Twenty-five-year mortality from coronary heart disease and its prediction in five cohorts of middle-aged men in Finland, The Netherlands, and Italy

Five cohorts of men ages 40-59 (Finland: 2 cohorts of 1,677 men; Netherlands: 1 cohort of 878 men; Italy: 2 cohorts of 1,712 men) were examined and evaluated for cardiovascular risk factors in 1959-1960 and subsequently followed-up for mortality over the next 25 years. Age-adjusted death rates from coronary heart disease were highest in Finland (244 per 1,000), intermediate in The Netherlands (195 per 1,000), and lowest in Italy (122 per 1,000) with a twofold range between the extremes. The Cox proportional hazards model was used for single cohorts and for the pools of national cohorts with coronary heart disease deaths as endpoints and 12 risk factors as covariates. It showed the significant and almost universal predictive value of these factors (with some rare exceptions). The most highly predictive values were age, blood pressure, total serum cholesterol, cigarette smoking, and physical activity (negative relationship). The prediction of events within each country using the risk function of the others produced errors ranging from -19% to +51%. The largest errors were those involving the Italian cohorts whose experience tended to underpredict coronary heart disease mortality elsewhere and to be overpredicted by the risk functions of the other countries. Solving a Cox model which included all the cohorts, and adding dummy variables for the identification of nationality, it appears that the relative risk, everything else being equal, is 1.49 and 1.34 for a Finnish man, compared with Italian and Dutch men, respectively.     

Improved functional status in 16 years of follow up of middle aged and elderly men and women in north eastern Finland

STUDY OBJECTIVE: To investigate age, period, and cohort effects on functional status. DESIGN: A prospective cohort study with measurements in 1981, 1990, and 1996. SETTING: Three municipalities in north east Finland. PARTICIPANTS: A regionally representative sample of 19 to 63 year old men and women was drawn from the census data in 1979, of which 758 men and 1033 women initially aged 39-63 years entered the study in 1980 and completed the follow up in 1996 (90.9% of the alive cohort). MEASUREMENTS AND MAIN RESULTS: Functional status was determined based on self estimated disabilities (difficulties or not able) to walk 2 km, climb several flights of stairs, and run 100 m. The age adjusted odds of disability in stair climbing and running were lower among the men and the women in 1990 and 1996 than among the men and the women in 1981. There was a declining trend in the odds of disability with succeeding birth cohorts among both the men (odds ratios (OR) 0.79 and 95% confidence intervals (CI) 0.70 to 0.88 for stair climbing and OR 0.88 and 95% CI 0.78 to 0.98 for running) and the women (OR 0.85 and 95% CI 0.77 to 0.93 for stair climbing and OR 0.85 and 95% CI 0.76 to 0.94 for running). No statistically significant differences in walking disability were found between the study periods or the study cohorts. CONCLUSIONS: The findings depict an improved time trend in functional status in the study population, with implications for future health and social care planning.     

Employment grade differences in cause specific mortality. A 25 year follow up of civil servants from the first Whitehall study

STUDY OBJECTIVE: To test the hypothesis that the association between socioeconomic status and mortality rates cuts across the major causes of death for middle aged and elderly men. DESIGN: 25 year follow up of mortality in relation to employment grade. SETTING: The first Whitehall study. PARTICIPANTS: 18,001 male civil servants aged 40-69 years who attended the initial screening between 1967 and 1970 and were followed up for at least 25 years. MAIN OUTCOME MEASURE: Specific causes of death. RESULTS: After more than 25 years of follow up of civil servants, aged 40-69 years at entry to the study, employment grade differences still exist in total mortality and for nearly all specific causes of death. Main risk factors (cholesterol, smoking, systolic blood pressure, glucose intolerance and diabetes) could only explain one third of this gradient. Comparing the older retired group with the younger pre-retirement group, the differentials in mortality remained but were less pronounced. The largest decline was seen for chronic bronchitis, gastrointestinal diseases and genitourinary diseases. CONCLUSIONS: Differentials in mortality persist at older ages for almost all causes of death.     

