Under- and overweight impact on mortality among middle-aged Japanese men and women: a 10-y follow-up of JPHC study cohort I

OBJECTIVE: Although obesity is a major health problem in Western countries, its impact may differ in another culture. This paper examines the association between body mass index (BMI; kg/m2) and mortality in Japan, where the mortality profile and BMI distribution differ substantially from Western countries. DESIGN: The JPHC Study cohort I, a population-based prospective study in four public health center areas, started in 1990 and was followed-up to the end of 1999. SUBJECTS: A total of 19,500 men and 21,315 women aged 40-59 y who submitted their body weight and height and did not report any serious disease at baseline. MEASUREMENT: Risk of death by category of BMI. RESULTS: During 10 y of follow-up, 943 and 483 deaths were documented in the men and women, respectively. The association between BMI and all-cause mortality was U-shaped: compared with a category of 23.0-24.9, the statistically significant elevations in relative risk were observed in both under- and overweight categories (2.26 in 14.0-18.9, 1.57 in 19.0-20.9, 1.33 in 21.0-22.9 and 1.38 in 27.0-29.9, 1.97 in 30.0-39.9 in men, 1.94 in 14.0-18.9 and 1.91 in 30.0-39.9 in women) after adjustment for possible confounders and weight change. The U-shaped association did not change after excluding deaths occurring in the first 5 y of follow-up or even after excluding subjects who reported a weight loss of 5 kg or more since 20-y-old, or after stratifying subjects by smoking status. CONCLUSION: Both under- and overweight are important determinants of premature death among the Japanese population.     

Cigarette smoking and risk for impaired fasting glucose and type 2 diabetes in middle-aged Japanese men

BACKGROUND: The contribution of cigarette smoking to development of impaired fasting glucose and type 2 diabetes remains unclear. OBJECTIVE: To investigate the association of cigarette smoking with development of impaired fasting glucose and type 2 diabetes. DESIGN: Prospective cohort study. SETTING: Work site in Osaka, Japan. PARTICIPANTS: 1,266 Japanese male office workers 35 to 59 years of age who did not have impaired fasting glucose or type 2 diabetes and were not taking medication for hypertension at study entry. MEASUREMENTS: Fasting plasma glucose levels were measured at annual health examinations from May 1994 through May 1999. Impaired fasting glucose was defined as a fasting glucose level of at least 6.1 mmol/L (110 mg/dL) but less than 7.0 mmol/L (126 mg/dL). Type 2 diabetes was defined as a fasting glucose level of 7.0 mmol/L or more or current receipt of hypoglycemic medication. RESULTS: 87 and 54 men developed impaired fasting glucose and type 2 diabetes during 5,817 and 5,937 person-years follow-up, respectively. After controlling for potential predictors of diabetes, the relative risk for impaired fasting glucose compared with never-smokers was 1.62 (95% CI, 0.85 to 3.10) for ever-smokers, 1.14 (CI, 0.58 to 2.25) for persons who smoked 1 to 20 cigarettes/d, 1.33 (CI, 0.63 to 2.80) for those who smoked 21 to 30 cigarettes/d, and 2.56 (CI, 1.32 to 4.95) for those who smoked 31 or more cigarettes/d (P for trend for current smokers only = 0.013). The respective multivariate-adjusted relative risks for type 2 diabetes compared with never-smokers were 1.08 (CI, 0.34 to 3.42), 1.88 (CI, 0.71 to 5.00), 3.02 (CI, 1.15 to 7.94), and 4.09 (CI, 1.62 to 1,029) (P for trend for current smokers only < 0.001). The number of pack-years of exposure was also positively related to development of impaired fasting glucose and type 2 diabetes (P for trend = 0.039 and 0.002, respectively). The relative risk for impaired fasting glucose and type 2 diabetes in current smokers versus never-smokers was stronger among men with a body mass index less than 242 kg/m2 than among men with a body mass index of 24.2 kg/m2 or more, although the absolute risk was greater in more obese men. CONCLUSION: The number of cigarettes smoked daily and the number of pack-years of exposure seem to be associated with development of impaired fasting glucose and type 2 diabetes in middle-aged Japanese men.     

