Factors associated with high density lipoprotein cholesterol in Japanese and American telephone executives

Continuous decline in mortality from coronary heart disease in Japan despite a continuous and marked rise in total cholesterol: Japanese experience after the Seven Countries Study

BACKGROUND

The Seven Countries Study in the 1960s showed very low mortality from coronary heart disease (CHD) in Japan, which was attributed to very low levels of total cholesterol. Studies of migrant Japanese to the USA in the 1970s documented increase in CHD rates, thus CHD mortality in Japan was expected to increase as their lifestyle became Westernized, yet CHD mortality has continued to decline since 1970. This study describes trends in CHD mortality and its risk factors since 1980 in Japan, contrasting those in other selected developed countries.

METHODS

We selected Australia, Canada, France, Japan, Spain, Sweden, the UK and the USA. CHD mortality between 1980 and 2007 was obtained from WHO Statistical Information System. National data on traditional risk factors during the same period were obtained from literature and national surveys.

RESULTS

Age-adjusted CHD mortality continuously declined between 1980 and 2007 in all these countries. The decline was accompanied by a constant fall in total cholesterol except Japan where total cholesterol continuously rose. In the birth cohort of individuals currently aged 50-69 years, levels of total cholesterol have been higher in Japan than in the USA, yet CHD mortality in Japan remained the lowest: >67% lower in men and > 75% lower in women compared with the USA. The direction and magnitude of changes in other risk factors were generally similar between Japan and the other countries.

CONCLUSIONS

Decline in CHD mortality despite a continuous rise in total cholesterol is unique. The observation may suggest some protective factors unique to Japanese.

Comparison of fatal coronary heart disease occurrence based on population surveys in Japan and the USA

BACKGROUND

Although vital statistics have indicated large Japanese-American differences in mortality rates for coronary heart disease (CHD), the magnitude of difference has not been documented well using comparable validation of cause of death.

METHODS

Population-based fatal CHD data were compared between the Oita Cardiac Death Survey, Japan and the Atherosclerosis Risk in Communities (ARIC) Study, USA. Both studies (population: Oita City 198 093; the ARIC comunities 286 820) identified possible fatal CHD events (International Classification of Diseases, Ninth Revision [ICD-9]: 410-414, 250, 401-402, 427-429, 440, and 798-799) among residents aged 35-74 years during 1992-1993. Comparable criteria for classifying cause of death were applied. Sex-specific, age-adjusted mortality rates of CHD were calculated by place of death.

RESULTS

In all, 330 deaths in Oita and 1398 in the ARIC communities had eligible ICD-9 death certificate codes; CHD codes (ICD-9 410-414) comprised 30.6% of investigated deaths in Oita and 58.6% in ARIC. For men, the non-validated rate ratio for CHD deaths (ARIC:Oita City) was 5.9 (95% CI : 4.2-8.5), which fell to 4.7 (95% CI : 3.5-6.4) with validation and inclusion of sudden deaths within one hour of onset as fatal CHD. For women, the overall non-validated rate ratio was 4.6 (95% CI : 2.8-7.6), which fell to 3.9 (95% CI : 2.4-6.3) with validation and but there was little further change when the sudden deaths were added.

CONCLUSIONS

Our results suggest that differences in fatal CHD rates between Japanese and Americans were not as large as suggested by vital statistics when events were validated and sudden deaths were included.

Correlates of uric acid and its association with asymptomatic carotid atherosclerosis: the ARIC Study. Atherosclerosis Risk in Communities

The correlates of serum uric acid and the association of uric acid with carotid intimal-medial thickness (an early measure of atherosclerosis) were investigated in participants of the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study. The study sample included 6522 women (74% white) and 4966 men (79% white) who were aged 45 to 64 years at baseline (1986-1989). Those with prevalent coronary heart disease or previous stroke and those taking uricosuric medication were excluded. The mean (SD) uric acid concentration was 5.9 (1.5) mg/dL. It was highest among black men 45-54 years old (6.9 [1.5] mg/dL), and lowest in white women aged 45-54 years old (5.0 [1.2] mg/dL). The uric acid level was positively correlated in both sexes with a variety of health-related factors, most notably body mass index, creatinine, triglycerides, diuretic use, alcohol intake, hypertension, diabetes, and insulin levels. In a linear regression model adjusting for age and ARIC center, the level of uric acid was directly and significantly associated with B-mode ultrasound carotid intimal-medial thickness in women and white men (but not in black men). However, when known risk factors for atherosclerotic disease and relevant behavioral and biological correlates of uric acid were controlled for in multivariate analysis, the association of uric acid with this early measure of atherosclerosis became negligible in white women and much weaker and not statistically significant in black women and white men. Thus, uric acid itself may not be a risk factor for atherosclerosis. Future analysis of cardiovascular events in the ARIC Study will further elucidate the role of uric acid in atherosclerotic disease.