Body size and mortality in women: a 29 year follow up of 12,000 pregnant women in northern Finland.

STUDY OBJECTIVE: To examine the association between body height, body mass index (BMI), and mortality in fertile women of childbearing age. DESIGN: A prospective cohort study with a 29 year mortality follow up. SETTING AND PARTICIPANTS: A cohort of women (n = 11,997) expected to deliver during 1966 in two northern provinces of Finland. Data on height and pre-pregnancy weight, collected with those on sociodemographic characteristics and smoking by questionnaire at the third trimester, were provided by 91% of the participants. Follow up for mortality using national registries was from delivery until the end of 1994. MAIN RESULTS: Height had a 'U' shaped association with total mortality over the whole follow up time. In women who were shorter than average, the death rate from cardiovascular diseases was increased and in taller women this was true for tumours. Compared with the women of 'normal weight' (BMI 21 to < 25 kg/m2), the obese subjects (BMI at least 29) did not have increased mortality during the first 20 years, but had a relative risk of 1.7 during the final nine years of follow up, primarily as a result of cardiovascular diseases. The lean women (BMI < 21) experienced a similar rate overall, but moderately overweight women (BMI 25 to < 29) had a consistently lower mortality than women of normal weight. CONCLUSIONS: Among fertile women of childbearing age, both the short and tall seem to have an increased total mortality compared with those of average body height, resulting from opposite trends in major causes of death. Obesity is associated with raised long term total mortality.     

Fish consumption and coronary heart disease mortality in Finland, Italy, and The Netherlands

Fish consumption seems to protect against death from coronary heart disease (CHD). If this association is due to n-3 polyunsaturated fatty acids, especially fatty fish may be responsible for this protective effect. The association between total, lean, and fatty fish consumption and the risk of CHD mortality was examined in 1,088 Finnish, 1,097 Italian, and 553 Dutch men participants in the Seven Countries Study who were aged 50-69 years and free of CHD around 1970. After 20 years of follow-up, 242 (22.2%) men in Finland, 116 (10.6%) men in Italy, and 105 (19.0%) men in the Netherlands had died of CHD. Cox proportional hazards analysis showed no association between total fish consumption and CHD mortality. After adjustments were made for age, body mass index, smoking, energy intake, and relevant dietary variables, the pooled relative risk for the highest quartile of total fish compared with no fish consumption in the three countries was 1.08 (95% confidence interval: 0.76, 1.53). Lean fish consumption also was not associated with CHD mortality in any country. Fatty fish compared with non-fatty-fish consumption was associated with lower CHD mortality; the adjusted, pooled relative risk for fatty fish consumers was 0.66 (95% confidence interval: 0.49, 0.90). These data suggest that especially fatty fish is protective against CHD mortality.     

Shift work, social class, and ischaemic heart disease in middle aged and elderly men; a 22 year follow up in the Copenhagen Male Study

OBJECTIVES: Shift work has been associated with an increased risk of ischaemic heart disease (IHD). Most published studies have had potential problems with confounding by social class. This study explores shift work as a risk factor for IHD after controlling for social class. METHODS: The Copenhagen male study is a prospective cohort study established in 1970-1 comprising 5249 men aged 40-59. Information obtained included working time, social class, and risk factors for IHD. A second baseline was obtained in 1985-6. The cohort was followed up for 22 years through hospital discharge registers for IHD, and cause of death was recovered from death certificates. RESULTS: One fifth of the cohort was shift working at entry with a significantly larger proportion of shift workers in lower social classes. Risk of IHD and all cause mortality over 22 years, adjusted for age only, for age and social class, and finally for age, social class, smoking, fitness, height, weight, and sleep disturbances, did not differ between shift and day workers. The relative risk of IHD, adjusted for age and social class was 1.0 (95% confidence interval (95% CI) 0.9-1.2). Men being shift workers in both 1971 and 1985 had the same risk as ex-shift workers in an 8 years follow up from the 1985-6 baseline. CONCLUSIONS: The present study questions shift work as an independent risk factor for IHD. The results of the study emphasise the importance of controlling adequately for the interplay of shift work and social class.       

