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Featured researches published by Noriaki Nakaya.


The Lancet | 2007

Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis.

Mitsuhiro Yokoyama; Hideki Origasa; Masunori Matsuzaki; Yuji Matsuzawa; Yasushi Saito; Yuichi Ishikawa; Shinichi Oikawa; Jun Sasaki; Hitoshi Hishida; Hiroshige Itakura; Toru Kita; Akira Kitabatake; Noriaki Nakaya; Toshiie Sakata; Kazuyuki Shimada; Kunio Shirato

BACKGROUND Epidemiological and clinical evidence suggests that an increased intake of long-chain n-3 fatty acids protects against mortality from coronary artery disease. We aimed to test the hypothesis that long-term use of eicosapentaenoic acid (EPA) is effective for prevention of major coronary events in hypercholesterolaemic patients in Japan who consume a large amount of fish. METHODS 18 645 patients with a total cholesterol of 6.5 mmol/L or greater were recruited from local physicians throughout Japan between 1996 and 1999. Patients were randomly assigned to receive either 1800 mg of EPA daily with statin (EPA group; n=9326) or statin only (controls; n=9319) with a 5-year follow-up. The primary endpoint was any major coronary event, including sudden cardiac death, fatal and non-fatal myocardial infarction, and other non-fatal events including unstable angina pectoris, angioplasty, stenting, or coronary artery bypass grafting. Analysis was by intention-to-treat. The study was registered at ClinicalTrials.gov, number NCT00231738. FINDINGS At mean follow-up of 4.6 years, we detected the primary endpoint in 262 (2.8%) patients in the EPA group and 324 (3.5%) in controls-a 19% relative reduction in major coronary events (p=0.011). Post-treatment LDL cholesterol concentrations decreased 25%, from 4.7 mmol/L in both groups. Serum LDL cholesterol was not a significant factor in a reduction of risk for major coronary events. Unstable angina and non-fatal coronary events were also significantly reduced in the EPA group. Sudden cardiac death and coronary death did not differ between groups. In patients with a history of coronary artery disease who were given EPA treatment, major coronary events were reduced by 19% (secondary prevention subgroup: 158 [8.7%] in the EPA group vs 197 [10.7%] in the control group; p=0.048). In patients with no history of coronary artery disease, EPA treatment reduced major coronary events by 18%, but this finding was not significant (104 [1.4%] in the EPA group vs 127 [1.7%] in the control group; p=0.132). INTERPRETATION EPA is a promising treatment for prevention of major coronary events, and especially non-fatal coronary events, in Japanese hypercholesterolaemic patients.


The Lancet | 2006

Primary prevention of cardiovascular disease with pravastatin in Japan (MEGA Study): a prospective randomised controlled trial

Haruo Nakamura; Kikuo Arakawa; Hiroshige Itakura; Akira Kitabatake; Yoshio Goto; Takayoshi Toyota; Noriaki Nakaya; Shoji Nishimoto; Masaharu Muranaka; Akira Yamamoto; Kyoichi Mizuno; Yasuo Ohashi

BACKGROUND Evidence-based treatment for hypercholesterolaemia in Japan has been hindered by the lack of direct evidence in this population. Our aim was to assess whether evidence for treatment with statins derived from western populations can be extrapolated to the Japanese population. METHODS In this prospective, randomised, open-labelled, blinded study, patients with hypercholesterolaemia (total cholesterol 5.69-6.98 mmol/L) and no history of coronary heart disease or stroke were randomly assigned diet or diet plus 10-20 mg pravastatin daily. The primary endpoint was the first occurrence of coronary heart disease. Statistical analyses were done by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT00211705. FINDINGS 3966 patients were randomly assigned to the diet group and 3866 to the diet plus pravastatin group. Mean follow-up was 5.3 years. At the end of study, 471 and 522 patients had withdrawn, died, or been lost to follow-up in the diet and diet plus pravastatin groups, respectively. Mean total cholesterol was reduced by 2.1% (from 6.27 mmol/L to 6.13 mmol/L) and 11.5% (from 6.27 mmol/L to 5.55 mmol/L) and mean LDL cholesterol by 3.2% (from 4.05 mmol/L to 3.90 mmol/L) and 18.0% (from 4.05 mmol/L to 3.31 mmol/L) in the diet and the diet plus pravastatin groups, respectively. Coronary heart disease was significantly lower in the diet plus pravastatin group than in the diet alone group (66 events vs 101 events; HR 0.67, 95% CI 0.49-0.91; p=0.01). There was no difference in the incidence of malignant neoplasms or other serious adverse events between the two groups. INTERPRETATION Treatment with a low dose of pravastatin reduces the risk of coronary heart disease in Japan by much the same amount as higher doses have shown in Europe and the USA.


