Serum cholesterol and risk of accidental or violent death in a 25-year follow-up. The Finnish cohorts of the Seven Countries Study.

In the two most recent cholesterol-lowering drug trials, the achieved reductions in coronary heart disease mortality were offset by increases in mortality due to accidents and violence. A possible biochemical explanation has been suggested for an association between low serum cholesterol level and increased risk of death due to injury. We, therefore, examined the association between serum cholesterol level and risk of death from accidents or violence in the 25-year follow-up of two cohorts of Finnish men (N = 1580). Although a statistically nonsignificant, negative association was observed in one cohort (hazard ratio, 0.84, with a 1 mmol/L increase in cholesterol), the other cohort showed a statistically significant, positive association in multivariate analysis (hazard ratio, 1.39). We conclude that the observed associations between serum cholesterol and deaths from injury in the present study and in cholesterol-lowering trials are probably determined by other, presently unknown factors, or by chance.

Importance of coronary risk factors in the presence or absence of myocardial ischemia.

Smoking history, systolic blood pressure, and serum cholesterol concentration were studied for their value in predicting 5-year coronary mortality in middle-aged and older Finnish men. Total experience consisted of 188 deaths from ischemic heart disease during 20,245 person-years. Initially, the men were divided into 3 groups according to the degree of myocardial ischemia: (1) previous myocardial infarction; (2) ischemic heart disease without infarction; and (3) no myocardial ischemia. The 3 main risk factors were associated, independently of each other and of age, with the relative risk of coronary death similarly in the 3 groups, whereas their absolute impact on mortality was strong among men with ischemic heart disease and even stronger among those with a prior myocardial infarction. For example, the estimated excess coronary mortality attributable to smoking 10 to 19 cigarettes per day was 6.3 deaths per 1,000 person-years in the group with no ischemia, 14.6 in the ischemia group, and 43.1 in the infarction group. The results suggest that secondary prevention of ischemic heart disease may be important. Screening of coronary disease among middle-aged and older men also appears justified.

Risk factor dynamics, mortality and life expectancy differences between eastern and western Finland: the Finnish Cohorts of the Seven Countries Study.

Prior studies have not accounted for male mortality being higher in east than west Finland. Efforts to identify the mechanisms producing higher mortality in the east, due primarily to cardiovascular diseases (CVD), initially focused on a search for new risk factors. An alternate approach is to examine the assumptions of the analysis. This was investigated using a model which described (a) changes in risk factors over time, (b) dependency of risk factor effects on age, and (c) interactions and nonlinear effects of risk factors on mortality. The model was applied to 25-year follow-up data from cohorts of eastern (N = 823) and western (N = 888) Finnish men using pulse pressure, diastolic blood pressure, body mass index, total cholesterol, vital capacity index, cigarette smoking, and heart rate as risk factors. At age 40, men in the west had a life expectancy 2.4 years higher. Of the difference 29% (0.7 years) was associated with area differences in risk factor means, variances, and their change with age. The remainder, 1.7 years, was associated with age differences in the relation of risk factor interactions to CVD mortality. Possible reasons for these differences, such as joint elevation of several risk factors inducing rapid progression of atherogenesis, are discussed. No significant area differences were observed for mortality from either cancer or other causes.

Dietary prevention of coronary heart disease in women: the Finnish mental hospital study.

A controlled intervention trial, with the purpose of testing the hypothesis that the incidence of coronary heart disease (CHD) could be decreased by the use of a serum-cholesterol-lowering (SCL) diet, was carried out in two mental hospitals near Helsinki in 1959-71. The subjects were hospitalized middle-aged women. One of the hospitals received the SCL diet, ie a diet low in saturated fats and cholesterol and relatively high in poly-unsaturated fats, while the other served as the control with a normal hospital diet. Six years later the diets were reversed, and the trial was continued another six years. The use of the SCL diet was associated with markedly lowered serum cholesterol values. The incidence of CHD, as measured by the appearance of certain electrocardiographic patterns and by the occurrence of coronary deaths, was in both hospitals during the SCL-diet periods lower than during the normal-diet periods. The differences, however, failed to reach statistical significance. An examination of a number of potential confounding variables indicated that the changes in them were small and failed to account for the reduction in the incidence of CHD. Although the results of this trial do not permit firm conclusions, they support the idea that also among female populations the SCL diet exerts a preventive effect on CHD.

Dietary prevention of coronary heart disease: the Finnish Mental Hospital Study.

A controlled intervention trial, with the purpose of testing the hypothesis that the incidence of coronary heart disease (CHD) could be decreased by the use of serum-cholesterol-lowering (SCL) diet, was carried out in 2 mental hospitals near Helsinki in 1959--71. The subjects were hospitalized middle-aged men. One of the hospitals received the SCL diet, i.e. a diet low in saturated fats and cholesterol and relatively high in polyunsaturated fats, while the other served as the control with a normal hospital diet. Six years later the diets were reversed, and the trial was continued another 6 years. The use of the SCL diet was associated with markedly lowered serum-cholesterol values. The incidence of CHD, as measured by the appearance of certain electrocardiographic patterns and by the occurrence of coronary deaths, was in both hospitals during the SCL-diet periods about half that during the normal-diet periods. An examination of a number of potential confounding variables indicated that the changes in them were small and failed to account for the considerable reduction in the incidence of CHD. It is concluded that the use of the serum-cholesterol-lowering diet exerted a substantial preventive effect on CHD.

