Coronary atherosclerosis in youths in Kyushu Island, Japan: histological findings and stenosis

n-3 Polyunsaturated Fatty Acids: Promising Nutrients for Preventing Cardiovascular Disease

The adoption of the Western-style diet, with decreased fish intake and lack of exercise, has increased the prevalence of cardiovascular disease (CVD) in Japan. Statin treatment has been established to reduce the risk of cardiovascular events; however, 60%–70% of these events occur despite its use. Thus, the residual risk for CVD should be identified and resolved to reduce further cardiovascular events. The serum levels of n-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid and docosahexaenoic acid, are reportedly associated with an increased incidence of cardiovascular events and mortality, whereas the addition of n-3 PUFA treatment to the statin treatment decreases cardiovascular events. Similar to statins, n-3 PUFAs have pleiotropic effects in addition to lipid-modifying effects. Pre-clinical and clinical studies have shown that n-3 PUFAs prevent cardiovascular events by ameliorating endothelial function and attenuating lipid accumulation, vascular inflammation, and macrophage recruitment, thereby causing coronary plaque development and rupture. Taken together, n-3 PUFAs are comprehensively able to attenuate the atherogenic response. Therefore, n-3 PUFA intake is recommended to prevent cardiovascular events, particularly in patients with multiple cardiovascular risk factors.

Reduced ratio of eicosapentaenoic acid and docosahexaenoic acid to arachidonic acid is associated with early onset of acute coronary syndrome

BACKGROUND

The hospitalization rate for acute coronary syndrome (ACS) for people aged ≤50 has remained stable over the past decade. Increased serum levels of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a decreased incidence of cardiovascular events and mortality in older patients; however, it is currently unknown whether reduced serum levels of n-3 PUFAs is also a risk factor for ACS in patients aged ≤50 years.

METHODS AND RESULTS

We retrospectively reviewed 102 (male/ female 73/29) Japanese ACS patients whose serum levels of EPA/arachidonic acid (AA) and DHA/AA were evaluated on admission. The EPA/AA ratio was the lowest in patients aged ≤50 compared to patients aged 51-74 and ≥75. Pearson correlation analysis showed that early ACS onset was associated with low EPA/AA and DHA/AA ratios, and multiple regression analysis determined that decreased ratios of EPA/AA and DHA/AA, and male sex, current smoker status, increased body mass index and triglyceride levels, independently correlated with early ACS onset. Conversely, low-density and high-density lipoproteins, glycated hemoglobin, and hypertension did not correlate with early ACS onset. Subgroup analyses of male patients revealed that decreased ratios of EPA/AA and DHA/AA independently correlated with early ACS onset.

CONCLUSION

Decreased EPA/AA and DHA/AA ratios may be risk factors for early onset of ACS, suggesting that reduced EPA/AA and DHA/AA may represent targets for preventing ACS in Japanese young people.

Overexpression of heme oxygenase-1 in coronary atherosclerosis of Japanese autopsies with diabetes mellitus: Hisayama study

Few studies regarding the topographical expression of heme oxygenase-1 (HO-1) and its pathophysiological role in human coronary atherosclerotic lesions, particularly in relation to type 2 diabetes mellitus (DM) and intimal angiogenesis, have been reported. HO-1 expression was immunohistochemically examined in 312 tissue blocks of coronary arteries obtained from 53 Japanese autopsy cases in Hisayama cohort study that included 19 diabetic subjects and 34 age- and sex-matched non-diabetic subjects (56-93 years old, mean+/-S.D.: 73+/-10). The HO-1 was ubiquitously distributed in atherosclerotic intima, and was mainly expressed by macrophages and endothelial cells, and partly by smooth muscle cells. The prevalence of HO-1 expression increased as the lesion type (as classified by the American Heart Association (AHA) Committee) and stenotic grade progressed (p<0.0001), and was significantly higher in diabetic than in non-diabetic subjects (p<0.01). This HO-1 overexpression was associated with greater CD-68-positive macrophage infiltration (p=0.005). Interestingly, the distribution of HO-1-positive cells was accentuated in coronary atherosclerotic lesions with intimal microvessels in diabetic subjects (p<0.05), particularly those with hypercholesterolemia (p<0.05), and was preferentially distributed in the shoulder region of atherosclerotic lesion type IV in the AHA classification (p<0.01). In conclusion, HO-1 expression was distributed in overall human coronary atherosclerotic lesions, particularly in diabetic subjects, indicating that HO-1 expression is intimately associated with atherogenesis and may play an important role as an adaptive molecule in the inflammatory-repair process. The association of HO-1 overexpression with a greater extent of intraplaque angiogenesis suggests a multi-faceted role for HO-1 in modulating the progression of atherosclerosis.

