Prevention of cardiovascular disease in Sweden: the Norsjö community intervention programme--motives, methods and intervention components.

OBJECTIVES: When epidemiologic data on cardiovascular disease (CVD) mortality rates in different Swedish regions were published in the early 1980s, there was great concern about the high CVD incidence in the northernmost counties of Sweden, namely Västerbotten and Norrbotten. This paper describe the development of a Northern Sweden community intervention programme for the prevention of CVD. METHODS: As there were no Swedish prototypes, the programme was designed by drawing on experiences from other community interventions. One unique emphasis of the Norsjö intervention programme was to combine a population strategy with efforts to contact each person individually when they became 30, 40, 50, and 60 years of age (the primary care approach). Using the primary care system as part of the community intervention, systematic risk factor screening and counselling by family medicine providers were carried out at the same time as the community intervention programme invoked other efforts to raise public awareness. RESULTS: During the first 10 years of the programme >90% of those invited participated in the individual health screening and counselling. A new food labelling system was introduced in the grocery stores, which after a few years became the official Swedish food labelling system. Sales statistics regarding dairy products showed a significant turnover of low fat products. According to public opinion, the health screening and counselling were reported to be the most influential factors supporting lifestyle changes. CONCLUSIONS: It was possible in Norsjö to create a local health promotion collaboration between healthcare providers, grocery stores, schools, municipal authorities, and the public in order to develop a Swedish model for community intervention. The different programme components were well received by the public.

Can a sustainable community intervention reduce the health gap?--10-year evaluation of a Swedish community intervention program for the prevention of cardiovascular disease.

OBJECTIVES: This paper evaluates the 10-year outcomes of a Northern Sweden community intervention program for the prevention of cardiovascular disease (CVD), with special reference to the social patterning of risk development. METHODS: Using a quasi-experimental design, trends in risk factors and predicted mortality in an intervention area (Norsjö municipality) are compared with those in a reference area (Northern Sweden region) by repeated independent cross-sectional surveys. RESULTS: There were significant differences in changes in total cholesterol level and systolic blood pressure between the intervention and reference populations. The predicted coronary heart disease mortality (based on the North Karelia risk equation). after adjustment for age and education, was reduced by 36% in the intervention area and by 1% in the reference area. CONCLUSIONS: We conclude that a long-term community-based CVD prevention program which combines population and individual strategies can substantially promote a health shift in CVD risk in a high risk rural population. When evaluated for different social strata, we found no signs of an increasing health gap between socially privileged and less privileged groups. Socially less-privileged groups benefited the most from the present prevention program.

Shifting the distribution of risk: results of a community intervention in a Swedish programme for the prevention of cardiovascular disease.

STUDY OBJECTIVE: To examine the impact of a systematic risk factor screening and counselling carried out by family physicians and family nurses within the larger framework of a community intervention programme for the prevention of cardiovascular disease (CVD). DESIGN: Quasi-experimental study comparing trends in an intervention area with those in a reference area. SETTING: A Northern Sweden municipality (5500 inhabitants) constituted the intervention area while the Northern Sweden region (510,000 inhabitants) served as the reference area. PARTICIPANTS: All 30, 40, 50, and 60 year old inhabitants were invited each year from 1985 to 1992. Among 2046 eligible 1893 participated (92.5%), which formed eight independent cross sections. One cross section, 1986, was re-surveyed forming a panel. MAIN RESULTS: In the cross sections, mean total cholesterol was reduced from 7.09 to 6.27 mmol/l for men (p < 0.001) and from 7.13 to 5.89 mmol/l for women (p < 0.001) and mean systolic blood pressure from 132.2 to 123.7 mm Hg for men (p < 0.05) and from 129.2 to 122.0 mm Hg for women (p < 0.001) during the eight years. Body mass index (BMI) increased from 25.6 to 26.2 for men (p < 0.05) and from 25.0 to 25.5 for women (NS). A corresponding reduction in cholesterol and blood pressure (for women) occurred in the panel, while BMI was unchanged. The risk for CVD, using the Framingham equation, was estimated to be reduced overall by 19% (p = 0.0021) when comparing early cross sections (1985/86) with the later cross sections (1990/91). CONCLUSIONS: It was concluded that a long term community based CVD prevention programme that combines population and individual strategies can substantially promote a health shift in CVD risk in a high risk rural population. The individual attention and evaluation provided by the health provider survey seem to accelerate, but not increase the amount of, risk reduction.

von Willebrand factor and fibrinolytic variables are differently affected in the insulin resistance syndrome.

OBJECTIVES: To test whether von Willebrand factor, a new cardiovascular risk factor, belongs to the group of risk factors forming part of the insulin resistance syndrome. DESIGN: A population-based, age-stratified, cross-sectional study. SETTING: A primary health care centre. SUBJECTS: All subjects aged 35, 45, 55, and 65 years in Norsjö municipality (n = 265) were invited, and 68% (82 males, 93 females) entered and completed the study. RESULTS: von Willebrand factor did not correlate with any measured lipid, anthropometric, or glucose metabolism variable. The higher levels of cardiovascular risk factors found in the subgroup of patients with electrocardiographical signs of ischaemic heart disease did not confound this result. CONCLUSION: von Willebrand factor plasma concentration is unrelated to the metabolic factors involved in the insulin resistance syndrome. Thus, it may be difficult to reduce elevated von Willebrand factor levels by conventional non-pharmacological cardiovascular high-risk intervention schemes.

