Longitudinal trends in total serum cholesterol levels in a Japanese cohort, 1958-1986

Longitudinal and secular trends in total cholesterol levels and impact of lipid-lowering drug use among Norwegian women and men born in 1905-1977 in the population-based Tromsø Study 1979-2016

OBJECTIVES

Elevated blood cholesterol is a modifiable risk factor for cardiovascular disease. Cholesterol level surveillance is necessary to study population disease burden, consider priorities for prevention and intervention and understand the effect of diet, lifestyle and treatment. Previous studies show a cholesterol decline in recent decades but lack data to follow individuals born in different decades throughout life.

METHODS

We investigated changes in age-specific and birth cohort-specific total cholesterol (TC) levels in 43 710 women and men born in 1905-1977 (aged 20-95 years at screening) in the population-based Tromsø Study. Fifty-nine per cent of the participants had more than one and up to six repeated TC measurements during 1979-2016. Linear mixed models were used to test for time trends.

RESULTS

Mean TC decreased during 1979-2016 in both women and men and in all age groups. The decrease in TC in age group 40-49 years was 1.2 mmol/L in women and 1.0 mmol/L in men. Both the 80th and the 20th percentile of the population TC distribution decreased in both sexes and all age groups. Longitudinal analysis showed that TC increased with age to a peak around middle age followed by a decrease. At any given age, TC significantly decreased with increase in year born. Lipid-lowering drug use was rare in 1994, increased thereafter, but was low (<3% in women and <5% in men) among those younger than 50 years in all surveys. Between 1994 and 2016, lipid-lowering drug treatment in individuals 50 years and older explained 21% and 28% of the decrease in TC levels in women and men, respectively.

CONCLUSIONS

We found a substantial decrease in mean TC levels in the general population between 1979 and 2016 in all age groups. In birth cohorts, TC increased with age to a peak around middle age followed by a decrease.

Traditional Risk Factors for Stroke in East Asia

Stroke is one of the leading causes of death and morbidity worldwide. The occurrence of stroke is strongly dependent on well-known vascular risk factors. After rapid modernization, urbanization, and mechanization, East Asian countries have experienced growth in their aged populations, as well as changes in lifestyle and diet. This phenomenon has increased the prevalence of vascular risk factors among Asian populations, which are susceptible to developing cardiovascular risk factors. However, differing patterns of stroke risk factor profiles have been noted in East Asian countries over the past decades. Even though the prevalence of vascular risk factors has changed, hypertension is still prevalent and the burden of diabetes and hypercholesterolemia will continue to increase. Asia remains a high tobacco-consuming area. Although indicators of awareness and management of vascular risk factors have increased in many East Asian countries, their rates still remain low. Here we review the burdens of traditional risk factors, such as hypertension, diabetes, hypercholesterolemia, and smoking in East Asia. We will also discuss the different associations between these vascular risk factors and stroke in Asian and non-Asian populations.

Age-Related Changes in the Cardiometabolic Profiles in Singapore Resident Adult Population: Findings from the National Health Survey 2010

We describe the centile trends of the blood pressure, glycemia and lipid profiles as well as renal function of a representative population who participated in the Singapore National Health Survey in 2010. Representative survey population was sampled in two phases, first using geographical/ residential dwelling type stratification, followed up ethnicity. 2,407 survey participants without any self-reported medical or medication history for diabetes mellitus, hypertension and dyslipidemia were included in this analysis. All biochemistry analyses were performed on Roche platforms. After excluding outliers using Tukey's criteria, the results of the remaining participants were subjected to lambda-mu-sigma (LMS) analysis. In men, systolic blood pressure increased linearly with age. By contrast, an upward inflection around late 40s was seen in women. The diastolic blood pressure was highest in men in the late 30s-50s age group, and in women in the late 50s-60s age group. All glycemia-related parameters, i.e. fasting and 2-hour plasma glucose and HbA1c concentrations increased with age, although the rate of increase differed between the tests. Total cholesterol and LDL-cholesterol concentrations increased with age, which became attenuated between the early 30s and late 50s in men, and declined thereafter. In women, total cholesterol and LDL-cholesterol concentrations gradually increased with age until late 30s, when there is an upward inflection, plateauing after late 50s. Our findings indicate that diagnostic performance of laboratory tests for diabetes may be age-sensitive. Unfavourable age-related cardiovascular risk profiles suggest that the burden of cardiovascular disease in this population will increase with aging population.