Atherosclerosis | 2008

Effects of EPA on coronary artery disease in hypercholesterolemic patients with multiple risk factors: sub-analysis of primary prevention cases from the Japan EPA Lipid Intervention Study (JELIS).

Yasushi Saito; Mitsuhiro Yokoyama; Hideki Origasa; Masunori Matsuzaki; Yuji Matsuzawa; Yuichi Ishikawa; S. Oikawa; Jun Sasaki; Hitoshi Hishida; Hiroshige Itakura; Toru Kita; Akira Kitabatake; Noriaki Nakaya; Toshiie Sakata; Kazuyuki Shimada; Kunio Shirato

BACKGROUND Japan EPA Lipid Intervention Study (JELIS) was a large-scale clinical trial examining the effects of eicosapentaenoic acid (EPA) on coronary artery disease (CAD) in hypercholesterolemic patients. Herein, we focused on risk factors other than low-density lipoprotein cholesterol (LDL-C) to investigate the effects of EPA on CAD among JELIS primary prevention cases. METHODS Hypercholesterolemic patients on statin therapy but without evidence of CAD (n=14,981) were randomly assigned to an EPA group (n=7503) or a control group (n=7478). The relationships between incident CAD, the number of CAD risk factors (hypercholesterolemia; obesity; high triglyceride (TG) or low high-density lipoprotein cholesterol (HDL-C); diabetes; and hypertension) and EPA treatment were investigated. RESULTS For the control and EPA groups combined, a higher number of risk factors was directly associated with an increased incidence of CAD. Incidence was lower for the EPA group than for the control group regardless of the numbers of risk factors. Compared to patients with normal serum TG and HDL-C levels, those with abnormal levels (TG >or=150 mg/dL; HDL-C <40 mg/dL) had significantly higher CAD hazard ratio (HR: 1.71; 95% CI: 1.11-2.64; P=0.014). In this higher risk group, EPA treatment suppressed the risk of CAD by 53% (HR: 0.47; 95% CI: 0.23-0.98; P=0.043). CONCLUSIONS Multiple risk factors besides cholesterol are associated with markedly increased incidence of CAD. High TG with low HDL-C represents a particularly potent risk factor. EPA was effective in reducing the incidence of CAD events for patients with this dyslipidemic pattern, suggesting that EPA may be especially beneficial in patients who with abnormal TG and HDL-C levels.


Stroke | 2008

Reduction in the Recurrence of Stroke by Eicosapentaenoic Acid for Hypercholesterolemic Patients: Subanalysis of the JELIS Trial

Kortaro Tanaka; Yuichi Ishikawa; Mitsuhiro Yokoyama; Hideki Origasa; Masunori Matsuzaki; Yasushi Saito; Yuji Matsuzawa; Jun Sasaki; S. Oikawa; Hitoshi Hishida; Hiroshige Itakura; Toru Kita; Akira Kitabatake; Noriaki Nakaya; Toshiie Sakata; Kazuyuki Shimada; Kunio Shirato

Background and Purpose— The JELIS trial examined the preventive effect of eicosapentaenoic acid (EPA) against coronary artery diseases. Hypercholesterolemic patients received statin only (no EPA group: n=9319) or statin with EPA (EPA group: n=9326) for around 5 years. EPA significantly suppressed the incidence of coronary events in previous analysis. Herein, we investigated the effects of EPA on the primary and secondary prevention of stroke. Methods— We conducted a subanalysis of JELIS with respect to stroke incidence in the primary and secondary prevention subgroups defined as those without and with a prior history of stroke using Cox proportional hazard ratios, adjusted for baseline risk factor levels. Results— As for primary prevention of stroke, this occurred in 114 (1.3%) of 8862 no EPA group and in 133 (1.5%) of 8841 EPA group. No statistically significant difference in total stroke incidence (Hazard Ratio, 1.08; 95% confidence interval, 0.95 to 1.22) was observed between the no EPA and the EPA groups. In the secondary prevention subgroup, stroke occurred in 48 (10.5%) of 457 no EPA group and in 33 (6.8%) of 485 EPA group, showing a 20% relative reduction in recurrent stroke in the EPA group (Hazard Ratio, 0.80; 95% confidence interval, 0.64 to 0.997). Conclusions— Administration of highly purified EPA appeared to reduce the risk of recurrent stroke in a Japanese population of hypercholesterolemic patients receiving low-dose statin therapy. Further research is needed to determine whether similar benefits are found in other populations with lower levels of fish intake. The trial is registered at ClinicalTrials.gov (number NCT00231738).


