Favourable trends in the incidence and outcome of myocardial infarction in nondiabetic, but not in diabetic, subjects: findings from the MONICA myocardial infarction registry in northern Sweden in 1989-2000.

BACKGROUND: The aim of this study was to compare time trends in incidence, case fatality and mortality due to myocardial infarction (MI) in patients with or without diabetes. METHODS: This study was based on the Northern Sweden MONICA Project MI registry with a target population of about 200,000 inhabitants in the age group 35--64 years in the two northernmost counties of Sweden. During 1989--2000, 6254 patients who had had an MI according to MONICA criteria were included in this study: 4569 patients had a first MI and 1685 had a recurrent MI. Sixteen per cent of the men and 20% of the women had had diabetes mellitus diagnosed prior the MI. RESULTS: Over the 12-year period, there was a declining trend in incidence and case fatality in first MI. Also, the event rates (first ever and recurrent MI) declined in men without diabetes. In women without diabetes favourable time trends were seen in first ever MI, recurrent MI and in case fatality. There were no favourable time trends for any of these outcomes in patients with diabetes. CONCLUSION: In nondiabetic subjects below the age of 65, the incidence of, and case-fatality in, MI declined. This led to a decreased mortality over the 12-year period. These favourable trends over time were not observed in diabetic subjects.

The Arctic Oscillation and incidence of acute myocardial infarction.

OBJECTIVES: To describe the relation between the Arctic Oscillation (AO) index and the incidence and mortality in acute myocardial infarction (AMI) in the northern, partly subarctic area of Sweden. DESIGN: Comparison of a time series of daily variations in the AO index and register data on the daily number of fatal and nonfatal AMIs. SETTING: The northernmost two Swedish counties, Norrbotten and Västerbotten. SUBJECTS: All inhabitants in the Norrbotten and Västerbotten counties were followed for the occurrence of an AMI between 1985 and 1999 within the framework of the WHO MONICA (multinational MONItoring of trends and determinants of CArdiovascular disease) Project. MAIN OUTCOME MEASURE: Fatal and nonfatal AMIs. RESULTS: There was a consistent positive relation between increasing AO index and an increase in AMI incidence and mortality. The maximum impact on AMI incidence of the AO came after a lag phase of 3 days. A one unit increase in AO index was associated with an increase in: the daily number of AMIs (+3.8%), the case fatality in AMI within 28 days (+5.1%), the number of nonfatal AMIs (+3.4%), and the number of sudden cardiac deaths (+8.3%). CONCLUSIONS: An AO index increase, bringing warmer weather over Scandinavia, was associated with an increase in the incidence and mortality in AMI in northern Sweden.

Trends in sudden cardiac death in the northern Sweden MONICA area 1985-99.

OBJECTIVES: To describe time trends in sudden cardiac death (SCD) occurrences between 1985 and 1999. DESIGN: Cohort study with analysis of a database of all symptomatic and/or fatal acute myocardial infarctions (AMI) in the two northernmost counties in Sweden, partly north of the Arctic Circle. SUBJECTS: A total of 1139 cases of SCD amongst men and women aged 35-64 years. MAIN OUTCOME MEASURE: Sudden cardiac death. RESULTS: Amongst men the proportion of SCD to all AMI deaths (within 28 days of an AMI) was 38% and for women 31%. The mean yearly incidence of SCD in this age group was 65 per 100,000 men and 12 per 100,000 women. Amongst men the mean yearly incidence decreased by 1.8% (95% confidence interval -3.2 to -0.3) and amongst women the decrease was 1.0% (95% confidence interval -4.4 to 2.4). Diabetes mellitus was more common in women compared with men (24% vs. 14%, P = 0.001). Men suffered an SCD more often around noon and on Saturdays, whereas women suffered their SCD on Mondays and Fridays. For season, men and women behaved similarly with a winter peak, although statistical significance was reached only for men. CONCLUSIONS: The SCD decreased amongst men between 1985 and 1999. There was also a decrease amongst women during the same time period but not to a statistically significant degree, possibly caused by lack of statistical power due to small numbers.