Mortality from Circulatory System Diseases among French Uranium Miners: A Nested Case-Control Study

A significant association has been observed between radon exposure and cerebrovascular disease (CeVD) mortality among French uranium miners, but risk factors for circulatory system diseases (CSD) have not been previously considered. We conducted new analyses in the recently updated (through 2007) French cohort of uranium miners (n = 5,086), which included 442 deaths from CSD, 167 of them from ischemic heart disease (IHD) and 105 from CeVD. A nested case-control study was then set up to collect and investigate the influence of these risk factors on the relationships between mortality from CSD and occupational external gamma ray and internal ionizing radiation exposure (radon and long-lived radionuclides) in this updated cohort. The nested case-control study included miners first employed after 1955, still employed in 1976 and followed up through 2007. Individual information about CSD risk factors was collected from medical files for the 76 deaths from CSD (including 26 from IHD and 16 from CeVD) and 237 miners who had not died of CSD by the end of follow-up. The exposure-risk relationships were assessed with a Cox proportional hazard model weighted by the inverse sampling probability. A significant increase in all CSD and CeVD mortality risks associated with radon exposure was observed in the total cohort [hazard ratios: HRCSD/100 working level months (WLM) = 1.11, 95% confidence interval (1.01; 1.22) and HRCeVD/100 WLM = 1.25 (1.09; 1.43), respectively]. A nonsignificant exposure-risk relationship was observed for every type of cumulative ionizing radiation exposure and every end point [e.g., HRCSD/100WLM = 1.43 (0.71; 2.87)]. The adjustment for each CSD risk factor did not substantially change the exposure-risk relationships. When the model was adjusted for overweight, hypertension, diabetes, hypercholesterolemia and smoking status, the HR/100WLM for CSD, for example, was equal to 1.21 (0.54; 2.75); and when it was adjusted for risk factors selected with the Akaike information criterion, it was equal to 1.44 (0.66; 3.14). To our knowledge, this is the first study to use a uranium miner cohort to consider the major standard CSD risk factors in assessing the relationships between ionizing radiation exposure and the risk of death from these diseases. These results suggest that the significant relationship between CeVD risk and radon exposure observed in the total French cohort is probably not affected by the CSD risk factors. Extending the collection of information about CSD risk factors to a larger subsample would be useful to confirm this result.

Association of foods enriched in conjugated linoleic acid (CLA) and CLA supplements with lipid profile in human studies: a systematic review and meta-analysis

Objective

The present study aimed to review the association of conjugated linoleic acid (CLA) consumption in two forms, foods enriched in CLA and CLA supplements, with serum lipid profile in human studies.

Design

Systematic review and meta-analysis.

Setting

Search process was conducted in PubMed, Cochrane Library, Google Scholar, Scopus and Science Direct. Clinical trials that investigated the association of CLA intakes either in the form of supplements or enriched foods with lipid profile in healthy adults were included. All outcomes were recorded as continuous variables, and the effect size was measured by analysis of the mean and standard deviation before and after the intervention for case and control groups.

Subjects

Healthy adult population.

Results

CLA supplementation was associated with a significant decrease in LDL cholesterol (mean difference=−0·218; 95 % CI −0·358, −0·077;P=0·002), a non-significant decrease in HDL cholesterol (mean difference=−0·051; 95 % CI −0·188, 0·086;P=0·468), a non-significant increase in total cholesterol (mean difference=0·009; 95 % CI −0·128, 0·146;P=0·896) and a non-significant decrease in TAG (mean difference=−0·065; 95 % CI −0·20, 0·07;P=0·344). Foods enriched with CLA were associated with significantly decreased LDL cholesterol (mean difference=−0·231; 95 % CI −0·438, −0·024;P=0·028), non-significantly increased HDL-C (mean difference=0·075; 95 % CI −0·121, 0·270;P=0·455), non-significantly decreased total cholesterol (mean difference=−0·158; 95 % CI −0·349, 0·042;P=0·124) and non-significantly decreased TAG (mean difference=−0·078; 95 % CI −0·274, 0·117;P=0·433).

Conclusions

According to our analysis, consumption of foods enriched with CLA or CLA supplements has favourable effects on LDL cholesterol levels.

Sarcopenia and sarcopenic obesity and their association with dyslipidemia in Korean elderly men: the 2008-2010 Korea National Health and Nutrition Examination Survey

BACKGROUND

Recently, aging has been shown to be associated with sarcopenic obesity (SO), of which decreased muscle mass and increased fat mass are features. Sarcopenia and obesity alone are known to be associated with abnormal lipid metabolism. However, it remains unclear whether SO has greater adverse effects on dyslipidemia than on sarcopenia or obesity alone.

AIM

We aimed to investigate the association between SO and dyslipidemia in elderly Koreans.

