Journal of Atherosclerosis and Thrombosis
`
`107
`
`Vol. 2, No. 2
`
`The Long-Term Effect of Eicosapentaenoic Acid on Serum Levels of
`Upoprotein (a) and Upids in Patients with Vascular Disease ,
`
`-Koj(Shinozaki, Jun~icbii Kambayashi, l):>mio. Kawasaki, Y oshio. Uemura, Masato Sakon,
`Eiichi Shiba, Takashi'"Shibuya, Takashi Nakamura, and Takesada 1 Mori
`
`yepartment of Surgery II, Osaka University Medical Schoa~Osaka, ~~~
`
`The effecls of elcosapentaenoic acid (EPA) on serum lipoprotein (a) (Lp(a)) and other lipid levels
`in patients with vascular disease were examined. The serum levels of Lp(a), total chOlesterol
`(TC), biglyceride (TG), low-density '"roteln (LDL) and very-low-density lipoprotein (VLDI..) were
`measured In 24 patients with vascular diseas8. An elevated serum Lp(a) level (39±22 mg/dQ
`was noted in 9 patients, elevated total cholesterol level (263±31mg/di)In12 patients, elevated
`triglyceride level (240±98 mg/di) in 10 patients and elevated LDL level (651±88 mg/dQ in 6
`patients before administration of EPA. EPA (1,800.mg/day) was given to these patients for long
`periods ranging from 6 to 24 months. The serum levels of Lp(a), TC, TG and LDL were lowered
`significantly (p.< 0.05) after EPA administration for 12 and 18 months, for 6, 12, 18 and 24 months,
`for 18 months and for 12 and 18 months, respectively. These findings indicated that long-term
`administration of EPA may lower Lp(a) and serum lipids, which is beneficial for patients with
`various arterial diseases In terms of preventing progression of the disease.
`J Atheroscler
`111romb, 1996 ; 2 : 107-109.
`
`Key words : Atherosclerosis, Oral Administration, Total cholesterol, Triglyceride
`
`Eicosapentaenoic acid (EPA) has been suggested to
`prevent arterial ttirombosis and development of athero(cid:173)
`sclerosis by altering lipid metabolism in addition to its known
`antiplatelet effect (1i Lipoprotein (a) (Lp(a)), described by
`Berg in 1963, is a variant of low-density lipoprotein (LDL),
`which has been reported to be correlated with an increased
`risk of atherosclerotic vascular disease (2). A high concen(cid:173)
`tration of Lp(a) in plasma has been reported to be an in(cid:173)
`dependent risk factor for acute myocardial infarction and to
`be increased in patients with peripheral vascular diseases (3).
`Some studies have suggested that the Lp(a) level is under
`tight genetic control and is not influenced by diet (4).
`However, nicotinic acid and stanozolol have been reported to
`lower the Lp (a) level (5, 6).
`We examined whether the long-term administration of
`EPA influenced the serum levels of Lp (a) and other lipids in
`In this study, the serum
`patients with vascular disease.
`
`Address for corresponding : Jun-ichi Kambayashi, Depart(cid:173)
`ment of ·surgery II, Osaka University Medical School, 2-2
`Yamada-Oka, Suita, Osaka 565, Japan.
`Received December 16, 1994.
`Accepted for publication March 22, 1995.
`
`levels of Lp (a), total cholesterol (TC), triglyceride (TG), low(cid:173)
`density lipoprotein (LDL) and very-low-density lipoprotein
`(VLDL) were measured in patients With arteriosclerosis oblit(cid:173)
`erans (ASO), Buerger's disease (TAO).and abdominal aortic
`aneurysm (AAA) before and after administration of EPA.
`
`Methods
`
`The subjects were 24 patients with vascular disease who
`visited our clinic from February 1991 to March 1992. The 24
`patients were comprised of 21 men and 3 women aged 38-
`75 years. Sixteen patients with ASO, 6 patients with TAO
`and 2 patients with AAA received oral administration of 1,800
`mg/day of EPA (Epadel, Machida Pharmaceutical Co.,
`Tokyo, Japan).
`Informed consent was obtained from all
`patients before administration of EPA. The serum levels of
`Lp(a) and various lipid parameters including TC, TG, LDL and
`VLDL were measured before and 6, 12, 18 and 24 months
`after the administration of EPA. Blood samples were
`obtained under strict fasting and serum was obtained by
`centrifugation of the blood at 1,200Xg for 5 min. The
`determination of Lp(a) was performed in the Biochemical
`
`ICOSAPENT_DFNDTS00011751
`
`Hikma Pharmaceuticals
`
`IPR2022-00215
`
`Ex. 1016, p. 1 of 3
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`

`

`108
`
`Shinozaki et al.
`
`Inc., Tokyo,
`Laboratory (Sumitomo Metal Bio-Science,
`Japan) by enzyme immunoassay (7). A Tint Elisa Lp(a)
`determination kit (Biopool AB, Umea, Sweden) was used.
`The principle of the ELISA is based on the sandwich tech(cid:173)
`nique in which two monoclonal antibodies react with differ(cid:173)
`ent antigenic determinations on the apo(a) molecule. Blood
`Lp(a) level was diagnosed as elevated when determined to
`be above 20 mg/di. Measurement of LDL and VLDL was
`performed by turbidometric assay using sodium heparin.
