AHA: Shared risk factors contribute to rising global burden of brain disease, CVD
Heart disease continues to stand as the leading global cause of death, but there has been a rapid rise in brain disease-related deaths, and risk factors for both are similar, according to an American Heart Association report.
Approximately 19 million deaths worldwide were attributed to CVD in 2020, representing an increase of about 18.7% from 2010, according to the AHA’s annual Heart Disease and Stroke Statistics update.
According to the update, there were approximately 1.89 million deaths attributable to Alzheimer’s disease and other dementias in 2020.
“Like cardiovascular disease, Alzheimer’s disease, dementia and other cognitive ailments are a tremendous emotional and economic burden across the globe,” Connie W. Tsao, MD, MPH, FAHA, assistant professor of medicine at Harvard Medical School, attending staff cardiologist at Beth Israel Deaconess Medical Center and chair of the statistical update writing group, said in a press release. “This new chapter on brain health was a critical one to add. The data we’ve collected brings to light the strong correlations between heart health and brain health and makes it an easy story to tell — what’s good for the heart is good for the brain.”
According to the update, there were 54.69 million cases of Alzheimer’s disease and other dementias worldwide in 2020, with the highest prevalence rates in East Asia and parts of high-income North America.
According to a systematic analysis of data from the Global Burden of Disease (GBD) study, Alzheimer’s disease and related dementia was the fourth most prevalent neurological disorder in the U.S. in 2017, affecting approximately 2.9 million people, and was the leading cause of neurological disorder-related mortality ahead of stroke (38 per 100,000 deaths per year).
In the U.S., the age-standardized incidence rate of Alzheimer’s disease and related dementia was approximately 85 per 100,000 people.
CV risk factors also associated with risk for brain disease include BP, HF, atrial fibrillation, CAD, diabetes, chronic kidney disease, obesity, sleep apnea, smoking and social determinants of health, according to the update.
The writing committee cited a meta-analysis of 12 randomized controlled trials that included more than 92,000 participants (mean age, 69 years; 42% women), in which researchers observed that use of antihypertensive agents was associated with lower risk for incident dementia or cognitive impairment during a mean follow-up of 4.1 years compared with controls (7% vs. 7.5%; OR = 0.93; absolute risk reduction, 0.39%).
According to the update, several studies reported that measures of ideal CV health are also associated with lower risk for cognitive decline or impairment.
In the Northern Manhattan Study (NOMAS) that included 1,033 participants (mean age, 72 years; 39% men; 65% Hispanic; 19% Black; 16% white), researchers observed that individuals with more ideal CV health experienced less decline in neuropsychological tests of processing speed. The association was driven by nonsmoking and better glucose levels, according to the update.
During the 25 years of follow-up in the Whitehall II study, researchers reported that metrics of ideal CV health at age 50 years were similarly associated with lower incidence of dementia.
In the 3C study that enrolled 6,626 adults (mean age, 74 years; 63% women), each additional metric of ideal CV health was associated with lower risk for developing dementia (HR = 0.9; 95% CI, 0.84-0.97).
According to the update, findings from the CARDIA trial, a Framingham 10-year CHD risk score of 10 or more was associated with accelerated cognitive decline 5 years later in midlife (OR = 2.29; 95% CI, 1.21-4.34).
In addition, the results of the Harvard Aging Brain study indicated that greater Framingham 10-year CVD risk score was associated with more cognitive decline later in life (beta, 0.064; 95% CI, 0.094 to 0.033).
“The global rate of brain disease is quickly outpacing heart disease. The rate of deaths from Alzheimer’s disease and other dementias rose more than twice as much in the past decade compared to the rate of deaths from heart disease, and that is something we must address,” Mitchell S.V. Elkind, MD, MS, FAHA, professor of neurology and epidemiology at Columbia University Vagelos College of Physicians and Surgeons, attending neurologist at NewYork-Presbyterian/Columbia University Irving Medical Center and immediate past president of the AHA, said in the release. “We are learning more about how some types of dementia are related to the aging, and how some types are due to poor vascular health. Many studies show that the same healthy lifestyle behaviors that can help improve a person’s heart health can also preserve or even improve their brain health. It’s becoming more evident that reducing vascular disease risk factors can make a real difference in helping people live longer, healthier lives, free of heart disease and brain disease.”
Trends in life expectancy and CVD mortality
As with prior years, the 2022 statistical update highlighted recent trends in life expectancy and CVD mortality.
Life expectancy in the U.S. for 2020 is estimated to decline, a figure attributed to COVID-19 mortality, and may disproportionately affect certain populations. According to the update, it is estimated that, from 2019 to the first half of 2020, life expectancy decreased from 74.7 to 72 years for Black individuals, from 81.8 to 79.9 years for Hispanic individuals and from 78.8 to 78 years for white individuals.
Mortality attributable to high BP also increased from 2009 to 2019 by approximately 34.2%, according to the update, and the actual number of deaths attributable to high BP rose 65.3%.
Based on a meta-analysis that focused on CVD among individuals diagnosed with COVID-19, the writing committee stated that preexisting CVD conferred an RR of 2.25 for death resulting from COVID-19.
Trends in adverse pregnancy outcomes
The 2021 statistical update was the first year the writing committee included data regarding trends in adverse pregnancy outcomes. Inclusion of these statistics continued in the 2022 update.
According to the update, adverse pregnancy outcomes, including hypertensive disorders of pregnancy, gestational diabetes, preterm birth and small for gestational age at birth, occur in 10% to 20% of pregnancies.
According to data from the multinational Hyperglycemia and Adverse Pregnancy Outcome trial, poor CV health based on risk factors, including BMI, BP, cholesterol, glucose and smoking status at 28 weeks’ gestation, was associated with greater risk for preeclampsia compared with women with ideal CV health (adjusted RR for 1 intermediate risk factors vs. ideal = 3.13; aRR for 1 poor risk factor vs. ideal = 5.34; aRR for 2 poor risk factors vs. ideal = 9.3).
According to data from the 2020 GBD study, the global incidence of maternal hypertensive disorders was highest throughout sub-Saharan Africa, with a prevalence among females aged 15 to 49 years of 916.72 per 100,000 female population.
In addition, the writing committee cited an analysis of Swedish national birth data that found gestational age at birth was inversely associated with the risks for type 1 diabetes, type 2 diabetes, hypertension and lipid disorders among individuals born preterm compared with those born to term.
“The processes leading to these interrelated disorders reflect a response to the ‘stress test’ of pregnancy, and they are associated with risk of poor future CV health outcomes in females and offspring, including CHD, stroke and HF,” the committee wrote. “Furthermore, growing rates of pregnancy-related morbidity and mortality in the United States are attributed predominantly to CVD. Because of this, the AHA has recognized the importance of raising awareness about these disorders in comprehensive CV health promotion and CVD prevention in females.”
- What’s good for the heart is good for the brain. newsroom.heart.org/news/whats-good-for-the-heart-is-good-for-the-brain. Published Jan. 26, 2022. Accessed Jan. 26, 2022.