HDL serum cholesterol and 24-year mortality of men in Finland.

Examinations of 'healthy' men in Helsinki and in rural west and east Finland in 1956 included estimation of total cholesterol and that in the HDL and beta fractions separated by electrophoresis. Vital status to the end of 1980 has been ascertained for all but eight of the 526 men aged 35-61 and for all but two of 261 men aged 30-34 at entry. Among the men aged 35-61, in 24 years 155 died, 63 from coronary heart disease; among the men aged 30-34, 36 died, 16 from coronary heart disease. All causes and coronary death rates were highest in east Finland where HDL cholesterol was also highest. Coronary death rates were not related to HDL cholesterol in east or west Finland but 16 men dead from coronary heart disease in Helsinki tended to have low HDL values. Consideration of five other entry characteristics did not change the picture with regard to HDL-mortality relationships. Solution of the multiple logistic equation using all those variables found the probability of 24-year coronary death was not significantly related to HDL but was significantly related, positively, to the non-HDL cholesterol concentration. HDL and total cholesterol mean values for men of the same age in the same area of Finland, with lipoprotein separation by the new recommended methods, agree closely with the means recorded in 1956. These 24-year findings are not necessarily in conflict with reports in the literature on an inverse relationship between coronary heart disease incidence and HDL cholesterol based on much shorter periods of follow-up and few data on mortality.

Socio-economic conditions in childhood and mortality and morbidity caused by coronary heart disease in adulthood in rural Finland.

In this study, the hypothesis that bad socio-economic conditions in childhood may increase the probability of coronary heart disease in adulthood is examined. The study is based partly on the data of the East-West Study in Finland, which is part of the Seven Countries Study. The study began with 823 men in Eastern Finland and 888 men in Western Finland in 1959. The mortality and morbidity of the cohorts were followed from 1959 to 1974. Risk factors were measured in medical examinations in 1959, 1964, 1969 and 1974. Parents of those included in the sample were traced by using parish registers from 1900 to 1919. Over 90% of those in the East-West Study were found. The parents' socio-economic position (socio-economic conditions in childhood) was determined. According to our findings, the relative risks of coronary death, myocardial infarction and ischemic heart disease are systematically increased for those born landless in East Finland. Variables partly explaining the increased risk were body height and smoking. The effect of cholesterol was negligible.

Physical activity and cardiovascular morbidity.

Habitual physical activity may appear as a determinant of cardiovascular morbidity because of (i) noncausal associations with other risk factors, (ii) an influence on known risk factors, and/or (iii) some, as yet, not defined mechanisms. The associations of physical activity with other life-style variables, such as smoking and plasma low-density lipoproteins, vary both in direction and strength with population, time, and type of physical activity (eg, work versus leisure time). On the other hand physical activity has been shown to cause an increase in plasma high-density lipoproteins and a decrease in plasma triglycerides and insulin and to predict a lower incidence of hypertension. In some multivariate analyses-of the incidence of coronary heart disease and strokes, physical activity has evolved as an independent predictor of reduced risk. On the type, intensity, and frequency of physical activity as needed for risk reduction, the results are not fully consistent. For delineating the mechanisms for the independent reduction of risk by physical activity, major investments of further research are still necessary.

Back complaints and findings in transport workers performing physically heavy work.

Transport work at an airport promotes the appearance of back diseases because of the lifting carrying, pulling, and pushing of loads in limited spaces. To clarify the nature of back disorders in such a group, a standardized interview for detecting subjective previous and present back symptoms was made of 366 transport workers, and 134 were given a clinical orthopedic examination for detecting objective findings. Sixty-six percent of the interviewed workers reported current back symptoms; these symptoms correlated significantly positively with height, age, and length of transport work experience. Eighty-three percent of te workers with present back symptoms also complained of former back pain. Validity tests between the interview and the clinical examination showed a sensitivity of 86% and a specificity of 31%. The results of our study suggest (i) that according to the high sensitivity the used interview is a valuable screening method for detecting back disorders, and (ii) that selection of workers according to the criteria of our results may be expected to lower the prevalence of back complaints.

Risk factors and 25 year risk of coronary heart disease in a male population with a high incidence of the disease: the Finnish cohorts of the seven countries study.