SUBJECTS AND METHODS

This study was based on data collected during the 2008-2010 Korea National Health and Nutrition Examination Survey. We included 1,466 men and 2,017 women aged 65 years and over. Sarcopenia was indicated in participants with height- or weight-adjusted appendicular skeletal muscle that was 1 standard deviation below the sex-specific mean for the young reference group, and obesity was defined as a body mass index ≥ 25 kg/m(2). Dyslipidemia was defined according to the National Cholesterol Education Program-Adult Treatment Panel III.

RESULTS

After adjusting for confounding factors, the SO group had a higher risk for dyslipidemia [odds ratio (OR) 2.82 (95 % confidence interval 1.76-4.51)] than the obese group [2.12 (1.11-4.07)] and sarcopenic group [1.46 (1.01-2.11)] (p < 0.001) only in men. Furthermore, the SO group in men had the highest OR for hypercholesterolemia, hypertriglyceridemia, hypo-high-density lipoprotein cholesterolemia, hyper-low-density lipoprotein cholesterolemia, and a high ratio of triglyceride to high-density lipoprotein cholesterol even after further adjustments.

CONCLUSIONS

In Korean elderly men, SO was associated with an increased risk for dyslipidemia compared with sarcopenia or obesity alone.

Epidemiology of cardiovascular risk factors in Asian countries

The distribution and burden of 5 conventional risk factors (elevated blood pressure, high total cholesterol, diabetes, obesity/overweight and smoking) for cardiovascular diseases (CVD) were reviewed in 10 selected Asian countries, in addition to the United Kingdom and the United States. Over the past 3 decades, age-standardized systolic blood pressure was on the decline in high-income countries but on the rise in low- to middle-income countries. Similar patterns were observed for total cholesterol levels, although the absolute levels remained higher in high-income countries. A pronounced increase in the prevalence of diabetes mellitus was seen in most of the Asian countries, corresponding to an increase in the levels of body mass index. The number of smokers declined markedly with time, particularly in men, in some selected Asian countries (Japan, Singapore, China, Vietnam). However, the prevalence of current smokers for all countries in 2011 remained excessive. The population-attributable risks for stroke and ischemic heart were highest for high blood pressure, followed by total cholesterol, obesity, and smoking. Evidence suggests that in both Asia and the West, no country is in sufficient control of any of these factors and that intervention programs to alter their effect on CVD are of equal importance.

A prospective follow-up study of the association of radiation exposure with fatal and non-fatal stroke among atomic bomb survivors in Hiroshima and Nagasaki (1980-2003)

OBJECTIVE

Use of medical radiotherapy has increased markedly in recent decades. Whether the consequence includes an increased risk of cardiovascular disease remains to be determined. The purpose of this study was to examine the association between radiation exposure and the incidence of stroke among Japanese atomic bomb survivors.

DESIGN

A prospective follow-up study.

SETTING AND PARTICIPANTS

Radiation exposure from the atomic bombing was assessed in 9515 subjects (34.8% men) with 24-year follow-up from 1980. Subjects were free of prevalent stroke when follow-up began.

OUTCOME MEASURES

Stroke events and the underlying cause of death were reviewed to confirm the first-ever stroke. Subtypes (ischaemic and haemorrhagic events) were categorised based on established criteria according to the definitions of typical/atypical stroke symptoms.

RESULTS

Overall mean radiation dose (±SD) in units of gray (Gy) was 0.38±0.58 (range: 0-3.5). During the study period, 235 haemorrhagic and 607 ischaemic events were identified. For men, after adjusting for age and concomitant risk factors, the risk of haemorrhagic stroke rose consistently from 11.6 to 29.1 per 10 000 person-years as doses increased from <0.05 to ≥2 Gy (p=0.009). Incidence also rose within the dose range <1 Gy (p=0.004) with no dose threshold. In women, the risk of haemorrhagic stroke rose with increasing radiation exposure but not until doses reached a threshold of 1.3 Gy (95% CI 0.5 to 2.3). Among women, for doses <1.3 Gy, differences in stroke risk were modest (13.5 per 10 000 person-years), while it increased to 20.3 per 10 000 person-years for doses that ranged from 1.3 to <2.2 Gy and to 48.6 per 10 000 person-years for doses that were higher (p=0.002). In both sexes, dose was unrelated to ischaemic stroke.

CONCLUSION

While the risk of haemorrhagic stroke increases with rising radiation exposure for both sexes, effects in women are less apparent until doses exceed a threshold at 1.3 Gy.

Integration of data from NIPPON DATA80/90 and National Nutrition Survey in Japan: for cohort studies of representative Japanese on nutrition

BACKGROUND

Diet is one of the most important lifestyle factors that a affect healthy life expectancy through onset of various lifestyle-related diseases. Large-scale cohort studies with sufficient baseline nutritional information are scarce. NIPPON DATA80/90 is cohort study of representative Japanese population, and the cohorts also participated in the National Nutrition Survey in Japan (NNSJ) at the baseline. The corresponding datasets could be combined.