Systolic time intervals in middle-aged men according to smoking habits and other risk factors of coronary heart disease.

In the course of a prospective study on coronary heart disease (CHD) risk factors, systolic time intervals (STI) were measured at rest in 92 men aged 52--56 yr and free of any clinical symptoms of CHD. The ratio preejection period/left ventricular ejection period (PEP/LVEP) was significantly augmented in current smokers vs nonsmokers (0.406 +/- 0.075 vs 0.384 +/- 0.068, P less than 0.05). The regression of this parameter on cigarette consumption per day, taking into account heart rate, systolic blood pressure, body mass index, serum cholesterol and triglycerides, remains significant. An acute experiment, involving 50 smokers recruited similarly, showed no significant variation of the STI after the smoking of 2 cigarettes. We concluded that the augmentation of the PEP/LVEP ratio may represent a chronic effect of tobacco smoking on cardiac function.     

Serum gamma-glutamyltransferase predicts non-fatal myocardial infarction and fatal coronary heart disease among 28,838 middle-aged men and women.

AIMS: Serum gamma-glutamyltransferase (GGT) concentration may be involved in atherosclerosis. This study examined if serum GGT predicted coronary heart disease (CHD), especially differentiating non-fatal myocardial infarction (MI) and fatal CHD event, among the general population or participants with type-2 diabetes. METHODS AND RESULTS: A prospective study of 28,838 Finnish men and women aged 25-74 years was performed (1467 incident CHD cases; a median follow-up time of 11.9 years). Serum GGT cutpoints were the 25th, 50th, 75th, and 90th sex-specific percentiles. After adjustment for known cardiovascular risk factors, compared with the lowest GGT category, hazard ratios (HR) were 1.15, 1.25, 1.27, and 1.57 among men and 1.03, 1.22, 1.32, and 1.44 among women in other four GGT categories (P for trend <0.01, respectively). However, stronger associations were observed among subjects aged <60 and among alcohol drinkers. The strength of association was similar for non-fatal MI and for fatal CHD. Among subjects with type-2 diabetes, the corresponding adjusted HRs were 1.29, 1.57, 1.88, and 1.78 (P trend=0.03, men and women combined). CONCLUSION: This study suggests an independent mechanism linking serum GGT to CHD among general population. Even though the strength of association appeared to be modest among all subjects, stronger associations were observed among subjects aged <60 and among alcohol drinkers. Especially, measurement of serum GGT among type-2 diabetics may be helpful to predict the future risk of CHD.     

Legume consumption and risk of coronary heart disease in US men and women: NHANES I Epidemiologic Follow-up Study.

BACKGROUND: Soybean protein and dietary fiber supplementation reduce serum cholesterol in randomized controlled trials. Consumption of legumes, which are high in bean protein and water-soluble fiber, may be associated with a reduced risk of coronary heart disease (CHD). METHODS: A total of 9632 men and women who participated in the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study (NHEFS) and were free of cardiovascular disease (CVD) at their baseline examination were included in this prospective cohort study. Frequency of legume intake was estimated using a 3-month food frequency questionnaire, and incidence of CHD and CVD was obtained from medical records and death certificates. RESULTS: Over an average of 19 years of follow-up, 1802 incident cases of CHD and 3680 incident cases of CVD were documented. Legume consumption was significantly and inversely associated with risk of CHD (P =.002 for trend) and CVD (P =.02 for trend) after adjustment for established CVD risk factors. Legume consumption 4 times or more per week compared with less than once a week was associated with a 22% lower risk of CHD (relative risk, 0.78; 95% confidence interval, 0.68-0.90) and an 11% lower risk of CVD (relative risk, 0.89; 95% confidence interval, 0.80-0.98). CONCLUSIONS: Our study indicates a significant inverse relationship between legume intake and risk of CHD and suggests that increasing legume intake may be an important part of a dietary approach to the primary prevention of CHD in the general population.     

