Heart disease deaths related to obesity increased by 180% in the U.S. between 1999 and 2020, especially among middle-aged men, Black adults, residents of Midwestern states and non-metropolitan areas, according to a preliminary study to be presented at the American Heart Association's Scientific Sessions 2024. The meeting, Nov. 16-18, 2024, in Chicago, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science.
Obesity is a serious risk factor for ischemic heart disease, and this risk is going up at an alarming rate along with the increasing prevalence of obesity. It is important for everyone, particularly people in high-risk groups, to take steps to manage their weight and reduce their risk of heart disease. Lifestyle changes are key, such as eating healthier, exercising regularly and working with health care professionals to monitor heart health."
Aleenah Mohsin, M.D., M.B.B.S., lead study author, post-doctoral research fellow at Brown University in Providence, Rhode Island
Ischemic heart disease is caused by narrowed arteries in the heart; this leads to less blood and oxygen reaching the heart muscle and can result in a heart attack. Obesity contributes to heart disease risks, including elevated cholesterol, high blood pressure, Type 2 diabetes and sleep disorders. It is also an independent risk factor for cardiovascular disease.
In an analysis of 21 years of data, researchers examined death rates attributed to obesity-related ischemic heart disease and whether certain groups of people -; based on their race, age, gender or where they live -; had higher rates than others. Public health data from the U.S. Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) database was reviewed for deaths related to ischemic heart disease from 1999 to 2020. Researchers measured the death rates adjusted for age, also known as age-adjusted mortality rates, which is intended to limit the possible bias of age as a factor in the death rates since people are more likely to die as they get older.
The analysis found that there was a significant and consistent increase in deaths from obesity-related ischemic heart disease from 1999 to 2020 in the U.S. Specifically:
- There was a 5.03 annual percentage increase in the overall rate of obesity-related heart disease deaths.
- The age-adjusted death rate in men rose from 2.1 deaths per 100,000 people in 1999 to 7.2 per 100,000 in 2020 – an increase of 243%. The rate among men ages 55-64 rose from 5.5 deaths per 100,000 people in 1999 to 14.6 deaths per 100,000 people in 2020 – an increase of 165%. For reference, the largest college football stadiums in the U.S. can each fit around 100,000 people.
- Among women, the age-adjusted death rate increased from 1.6 deaths per 100,000 people in 1999 to 3.7 per 100,000 in 2020 – a 131% increase.
- The age-adjusted death rate was highest among Black adults at 3.93 deaths per 100,000 people.
- Geographically, the highest death rates were observed among people living in Midwestern states (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin), with an age-adjusted death rate of 3.3 deaths per 100,000 people, compared to people who lived in the Northeast (Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont), which had the lowest rate at 2.8 deaths per 100,000 people. Vermont was the exception in the Northeast, with the highest age-adjusted death rate attributed to obesity-related ischemic heart disease at 10.4 deaths per 100,000 people. Alabama had the lowest rate at 1.5 deaths per 100,000 people.
- In 2020, the age-adjusted death rate was 4.0 deaths per 100,000 for people living in non-metropolitan areas, compared to 2.9 per 100,000 for those in urban areas.
"We did expect an increase in deaths related to obesity since the prevalence of obesity has been rising steadily for years. However, we did not anticipate this magnitude of increase in mortality, especially among middle-aged men," Mohsin said. "The racial disparities, particularly the higher rates of death among Black individuals, were also striking and suggest that social and perhaps environmental factors may also be playing a significant role. In addition, the fact that Vermont, a state not typically associated with high obesity rates, had the highest death rate for obesity-related CVD death was unexpected and warrants further investigation, as does the finding that Alabama had the lowest death rate for obesity-related CVD deaths."
"Our findings underscore the need to explore the underlying causes of these disparities, such as differences in health care access, socioeconomic factors and regional health policies," she said. "Understanding these factors is the first step in identifying and designing more effective public health interventions."
Study background and details:
- Data from 1999 to 2020 from the CDC WONDER (Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research) database was examined for ischemic heart disease and obesity-related deaths in people of all ages. Both crude death rates and age-adjusted death rates per 100,000 individuals were reviewed.
- 226,267 ischemic heart disease obesity-related deaths were documented over the 21 years.
The study's limitations include that the analysis calculated using mortality data and did not measure non-fatal cases of heart disease, meaning the analysis may have underestimated the true impact of obesity on heart disease. Additionally, while the study adjusted for individuals' age in the analysis, other factors, such as income, education or access to health care, may have influenced the results but could not be accounted for because this information is not available in the WONDER database.
"This abstract highlights the importance of obesity as a key risk factor for ischemic heart disease," said Sadiya S. Khan, M.D., M.Sc., FAHA, chair of the writing group for the Association's 2023 scientific statement "Novel Prediction Equations for Absolute Risk Assessment of Total Cardiovascular Disease Incorporating Cardiovascular-Kidney-Metabolic Health." Khan is the Magerstadt Professor of Cardiovascular Epidemiology and an associate professor of cardiology, medical social sciences and preventive medicine (epidemiology) at Northwestern School of Medicine in Chicago, as well as chair of the writing group for the Association's PREVENT equations. She was not involved in the study.
"The relative change in ischemic heart disease deaths related to obesity that was observed in this study between 1999 and 2020 was greater than the overall increase in obesity prevalence that we've seen in the United States, from about 30% to about 40% over this same time frame," Khan said. "There are a few potential reasons that could be the case. It may just be that people are more aware of obesity as a risk factor or are more likely to treat obesity, and, therefore, it is more likely to be included on death certificates, which were the basis of these data. The important thing is that we know we need to do more to identify, manage and treat obesity-related risk."
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