Endurance physical activity, diet and fibrinolysis.

The impact of long-term, heavy exercise on recently established cardiovascular/thromboembolic risk factors of the fibrinolytic system, tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI-1) in relation to food composition was studied. Twenty healthy men, aged 18-55 years participated in a 14-day skiing tour through the Swedish mountains, carrying a pack load of 30 kg, and spending each night in self-dug igloos (ambient temp -10 degrees to -25 degrees C), and were randomized to 2 food regimens having 30 or 40 energy percent of fat. Individual records were kept of all consumed food. Citrated plasma was obtained before and after 1 and 2 weeks of exercise: tPA release was assessed by a 10 min venous occlusion (VO) test. At baseline, daily dietary fiber intake correlated negatively with PAI-1 activity. Already after the first week of the skiing tour there were significant drops in PAI-1 activities, cholesterol and triglycerides. The tPA mass concentrations also dropped, both before and after VO, but tPA activities were unchanged, as were von Willebrand factor (vWF) levels. These changes were related mainly to the expenditure of energy, calculated from the food consumption, and appeared to be mediated through changed insulin sensitivity and decreased body fat mass. The energy percent of fat in the food had no differential impact. The effects receded a few weeks after cessation of the endurance exercise. Thus, endurance physical activity improves the fibrinolytic risk factor profile by reducing PAI-1 while leaving tPA activity unaffected, independently of food composition. A low dietary fiber intake appears to be associated with higher PAI-1 activities at baseline.

Are people willing to pay for a community-based preventive program.

This pilot study is the first known attempt to test the willingness-to-pay or willingness-to-accept (WTP/WTA) method of assessment on a community-based primary prevention program against cardiovascular disease. The results indicate that the population's perceived WTA outweighs the program's costs by at least three to one. However, the methodological problems of using the WTP/WTA method in community-based programs are far from solved, and further research in this area is required.

Hemorrhagic fever with renal syndrome: a study of sequelae following nephropathia epidemica.

Sequelae following Nephropathia epidemica (NE) were investigated in 792 individuals living in an endemic area of Sweden. Volunteers were tested for presence of Puumala (PUU) virus specific IgG antibodies in serum, as well as several parameters linked with renal dysfunction and cardiovascular disease (systolic and diastolic blood pressure, ECG, BMI, total cholesterol and serum creatinine). No differences were seen in any of the variables tested between PUU virus antibody positive (n = 110) and negative individuals (n = 682). In addition, the blood pressure was measured in 62 serologically confirmed patients diagnosed with clinical NE 2-6 years previously. One patient with moderate hypertension was found.

Plasma thrombomodulin concentrations in relation to cardiovascular risk factors in a population sample.

Plasma thrombomodulin (TM) concentrations were studied in a population sample of 175 subjects aged 35-65 years. There was no age variation in males (mean value 65 +/- 15 micrograms/l) but females aged 35-45 years had lower values than women aged 55-65 years, suggesting an effect of the menopause. The TM levels were unrelated to body build measurements (body mass index, waist/hip ratio) and blood pressure, and also to lipid levels (triglycerides, total cholesterol) and insulin before and during an oral glucose tolerance test. There was no difference in mean TM levels in subjects with and without electrocardiographic signs of ischaemic heart disease. Tobacco smokers had 15% lower mean levels of plasma TM than non-smokers.

Effects on fibrinolytic activity of corn oil and a fish oil preparation enriched with omega-3-polyunsaturated fatty acids in a long-term study.

In addition to their beneficial effects in reducing platelet responsiveness, it has been a matter of controversy whether polyunsaturated fatty acids impair the fibrinolytic system or not. In a double-blind, parallel clinical trial, 40 subjects were randomized to treatment with 6 g/day of corn oil, or to 6 g/day of a fish oil preparation, enriched with omega-3-polyunsaturated fatty acids (2.0 g/day of omega-3-PUFA). Clinical and fibrinolytic variables were measured before and after 5 months of treatment. In the corn oil group, plasminogen activator inhibitor (PAI-1) decreased significantly but in the cod liver oil group, PAI-1 remained unchanged. Activities and mass concentrations of tissue plasminogen activator (t-PA) were unchanged in both groups. It is concluded that, in the doses given here, both these preparations have small or no effects on the fibrinolytic system.

Increased plasminogen activator inhibitor and tissue plasminogen activator levels in subjects with electrocardiographic abnormality indicative of ischaemic heart disease: a cross-sectional study in Norsjö, Sweden.