Ten-year predicted coronary heart disease risk in HIV-infected men and women.

BACKGROUND: Highly active antiretroviral therapy (HAART), in addition to traditional vascular risk factors, may affect coronary heart disease (CHD) risk in individuals with human immunodeficiency virus (HIV) infection. METHODS: Among HIV-infected (931 men and 1455 women) and HIV-uninfected (1099 men and 576 women) adults, the predicted risk of CHD was estimated on the basis of age, sex, lipid and blood pressure levels, the presence of diabetes, and smoking status. RESULTS: Among HIV-infected men, 2% had moderate predicted risk of CHD (10-year CHD risk, 15%-25%), and 17% had high predicted risk (10-year CHD risk of > or = 25% or diabetes). Among HIV-infected women, 2% had moderate predicted CHD risk, and 12% had high predicted CHD risk. Compared with users of protease inhibitor-based HAART, the adjusted odds ratio (OR) for moderate-to-high risk of CHD was significantly lower among HAART-naive individuals (OR, 0.57; 95% confidence interval [CI], 0.36-0.89). Users of HAART that was not protease inhibitor based (OR, 0.74; 95% CI, 0.53-1.01) and former HAART users (OR, 0.68; 95% CI, 0.46-1.03) were also less likely than users of protease inhibitor-based HAART to have moderate-to-high CHD risk, although 95% CIs overlapped the null. Low income was associated with increased likelihood of moderate-to-high CHD risk (for annual income < $10,000 vs. > $40,000: OR, 2.32; 95% CI, 1.51-3.56 ). Elevated body mass index (calculated as weight in kilograms divided by the square of height in meters) predicted increased likelihood of moderate-to-high CHD risk (for BMI of 18.5-24.9 vs. BMI of 25-30: OR, 1.41 [95% CI, 1.03-1.93]; for BMI of 18.5-24.9 vs. BMI > or = 30: OR, 1.79 [95% CI, 1.25-2.56]). CONCLUSIONS: Among HIV-infected adults, in addition to antiretroviral drug exposures, being overweight and having a low income level were associated with increased predicted CHD risk. This suggests a need to target HIV-infected men and women with these characteristics for vascular risk factor screening.     

Fibrinogen as a risk factor for coronary heart disease and mortality in middle-aged men and women: The Scottish Heart Health Study

Aims Fibrinogen was measured in 5095 men and 4860 men aged 40–59in a random population sample from 25 districts of Scotlandrecruited during 1984–87: the Scottish Heart Health Study.Fibrinogen was then related to the chance of fatal and non-fatalcoronary events and death from any cause during a subsequentfollow-up period of around 8 years. Methods and results Fibrinogen was measured by the Clauss assay.The effect of fibrinogen on coronary heart disease and deathwas assessed through age-adjusted means and Cox proportionalhazards regression models, accounting for age, cotinine (a measureof tobacco smoke inhalation) and 11 other major coronary riskfactors. Fibrinogen was found to be an important risk factorfor coronary heart disease in men and women, with and withoutpre-existing coronary heart disease. There appears to be a thresholdeffect, with those in the highest fifth of the distributionhaving a much increased risk. Estimated age- adjusted hazardratios by sex and pre-existing coronary heart disease groupfor the highest to lowest fifth of fibrinogen range between1·93 and 4·86. Fibrinogen is also important asa risk factor for coronary death and all-causes mortality, witha similar threshold effect. Comparing the two extreme fifths,the hazard ratios for coronary death are 3·01 and 3·42,and for all-cause mortality are 2·59 and 2·20,for men and women respectively. Adjustment for cotinine reducesthe hazard ratios, but further adjustment for the other 11 riskfactors has little effect for coronary heart disease events.After full adjustment there is a remaining significant (P<0·05)hazard ratio for coronary death and death from any cause andfor a coronary heart disease event for those free of coronaryheart disease at baseline, amongst men, comparing the highestto the lowest fifth. Conclusion Fibrinogen is a strong predictor of coronary heartdisease, fatal or non-fatal, new or recurrent, and of deathfrom an unspecified cause, for both men and women. Its effectis only partially attributable to other coronary risk factors,the most important of which is smoking.     