Atherosclerosis | 2002

A randomized, double-blind trial comparing the efficacy and safety of pitavastatin versus pravastatin in patients with primary hypercholesterolemia

Yasushi Saito; Nobuhiro Yamada; Tamio Teramoto; Hiroshige Itakura; Yoshiya Hata; Noriaki Nakaya; Hiroshi Mabuchi; Motoo Tushima; Jun Sasaki; Nobuya Ogawa; Yuichiro Goto

Pitavastatin (p-INN) is a novel and fully synthetic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, with a cholesterol-lowering action stronger than that of other statins currently in use. A 12-week, multi-center, randomized, double-blind, controlled study was conducted to confirm the efficacy and safety of pitavastatin compared with pravastatin, an agent for using to reduce low density lipoprotein cholesterol (LDL-C) in hypercholesterolemic patients. Patients were recruited at 43 institutes in Japan. Following more than 4 weeks run-in period, 240 patients were randomized to receive 2 mg of pitavastatin or 10 mg of pravastatin daily. At 12 weeks post-randomization, the pitavastatin group showed significantly lower LDL-C levels by -37.6% from baseline compared with -18.4% in the pravastatin group (P<0.05). Pitavastatin also significantly lowered total cholesterol (TC) by -28.2% compared with -14.0% of pravastatin (P<0.05). The LDL-C target level of <140 mg/dl was attained in 75% of the patients treated with pitavastatin, compared with 36% of those in the pravastatin group (P<0.05). Pitavastatin also significantly reduced triglycerides (TG), apo B, C-II and C-III, compared with pravastatin, and increased HDL-C, apo A-I and A-II, to the same extent of pravastatin. Safety was assessed by monitoring adverse events and measuring clinical laboratory parameters. The adverse event profile was similar for both treatment groups and neither treatment caused clinically relevant laboratory abnormalities. These results indicated that pitavastatin was more effective than pravastatin, and both drugs were well-tolerated in the treatment of hypercholesterolemia.


Circulation | 2008

Usefulness of Pravastatin in Primary Prevention of Cardiovascular Events in Women Analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA Study)

Kyoichi Mizuno; Noriaki Nakaya; Yasuo Ohashi; Naoko Tajima; Toshio Kushiro; Tamio Teramoto; Shinichiro Uchiyama; Haruo Nakamura

Background— It is well known that statins reduce the risk of cardiovascular disease. However, the effect of statins in women for the primary prevention of cardiovascular disease has not been determined. We conducted an exploratory analysis of the effect of diet plus pravastatin therapy on the primary prevention of cardiovascular events in women with data from a large-scale primary prevention trial with pravastatin. Methods and Results— Patients with hypercholesterolemia (5.7 to 7.0 mmol/L) and no history of coronary heart disease or stroke were randomized to diet or diet plus pravastatin 10 to 20 mg/d and followed up for ≥5 years. We investigated the effect of diet plus pravastatin treatment on cardiovascular events in 5356 women during the 5-year follow-up. The incidence of cardiovascular events in the women was 2 to 3 times lower than that in men. The occurrence of cardiovascular events was 26% to 37% lower in the diet plus pravastatin treatment group than in the diet alone group. Although these differences did not reach statistical significance, the overall risk reductions were similar to those in men. Notably, women ≥60 years of age treated with diet plus pravastatin had markedly higher risk reductions for coronary heart disease (45%), coronary heart disease plus cerebral infarction (50%), and stroke (64%) than did women treated with diet alone. Conclusions— Treatment with pravastatin in women with elevated cholesterol but no history of cardiovascular disease provides a benefit similar to that seen in men, and this benefit is more marked in older women. This treatment should be considered routinely for primary cardiovascular protection in women with elevated cholesterol levels.


Atherosclerosis | 2009

Suppressive effect of EPA on the incidence of coronary events in hypercholesterolemia with impaired glucose metabolism: Sub-analysis of the Japan EPA Lipid Intervention Study (JELIS).

