Trends in educational inequalities in cardiovascular risk factors: a longitudinal study among 48,000 middle-aged Norwegian men and women.

The aim of the study was to compare educational and gender specific trends in the classical cardiovascular risk factors body mass index (BMI), cholesterol, systolic blood pressure and smoking in a Norwegian population during a period when the coronary heart disease mortality had just reached its peak in the late 1970s and 1980s. We used The Norwegian Counties study: a longitudinal study with three screenings on the same individuals in Oppland, Sogn og Fjordane and Finnmark counties in Norway in the period 1974-1988. All residents aged 35-49 were invited and 48,422 participated (89%) in the baseline screening. To estimate the cardiovascular risk factor change in individuals over time longitudinal statistical methods were used. BMI, cholesterol and blood pressure levels increased with age, while the amount of daily smokers decreased. The higher the educational level the lower the level of BMI, blood pressure, smoking and cholesterol. This pattern persisted through the whole study period. In men, however, the educational gradient in cholesterol diminished in the last screening. Among women there was an increase in inequality in systolic blood pressure, and for smoking there was a steeper decrease for men than women across all educational groups. The educational differences in classical cardiovascular risk factors persisted, except for BMI, cholesterol and daily smokers in men which tended to decrease.