No increase in the prevalence of known diabetes between 1986 and 1999 in subjects 25-64 years of age in northern Sweden.

AIMS: A global increase in diabetes is predicted due to higher body weight and less physical activity. Over the period 1986-1999, the body mass index (BMI) of the adult population of northern Sweden increased from 25.3 to 26.2 and the prevalence of obesity (BMI > or = 30) from 11% to 15%, although this was more distal than central adiposity. Our hypothesis was that this would lead to a higher prevalence of diabetes. METHODS: Four population surveys with new and independent cohorts of 2000 invited subjects, 25-64 years old, in 1986, 1990, 1994 and 1999. In the first three surveys an oral glucose tolerance test was carried out in 47%. RESULTS: Over the time period 1986-1999 there was no increase in the prevalence of known diabetes. No trends were noted in the finding of previously undiagnosed diabetes or impaired glucose tolerance over the period 1986-1994, although the confidence intervals are wide. Fasting, but not post-load, glucose levels increased with 0.040 mmol/year (95% CI 0.026; 0.055) in men and 0.033 mmol/year (0.023; 0.044) in women. CONCLUSION: In spite of a marked increase in BMI, we found no increased prevalence of known diabetes over a 13-year observation period, although our data cannot exclude minor increases in undiagnosed diabetes. The development of more distal than abdominal obesity, a diet with less saturated fat and lower glycaemic index and fewer regular smokers in the population may contribute to this. The effects of obesity may thus be attenuated by other secular trends in society and highlight potential ways of curbing the worldwide increase in diabetes.

No covariation between the geomagnetic activity and the incidence of acute myocardial infarction in the polar area of northern Sweden.

This study was undertaken to investigate whether there was any relation between the aurora borealis (measured as the geomagnetic activity) and the number of acute myocardial infarctions (AMI) in the northern, partly polar, area of Sweden. The AMI cases were collected from The Northern Sweden MONICA (multinational MONItoring of trends and determinants of CArdiovascular disease) AMI registry between 1985 and 1998, inclusive, and the information on the geomagnetic activity from continuous measurements at the Swedish Institute of Space Physics, Kiruna. In the analyses, both the relation between the individual AMI case and ambient geomagnetic activity, and the relation between the mean daily K index and the daily number of AMI cases were tested. We found no statistically significant relation between the number of fatal or non-fatal AMI cases, the number of sudden deaths or the number of patients with chest pain without myocardial damage, and geomagnetic activity. Our data do not support a relation between the geomagnetic activity and AMI.

Exploring sex differences in case fatality in acute myocardial infarction or coronary death events in the northern Sweden MONICA Project.

OBJECTIVES: To investigate sex differences in reaching diagnosis, medical management and case fatality (CF) in acute myocardial infarction (AMI) in the population aged 35-64 years in northern Sweden. METHODS: Within the framework of the World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases (MONICA) Project, definite AMI was monitored in people aged 35-64 years from 1989 through 1995 (target population 510 000 in 1991). SETTING: In a population based coronary register, all coronary events were recorded in nine hospitals in 1989-95. RESULTS: The number of events included in the definite coronary myocardial infarction register was 2483 men and 669 women. On admission, a higher proportion of men with definite AMI had chest pain or ECG changes typical for AMI (P < 0.0001). Disagreement between clinical diagnosis and classification by MONICA criteria occurred more often in women (P=0.008). A significantly higher proportion of men was admitted in the coronary care unit and they were significantly more often treated with thrombolytics, nitroglycerine, beta-blockers, or antiplatelet agents. Women received significantly more diuretics, inotropics or calcium antagonists. Diabetes, conferring a worse prognosis, was more common in women (20 vs. 15%; P=0.003). Prehospital CF was significantly higher in men (24.1 vs. 18.3%; P=0.005), but in patients treated in hospital, the CF was significantly lower in men (12.7 vs. 21.2%; P < 0.001). Total CF was equal in men and women. CONCLUSIONS: Several factors contributing to the excess in-hospital CF in women were identified, including greater problems in diagnosis of AMI in women which may be one of the reasons for less intensive treatment in women. Differences in co-morbidity, most notably diabetes and medical treatment between men and women with acute AMI may also have played a part.