Shinichi Oikawa; Mitsuhiro Yokoyama; Hideki Origasa; Masunori Matsuzaki; Yuji Matsuzawa; Yasushi Saito; Yuichi Ishikawa; Jun Sasaki; Hitoshi Hishida; Hiroshige Itakura; Toru Kita; Akira Kitabatake; Noriaki Nakaya; Toshiie Sakata; Kazuyuki Shimada; Kunio Shirato

BACKGROUND JELIS was a large-scale clinical trial that investigated the effects of eicosapentaenoic acid (EPA) on coronary artery disease (CAD). In this paper, the data of patients registered in JELIS were analysed to compare the incidence of CAD between patients with impaired glucose metabolism (IGM) and normoglycemic (NG) patients. The effect of EPA on the incidence of CAD in patients with IGM was also assessed. METHODS The 18,645 hypercholesterolemic patients registered in JELIS were divided into two groups. One group consisted of patients with IGM (n=4565), which included the patients who had diabetes mellitus and patients who had a fasting plasma glucose of 110mg/dL or higher, either at the time of registration or after 6 months. The other group consisted of NG patients (n=14,080). CAD incidence of the two groups over the average 4.6-year follow-up period was compared, and the effect of EPA was assessed. RESULTS Compared to NG patients, IGM patients had a significantly higher CAD hazard ratio (1.71 in the non-EPA group and 1.63 in the EPA group). The treatment with EPA resulted in a 22% decrease in the CAD incidence (P=0.048) in IGM patients and an 18% decrease (P=0.062) in NG patients. CONCLUSIONS It was found that the CAD risk in IGM patients is higher than in NG patients, and that highly purified EPA is very effective in decreasing the incidence of CAD among Japanese IGM patients, even though the intake of fish is high.


Atherosclerosis | 2008

Pravastatin reduces the risk for cardiovascular disease in Japanese hypercholesterolemic patients with impaired fasting glucose or diabetes: Diabetes subanalysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study

Naoko Tajima; Hideaki Kurata; Noriaki Nakaya; Kyoichi Mizuno; Yasuo Ohashi; Toshio Kushiro; Tamio Teramoto; Shinichiro Uchiyama; Haruo Nakamura

Diabetes mellitus (DM) is a major risk factor for cardiovascular disease (CVD) in patients with no history of CVD. Evidence for the effect of statins on CVD in the diabetic population in low-risk populations (e.g., Japanese) is limited. We evaluated the effect of pravastatin on risk reduction of CVD related to baseline glucose status in a primary prevention setting. The Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, in patients with mild-to-moderate hypercholesterolemia (220-270 mg/dL), showed that low-dose pravastatin significantly reduced the risk for CVD by 26%. This exploratory subanalyses examined the efficacy of diet plus pravastatin on CVD in 2210 patients with abnormal fasting glucose (AFG, including 1746 patients with DM and 464 patients with impaired fasting glucose (IFG) at 5 years in the MEGA Study. CVD was threefold higher in AFG patients (threefold higher in DM, and twofold higher in IFG) compared with normal fasting glucose (NFG) patients in the diet group. Diet plus pravastatin treatment significantly reduced the risk of CVD by 32% (hazard ratio 0.68, 95% CI 0.48-0.96, number needed to treat, 42) in the AFG group compared with the diet alone group, and no significant interaction between AFG and NFG (interaction P=0.85) was found. Safety problems were not observed during long-term treatment with pravastatin. In conclusion, pravastatin reduces the risk of CVD in subjects with hypercholesterolemia and abnormal fasting glucose in the primary prevention setting in Japan.


Hypertension | 2009

Pravastatin for Cardiovascular Event Primary Prevention in Patients With Mild-to-Moderate Hypertension in the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study

Toshio Kushiro; Kyoichi Mizuno; Noriaki Nakaya; Yasuo Ohashi; Naoko Tajima; Tamio Teramoto; Shinichiro Uchiyama; Haruo Nakamura

Lipid-lowering therapy in individuals with high risk of cardiovascular disease reduces the incidence of coronary heart disease. However, few studies have assessed the benefits of cholesterol lowering for primary prevention of coronary heart disease in hypertensive patients with mild dyslipidemia or without conventional dyslipidemia. The large, randomized Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese Study showed a 33% reduction in coronary heart disease incidence with pravastatin as the primary prevention in Japanese patients. We conducted an exploratory analysis of the effect of diet plus pravastatin therapy on the primary prevention of cardiovascular events (coronary heart disease, coronary heart disease plus cerebral infarction, and cardiovascular disease) in the 3277 patients with hypertension during the 5-year follow-up. There were no significant differences in mean baseline total cholesterol, blood pressure levels, or variation in blood pressure during the 5-year period between the diet (n=1664) and diet plus pravastatin (n=1613) groups. In the diet plus pravastatin group, the relative risk of coronary heart disease plus cerebral infarction was reduced by 35% (hazard ratio: 0.65; CI: 0.46 to 0.93; P=0.02), cerebral infarction by 46% (hazard ratio: 0.54; CI: 0.29 to 0.98; P=0.04), and cardiovascular disease by 33% (hazard ratio: 0.67; CI: 0.49 to 0.91; P=0.01). In patients without a history of cardiovascular disease who have hypertension and mildly elevated cholesterol, pravastatin was effective in reducing the incidence of cardiovascular disease, particularly cerebral infarction. Hence, in patients with hypertension with mildly elevated cholesterol levels, treatment with a statin is advisable to reduce the burden of cardiovascular disease.