Comparative total mortality in 25 years in Italian and Greek middle aged rural men

STUDY OBJECTIVE: Mortality over 25 years has been low in the Italian and very low in the Greek cohorts of the Seven Countries Study; factors responsible for this particularity were studied in detail. PARTICIPANTS AND SETTINGS: 1712 Italian and 1215 Greek men, aged 40-59 years, cohorts of the Seven Countries Study, representing over 95% of the populations in designated rural areas. DESIGN: Entry (1960-61) data included age, systolic blood pressure (SBP), smoking habits, total serum cholesterol, body mass index (BMI), arm circumference, vital capacity (VC), and forced expiratory volume in 3/4 seconds (FEV); the same data were obtained 10 years later. Multivariate Cox analysis was performed with all causes death in 25 years as end point. MAIN RESULTS: Italian men had higher entry levels of SBP, arm circumference, BMI, and VC; Greek men had higher cholesterol levels, smoking habits, and FEV. Mortality of Italian men was higher throughout; at 25 years cumulative mortality was 48.3% and 35.3% respectively. Coronary heart disease and stroke mortality increased fivefold in Italy and 10-fold in Greece between years 10 and 25. The only risk factor with a significantly higher contribution to mortality in Italian men was cholesterol. However, differences in entry SBP (higher in Italy) and FEV (higher in Greece) accounted for, according to the Lee method, 75% of the differential mortality between the two populations. At 10 years increases in SBP, cholesterol, BMI, and decreases in smoking habits, VC, FEV, and arm circumference had occurred (deltas). SBP increased more and FEV and VC decreased more in Italy than in Greece. Deltas, fed stepwise in the original model for the prediction of 10 to 25 years mortality, were significant for SBP, smoking, arm circumference, and VC in Greece, and for SBP and VC in Italy. CONCLUSION: Higher mortality in Italian men is related to stronger positive effects of entry SBP and weaker negative (protective) effects of FEV; in addition 10 year increases in SBP are higher and 10 year decreases in FEV are larger in Italy. Unaccounted factors, however, related to, for example, differences in the diet, may also have contributed to the differential mortality of these two Mediterranean populations.     

Relation between number of siblings and adult mortality and stroke risk: 25 year follow up of men in the Collaborative study

STUDY OBJECTIVE: To investigate the relation between number of siblings, mortality risk, and stroke risk. DESIGN: Prospective cohort study. SETTING: 27 workplaces in Scotland. PARTICIPANTS: 5765 employed men aged 35-64 from a variety of different workplaces, screened between 1970 and 1973. MAIN RESULTS: There were strong relationships between number of siblings and socioeconomic variables and also with adult behavioural measures. Men with greater numbers of siblings had an increased risk of dying of all causes, coronary heart disease, lung cancer, stomach cancer, and respiratory disease over a 25 year follow up period. Adjustment for risk factors could explain these associations, excepting stomach cancer mortality. With the definition of stroke as either a hospital admission for stroke or death from stroke, there was a strong relation between number of siblings and haemorrhagic stroke, but not ischaemic stroke. CONCLUSIONS: Number of siblings is strongly related to mortality risk, but as it is also related to many risk factors, adjustment for these can generally explain the relation with mortality. The exceptions are stomach cancer mortality and haemorrhagic stroke, which are known to be related to deprivation in childhood, and, in the case of stomach cancer to childhood infection.     

