Changes over time in the prevalence and treatment of cardiovascular risk factors, and contributions to time trends in coronary mortality over 25 years in the Lille urban area (northern France).

Background: The long-term collection of population-based data should improve our knowledge of the contribution of trend in cardiovascular risk factors to the steady fall in mortality associated with coronary heart disease in high-income countries.

Aims: To assess long-term time trends in the prevalence of cardiovascular risk factors, estimated coronary heart disease risk and mortality between 1986 and 2013 in the Lille urban area (northern France).

Methods: We studied representative samples of inhabitants of the Lille urban area (aged 40-64 years) in 1986-1988 (n=860), 1995-1996 (n=1021), 2005-2007 (n=1021) and 2011-2013 (n=1636), together with data from the Lille MONICA registry.

Results: In men, the age-standardized prevalence fell between 1986 and 2013 from 70.5% to 42.5% for hypertension, from 71.1% to 58.3% for dyslipidaemia and from 44.1% to 24.7% for smoking (all P<0.001). The prevalence of being overweight increased from 59.6% to 65.1% (P<0.05). In women, the prevalences decreased from 56.6% to 34.3% for hypertension and from 60.9% to 42.2% for dyslipidaemia (both P<0.001). The prevalences of smoking (17%) and being overweight (50%) were stable. The mean 10-year (95% confidence interval) predicted risk of fatal coronary heart disease (estimated with the Systematic Coronary Risk Evaluation equation) decreased by 2.02% (1.78-2.25%) per year for men and by 1.55% (1.32-1.78%) for women. The observed coronary mortality rate fell by 2.6% (2.2-3.0%) in men and 2.8% (1.9-3.6%) in women.

Conclusions: Prevalences of main risk factors and estimated coronary mortality risk decreased concomitantly with the observed coronary mortality - indicating that primary prevention made a major contribution to the decrease in mortality.