OBJECTIVE: To assess the efficacy of high serum cholesterol concentration, raised blood pressure, and smoking as predictors of coronary heart disease. DESIGN: Prospective cohort study of middle aged men conducted over 25 years. SETTING: Finish components of an ongoing international study (seven countries study). PARTICIPANTS: 1520 Men who at age 40-59 in 1959 were free of clinically evident heart disease. INTERVENTIONS: At each follow up visit a detailed medical examination including resting electrocardiography was performed, blood pressure and serum total cholesterol concentration were measured, and smoking was assessed. MEASUREMENTS AND MAIN RESULTS: 825 Deaths (54% of participants) occurred during follow up, of which 335 were due to coronary heart disease. The hazard ratio for death from coronary heart disease with respect to risk factors at entry were: for serum cholesterol concentrations above 8.4 mmol/l v below 5.2 mmol/l, 2.68 (95% confidence interval 1.62 to 4.42); for systolic blood pressure in the highest quintile v that in the lowest quintile, 2.46 (1.72 to 3.50); and for smoking 10 or more cigarettes daily v never smoking, 1.95 (1.36 to 2.79). The hazard ratios with respect to cholesterol concentrations and blood pressure remained constant during follow up but the ratio with respect to smoking diminished, mainly owing to men giving up the habit. The estimated conditional probability of a 50 year old man dying of coronary heart disease in the next 25 years ranged from 12% among those with the most favourable risk factor profile to 75% among those with the least favourable profile. CONCLUSIONS: High risk factor levels (as determined in this study) in middle aged men may greatly increase the absolute probability of death from coronary heart disease when the period of study is relevant to the human life span.

Time-budget studies of policemen in weekly or swiftly rotating shift systems.

For 8 days 120 policemen kept special diaries including working time, travelling to and from work, leisure time and sleeping time. By analysing the data of leisure and sleep in relation to the time of day and the type of shift it is possible to find out critical points within a shift system. The mean duration of sleep was reduced before morning shifts, between night shifts and after a morning shift that was followed by a night shift on the same day. The leisure time was limited in connection with afternoon shifts and between the combined morning and night shift. It is recommended not to have double shifts on one day. Rapidly rotated shift systems had more advantages referring to the total amount of night sleep than weekly rotated shift systems. The backward rotation of shifts was unfavourable because of the short time off between the last afternoon shift and the first morning shift. Furthermore, short nightwork periods and a start of the morning shift which is not too early seem to be preferable.

Analysis of 120 shift systems of the police in the Federal Republic of Germany.

120 shift rotas of the police were collected and analysed. The frequency distribution of the shift cycles, the duration of shifts, the start and end of shifts, the maximal number of consecutive night shifts, as well as the frequency of different kinds of free weekends, were determined. The shift systems are compared with recommendations for the design of shift rotas which are based on physiological, psychological and social criteria.

Genetic susceptibility to non-insulin dependent diabetes mellitus and glucose intolerance are located in HLA region.

OBJECTIVES: To test the hypothesis that the genetic susceptibility to non-insulin dependent diabetes mellitus is the same as that to insulin dependent disease and to see whether glucose intolerance is associated with specific HLA haplotypes. DESIGN: Population based study of men in 1989 first tested for glucose tolerance in 1984. HLA haplotypes, including HLA-A, C, B, DR, and DQ, were defined serologically. HLA haplotype data from a population based Finnish study of childhood diabetes were used for predicting non-insulin dependent diabetes and impaired glucose tolerance. SETTING: Two communities in Finland. SUBJECTS: Representative cohort of Finnish men aged 70-89, comprising 98 men with non-insulin dependent diabetes mellitus and a randomly selected group of 74 men, who served as controls, who were tested for glucose tolerance twice within five years. MAIN OUTCOME MEASURES: Non-insulin dependent diabetes, impaired glucose tolerance, blood glucose concentration. RESULTS: Diabetes associated HLA haplotypes were present in 94% (85/90) of diabetic subjects, 79% (27/34) of subjects with impaired glucose tolerance, and only 13% (3/23) of non-diabetic subjects. In this group of elderly men sensitivity of the diabetes associated HLA haplotypes for non-insulin dependent diabetes and impaired glucose tolerance was 90%, specificity 87%, and predictive power 97%. Mean fasting blood glucose concentration was only just significantly higher in men with diabetes associated haplotypes than in men with no such haplotypes, but there was a substantial difference in blood glucose values two hours after glucose loading (10.4 and 6.4 mmol/l in men with diabetes associated HLA haplotypes and men with no such haplotypes, respectively (p < 0.0001)). CONCLUSIONS: These findings support the hypothesis that specific HLA haplotypes exhibit a common genetic determinant for insulin dependent and non-insulin dependent diabetes. Furthermore, HLA is a major genetic determinant of glucose intolerance in elderly Finnish men. The belief that the HLA predisposition to diabetes is specific for insulin dependent diabetes mellitus is largely incorrect.

Sports and longevity.

The mortality of 396 Finnish champion skiers born from 1845 to 1910 was followed up to the end of 1967. Their median life expectancy was 73.0 years, ie.e 4.3 years longer than that for the Finnish male population during the same period. Former skiers have low blood pressure, seldom smoke and are physically active. Increased longevity has been reported also for American college oarsmen and baseball players.