Alcohol consumption and other risk factors for self-reported diabetes among middle-aged Japanese: a population-based prospective study in the JPHC study cohort I.

AIMS: Few prospective studies have examined the relationship between lifestyle characteristics and the incidence of diabetes mellitus in an Asian general population. This study was undertaken to evaluate the risk factors for Type 2 diabetes in a population-based prospective study of middle-aged Japanese. METHODS: We investigated 12,913 men and 15,980 women, aged 40-59 years at baseline (year 0), who participated in the Japan Public Health Center-based prospective study on cancer and cardiovascular diseases (JPHC Study) Cohort I. The participants were followed for up to 10 years. Incident cases of diabetes were identified by self-reporting of a physician's diagnosis on two questionnaires sent to each participant, one at year 5 and the second at year 10. RESULTS: During the 10-year follow-up, 703 men and 482 women reported newly diagnosed diabetes. Age, body mass index (BMI), family history of diabetes and cigarette smoking were independent risk factors in both genders by multivariate analysis. Among men with a BMI < or = 22 kg/m2, a significant positive association was observed between the diabetes incidence and moderate (23.0 < 46.0 g/day) to high (> 46.0 g/day) alcohol consumption, odds ratio 1.91 (95% CI, 1.05-3.46) and 2.89 (1.63-5.11), respectively. Among men with a BMI > 22 kg/m2, a small non-significant increase in odds ratio was observed with alcohol consumption. CONCLUSIONS: Established risk factors for diabetes in western populations were also identified as predictors of the disease among Japanese. Moderate to high alcohol consumption was positively associated with the incidence of diabetes in Japanese lean (BMI < or = 22 kg/m2) men.     

Cigarette smoking and ventricular arrhythmia in coronary heart disease

With use of 24-hour ambulatory electrocardiographic monitoring, the effect of 1 hour of cigarette smoking on cardiac rhythm in 73 patients with coronary heart disease was studied. Fifteen subjects had no arrhythmia; 37 subjects had fewer than 2 atrial or ventricular premature complexes (APCs or VPCs)/hour, with APCs possibly related to smoking in 2 and VPCs related to smoking in 1. Nineteen subjects had more than 2 VPCs/hour (range 4 to 368) and had 16 ± 29 VPCs/hour (± standard deviation) less during than before smoking (p <0.05), associated with an increase in heart rate of 4.6 ±6.8 beats/min (p <0.01). In none of the 9 subjects with unifocal VPCs did multiform beats develop during or after smoking, whereas 3 of 10 subjects with multiform VPCs had only unifocal beats during and immediately after smoking. In 1 of these 19 subjects, frequent APCs developed during smoking. One other subject had frequent APCs unaffected by smoking and another had sinoatrial block, which disappeared during smoking on 1 of 3 monitorings. In conclusion, no sustained or high-grade ventricular arrhythmia was provoked by smoking; although APCs may have been related to smoking in a few persons, the frequency and complexity of VPCs tended to be reduced in these subjects with coronary artery disease.     

Association between Chlamydophila pneumoniae infection and risk of coronary heart disease for Japanese: The JPHC study

Background

Chlamydophila pneumoniae infection is considered a risk factor for atherosclerosis and coronary heart disease in western countries. However, evidence of it being a risk for Japanese is very limited because of a lower risk of coronary heart disease than for western people. The aim of this study was to examine further the association between C. pneumoniae infection and risk of coronary heart disease in Japanese.