METHODS

Individual records of NIPPON DATA and NNSJ were compared and integrated. Intakes of nutrients and food groups for individual participants were calculated by distributing intakes in the each household in NNSJ, considering age and sex of the individuals. The results from an international cooperative epidemiological study (INTERMAP) were utilized to estimate intakes of 75 nutrients for NNSJ80 and 70 nutrients for NNSJ90. Nutrient intakes calculated utilizing INTERMAP data were compared with those in the NNSJ datasets.

RESULTS

NIPPON DATA80/90 datasets were enhanced with detailed baseline nutrient intake data (the numbers of participants combined were 10,422 and 8342 for NIPPON DATA80 and 90, respectively). The mean nutrient intakes calculated through utilizing INTEMRAP data and those calculated from the NNSJ datasets were similar, and the calculated values were strongly correlated with those calculated from NNSJ datasets (Pearson's correlation coefficients greater than 0.8 [P < 0.001]). Detailed nutrient intakes (eg, cholesterol, fatty acids, amino acids, and dietary fiber) were complemented.

CONCLUSIONS

The nutrient intakes calculated from NNSJ datasets for the participants of NIPPON DATA are appropriate as the baseline nutrient intake data. The enhanced cohort datasets are suitable for investigations of baseline dietary habits and the consequent health status.

Prevalence of dyslipidemia and its associated factors among Jordanian adults

BACKGROUND

Dyslipidemia, which has been closely linked to pathophysiology of cardiovascular diseases, is a key independent modifiable risk factor for cardiovascular diseases. Estimation of the prevalence of dyslipidemia ensures proper planning of health actions for both primary and secondary prevention of cardiovascular diseases.

OBJECTIVES

To estimate the prevalence of various types of dyslipidemia and determine their associated factors among adults in north of Jordan.

METHOD

Data were analyzed from a cross-sectional study that included a random sample of 1121 Jordanians aged 25 years and older. High total cholesterol (TC) was defined as TC ≥200 mg/dL and hypertriglyceridemia as serum triglycerides level ≥150 mg/dL. Low high-density lipoprotein cholesterol (HDL-C) was defined as serum HDL-C <40 mg/dL. High low-density lipoprotein cholesterol (LDL-C) was defined as serum LDL-C ≥130 mg/dL.

RESULTS

Of a total of 1121 subjects, 48.8% had high TC level, 40.7% had high LDL-C, 40.1% had low HDL-C, 43.6% had high triglyceride levels, and 75.7% had at least one abnormal lipid level. Age was associated with high triglycerides, high LDL-C, and high TC. Men were more likely than women to have a high triglycerides level and low HDL-C. Compared with people with a body mass index <25, overweight and obese subjects had greater odds of having high triglycerides, high TC, and low HDL-C. Diabetes was associated with increased odds of high triglycerides only.

CONCLUSION

The prevalence dyslipidemia is high in Jordan, which necessitates appropriate the institution of community-based intervention strategies to prevent and manage cardiovascular risk factors.

Trends in acute myocardial infarction incidence and mortality over 30 years in Japan: report from the MIYAGI-AMI Registry Study

BACKGROUND

Worldwide, the rate of aging is highest in Japan, especially the female population. To explore the trends for acute myocardial infarction (AMI) in Japan, the MIYAGI-AMI Registry Study has been conducted for 30 years since 1979, whereby all AMI patients in the Miyagi prefecture are prospectively registered.

METHODS AND RESULTS

In 1979-2008, 22,551 AMI patients (male/female 16,238/6,313) were registered from 43 hospitals. The age-adjusted incidence of AMI (/100,000persons/year) increased from 7.4 in 1979 to 27.0 in 2008 (P<0.001). Although control of coronary risk factors remained insufficient, the rates of ambulance use and primary percutaneous coronary intervention (PCI) have increased, and the overall in-hospital mortality (age-adjusted) has decreased from 20.0% in 1979 to 7.8% in 2008 (P<0.0001). However, the in-hospital mortality remains relatively higher in female than in male patients (12.2% vs 6.3% in 2008). Female patients were characterized by higher age and lower PCI rate.

CONCLUSIONS

The MIYAGI-AMI Registry Study demonstrates the steady trend of an increasing incidence, but decreasing mortality, for AMI in Japan over the past 30 years, although the female population still remains at higher risk for in-hospital death, despite improvements in the use of ambulances and primary PCI. (Circ J 2010; 74: 93 - 100).