Comparison of diets of diabetic and non-diabetic elderly men in Finland, The Netherlands and Italy

OBJECTIVE: To evaluate whether dietary recommendations for subjects with diabetes are met among Finnish, Dutch and Italian elderly men with diabetes, and whether the diets of diabetic and non-diabetic men differ in these three countries. DESIGN: A dietary survey using cross-check dietary history method. A cross-sectional comparison. SETTING: Thirty-year follow-up of survivors from the Finnish, Dutch and Italian cohorts of the Seven Countries Study. SUBJECTS: 227 elderly men from Finland, 537 from The Netherlands, and 417 from Italy, of whom 8-9% had diabetes. MAIN RESULTS: The diets of non-diabetic men from the three countries differed markedly from each other. In all three countries diabetic men consumed less added sugar than non-diabetic men. In Italy, in addition, diabetic men consumed more fruits and berries and vegetables. The Dutch diabetic men ate relatively more cereal products, fruits and berries, milk and milk products, cheese, and meat and meat products and drank less alcoholic beverages than non-diabetic men. The diet of both diabetic and non-diabetic Finnish and Dutch men was characterized by high fat content (41% and 40% of energy, respectively). The fat content of the diet was even higher for diabetic than non-diabetic men in Finland and The Netherlands, but not in Italy. The fibre content of the diet was the highest among Dutch men and diabetic men received more dietary fibre than non-diabetic men in The Netherlands and Italy, but not in Finland. The diet of diabetic and non-diabetic Finnish men differed little from each other and was characterized by high nutrient density of several vitamins and minerals. The proportion of protein of energy intake was higher among diabetic than non-diabetic Dutch and Italian men. CONCLUSIONS: The diet of the diabetic men from Finland, the Netherlands, and Italy resembled more the diet of non-diabetic men from the respective countries than the diet of diabetic men from the other countries. In the diet of Italian diabetic men, the proportions of fat, saturated fatty acids and carbohydrates were nearest the recommended levels. SPONSORSHIP: The National Institute on Aging, Bethesda, USA, the Dutch Prevention Foundation, the Hague, The Netherlands, the Academy of Finland, and the Sandoz Gerontological Foundation.     

Total and HDL cholesterol and their correlates in elderly men in Finland, Italy, and The Netherlands

In 1984 and 1985, 25-year follow-up studies were carried out in the Italian, Finnish, and Dutch cohorts of men originally examined around 1960 in the Seven Countries Study. Risk factors for coronary heart disease were determined in 2,255 men aged 65-84 years. The average serum total cholesterol levels of the elderly men in Finland and the Netherlands were similar, at around 236 mg/dl (6.10 mmol/liter). The average serum total cholesterol levels of the elderly men in Italy were about 10 mg/dl (0.26 mmol/liter) lower. During 25 years of follow-up, the average serum total cholesterol level increased by 29 mg/dl (0.75 mmol/liter) among the Italian survivors, decreased by 23 mg/dl (0.59 mmol/liter) in the Finnish survivors, and did not change in the Dutch survivors. Age, Quetelet index, and coffee consumption were the most important correlates of total cholesterol in these elderly men. Quetelet index, alcohol consumption, age, and cigarette smoking were significantly associated with high density lipoprotein (HDL) cholesterol. The results of this study suggest that modifiable risk factors are related to total and HDL cholesterol in elderly men in different cultures.     

Total but not high-density lipoprotein cholesterol is consistently associated with coronary heart disease mortality in elderly men in Finland, Italy, and The Netherlands

We studied the relation between serum total and high-density lipoprotein (HDL) cholesterol and 10-year coronary heart disease mortality in elderly men in different European countries. The Finland, Italy and the Netherlands Elderly (FINE) Study is a prospective follow-up study in 2,132 elderly men ages 65-84 years in Finland, the Netherlands, and Italy. We estimated relative risks using Cox proportional hazard analysis with time-dependent covariates. Total cholesterol was positively related to coronary heart disease mortality in all three countries. The combined relative risk for the total population of the FINE Study was 1.17 (95% confidence interval = 1.06-1.29) for each 1.00 mmol/liter increase in total cholesterol. HDL cholesterol was inversely related to coronary heart disease mortality in Finland, but not in the Netherlands and Italy. In Italy we noted an interaction among HDL cholesterol, body mass index, and alcohol intake, with an inverse association for HDL cholesterol in lean men who drank <40 gm of alcohol daily and a positive association for HDL cholesterol among overweight men who drank > or =40 gm of alcohol per day. Serum total cholesterol remains an important predictor of coronary heart disease mortality in elderly men in different European countries. The effect of HDL cholesterol differed among the three countries.     