Smoking, consumption of alcohol and sedentary life style in population grouping and their relationships with lipemic disorders

The study, part of the project "Atherosclerotic cardiovascular diseases, lipemic disorders, hypertension, obesity and diabetes mellitus in a population of the metropolitan area of the southeastern region of Brazil", had the following objectives: a) the characterization and distribution among typical human socio-economic groupings, of the prevalence of some particular habits which constitute aspects of life-style-the use of tobacco, the use of alcohol and sedentary activity; b) the establishment of the interrelation between the above-mentioned habits and some lipemic disorders. The prevalence of the habits cited behaved in the following manner: the use of tobacco predominated among men, distributed uniformly throughout the social strata; among the women the average percentage of smokers was 18.9%, a significant difference occurring among the highest socio-economic class, where the average was of 40.2%. The sedentary style of life presented high prevalence, among both men and women with exception of the women of the highest socio-economic level and of the skilled working class. The use of alcohol, as one would expect, is a habit basically practised by the men, without any statistically significant differences between classes.(ABSTRACT TRUNCATED AT 250 WORDS)

HDL cholesterol and mortality in Finnish men with special reference to alcohol intake

BACKGROUND

There is substantial evidence that a low serum level of HDL cholesterol (HDLC) is a risk factor for coronary deaths. However, data on older people are scarce, and previous studies have not examined this association in relation to alcohol intake.

METHODS AND RESULTS

Coronary mortality, all-cause mortality, and mortality due to alcohol and violence were related to HDLC levels among 7052 male smokers 50 to 69 years old in south and west Finland enrolled from 1984 to 1988 in the ATBC (AT, alpha-tocopherol; BC, beta-carotene) Study placebo group. During the average follow-up period of 4.7 years, 620 men died; 222 of these deaths were from coronary heart disease and 82 from causes related alcohol and violence. HDLC levels were inversely associated with coronary mortality, irrespective of age, whereas high total cholesterol was positively associated with coronary mortality among the younger men, 50 to 59 years of age, but not among the older men, 60 to 69 years old. Correction for temporal variation in HDLC measurement indicated a 43% stronger inverse association between HDLC and coronary mortality compared with that based only on a single value. The inverse association of HDLC and coronary mortality was less marked at higher levels of alcohol intake. All-cause and alcohol- and violence-related mortality were positively associated with HDLC among the younger men. All-cause mortality showed a U-shaped dose response among men > or = 60 years old.

CONCLUSIONS

Previous studies may have underestimated the beneficial effect of high HDLC because of regression-dilution bias and the confounding effect of heavy alcohol intake. This study supports the view that, particularly among older men, lipoprotein fractions may be more appropriate for screening than total cholesterol.

Body mass, fat distribution and cardiovascular risk factors in a lean population of south China

The associations of body mass index and abdominal adiposity, represented by an elevated waist/hip circumference ratio, with cardiovascular risk factors were examined in men and women, aged 28-69 years, from urban and rural areas of Guangzhou, China. Mean body mass index ranged from 20.1 to 21.9 kg/m2 across the four sex- and area-groups. Mean waist/hip ratio was 0.84 in men and 0.80 in women. After accounting for age and body mass index, waist/hip ratio was associated negatively (p < 0.05) with fasting serum HDL cholesterol (both sexes), and positively with serum triglycerides (both sexes), total and LDL cholesterol (men only), uric acid (both sexes), glucose (women only), and mean systolic blood pressure (women only). Body mass index was associated in a similar direction with most of these risk factors. These data confirm that abdominal adiposity is independently associated with cardiovascular disease risk factors, even in a lean Asian population.