Marked improvement in survival after acute myocardial infarction in middle-aged men but not in women. The Northern Sweden MONICA study 1985-94.

OBJECTIVES: The aim of this study was to analyse time trends in survival after acute myocardial infarction with special emphasis on sex differences. DESIGN: Within the framework of the population-based WHO MONICA Project, all acute myocardial infarction events were recorded in the age group 25-64 years in northern Sweden during the period 1985-94. All first-ever myocardial infarction patients were followed for information on vital status. SUBJECTS: A total of 3397 men and 860 women with acute myocardial infarction, during the period between 1985 and 1994. MAIN OUTCOME MEASURES: Case fatality rates after first-ever acute myocardial infarction. RESULTS: When compared with the 1985-86 cohort, the age-adjusted odds ratio for death within 1 year after acute myocardial infarction was 0.59 (95% CI 0.46-0.76) in the 1993-94 male cohort but 0.99 (95% CI 0.61-1.60) in the female 1993-94 cohort. Corresponding age-adjusted proportions of death within 1 year were 33.3% and 22.9% in men and 27.5% and 27.3% in women in 1985-86 and 1993-94, respectively. The odds ratio for 3-year case fatality amongst those who survived the first 28 days was 0.34 (95% CI 0.21-0.55) in 1991-92 compared with 1985-86 in men and 0.91 (0.43-1.94) in women. CONCLUSION: Both short- and long-term survival after AMI have improved markedly in men over the last decade. There is a disturbing sex difference in that, during the same period, survival in women with AMI has not improved at all. This sex difference was not explained by differences in conventional prognostic factors.

Social patterning of myocardial infarction and stroke in Sweden: incidence and survival.

Cardiovascular disease morbidity and mortality rates show marked social patterning in industrialized countries. The aim of this study was to analyze if not only incidence but also survival after acute myocardial infarction (AMI) and stroke differ among socioeconomic groups. Within the framework of the population-based World Health Organization's Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) Project, all first-ever AMI (ages 25-64 years) and stroke (ages 25-74 years) events were recorded in northern Sweden during the period 1985-1994. The numbers of first-ever AMI and stroke patients included in the study were 3,466 and 4,215, respectively. Incidence rates for both AMI and stroke showed a distinct social pattern, with high rates in workers and self-employed nonprofessionals and low rates in professionals. The pattern was similar in men and women. In men, early survival after an AMI follows the same socioeconomic pattern, whereas it is less clear if socioeconomic differences in survival contribute to explain differences in mortality in AMI among women and mortality in stroke (both sexes). The high case fatality among male workers and self-employed professionals with AMI is, in turn, attributed to a very marked increase in the risk for sudden death.

Smokeless tobacco as a possible risk factor for myocardial infarction: a population-based study in middle-aged men.

OBJECTIVES: To explore whether the use of snuff affects the risk of myocardial infarction (MI). BACKGROUND: Snuff and other forms of smokeless tobacco are widely used in some populations. Possible health hazards associated with the use of smokeless tobacco remain controversial. METHODS: In a population-based study within the framework of the Northern Sweden center of the World Health Organization Multinational Monitoring of Trend and Determinants in Cardiovascular Disease (WHO MONICA) Project, tobacco habits were compared in 25- to 64-year-old men with first-time fatal or nonfatal MI and referent subjects matched for age and place of living (687 cases, 687 referents). RESULTS: The unadjusted odds ratio (OR) for MI in regular cigarette smokers as compared with men who never used tobacco was 3.65 (95% confidence interval [CI] 2.67 to 4.99). When nonsmoking regular snuff dippers were compared with never-users of tobacco, the unadjusted OR was 0.96 (0.65 to 1.41). After adjustment for multiple cardiovascular risk factors, the OR was 3.53 (95% CI 2.48 to 5.03) for regular smoking and 0.58 (95% CI 0.35 to 0.94) for regular snuff dipping. Restricting the analyses to fatal cases of myocardial (including sudden death) showed a tendency towards increased risk among snuff dippers 1.50 (95% CI 0.45 to 5.03). CONCLUSIONS: The risk of MI is not increased in snuff dippers. Nicotine is probably not an important contributor to ischemic heart disease in smokers. A possible small or modest detrimental effect of snuff dipping on the risk for sudden death could not be excluded in this study due to a limited number of fatal cases.