Methods

We conducted a nested case–control study of 49,011 Japanese men and women who participated in The Japan Public Health Center (JPHC) study. By the end of 2004, 196 cases of coronary heart disease and 155 cases of myocardial infarction had been documented among the participants. Two controls were selected for each case. For these subjects, we examined the association between serum anti C. pneumoniae IgA and IgG on the one hand and risk of coronary heart disease on the other.

Results

Concentration of C. pneumoniae IgA antibody was positively associated with risk of coronary heart disease and more specifically myocardial infarction. Subjects with the highest quartile of IgA antibody showed 2.29 (95%CI, 1.21–4.33) times higher risk of coronary heart disease and 2.58 (95%CI, 1.29–5.19) times higher risk of myocardial infarction than those with lowest quartile. However, no such association was detected for IgG antibody.

Conclusion

C. pneumoniae infection was found to be positively associated with risk of coronary heart disease.     

Favorable cardiovascular risk profile and 10-year coronary heart disease incidence in women and men: results from the Progetto CUORE.

BACKGROUND: Cardiovascular risk factor research has recently broadened its focus based on new data indicating the benefits of low risk, i.e. favorable levels of all major risk factors. The aims of this study were to assess further the relation of low risk to coronary heart disease risk, and implications for prevention. DESIGN: We conducted a prospective population-based Italian study, of 7438 men and 13 009 women aged 35-69 years, with a mean follow-up of 10.4 years and validated first coronary events. METHODS: Baseline coronary heart disease risk was classified into three categories: low risk; unfavorable but not high risk; and high risk. To analyze the relation of these risk profiles to coronary heart disease incidence, age-adjusted, sex-averaged coronary heart disease incidence was calculated for persons free of coronary heart disease and stroke, stratified as baseline low risk, unfavorable but not high risk or high risk. To assess the independent relationship of individual risk factors to coronary heart disease incidence, multivariate proportional hazards models were computed for combinations of risk factors. RESULTS: Only 2.7% of participants met low risk criteria; 81.4% were high risk. Age-adjusted coronary heart disease incidence for the whole cohort was 37.1 out of 10000 person-years (men 59.0; women 15.3). No coronary heart disease events occurred in low-risk men, only two in low-risk women. For women and men who were not high risk, the age-sex standardized coronary heart disease rate was 62% lower than for high-risk participants. Blood pressure, need for antihypertensive medication, smoking, hyperglycemia, diabetes, total and high-density lipoprotein cholesterol were independently related to coronary heart disease risk. CONCLUSIONS: Favorable levels of all modifiable readily measured risk factors - rare among Italian adults - assure minimal coronary heart disease risk. Population-wide prevention is needed, especially improved lifestyles, to increase the proportion of the population at low risk.     

Trends in the incidence of coronary heart disease and stroke and the prevalence of cardiovascular risk factors among Japanese men from 1963 to 1994

PURPOSE: To determine trends in the incidence of cardiovascular disease in Japan, we examined observational data on coronary heart disease, stroke, and cardiovascular risk factors among urban Japanese working men. SUBJECTS AND METHODS: The surveyed population included all male employees aged 40 to 59 years who worked for eight industrial companies in Osaka, the second largest metropolitan city in Japan. Surveillance for cardiovascular disease and risk factors was conducted from 1963 to 1994. RESULTS: The age-adjusted incidence of coronary heart disease increased from 0.4 per 1000 person-years during 1963 to 1970, to 1.5 per 1000 person-years during 1979 to 1986, and then plateaued until 1987 to 1994 (P for trend = 0.002), whereas the incidence of stroke declined from 1.2 per 1,000 person-years during 1971 to 1978, to 0.6 per 1,000 person-years in 1987 to 1994 (P for trend = 0.02). The age-adjusted mean (+/- SD) total cholesterol level, which was 4.87 +/- 2.88 mmol/L during 1963 to 1966, increased to 5.11 +/- 0.62 mmol/L during 1982 to 1983 (P <0.001), and 5.09 +/- 0.75 mmol/L during 1990 to 1991. Both mean systolic and diastolic blood pressures increased by 1 mm Hg between the periods of 1966 to 1967 and 1982 to 1983, and declined below the 1966 to 1967 levels during 1990 to 1991. The prevalence of smoking declined from 72% during 1975 to 1976, to 58% during 1990 to 1991 (P for trend <0.001). CONCLUSION: Although these findings were limited to urban middle-aged men, the increase in serum cholesterol is likely to attenuate the reduction in future rates of coronary heart disease in Japan that would have been expected to result from the declining prevalence of smoking.     