Plasma lipoprotein and apolipoprotein levels in Taipei and Framingham

We compared the plasma lipoprotein cholesterol, triglyceride, apolipoprotein (apo) A-I, apoB, and lipoprotein(a) [Lp(a)] concentrations in a low coronary heart disease (CHD) risk population (n = 440) in Taipei with a high CHD risk population (n = 428) in Framingham matched for age, sex, and menopausal status. Taipei men had significantly lower low-density lipoprotein cholesterol (LDL-C) (-20 mg/dL, -14%, P < .01) and apoB (-7 mg/dL, -6%, P < .05) levels and significantly higher high-density lipoprotein cholesterol (HDL-C) levels (6 mg/dL, 13%, P < .01) than Framingham men. Taipei women had significantly lower LDL-C (-18 mg/dL, -15%, P < .01) and higher HDL-C (4 mg/dL, 7%, P < .01) levels than Framingham women. Median concentrations and distributions of Lp(a) by sex were similar in Taipei and Framingham. After adjusting for body mass index and smoking status, only differences in total cholesterol and LDL-C levels remained significantly different for both sexes between the two populations (P < .01). Gender differences for lipids within populations were similar. After adjusting for age, body mass index, and smoking status, women in both Taipei and Framingham had significantly lower mean triglyceride, LDL-C, and apoB levels and significantly higher HDL-C and apoA-I levels than men. Postmenopausal women in Taipei had significantly higher mean total cholesterol, LDL-C, HDL-C, apoA-I, apoB, and Lp(a) levels than premenopausal women (P < .05), whereas in Framingham postmenopausal women had significantly higher total cholesterol, triglyceride, LDL-C, and apoB levels than premenopausal women (P < .05). Our data are consistent with the concept that plasma lipoprotein cholesterol levels (especially LDL-C) but not apolipoprotein values explain some of the twofold difference in age-adjusted CHD mortality between these two populations.

Alcohol use and blood pressure in an unacculturated society

Alcohol intake has been associated with higher blood pressure in acculturated populations but not in unacculturated societies. We performed a cross-sectional survey of a random community sample of 5023 male Yi rural farmers and 1656 Yi and 2173 Han men living in an urban setting. Average alcohol intake among drinkers was 36.4 g/d in Yi farmers, 56.5 g/d in Yi migrants, and 38.7 g/d in Han men. Age-adjusted mean diastolic blood pressure was 66.9, 70.5, and 71.7 mm Hg, respectively. Diastolic blood pressure was higher at higher alcohol intakes in all three groups (all P < .001). After adjustment for age, body mass index, heart rate, smoking, and physical activity, the change (95% confidence interval) in diastolic blood pressure for each standard drink was 0.50 (0.38-0.62), 0.31 (0.18-0.43), and 0.24 (0.07-0.40) mm Hg for Yi farmers, Yi migrants, and Han men, respectively. The percentage of variance in diastolic blood pressure explained by alcohol intake was 5% for Yi farmers, 4% for Yi migrants, and 2% for Han men. In a random sample of 831 men, these associations were independent of urinary sodium, potassium, calcium, and magnesium and sodium-potassium ratio. In the Yi farmers, associations were less strong for systolic blood pressure and no longer significant after adjustment. Approximately 33% of hypertension could be attributed to daily alcohol use in the Yi groups compared with 9.5% in the Han people.(ABSTRACT TRUNCATED AT 250 WORDS)

The independent roles of diet and serum lipids in the 20th-century rise and decline of coronary heart disease mortality

Risk factors are causally related to coronary heart disease (CHD), but in widely varying historic, geographic, socioeconomic, and individual relationships. Serum cholesterol is only one of many risk factors that, even when considered together in prospective studies, account for well under half of the CHD incidence. It is neither primarily regulated by the diet nor significantly related to it. Many findings discordant with widespread beliefs about a causal role of the diet in CHD are reviewed. It may be concluded that dietary fats are largely not responsible for relationships of serum cholesterol to CHD, or for its 20th-century rise and decline.

Lipids in psychological research: the last decade

We review the recent literature examining lipid changes during stressful experiences, and the psychological and constitutional differences that influence lipid levels at rest and that may modulate lipid response to stress. Mild forms of chronic or episodic stress are apparently not associated with alterations in lipids and lipoproteins, but severe forms of real or perceived stress do appear to alter lipid levels. Acute laboratory stress is frequently associated with short-term alterations in lipids and lipoproteins, but the significance of these changes is unclear. Several individual characteristics, such as heightened neuroendocrine or autonomic reactivity to stressors, Type A component behavior, and other aspects of personality, appear to be associated with an atherogenic lipid profile. Stress may influence lipid concentrations and metabolism through a variety of physiological and behavioral mechanisms, but none have been clearly elucidated. Future research should concentrate on understanding these mechanisms.