Secular trends in social patterning of cardiovascular risk factor levels in Sweden. The Northern Sweden MONICA Study 1986-1994. Multinational Monitoring of Trends and Determinants in Cardiovascular Disease.

OBJECTIVES: In the Northern Sweden MONICA Study, levels of cardiovascular risk factors were determined in 1986, 1990 and 1994. The aim of this study was to assess the trends in cardiovascular risk factors, and to analyse the relationship between levels of risk factors and level of education. DESIGN: Cardiovascular risk factors were determined in cross-sectional population studies of randomly selected 25-64 year old men and women in 1986, 1990 and 1994 (a total of 4742 individuals). RESULTS: Throughout the years 1986 to 1994, cardiovascular risk factor levels showed a marked social pattern, generally being more favourable among people with a university education. Serum cholesterol levels declined in all educational groups, but blood pressure declined significantly only in women with a university education. Body mass index increased, most markedly in men with university and in women with a secondary school education. Prevalence of cigarette smoking decreased significantly in young men. It increased markedly in low-educated women so that the social gaps in smoking widened substantially over time. The improved level of education in the population at large was calculated to explain only a little of the risk factor changes between 1986 and 1994. CONCLUSIONS: Trends in risk factor levels in different educational groups have been more diverging for women than for men. The most marked change in risk factor levels has been the decline in total serum cholesterol for both men and women in all educational groups.

Diabetes as a risk factor for myocardial infarction: population and gender perspectives.

OBJECTIVES: To investigate diabetes as a risk factor for acute myocardial infarction (AMI) from a population perspective in a region with high cardiovascular disease (CVD) risk. DESIGN: Population screenings for diabetes and a population-based AMI register. SETTING: Northern Sweden MONICA area. SUBJECTS: Representative sample (Norrbotten and Västerbotten counties) of 2432 men and women 35-64 years was investigated 1990 and 1994. All patients with AMI aged 35-64 years were included, in total 3031 between 1989 and 1993. RESULTS: The prevalence of diabetes was 5% in men and 4.4% in women. The relative risk (RR) in diabetic men was 2.9; 95% confidence interval (CI) 2.6-3.4, and in diabetic women, RR 5.0; CI 3.9-6.3. The risk for re-infarction was about twice as large in patients with diabetes as in patients without diabetes. In both sexes the overall 28 day case fatality (CF) was significantly higher in diabetic compared to non-diabetic subjects. When compared to the non-diabetic population, the overall mortality from AMI in the diabetic population was 4 times higher among men and 7 times higher among women. The population attributable risk (PAR), a crude estimate of all AMIs ascribed to diabetes, was 11% in men and 17% in women. CONCLUSIONS: Diabetes increases the risk for AMI attack rate, incidence, case-fatality, recurrence and mortality and is an important contributor to all AMIs in middle-aged people.

Fatalities from myocardial infarction in Nordic countries and Lithuania. The MONICA Investigators.

AIM: To investigate fatalities from myocardial infarction at 28 days and one-year among patients aged 35-64 years in the Nordic and Lithuanian centres participating in the World Health Organization MONICA (Monitoring of Trends and Determinants of Cardiovascular Disease) Project. METHODS AND RESULTS: Altogether 9100 myocardial infarction events registered according to the protocol of the MONICA Project were included in the study. For these events, one-year follow-up was carried out using routine mortality statistics. Fatalities were expressed as age-standardized means per year for a 3-year period from the mid-1980s. The myocardial infarction fatalities at 28 days (including out-of-hospital deaths) in the eight participating populations varied among men, between 36.5% (95% confidence interval 32.6-40.4%) in Iceland and 54.6% (51.2-57.9%) in Kaunas, Lithuania, Among women, it varied from 32.4% (26.4-38.4%) in Iceland to 57.5% (51.8-63.2%) in Glostrup, Denmark. More than half of this mortality occurred suddenly and the patient did not reach hospital alive. Fatalities for the period from day 28 to one year varied among men, from 5.3% (2.9-7.6%) in Iceland to 10.9% (8.0-13.8%) in North Karelia, Finland, and among women from 3.5% (0.4-6.5%) in Kuopio, Finland, to 13.5% (7.2-19.7%) in Glostrup, Denmark. CONCLUSIONS: Approximately half of the myocardial infarction patients died within one year after the onset of the attack and half of those who died, died out-of-hospital. While the myocardial infarction fatalities differed considerably between the participating populations, differences of this magnitude are unlikely to be totally explained by differences in the registration procedures. Further comparisons of acute coronary care and secondary prevention measures are warranted.

