Geographical variation in cardiovascular disease mortality in Norway: The role of life course socioeconomic position and parental health

Despite substantial geographical variation in cardiovascular (CVD) mortality within countries, little is known about whether this variation can be explained by individuals' life course socioeconomic position (SEP) or differences in family history of premature CVD deaths. Cox proportional hazards models were used to investigate the association between the county of residence at ages 50-59 and CVD death in Norwegians born between 1940 and 1959 and survived to at least age 60, using national data. Individual life course SEP and family history of premature CVD death reduced the geographical variation in CVD mortality across Norwegian counties, but some significant differences remained. Furthermore, CVD risk varied by residents' migration histories between two counties with distinct CVD and socioeconomic profiles.

Joint mapping of cardiovascular diseases: comparing the geographic patterns in incident acute myocardial infarction, stroke and atrial fibrillation, a Danish register-based cohort study 2014-15

BACKGROUND

Disease mapping aims at identifying geographic patterns in disease. This may provide a better understanding of disease aetiology and risk factors as well as enable targeted prevention and allocation of resources. Joint mapping of multiple diseases may lead to improved insights since e.g. similarities and differences between geographic patterns may reflect shared and disease-specific determinants of disease. The objective of this study was to compare the geographic patterns in incident acute myocardial infarction (AMI), stroke and atrial fibrillation (AF) using the unique, population-based Danish register data.

METHODS

Incident AMI, stroke and AF was modelled by a multivariate Poisson model including a disease-specific random effect of municipality modelled by a multivariate conditionally autoregressive (MCAR) structure. Analyses were adjusted for age, sex and income.

RESULTS

The study included 3.5 million adults contributing 6.8 million person-years. In total, 18,349 incident cases of AMI, 28,006 incident cases of stroke, and 39,040 incident cases of AF occurred. Estimated municipality-specific standardized incidence rates ranged from 0.76 to 1.35 for AMI, from 0.79 to 1.38 for stroke, and from 0.85 to 1.24 for AF. In all diseases, geographic variation with clusters of high or low risk of disease after adjustment was seen. The geographic patterns displayed overall similarities between the diseases, with stroke and AF having the strongest resemblances. The most notable difference was observed in Copenhagen (high risk of stroke and AF, low risk of AMI). AF showed the least geographic variation.

CONCLUSION

Using multiple-disease mapping, this study adds to the results of previous studies by enabling joint evaluation and comparison of the geographic patterns in AMI, stroke and AF. The simultaneous mapping of diseases displayed similarities and differences in occurrence that are non-assessable in traditional single-disease mapping studies. In addition to reflecting the fact that AF is a strong risk factor for stroke, the results suggested that AMI, stroke and AF share some, but not all environmental risk factors after accounting for age, sex and income (indicator of lifestyle and health behaviour).

Calcium:magnesium ratio in local groundwater and incidence of acute myocardial infarction among males in rural Finland

Several epidemiologic studies have shown an association between calcium and magnesium and coronary heart disease mortality and morbidity. In this small-area study, we examined the relationship between acute myocardial infarction (AMI) risk and content of Ca, Mg, and chromium in local groundwater in Finnish rural areas using Bayesian modeling and geospatial data aggregated into 10 km times symbol 10 km grid cells. Data on 14,495 men 35-74 years of age with their first AMI in the years 1983, 1988, or 1993 were pooled. Geochemical data consisted of 4,300 measurements of each element in local groundwater. The median concentrations of Mg, Ca, and Cr and the Ca:Mg ratio in well water were 2.61 mg/L, 12.23 mg/L, 0.27 microg/L, and 5.39, respectively. Each 1 mg/L increment in Mg level decreased the AMI risk by 4.9%, whereas a one unit increment in the Ca:Mg ratio increased the risk by 3.1%. Ca and Cr did not show any statistically significant effect on the incidence and spatial variation of AMI. Results of this study with specific Bayesian statistical analysis support earlier findings of a protective role of Mg and low Ca:Mg ratio against coronary heart disease but do not support the earlier hypothesis of a protective role of Ca.

Geographical variation in the incidence of acute myocardial infarction in eastern Finland--a Bayesian perspective

BACKGROUND

Large geographical variation in the incidence and mortality of cardiovascular disease (CHD) has been repeatedly reported in Finland with persistent difference between east and west. We undertook this study to estimate the geographical distribution of Acute Myocardial Infarction (AMI) incidence in the high-risk province of North Karelia and in the province of Kuopio.

METHODS

Data on men aged 25-64 years with first event of acute myocardial infarction (AMI) were obtained from the FINMONICA AMI register, which recorded detailed information of AMI events during the period 1983 to 1992. The geographical pattern of AMI incidence was studied in two five-year periods 1983 to 1987 and 1988 to 1992 separately in 10 km x 10 km grid cells employing the Geographical Information System (GIS) and a Bayesian hierarchical approach.

RESULTS

In both periods Bayesian modeling revealed a geographical pattern of AMI incidence and high risk (probability that incidence exceeds the observed mean incidence) in the remote rural areas.

CONCLUSIONS

Detection of high-risk areas in both provinces showed that underlying environmental and/or genetic risk factors of AMI are not evenly distributed within the province but enriched in certain geographical non-administratively defined locations in eastern Finland.