`The values of blood lipid levels were diagnosed as elevated
`when TC, TG, LDL and VLDL were above 221, 151, 571 and
`410, respectively. Statistical analysis was performed using
`the pair'ed Wilcoxon test to compare pre- and post-treat(cid:173)
`ment values.
`
`Results
`Of the 24 patients studied, an elevated serum Lp(a) level of
`more than 20 mg/di (39±22 mg/di) was noted in 9 patients
`(7 in ASO, 1 in TAO and 1 in AAA), elevated TC level of more
`than 220 mg/di (263±31 mg/di) in 12 patients (9 in ASO and
`3 in TAO), elevated TG level of more than 150 mg/di (240±
`98 mg/di) in 10 patients (7 in ASO, 2 in TAO and 1 in AAA)
`and elevated LDL level of more than 570mg/dl (651±88
`mg/di) in 6 patients (5 in ASO, 1 in TAO) before administra(cid:173)
`tion of EPA The levels of VLDL were within the normal limit
`in all patients. EPA (1,800 mg/day) was given to these
`patients for 24 months and the data from these patients were
`analyzed. The serum level of Lp(a) in the patients with
`elevated Lp(a) levels before EPA administration were lowered
`significantly (p< 0.05) after administration for 12 and 18
`months. The levels of Lp(a) in patients in which it was
`initially normal did not change significantly (Fig. 1). The
`
`serum level of TC in patients with elevated TC level was
`lowered significantly after administration of EPA for 6, 12, 18
`and 24 months (Fig. 2). The TG level in patients in which it
`was elevated before administration was lowered significantly
`after EPA administration for 18 months (Fig. 3).
`In the
`patients with an elevated LDL level before treatment, the
`LDL level was lowered after administration of EPA for 12 and
`In all patients in the present study, no
`18 months (Fig. 4).
`marked side effects such as liver dysfunction were seen
`after long-term administration of EPA.
`
`280
`
`260
`
`,.-_
`
`.......,
`
`fl)
`
`~
`~
`0 200
`
`:a --Oil s 240
`e 220
`..= Q s 180
`
`0
`~
`
`160
`0
`
`6
`
`18
`
`24
`
`12
`Months
`F19. 2. Effects of administration of EPA on serum total
`cholesterol (TC) levels. Serum level of TC was measured
`during EPA treatment. Patients with pretreatment serum
`levels higher than the normal range (closed circles), and
`those with normal pretreatment serum levels (open cir(cid:173)
`cles). Asterisks denote significant differences (p<0.05)
`from the pretreatment values.
`
`--e- LP(a)>20
`-0 - LP(a)<20
`
`250
`
`~
`·~ 150
`Q
`;>..
`Oh
`·;::: 100
`~
`
`--e- TG>150
`- 0 - TCk150
`
`6
`
`18
`
`24
`
`12
`Months
`Fig. 1. Effects of administration of EPA on serum Lp(a)
`levels. Serum level of Lp (a) was measured during EPA
`treatment. Patients with pretreatment serum
`levels
`higher than the normal range (closed circles), and those
`with nomial pretreatment serum levels (open circles).
`Each value is the mean± SE. Asterisks denote signifi(cid:173)
`cant differences (p<0.05) from the pretreatment values.
`
`so+-~~~-.-~~~~~~~~~~~~
`
`0
`
`6
`
`12
`Months
`
`18
`
`24
`
`Fig. 3. Effects of administration of EPA on serum total
`triglyceride (TG) levels. Serum level of TG was measured
`during EPA treatment. Patients with pretreatment serum
`levels higher than the normal range (closed circles), and
`those with. normal pretreatment serum levels (open cir(cid:173)
`cles). Asterisks denote significant differences (p < 0.05)
`from the pretreatment values.
`
`ICOSAPENT _DFNDTS00011752
`
`Hikma Pharmaceuticals
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`IPR2022-00215
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`Ex. 1016, p. 2 of 3
`
`

`

`The Effect of EPA on Lp(a) and Lipids
`
`109
`
`,....... 600
`~
`5 500
`9 400
`
`300-+-~~~..-~~.......,.~~~--..-~~~-,--'
`
`0
`
`6
`
`12
`Months
`
`18
`
`24
`
`Fig. 4. Effects of administration of EPA on serum low(cid:173)
`density lipoprotein (LDL) levels. Serum level of LDL was
`measured during EPA treatment. Patients with pretreat(cid:173)
`ment serum levels higher than the normal range (closed
`circles), and those with normal pretreatment serum levels
`(open circles).. Asterisks denote significant differences
`(p<0.05) from the pretreatment values.
`·
`
`Discussion
`
`Lp(a) has been assumed to be an additional risk factor for
`atherosclerotic diseases (8). Therefore, reduction of the
`serum concentration of Lp(a) would be of grea~ clinical
`interest. Recently, the effects of several drugs to reduce
`the effect of Lp(a) have been studied. Carlson et al. report(cid:173)
`ed the pronounced Lp(a)-lowering effect of nicotinic acid in
`hyperlipidemic subjects (5). Vessby et al. studied the effects
`of cholestyramine (9) and Schmidt et al. investigated the
`effects of n-3 polyunsaturated fatty acids on Lp(a) (10).