All-cause and cause specific mortality in a cohort of 20 000 construction workers; results from a 10 year follow up

Background: Construction workers are potentially exposed to many health hazards, including human carcinogens such as asbestos, silica, and other so-called "bystander" exposures from shared work places. The construction industry is also a high risk trade with respect to accidents.

Methods: A total of 19 943 male employees from the German construction industry who underwent occupational health examinations between 1986 and 1992 were followed up until 1999/2000.

Results: A total of 818 deaths occurred during the 10 year follow up (SMR 0.71; 95% CI 0.66 to 0.76). Among those were 299 deaths due to cancer (SMR 0.89; 95% CI 0.79 to 1.00) and 312 deaths due to cardiovascular diseases (SMR 0.59; 95% CI 0.51 to 0.68). Increased risk of mortality was found for non-transport accidents (SMR 1.61; 95% CI 1.15 to 2.27), especially due to falls (SMR 1.87; 95% CI 1.18 to 2.92) and being struck by falling objects (SMR 1.90; 95% CI 0.88 to 3.64). Excess mortality due to non-transport accidents was highest among labourers and young and middle-aged workers. Risk of getting killed by falling objects was especially high for foreign workers (SMR 4.28; 95% CI 1.17 to 11.01) and labourers (SMR 6.01; 95% CI 1.63 to 15.29).

Conclusion: Fatal injuries due to falls and being struck by falling objects pose particular health hazards among construction workers. Further efforts are necessary to reduce the number of fatal accidents and should address young and middle-aged, semi-skilled and foreign workers, in particular. The lower than expected cancer mortality deserves careful interpretation and futher follow up of the cohort.

     

Obesity and mortality among older Thais: a four year follow up study

Background  

To assess the association of body mass index with mortality in a population-based setting of older people in Thailand.     

The Epping jaundice outbreak: a 24 year follow up.

STUDY OBJECTIVE--The aim was to trace 84 cases of jaundice that occurred following accidental ingestion of methylene dianiline (MDA) in Epping in 1965, and to look at long term health effects. DESIGN--The original case notes of the cases were used to identify the patients. Subsequent tracing procedures included local general practitioners, the Central NHS Registry, electoral rolls, and company records. SETTING--This was a community based survey. MAIN RESULTS--The health status of 68 (81%) of the group was established with 18 deaths. Of the 50 cases known to be alive, 58% completed a health questionnaire. The causes of death were unremarkable except for one case of carcinoma of the biliary tract. Two surviving cases had suffered retinal pathology. Four other surviving cases had had a further, perhaps unrelated, episode of jaundice. CONCLUSIONS--Although the dose and route of administration in the epidemic differed from occupational exposure, this follow up study a generation on provides little, if any, evidence of long term health sequelae. Nevertheless, in the absence of well documented exposure and health effects data, such accidental poisonings with proven animal carcinogens warrant long term follow up. The identified cohort will be the subject of further study.     

Six year follow up of lung function in men occupationally exposed to formaldehyde.