Atherosclerosis | 1999

Analysis of serum lipid levels in Japanese men and women according to body mass index. Increase in risk of atherosclerosis in postmenopausal women

Akira Yamamoto; Hiroshi Horibe; Hiroshi Mabuchi; Toru Kita; Yuji Matsuzawa; Yasushi Saito; Noriaki Nakaya; Takayuki Fujioka; Hitomi Tenba; Akito Kawaguchi; Haruo Nakamura; Yuichiro Goto

Relatively low serum lipid levels are thought to be an important factor contributing to the low incidence of ischemic heart diseases (IHD) in Japanese. It has been proven that obesity or overweight constitutes a basal condition for several risk factors in atherosclerosis. The purpose of this study is to obtain data on serum lipids and lipoprotein profiles in relation to body mass index (BMI), which will enable us to compare the nature and weight of metabolic risk factors in atherosclerosis between Japanese and people in Western countries. Data of total serum cholesterol, triglyceride, and HDL-cholesterol levels of Japanese men and women obtained from a large-scale survey in 1990 were analysed according to BMI for different age groups. Apolipoprotein A-I and B and Lp(a) were also measured in randomly selected samples and their contribution as a risk factor was estimated especially in postmenopausal women. The subjects in two age groups of men (20-39 and 40 59 years) and women (20 39 and 50-69 years) were graded into quintiles according to the BMI. The middle grades of BMI were 21.9-23.3 and 22.4-23.6 for younger and older men, and 20.0-21.1 and 22.2-23.6 for younger and older women, respectively. These values are much lower than those in Western populations, the border between the IVth and the top quintile almost corresponding to the average for Americans. Total cholesterol showed a tendency to shift into higher ranges in all age groups in both men and women as BMI increased, with the highest distribution remaining in the range of 160-199 mg/dl (4.2-5.2 mmol/l). The average cholesterol levels for the top quintile of BMI were still lower than most of the average values in Western populations. The distribution of cholesterol in higher ranges was much greater and the difference according to BMI was smaller in older women than in men. In both men and women, whether younger or older, about 90% of the subjects in the lower quintiles of BMI had triglyceride levels lower than 150 mg/dl. The distribution in the higher range of triglyceride was small in women, not only at younger ages but also in postmenopausal women at the top quintile of BMI. About 85% of the younger women with a middle grade of BMI had an HDL-cholesterol level higher than 50 mg/dl. The values in postmenopausal women were still higher than in men aged 40-59 years. Shift of the distribution curves of HDL-cholesterol according to BMI was similar in all groups and more remarkable than the change in triglyceride. The average HDL-cholesterol levels at the top quintile were almost comparable to the average values in Western countries; the difference in HDL-cholesterol levels between the two populations can mostly be explained by the difference in BMI. Smokers showed a slightly lower total cholesterol and significantly (3-4 mg/dl) lower HDL-cholesterol levels, although there was no difference in distribution of BMI between smokers and non-smokers. Relatively low total cholesterol levels even in smokers has probably contributed to the low incidence of IHD in spite of the high frequency of smoking in Japanese population. Mean Lp(a) levels showed a tendency to increase after age 40 in women. BMI itself did not have a correlation with serum Lp(a) levels. The distribution curve of Lp(a) shifted to higher levels as total cholesterol increased and the tendency was most remarkable in women around or after the menopause. It was remarkable in older women that as the total cholesterol or apo B level increased there was also an increased prevalence of abnormal ECG with a pattern of myocardial ischemia. Postmenopausal women seem to have a great risk of atherosclerosis regarding the lipid and lipoprotein profile even in the Japanese population.

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Hiroshige Itakura

Ibaraki Christian University

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Jun Sasaki

International University of Health and Welfare

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