Diabetes in Japan: a review of disease burden and approaches to treatment

In recent years there has been rapid growth in diabetes in Japan which now is one of the nations most affected by the worldwide diabetes epidemic. Diabetes has been identified as a healthcare priority by the Ministry of Health, Labour and Welfare (MHLW). Type 1 diabetes is rare in Japan, and type 2 diabetes predominates in both adults and children. The growth in diabetes is due to increases in the number of people with type 2 diabetes associated with increased longevity and lifestyle changes. Approximately 13.5% of the Japanese population now has either type 2 diabetes or impaired glucose tolerance. This high prevalence of type 2 diabetes is associated with a significant economic burden, with diabetes accounting for up to 6% of the total healthcare budget. The costs of diabetes are increased in patients with co-morbidities such as hypertension and hyperlipidaemia and in patients who develop complications, of which retinopathy has the highest cost. Costs increase with increasing number of complications. Current guidelines from the Japan Diabetes Society (JDS) recommend a target HbA(1c) of 6.5% for glycaemic control. This is achieved in approximately one third of patients with type 2 diabetes, and Japanese patients typically have lower HbA(1c) than patients in Western countries (e.g. US, UK). Japanese patients with type 2 diabetes have better adherence with diet and exercise recommendations than their peers in Western countries. Sulfonylureas have been the most widely prescribed first-line treatment for type 2 diabetes, although there is increasing use of combination therapy and of insulin.

A strong secular trend in serum gamma-glutamyltransferase from 1996 to 2003 among South Korean men

Serum gamma-glutamyltransferase (GGT) concentration, within its normal range, has recently been proposed as a reliable marker of oxidative stress. Oxidative stress plays a central pathogenic role in many metabolic and/or cardiovascular diseases, incidences of which have recently increased in South Korea. Since serum GGT has strong associations with these diseases and their risk factors, the authors hypothesized a corresponding secular trend of increasing serum GGT levels in South Korea. Study subjects were 8,072 male workers at a large steel company who were aged 24-44 years at baseline and had received annual physical examinations from 1996 to 2003. The secular trend was a 0.1066-units/liter increase in ln(GGT) level per calendar year (a 180% increase during the 7-year follow-up period) (p < 0.01). Adjustment for body mass index, alcohol consumption, smoking, exercise, and cholesterol level as time-dependent covariates did not change the results. Although cholesterol is commonly used as a marker of epidemiologic transition, there was a less dramatic secular trend in ln(serum cholesterol) level, and it disappeared after adjustment for the secular trend in serum GGT. These findings suggest that serum GGT concentration can be used as a sensitive marker of epidemiologic transition, and they portend a continuing rise in incidences of metabolic and/or cardiovascular diseases in this population in the coming years.

Diabetes in Japan

In this article, we introduce the increasing prevalence of type 2 diabetes in the Japanese population and discuss the reasons for such an explosive increase. Diabetes has been brought into prominence in Japan by enhanced insulin resistance, through the change of lifestyle against the background of fragile beta-cell function and thrifty genotypes.

Culture and symptom reporting at menopause

The purpose of the present paper is to review recent research on the relationship of culture and menopausal symptoms and propose a biocultural framework that makes use of both biological and cultural parameters in future research. Medline was searched for English-language articles published from 2000 to 2004 using the keyword 'menopause' in the journals--Menopause, Maturitas, Climacteric, Social Science and Medicine, Medical Anthropology Quarterly, Journal of Women's Health, Journal of the American Medical Association, American Journal of Epidemiology, Lancet and British Medical Journal, excluding articles concerning small clinical samples, surgical menopause or HRT. Additionally, references of retrieved articles and reviews were hand-searched. Although a large number of studies and publications exist, methodological differences limit attempts at comparison or systematic review. We outline a theoretical framework in which relevant biological and cultural variables can be operationalized and measured, making it possible for rigorous comparisons in the future. Several studies carried out in Japan, North America and Australia, using similar methodology but different culture/ethnic groups, indicate that differences in symptom reporting are real and highlight the importance of biocultural research. We suggest that both biological variation and cultural differences contribute to the menopausal transition, and that more rigorous data collection is required to elucidate how biology and culture interact in female ageing.

Does waist indicate dyslipidemia better than BMI in Korean adult population?