The long term effects of formaldehyde on the respiratory tract have been investigated in a group of 164 workers exposed daily to the chemical during the production of urea formaldehyde resin, together with 129 workers not exposed to free formaldehyde. Exposure was classified as high (corresponding to an eight hour time weighted exposure of more than 2.0 ppm), medium (0.6 to 2.0 ppm), or low (0.1 to 0.5 ppm). Twenty five per cent of workers had had high exposure at some time and 17% moderate exposure. Both the exposed and unexposed groups had an annual assessment that included lung function. The proportion with self reported respiratory symptoms was similar in the two groups, 12% and 16% reporting breathlessness on hurrying and 26% and 20% wheezing. The initial forced expiratory volume in one second (FEV1) was within 0.5 l (approximately one standard deviation (SD)) of the predicted value (by age and height) in 65% of the exposed and 59% of unexposed workers and more than 0.5 l below the predicted value in 9% of exposed and 11% of unexposed workers. The mean decline in FEV1 was 42 ml a year (SD 45) in the exposed group and 41 ml a year in the unexposed group (SD 40 ml a year). The rate of decline showed the expected association with smoking in the unexposed group, but in the exposed group the mean rate of decline in the never smokers was similar to that in current smokers. There were, however, relatively few never smokers and considerable variation in the rates of decline. In the exposed group no association was found between the rate of decline and indices of exposure to formaldehyde. Thus there is no evidence from this study of an excess of respiratory symptoms or decline in lung function in the workers exposed to formaldehyde. The similar rate of decline of FEV1 however in never smokers and smokers of the exposed group is consistent with findings of other studies for workers exposed to formaldehyde and to toluene di-isocyanate.     

The 25 year estimated probability of death from some specific causes as a function of twelve risk factors in middle aged men

Twelve risk factors previously identified as predictors of all causes of death in a 25-year follow-up of a sample of 1530 men aged 40–59 at entry, have been tested as predictors of specific causes of death. They were age (AGE), mean blood pressure (MBP), cigarette smoking (CIG), forced expiratory volume (FEV), arm circumference (ARM), father-life status (FHAS), mother-life status (MHOS), shoulder-pelvis ratio (SPR), vital capacity (VC), arcus senilis (ARCS), serum cholesterol (CHOL) and xantelasma (XANT). Using the proportional hazards model and considering coronary heart diseases, strokes, cancers, violent deaths, and other causes as end-points, AGE and MBP were significant predictors for all conditions, including violent deaths. CIG predicted coronary heart disease, stroke and cancer; FEV, VC, and ARM were protective for all end-points but significant only for a few of them. FHAS and MHOS were positively associated with all end-points but significant only for a few of them. ARCS and XANT were predictive for only a few conditions and, surprisingly, XANT was a significant risk factor for cancer. Finally CHOL was specifically predictive only for coronary heart disease.     

Impact of social network on cardiovascular mortality in middle aged Danish men.

STUDY OBJECTIVE--To estimate quantitatively (the aetiological fraction) the impact of poor social network on premature death from cardiovascular disease in middle aged, white men. DESIGN--The causality of the relationship has already been discussed in a large review, and it is assumed to be well documented. The numerical estimation of the impact was based on a review of all published cohort studies on the relationship between social network and mortality in white, middle aged men. RESULTS--The studies reviewed are all of high epidemiological quality and present a consistent and stable dose-response pattern. The aetiological fraction was estimated to be 30%, with a plausible range of 20-40%. CONCLUSIONS--Social network was an important, independent, risk factor for cardiovascular disease in white, middle aged men. It had a strong impact on mortality, comparable to that of traditional risk factors. Social network should have a more central role in future epidemiological research into cardiovascular disease. The factors that result in a strong social network should be identified and strategies applicable in preventive work should be developed.     

Cancer mortality in the asphalt industry: a ten year follow up of an occupational cohort.

A historical cohort study was conducted to study the possible risk of cancer associated with exposure to asphalt. Altogether 1320 unskilled workers employed in the asphalt industry were followed up over a ten year period and compared with 43,024 unskilled men in terms of cause specific mortality. Both groups were identified from census records and followed up by an automatic record link that had been established previously between the census register, National Register, and Death Certificate Register. The cancer mortality was significantly increased in asphalt workers aged 45 or more, when five years' latency from enrolment into the study was allowed for (SMR for cancer: 159, 95% confidence interval: 106-228). Non-significant increases were seen for respiratory, bladder, and digestive cancers but a significant increase was seen for brain cancer (SMR = 500, 95% CI: 103-1461). Components of asphalt fumes may have been important to the observed association between risk of cancer and employment in the asphalt industry.