Cigarette smoking, adiposity, non-insulin-dependent diabetes, and coronary heart disease in Japanese-American men

PURPOSE: Coronary heart disease has been described to be increased with both glucose intolerance and cigarette smoking. All three of these have also been reported to be associated with central adiposity (disproportionate deposition of fat on the trunk compared to the extremities). The purpose of this analysis was to determine the relationship of cigarette smoking to glucose intolerance and coronary heart disease, the relationship of cigarette smoking to risk factors such as adiposity, body fat distribution, and plasma lipoprotein and insulin levels, the relationship of cigarette smoking to these risk factors independent of disease status, and whether these risk factors could account for any of the relationship between cigarette smoking and disease status. PATIENTS AND METHODS: The study design was cross-sectional. The study sample contained 219 middle-aged and elderly Japanese-American men: 77 with normal and 74 with impaired glucose tolerance and 68 with type II diabetes. There were 54 men with coronary heart disease. A detailed smoking history was obtained. Glucose tolerance status was established by medical history and a 75-g oral glucose tolerance test. Coronary heart disease was determined by medical history and a resting electrocardiogram. Adiposity and fat distribution measurements were body mass index (kg/m2), skinfold thicknesses, body circumferences, and cross-sectional fat areas by computed tomography. Levels of insulin, C-peptide, cholesterol (total, low-density lipoprotein [LDL], high-density lipoprotein [HDL], HDL2, HDL3, very-low-density lipoprotein [VLDL]), and triglyceride (total, VLDL) were measured in fasting blood specimens. RESULTS: A central pattern of body fat was associated with both non-insulin-dependent diabetes mellitus and coronary heart disease. Smoking history was related to both adiposity and body fat distribution, and was strongly related to coronary heart disease but not to diabetes. Past smokers who had smoked up to a month ago were the heaviest while present smokers who were currently smoking or had smoked within the past month were the leanest. However, although present smokers had reduced amounts of fat, this was attributable to those present smokers without heart disease. Present smokers with heart disease were not as lean and had increased amounts of intra-abdominal fat. Past smokers had the greatest amount of central fat and this was attributable to those with heart disease. By two-way (smoking history and coronary heart disease status) analysis of covariance, smoking history was significantly related only to subcutaneous fat disposition on the chest and abdomen independent of coronary heart disease, while coronary heart disease status was strongly related to plasma levels of insulin C-peptide, VLDL, HDL, HDL2, and HDL3 cholesterol, and total and VLDL triglyceride, independent of smoking history. Further analysis showed that none of the body fat variables could account for the risk of coronary heart disease associated with smoking history. Higher fasting plasma C-peptide levels in past smokers accounted statistically for part of the risk of coronary heart disease associated with cigarette smoking. However, this effect was not mediated by any of the body fat measurements. CONCLUSIONS: Disproportionately increased intra-abdominal fat is related to coronary heart disease but not to smoking history. Smoking history is related to coronary heart disease but not to diabetes. Weight gain is associated with smoking cessation and appears to be concentrated in the central subcutaneous regions, especially for those who have coronary heart disease. Weight gain associated with cessation of smoking appears to be unrelated to atherogenic changes in lipids, lipoproteins, or insulin. Other pathogenic processes must be considered in the association between smoking and coronary heart disease.