Obesity is an independent and modifiable risk factor for cardiovascular disease, and known as a core of the metabolic syndrome. Obesity has been largely diagnosed based upon anthrompometric measurements like waist circumference (WC) and body mass index (BMI). We sought to determine associations between anthropometric measurements and dyslipidemia in a community adult sample composed of 1,032 community residents (356 men, 676 women) aged 50 yr and over in Namwon, Korea. Blood tests for lipid profiles, including total cholesterol (TC) and HDL cholesterol (HDL) were performed, and dyslipidemia was defined as TC/HDL greater than 4. Anthropometric measurements included WC, waist-to-height ratio (WHtR), waist-to-hip ratio, and BMI. All anthropometric measures were categorized into quartiles and evaluated for associations with dyslipidemia. TC/HDL showed the significant associations with the anthropometric measures, independently of potential confounders. In women, increases of obesity indexes by quartile analyses showed linear increases of odds ratios for dyslipidemia (p values <0.01 by trend test). In men, except BMI, same patterns of association were noted. WC and WHtR were significantly associated with dyslipidemia in Korean adult population. As a simple and non-invasive method for a detection of obesity and dyslipidemia, anthropometric measurements could be efficiently used in clinical and epidemiologic fields.

Lifestyle, Serum Lipids and Coronary Artery Disease:Comparison of Japan with the United States

Westernization of the Japanese lifestyle has been steadily progressing, and the percent energy intake as fat has increased 3.8 fold over the past 50 years. Although the serum cholesterol (C) level has also increased, the death rate due to coronary artery disease (CAD) is not increasing. Consumption of dietary fat in the United States (US) is decreasing and serum C levels are also decreasing. Although the death rate due to CAD is markedly decreasing in men and women in the US, it is still 4 times higher than that of Japanese. The percent energy intake as fat in Japanese migrants to the US (Japanese-American: JA) lies between that of native Japanese and US populations, and their C values are higher than those of native Japanese. Compared with native Japanese, JA showed a significant increase in carotid intima-media wall thickness, and deaths from CAD are also higher than those of Japanese in Japan. Although the death rate due to CAD has not yet increased in Japan, Japanese have the potential for further progression of atherosclerosis and increasing CAD.

Intake of animal products and stroke mortality in the Hiroshima/Nagasaki Life Span Study

BACKGROUND

To determine whether intake of animal products was associated with a reduced risk of stroke mortality in a large-scale population-based cohort in Japan.

METHODS

A self-administered questionnaire, including questions on dietary habits, was mailed to the members of the Life Span Study, a cohort of people exposed and non-exposed to atomic bomb radiation, who were alive as of 1 September 1979. Animal products included frequency intake of beef/pork, chicken, ham/sausage, milk, dairy products, eggs, fish, and broiled fish. Responses were obtained from 40 349 people (72%): 15 350 men (mean age 54 years) and 24 999 women (mean age 58 years). The subjects were followed for 16 years, and deaths were ascertained by linkage to the nationwide family registration system of Japan. The associations between diet and stroke mortality were examined using a Cox proportional hazard model.

RESULTS

During the follow-up period, 1462 stroke deaths occurred. Four animal products comprising eggs, dairy products, fish, and broiled fish were independently associated with a decreased risk of stroke mortality; while beef/pork, chicken, ham/ sausage, and milk consumption were not associated with stroke death. A composite measure of eggs, dairy products, fish, and broiled fish intake was calculated, and the highest tertile was significantly inversely associated with total stroke mortality (Hazards Ratio [HR] = 0.80, 95% CI: 0.68, 0.93) compared with the lowest tertile. The protective effect of animal product intake on total stroke death was largely confined to intracerebral haemorrhage death; the RH of intracerebral haemorrhage death for the highest tertile of consumption was 0.72 (95% CI: 0.53-0.98) compared with the lowest tertile; animal products intake was not related to cerebral infarction mortality (HR = 0.84; 95% CI: 0.67-1.06).

CONCLUSIONS

Intake of animal products such as eggs, dairy products, and fish may be protective against intracerebral haemorrhage, but is not related to cerebral infarction mortality.

Lipids and coronary heart disease in Asia

In Western countries, it has been shown that coronary heart disease (CHD) is related to high serum total cholesterol (TC) levels. In less developed continents such as Asia and Africa, serum lipid levels are low and CHD incidence is much lower as compared with Western countries. With growing urbanization and industrialization in Asia, it has been shown that there is a concomitant rise in the level of serum TC and with it a rise in CHD. In all the Asian countries, serum TC levels are also higher in the urban compared with the rural population. Singapore, the only Asian country which is 100% urbanized since 1980, showed a rise of serum TC similar to that seen in the US and UK from the 1950s to the 1980s followed thereafter by a fall. This is reflected in the trend (rise followed by a fall) of CHD morbidity and mortality as well. In spite of a declining trend in serum TC level, CHD morbidity and mortality are still high in Singapore and comparable to the Western countries. The rest of the Asian countries show a different pattern from Singapore. In general, there is still a rising trend in serum TC level and in CHD mortality in most Asian countries. However, Japan is considered an exception in having a decreasing CHD mortality in spite of an increasing trend in serum TC. This may be attributed to a better control of other CHD risk factors such as hypertension and smoking. The rising trend in serum TC level remains a cause for concern, as this will emerge as a major problem for CHD morbidity and mortality in the future.

