Trio of Factors Behind Falling Heart Disease Mortality

Changes in smoking prevalence, serum cholesterol, and systolic blood pressure (BP) have been the major reason behind falling coronary heart disease (CHD) mortality over the past 40 years, according to a new study.

Researchers at the Finnish National Institute for Health and Welfare (Helsinki, Finland) conducted a population-based observational study to estimate how changes in the main risk factors of cardiovascular disease (CVD) can explain the reduction in CHD mortality observed among the working age population in eastern Finland. Participants included 34,525 men and women aged 30–59 years of age who participated in national studies between 1972 and 2012. The main outcome measures were predicted and observed age standardized mortality due to CHD.

The results showed that during the 40 years of the study, CHD mortality decreased by 82% and 84% among men and women aged 35–64 years, respectively. During this time, levels of the three major CVD risk factors decreased, except for a small increase in serum cholesterol levels between 2007 and 2012. Since the mid-1980s, the observed reduction in mortality has been larger than predicted, with about two thirds of the reduction explained by changes in the three main risk factors, and the remaining third by other factors. The study was published on March 1, 2016, in BMJ.

“Although secondary prevention and treatment protocols have markedly developed in recent decades, primary prevention and reduction in levels of the main classical factors contributing to cardiovascular risk should still be considered as the main strategy to reduce disease burden and mortality due to coronary heart disease,” concluded lead author Pekka Jousilahti, MD, PhD. “The changes in the three target risk factors during the first ten years of the study contributed to nearly all of the observed mortality reduction.”

Mortality from CHD started to increase in Finland in the 1950s, associated with an increasing standard of living, dietary causes, and other lifestyle changes. In the late 1960s, this mortality was the highest in the world, and was particularly high among working aged men in the eastern part of the country. As a result, the North Karelia Project was launched in 1972, with the aim of reducing the extremely high mortality from CHD by focusing on behavioral change through community action and participation, supported by screening of high risk individuals and medical treatment.

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Finnish National Institute for Health and Welfare