The North-East-South gradient of coronary heart disease mortality and case fatality rates in France is consistent with a similar gradient in risk factor clusters

In France, the mortality and case fatality rates of coronary heart disease follow a decreasing North-East-South gradient. The aim of the study was to evaluate the contribution of major cardiovascular risk factors to this gradient. To this end, the results of the third population survey of the WHO-MONICA Project conducted in three French geographically contrasted regions (the Urban Community of Lille in the North, the district of Bas-Rhin in the East and the district of Haute-Garonne in the South) are presented. One thousand seven hundred seventy-eight men and 1730 women aged 35-64 years were randomly selected from the electoral rolls. Major coronary heart disease risk factors (hypertension, hypercholesterolemia, low high-density lipoprotein (HDL)-cholesterol, obesity, smoking, physical inactivity, diabetes) were studied. The results show that the distribution of major coronary heart disease risk factors is heterogeneous among geographical areas in France. However, the proportion of subjects with more than three risk factors is higher in the North than in the other regions and the number of subjects with no risk factor is higher in the South than in the other areas. This distribution of risk factors among regions supports the hypothesis that accumulation of coronary heart disease risk factors contributes to the decreasing North-East-South gradient of cardiovascular mortality rates in France.