Longitudinal trends of hemoglobin levels in a Japanese population--RERF's Adult Health Study subjects

Conflicting results have been reported on the long-term relationship between hemoglobin (Hb) level and age. We analyzed that relationship over a 40-yr period in a Japanese population, adjusting for the effects of sex, birth cohort, smoking, and anemia-associated diseases. We used Hb levels measured biennially between 1958 and 1998 for 4858 Adult Health Study subjects of the Radiation Effects Research Foundation. Using the mixed-effects model, we showed that the aging Hb profile varied by sex (P < 0.001) and birth cohort (P < 0.001). Male Hb levels peaked in the third and fourth decades and then decreased while female Hb levels dipped slightly in the third decade, peaked in the sixth and seventh, and then decreased. Levels were higher in younger cohorts. The rate of Hb decline after the sixth decade of life was greater for subjects with anemia-associated diseases (P = 0.002). The annual rate of decline between 70 and 80 yr of age for disease-free men ranged from 0.083 to 0.042 g/dL and for disease-free women from 0.049 to 0.036 g/dL. Levels were higher for ever-smokers (P < 0.001), more so for women than men. A decreasing trend in Hb concentration with advancing age was detected for elderly men and women after controlling for anemia-associated diseases, suggesting that anemia in the elderly is due not only to disease but also to aging. Cohort and smoking effects on Hb levels were also observed.

The effects of aging and radiation exposure on blood pressure levels of atomic bomb survivors

The Adult Health Study (AHS) is a longitudinal study that has included biennial blood pressure measurements since 1958. In the present study, we applied the mixed effects model for serially measured data on the AHS population to (1) examine age-related changes in blood pressure and (2) detect possible radiation effects. The estimated longitudinal model of systolic blood pressure (SBP) depicted a linear increase from 30 to 80 years of age for both sexes. The diastolic blood pressure (DBP) rose linearly to about 65 years of age and then leveled off. There were marked differences in the longitudinal trends of DBP among birth cohorts, particularly for men, with higher DBP levels in the younger cohort. The present analysis demonstrated a small but statistically significant effect of ionizing radiation on the longitudinal trends of both SBP and DBP. This phenomenon is compatible with the degenerative effect of ionizing radiation on blood vessels.

Diabetes trends in Japan

The prevalence of diabetes is increasing in Japan, and it is estimated that more than 12 million Japanese people are hyperglycemic. This high prevalence is most likely the result of a complex interplay between genetic and environmental factors specific to Japan. The lifestyle and diet of the Japanese population have changed significantly since the end of World War II. In general, the Japanese have become more sedentary and they consume more fat than in the past. Among Japanese men, these changes have been associated with a steadily increasing body mass index (BMI), a well-known risk factor for the development of insulin resistance, impaired glucose tolerance, and diabetes. Genetic characteristics common to many Japanese may also contribute to their higher prevalence of diabetes. The Japanese have a higher prevalence of polymorphisms for at least three genes that code for proteins thought to play key roles in lipid and glucose metabolism: the beta 3-adrenergic receptor, the peroxisome proliferator-activated receptor gamma, and calpain-10. The interaction between changes in lifestyle and the 'thrifty' genotype characteristic of many Japanese people may play a significant role in the increasing prevalence of diabetes and associated cardiovascular risk in this population.

Changes in serum lipid levels during a 10 year period in a large Japanese population. A cross-sectional and longitudinal study

To determine the recent secular trends in serum lipid levels and characterize their influence on the aging process, we examined a large cohort of Japanese cross-sectionally and longitudinally. The participants included 80331 Japanese men and women 20-79 years of age, who had received annual health examinations from 1989 to 1998. In cross-sectional analysis, an increase in total and LDL cholesterol as well as triglyceride levels was observed in the population during the period of 1989-1998. The longitudinal changes showed that total and LDL cholesterol increased with age in men between the birth cohorts of the 1920s and 1960s. In women, these cholesterol levels increased in the 1930s and younger cohorts. HDL cholesterol decreased in men of all birth cohorts. However, HDL cholesterol increased in women of the 1940s and younger cohorts. Triglyceride levels increased in men of the 1940s and younger cohorts but decreased in the 1930s and older. Triglyceride levels increased in women of the 1930s and younger. Longitudinal analysis also suggested a birth cohort effect except for the triglyceride level for women. These results suggest that Japanese serum lipid levels continue to increase and that there exist birth cohort effects regarding serum lipid levels in the Japanese population.