The plasma levels of tissue plasminogen activator (tPA) antigen concentration and plasminogen activator inhibitor (PAI) activity were measured in a random sample of 260 subjects, 30, 40, 50, or 60 years of age. Electrocardiographic Q, ST and/or ST-T changes, suggestive of definite or possible ischaemic heart disease (IHD), were found in 21% of the 50-year-old and 37% of the 60-year-old subjects. As compared to subjects lacking such signs, plasma tPA and PAI levels were significantly increased in the 60-year-old group, and PAI tended to be increased in the 50-year-old group. Previous case-control studies, usually performed at specialized centres and liable to sampling biases, have suggested an association between increased PAI levels and ischaemic heart disease. This cross-sectional population study provides independent data that patients with electrocardiographic signs of IHD have increased levels of both PAI and tPA antigen.

Blood lipids and diet in Swedish adolescents living in Norsjö, an area with high incidence of cardiovascular diseases and diabetes.

In Norsjö in Northern Sweden a cardiovascular intervention programme, for adults is presently tested. The aim of the present study was to investigate the presence of factors related to cardiovascular disease in all 15-year-old adolescents living in Norsjö in 1987 and 1988. The total cholesterol concentration in serum, as an average for the test period, was 4.2 mmol/l and 4.7 mmol/l for boys and girls, respectively. Fourteen per cent of the boys and 32% of the girls had a total cholesterol concentration exceeding 5 mmol/l. Twenty-seven per cent of the adolescents had high values for two or more variables related to risk of developing cardiovascular disease. The evaluation of the dietary registrations showed unsatisfactory values for fibre, P/S ratio and total fat. The dietary habits were better in the 15-year-olds in 1988 than in 1987 as judged by significantly higher average daily intake of fibre as well as a higher content of fibre per megajoule in the food.

Reduced plasminogen activator inhibitor activity in high consumers of fruits, vegetables and root vegetables.

We studied a cross-sectional sample of 260 subjects aged 30-60 years, in order to assess the relation between food intake habits and factors of the fibrinolytic system. Plasma samples of tissue plasminogen activator (tPA) antigen, and plasminogen activator inhibitor (PAI-1) activity were obtained for the assay. The dietary pattern was determined using a food frequency questionnaire, according to which the subjects were grouped as high, low or medium consumers. The subjects who were high consumers of fruit, vegetables, and root vegetables showed the lowest levels of PAI-1, those who were low consumers had the highest levels, whereas the medium consumers showed intermediate values. The tPA levels did not differ between the three groups, and there were no significant differences in other variables that covaried with PAI-1 levels, such as age, anthropometric variables, or serum lipid levels, which could confound the PAI-1/food pattern relationship. The data, which show that a frequent intake of fruit, vegetables, and root vegetables--foodstuffs rich in vitamin C and fibre--is associated with lower PAI-1 levels, are consistent with increased activity of the fibrinolytic system and thus a reduced risk of thromboembolic and cardiovascular disease in subjects who exhibit this food intake pattern.

Interrelationships between plasma levels of plasminogen activator inhibitor, tissue plasminogen activator, lipoprotein (a), and established cardiovascular risk factors in a north Swedish population.

Serum lipids, lipoprotein (a), plasminogen activator inhibitor and tissue plasminogen activator levels were measured in 260 subjects, constituting a cross-section sample of 30-60-year-old men and women. For Lp(a), there were positive correlations with age and cholesterol, but not with any of other measured parameters. Triglyceride, cholesterol, and HDL-cholesterol (inversely) levels were associated with waist-to-hip girth circumference ratio: this variable remained significant in a multiple regression model. PAI-1 activity and tPA antigen levels were positively associated with triglycerides and inversely associated with HDL-cholesterol. Moreover, tPA antigen was positively related to total cholesterol level. In multiple regression analysis, however, only triglycerides were found to contribute significantly to the variance of tPA antigen and PAI-1 activity levels, when BMI (in men) and abdominal skinfold thickness (in women) were entered into the model. Insulin or glucose postload responses to an OGTT were not independently related to any lipid or fibrinolytic variable. These data demonstrate the importance of anthropometric variables both for fibrinolytic variables and traditional lipid risk factors. Only Lp(a) was found to be largely unrelated to the endocrine-metabolic and anthropometric variables.

Fibrinolytic variables are related to age, sex, blood pressure, and body build measurements: a cross-sectional study in Norsjö, Sweden.

Levels of the fibrinolytic variables, tissue plasminogen activator (tPA) antigen concentration and plasminogen activator inhibitor (PAI-1) activity, were measured in a cross sectional sample of 260 subjects aged 30, 40, 50, or 60 years. There was a significant increase of tPA with age in both sexes, but PAI-1 increased only in women. Linear regression analysis was used to assess relations between tPA or PAI-1 and the anthropometric data. In men, tPA levels were related to body mass index and waist-to-hip ratio, whereas in women, it was also related to systolic and diastolic blood pressures and with abdominal or triceps skinfold thicknesses. PAI-1 levels were related to body mass index and waist-to-hip ratio in men, and in women it was in addition related to systolic and diastolic blood pressures and to abdominal and triceps skinfold thicknesses. These data offer new insight into pathophysiological mechanisms whereby age, sex, blood pressure, and body composition variables such as body mass index or waist-to-hip ratio, might act as cardiovascular risk factors.