Dental status, diet and cardiovascular risk factors in middle-aged people in northern Sweden.

The aim of the present study was to compare the dietary intake and the levels of traditional cardiovascular (CVD) risk factors in edentulous middle-aged individuals and individuals of the same age and sex who still had natural teeth. The study was performed within the framework of the MONICA-project. Population registers were used to sample randomly 1287 men and 1330 women aged 25-64 yr. Data were collected from a mailed questionnaire, blood analyses, registrations of blood pressure and anthropometric measures. The estimated daily energy intake did not differ between the two groups, but edentulous men and women ate more sweet snacks compared to those who still had teeth. Edentulous men also ate less fruits, vegetables and fibre and edentulous women ate more fat than dentates. Edentulous men and women were more obese and had lower serum HDL-cholesterol concentrations than those with remaining teeth. Edentulous women also had significantly higher concentrations of total cholesterol and triglycerides in serum than dentate women. Edentulous men and women were more often regular smokers, but not snuff users, than dentates of the same age and sex. Thus, the presence of two or more cardiovascular risk factors was more common in edentulous individuals than in those who still had natural teeth. In summary, these results support the hypothesis that edentulous middle-aged individuals have a more unfavourable risk factor profile for CVD. Counselling on balanced dietary habits and non-smoking given by dental personnel to orally diseased patients--recommendations given to improve resistance to dental caries or periodontitis--might therefore improve general health and possibly also improve risk factors for CVD.

Tobacco and myocardial infarction: is snuff less dangerous than cigarettes?

OBJECTIVE: To estimate the risk of myocardial infarction in snuff users, cigarette smokers, and non-tobacco users in northern Sweden, where using snuff is traditional. DESIGN: Case-control study. SETTING: Northern Sweden. SUBJECTS: All 35-64 year old men who had had a first myocardial infarction and a population based sample of 35-64 year old men who had not had an infarction in the same geographical area. MAIN OUTCOME MEASURE: Tobacco consumption (regular snuff dipping, regular cigarette smoking, non-tobacco use) and risk of acute myocardial infarction. RESULTS: 59 of 585 (10%) patients who had a first myocardial infarction and 87 of 589 (15%) randomly selected men without myocardial infarction were non-smokers who used snuff daily. The age adjusted odds ratio for myocardial infarction was 0.89 (95% confidence interval 0.62 to 1.29) for exposure to snuff and 1.87 (1.40 to 2.48) for cigarette smoking compared with non-tobacco users, showing an increased risk in smokers but not in snuff dippers. Regular cigarette smokers had a significantly higher risk of myocardial infarction than regular snuff dippers (age adjusted odds ratio 2.09; 1.39 to 3.15). Smoking, but not snuff dipping, predicted myocardial infarction in a multiple logistic regression model that included age and level of education. CONCLUSIONS: In middle aged men snuff dipping is associated with a lower risk of myocardial infarction than cigarette smoking.

Multi-media orientation and education programs for MEDLARS used the the Medical Information Center (MIC), Stockholm.

The Mediatron is a modified stereo-tape recorder which is designed to carry out simultaneous recording of audio-commentaries, trigger pulses for photographic slides, and digital signals from a computerized information-retrieval system. Two MEDLARS programs were produced: an orientation program and a self-instructional package. Technical procedures and experiences are briefly discussed.