Role of thrombogenic factors in the development of atherosclerosis

Hemostatic factors play a crucial role in generating thrombotic plugs at sites of vascular damage (atherothrombosis). However, whether hemostatic factors contribute directly or indirectly to the pathogenesis of atherosclerosis remains uncertain. Autopsy studies have revealed that intimal thickening represents the first stage of atherosclerosis and that lipid-rich plaque arises from such lesions. Several factors contribute to the start of intimal thickening. Platelets release several growth factors and bioactive agents that play a central role in development of not only thrombus but also of intimal thickening. We have been investigating which coagulation factors simultaneously, or subsequently with platelet aggregation, participate in thrombus formation. Tissue factor (TF) is an essential initiator of blood coagulation that is expressed in various stages of atherosclerotic lesions in humans and other animals. Factors including thrombin and fibrin, which are downstream of the coagulation cascade activated by TF, also contribute to atherosclerosis. TF is involved in cell migration, embryogenesis and angiogenesis. Thus TF, in addition to factors downstream of the coagulation cascade and the protease-activated receptor 2 activation system, would be a multifactorial regulator of atherogenesis.

Serum fatty acid composition in primary school children is associated with serum cholesterol levels and dietary fat intake

OBJECTIVE

To examine the serum fatty acid composition, serum cholesterol levels, and dietary fat intake associated with body composition in primary school children of both urban and rural regions in Taiwan.

DESIGN

Subjects were randomly stratified by region and primary school. The sample consisted of 870 children aged 10 and 11 y old. The sample was equally distributed between an urban region (Kaohsiung City) and a rural region (Yunlin County). The gender ratio of samples from each area was matched. Food record-assisted 24-h dietary recalls and serum lipid measurements were collected for each child, and associations between serum total cholesterol (TC) and fatty acids composition as well as between body mass index (BMI) and triceps skinfold (TSF) were evaluated for both urban and rural regions.

RESULTS

Compared with students in the urban region, those in the rural region had significantly lower total fat intake, BMI, TSF, TC, and LDL cholesterol (LDL-C) and higher HDL-cholesterol (HDL-C) (P<0.05). Increased total fat (P<0.05) as a proportion of total energy was associated with increased TC and LDL-C. Lauric, myristic, and oleic acid levels in the serum of urban boys were significantly higher (P=0.0001, 0.0003, and 0.0398, respectively) than those of rural boys. In girls, the different fatty acid compositions affected TC concentrations, and palmitic and stearic acids of serum in the high-TC group were significantly lower (P=0.0179 and 0.0001, respectively) than those in the low-TC group.

CONCLUSIONS

Urban children had a dietary fat intake that both quantitatively and qualitatively differed from the traditional rural Chinese diet in Taiwan as reflected in rural children. Consumption of total fat was positively associated with BMI, TSF, TC, and LDL-C levels in Taiwanese children aged 10 and 11 y.

SPONSORSHIP

This study was partly sponsored by a research grant from the Department of Health, Taiwan, ROC.

Blood lipids, fatty acids, diet and lifestyle parameters in adolescents from a region in northern Norway with a high mortality from coronary heart disease

INTRODUCTION

Students aged 13 and 14 y, in a region in northern Norway with high blood cholesterol levels and high mortality from coronary heart disease (CHD) in the adult population, were studied with respect to lifestyle, dietary habits, nutritional intake and blood lipids including fatty acids in serum. The students came from a coastal community with seawater fish as an important part of the traditional diet, and an inland community with meat from reindeer as a major constituent of the diet.

OBJECTIVE

To investigate whether the traditional diet was maintained among the adolescents and to evaluate the lifestyle and blood lipids. The study was followed up after 1 y.

RESULTS

The adolescents from the coastal region did not maintain the traditional diet. In the inland region the students had a high intake of meat, probably reflecting the traditional food culture. The inland boys had higher mean body mass index (BMI) than the coastal boys, and 12% had BMI>28, as compared to none of the coastal boys. Other findings showed that the students had higher levels of blood cholesterol than in the south of Norway and several other countries (about 25% had total cholesterol >5.2 mmol/l), higher intake of dietary sugar and fat than the national recommendations and little intake of seawater fish with corresponding low levels of n-3 fatty acids. This did not change after 1 y of follow up. Some 10-20% reported daily smoking and 8-13% reported that they rarely or never did physical exercise. About 30% of the students presented no factors negatively related to development of cardiovascular disease.

CONCLUSION

The findings demonstrate, in the majority of students at the age of 13 and 14 y, the appearance of factors contributing to development of cardiovascular disease (CHD).

SPONSORSHIP

This study was supported by the program 'Medisinsk forskning i Finnmark, University of Tromsø'.