Heart disease and stroke mortality rates have almost stopped declining in many high-income countries, including Australia, and are even increasing in some countries, according to researchers at the University of Melbourne. They analyzed trends in cardiovascular disease mortality, which consists of mainly heart disease and stroke, in 23 high-income countries since the year 2000.
The scientists, who found that cardiovascular disease mortality rates for people aged 35- to 74-years-old are now barely declining, or are increasing, in 12 of the 23 countries, published their study (“Is the long-term decline in cardiovascular-disease mortality in high-income countries over? Evidence from national vital statistics”) in the International Journal of Epidemiology.
“The substantial decline in cardiovascular-disease (CVD) mortality in high-income countries has underpinned their increasing longevity over the past half-century. However, recent evidence suggests this long-term decline may have stagnated, and even reversed in younger populations. We assess recent CVD-mortality trends in high-income populations and discuss the findings in relation to trends in risk factors,” the investigators wrote.
“We used vital statistics since 2000 for 23 high-income countries published in the World Health Organization Mortality Database. Age-standardized CVD death rates by sex for all ages, and at ages 35-74 years, were calculated and smoothed using LOWESS regression. Findings were contrasted with the Global Burden of Disease (GBD) Study.
“The rate of decline in CVD mortality has slowed considerably in most countries in recent years for both males and females, particularly at ages 35–74 years. Based on the latest year of data, the decline in the CVD-mortality rate at ages 35–74 years was <2% (about half the annual average since 2000) for at least one sex in more than half the countries.
“In North America (U.S. males and females, Canadian females), the CVD-mortality rate even increased in the most recent year. The GBD Study estimates, after correcting for misdiagnoses, suggest an even more alarming reversal, with CVD death rates rising in seven countries for at least one sex in 2017. The rate of decline and initial level of CVD mortality appear largely unrelated.
“A significant slowdown in CVD-mortality decline is now apparent across high-income countries with diverse epidemiological environments. High and increasing obesity levels, limited potential future gains from further reducing already low smoking prevalence, especially in English-speaking countries, and persistent inequalities in mortality risk pose significant challenges for public policy to promote better cardiovascular health.”
In the United States and for Canadian females, cardiovascular disease mortality rates have increased in the most recent year, while in Australia, the United Kingdom, and New Zealand annual declines in deaths from cardiovascular disease are now only 20–50% of what they were in the 2000s.
Alan Lopez, PhD, a University of Melbourne expert on the global burden of disease, said research believes that obesity, or at least poor diet, may have been a significant contributor to the slowdown in the decline of cardiovascular disease deaths.
“Each of these countries have very high levels of obesity. In Australia, close to one-third of adults are obese,” Lopez said. “These increases in obesity levels mean that a significant portion of the population has been exposed to the cardiovascular disease risks associated with being overweight for several decades.”
However, obesity is only one of many risk factors for cardiovascular disease mortality. Others include smoking, high blood pressure, high cholesterol, and diabetes.
Researchers found obesity levels are low in Italy and France where the slowdown in cardiovascular disease mortality in recent years is among the most notable of all countries.
Tim Adair, a University of Melbourne researcher and co-author of the paper, noted that the research shows that the effect of successful public health interventions on cardiovascular disease mortality over the past 50 years is diminishing.
“In order to combat this, significant investment in preventive health measures is needed, particularly those aimed at increasing physical activity, improving diet and reducing obesity,” Adair said. “Failure to address these issues could confirm the end of the long-term decline in cardiovascular disease deaths and threaten future gains in life expectancy.”