Anacetrapib is a potent inhibitor of CETP that significantly increased HDL-cholesterol levels (129-139%) and reduced LDL- cholesterol levels by 38-40%. The phase III outcomes trial, Randomized Evaluation of the Effects of Anacetrapib Through Lipid-Modification (REVEAL) is currently ongoing and will enroll 30,000 patients with occlusive arterial disease (NIH clinical trials). Evacetrapib is another potent CETP inhibitor currently in clinical development. There are no adverse effects on blood pressure in preclinical studies. A Study of Evacetrapib in High-Risk Vascular Disease (ACCELERATE) trial has completed enrollment. 29  5. PHARMACOLOGY OF ATHEROSCLEROSIS Omega-3 fatty acids are essential fatty acids that are predominantly used for triglyceride lowering. Omega-3 fatty acids inhibit VLDL and triglyceride synthesis in the liver. EPA and DHA are found in marine sources. Over-the-counter fish oil capsules (EPA/DHA) can be used for supplementation. Omega-3 fatty acid ethyl esters (Lovaza) is considered an antihyper- lipidemic Please consider the FDA qualified health claim from 2019 “…this evidence is inconclusive and highly inconsistent”. 30