`In
`this latter study, patients were given n-3 polyunsaturated
`fatty acids including EPA and DHA for 6 or 12 weeks, but no
`effect on Lp(a) was observed.
`In the present study, cap(cid:173)
`sules containing 100% pure eicosapentaenoic acid were
`used. When analyzing the data, patients were diVided into
`two groups according to the Lp(a) level before EPA adminis(cid:173)
`tration. The level of Lp(a) in patients with a high level before
`administration decreased after 12 and 18 months of EPA
`administration. The mechanism of synthesis and degrada(cid:173)
`tion of Lp(a) is not clear at present, and there is no good
`explanation for the observed effect of EPA. Since Lp(a)
`contains an LDL component (apo-8) linked to apo(a) by a
`single disulfide bridge (11), the significant reduction of LDL
`after administration for 12 and 18 months is of interest.
`Intake of EPA might reduce hepatic synthesis of low-density
`lipoproteins and decrease the production of Lp(a) in the liver.
`We also studied the changes in the levels of TC, TG and
`LDL The serum levels of TC, TG and LDL in the patients in
`which these levels were high before treatment were lowered
`significantly after administration of EPA for 6, 12, 18 and 24
`months, for 18 months and for 12 and 18 months, respectively.
`
`Harris et al. reported that intake of n-3 fatty acids produced
`persistent reductions in TG levels, but not in TC or LDL levels
`(12), and Gries et al. reported that n-3 fatty acids could
`reduce the TG level after 6 months of treatment (13~ The
`effect of EPA on TG in the present study was compatible
`with the results of these previous studies. However, the
`long-term effects of administration of highly purified EPA for
`more than 1 year have not been reported. The present
`study showed that the long-tenn administration of EPA
`reduced not only the Lp(a) level, but also the serum levels of
`TC, TG and LDL
`In conclusion, these findings indicate that long-term
`administration of EPA may lower the levels of Lp(a) and
`serum lipids such as triglyceride and LDL, and that this
`treatment is safe and beneficial for patients with various
`arterial diseases in tenns of preventing progression of the
`disease.
`
`References
`
`( 1 ) Needleman P and Raz A: Triene prostaglandins ; pros(cid:173)
`tacycline and thromboxane biosynthesis and unique biolog(cid:173)
`ical properties. Proc Natl Acad Sci USA, 76 : 944-948,
`1979
`( 2 ) Berg K : A new serum system in man. - The LP system.
`Acta Pathol Microbiol Scand, 59: 369-382, 1963
`( 3 ) Widmann MD and Sumpio BE : Lipoprotein(a) ; A risk fac(cid:173)
`tor for peripheral vascular disease. Ann Vase Surg, 7 :
`446-451, 1993
`( 4 ) Utermann G, Menzel HJ, and Kraft HG : Lp(a) glycoprotein
`phenotypes ; Inheritance and relation to Lp(a)-lipoprotein
`concentrations in plasma, J Clin Invest. 80 : 458-465, 1987
`( 5 ) Carlson LA, Hamsten A, and Asplund A : Pronounced
`lowering of serum levels of lipoprotein Lp(a) in hyper(cid:173)
`lipidaemic subjects treated with nicotinic acid. J Intern
`Med, 226 : 271-276, 1989
`( 6 ) Thompson PD, Cullinane EM, and Sady SP : Contrasting
`effects of testosterone and stanozolol on serum lipoprotein
`levels. JAMA, 261: 1165-1168, 1989
`( 7 ) Abe A, Maeda S, and Makino K : Enzyme-linked im(cid:173)
`munosorbent assay of lipoprotein(a) in serum and cord
`blood. Clin Chim Acta, 177: 31-40, 1988
`( 8 ) Rhoads GG, Dahlen G, and Berg K : Lp(a) lipoprotein as a
`risk factor for myocardial infarction. JAMA, 256 : 2540-
`2544, 1986
`( 9 ) Vessby B and Kostner G : Diverging effects of cholestyr(cid:173)
`amine on apoprotein B and lipoprotein Lp(a), Athero(cid:173)
`sclerosis, 44: 61-71, 1982
`(10) Schmidt EB, Klausen IC, and Kristensen SD : The effect of
`n-3 polyunsaturated fatty acids on Lp(a). Clin Chim Acta,
`198: 'Zl1-277, 1991
`(11) Joseph L : Lipoprotein (a) A unique risk factor for athero(cid:173)
`thrombotic disease. Arteriosclerosis, 10 : 672-679, 1990
`(12) Harris WS, Windsor SL, and Dujovne CA : Effect of four
`doses of n-3 fatty acids given to hyperlipidemic patients for
`six months. J Ame Coll Nutr, 10 : 220-227, 1991
`(13) Gries A, Malle E, Wurm H, and Kostner GM : Influence of
`dietary fish oils on plasma Lp(a) levels. Thromb Res, 58 :
`667-668, 1990
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