Involvement of oxidation-sensitive mechanisms in the cardiovascular effects of hypercholesterolemia

Hypercholesterolemia is a common clinical metabolic and/or genetic disorder that promotes functional and structural vascular wall injury. The underlying mechanisms for these deleterious effects involve a local inflammatory response and release of cytokines and growth factors. Consequent activation of oxidation-sensitive mechanisms in the arterial wall, modulation of intracellular signaling pathways, increased oxidation of low-density lipoprotein cholesterol, and quenching of nitric oxide can all impair the functions controlled by the vascular wall and lead to the development of atherosclerosis. This cascade represents a common pathological mechanism activated by various cardiovascular risk factors and may partly underlie synergism among them as well as the early pathogenesis of atherosclerosis. Antioxidant intervention and restoration of the bioavailability of nitric oxide have been shown to mitigate functional and structural arterial alterations and improve cardiovascular outcomes. Elucidation of the precise nature and role of early transductional signaling pathways and transcriptional events activated in hypercholesterolemia in children and adults, including mothers during pregnancy, and understanding their downstream effects responsible for atherogenesis may help in directing preventive and interventional measures against atherogenesis and vascular dysfunction.

The Framingham Study: ITS 50-year legacy and future promise

The Framingham Study was initiated in 1948 to investigate an epidemic of coronary disease in the USA, using a prospective epidemiological approach. Insights were provided into the prevalence, incidence, full clinical spectrum and predisposing factors. The major "risk factors" (a term coined by the Framingham Study) for coronary disease, stroke, peripheral artery disease and heart failure were identified and clinical misconceptions dispelled about isolated systolic hypertension, left ventricular hypertrophy, dyslipidemia, atrial fibrillation and glucose intolerance. Average values for blood lipids, blood pressure, body weight, glucose and fibrinogen were shown to be dangerously suboptimal and to have a continuous graded relationship to cardiovascular disease without critical values. Dyslipidemia, glucose intolerance and elevated fibrinogen were shown to have smaller hazard ratios in the elderly, but this was offset by a higher absolute risk. Diabetes was shown to operate more strongly in women, eliminating their advantage over men. Serum total cholesterol was shown to derive its atherogenic potential from its LDL component and also to reflect cholesterol being removed in the HDL fraction. The total/HDL-cholesterol ratio was demonstrated to be the most efficient lipid profile for predicting coronary disease. LDL was shown to be correlated with hemostatic factors, suggesting that there would be additional benefits to lowering LDL. High triglyceride associated with reduced HDL, indicating insulin resistance and small dense LDL, was shown to be associated with excess coronary disease. All the risk factors tended to cluster, and this was shown to be promoted by insulin resistance induced by weight gain. Multivariate risk profiles were produced to facilitate risk stratification of candidates for coronary disease, stroke, peripheral artery disease and heart failure. The Framingham Study is now engaged in quantifying the independent contributions of homocysteine Lp(a), insulin resistance, small dense LDL, C reactive protein, clotting factors and genetic determinants of cardiovascular disease. We are now able to estimate the lifetime risk of all the atherosclerotic cardiovascular disease outcomes.

Dyslipidemia and abdominal obesity: an assessment in three general populations

Several studies show a relationship between abdominal obesity and cardiovascular diseases, partially mediated through an altered metabolism of dyslipidemia. The present study was aimed at testing the robustness of this association across three contrasted populations and at assessing the performances of abdominal obesity as a screening tool for dyslipidemia. Data were drawn from three population health surveys recently conducted in two regions of a developed country (Switzerland, mostly of Caucasian origin, n = 2650) and in a less developed country (Seychelles, Indian Ocean, mostly of black descent, n = 806). Dyslipidemia was defined as a ratio of total cholesterol to high-density lipoprotein cholesterol (TC-HDL) greater than 5. Two anthropometric circumference measurements, waist-to-hip ratio (WHR) and waist circumference (WC), were used to define abdominal obesity either as WHR >/= 0.9 in men and WHR >/= 0.8 in women or as WC >/= 94 cm and WC >/= 80 cm, respectively. A consistent direct association between abdominal obesity and dyslipidemia (odds ratios varying from 1.85 to 4.56) was found in the three populations, independently of gender, age, body mass index, blood pressure, and smoking. This consistency across ethnicities and environments strengthens the hypothesis of a common etiopathological mechanism. The sensitivity for detecting dyslipidemia was generally higher for abdominal obesity, based on either WHR or WC, than for criteria based on the other risk factors under study. In addition, the sensitivity was higher in the study populations with a low prevalence of dyslipidemia (Swiss women and Seychellois of both sexes) than in the others. These findings support that WHR and WC may be useful as simple and inexpensive screening tools to select individuals eligible for more sophisticated and costly serum lipid determinations, especially in developing countries.