One in five deaths in the US is attributable to heart disease.
Approximately 697,000 fatalities will be attributable to heart disease in the United States in 2020, according to the Centers for Disease Control and Prevention (CDC).
The most prevalent form of heart disease, coronary heart disease, has different risks and associated mortality depending on race and ethnicity. According to recent studies, it is impossible to predict coronary heart disease in all ethnic groups using established risk factors. Low levels of HDL were shown to raise illness risk in the study’s white participants but not in Black or African Americans. Over 10% of persons have coronary heart disease (CHD), the most prevalent form of heart disease, older than 45.
The prevalence of CHD varies by racial/ethnic group, with white Americans having the highest rate (11.4%), followed by Black or African Americans (10%), Hispanics (8.8%), and Asians and Pacific Islanders (6.3%).
Black or African Americans experience higher rates of mortality as a result of CHD-related events, despite having lower overall rates of CHD and a lower risk of the illness than white Americans.
The condition is characterised by a decreased heart’s blood supply. A condition known as atherosclerosis occurs when fatty deposits gradually restrict the blood vessels. The liver produces cholesterol, a lipid that is necessary for healthy cells but too much can increase the risk of CHD. It is a crucial part of the deposits of fatty atheroma.
The three primary lipid categories that have an effect on heart health are the majority of lipoproteins in the body are low-density lipoproteins (LDL), a high risk of heart disease and stroke is linked to excess and LDL is removed from the body by high-density lipoprotein (HDL), which carries it to the liver. Triglycerides are a form of fat that the body uses as fuel. The health of the heart and blood vessels is protected by HDL, according to earlier research.
Due to its function in eliminating extra cholesterol from the body through reverse cholesterol transport, HDL has a favourable effect.
Dr. Yu-Ming Ni, a cardiologist specialising in non-invasive cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, California, who was not involved in the study, stated in an interview with Medical News Today that HDL cholesterol has historically been referred to as the “good” cholesterol because HDL particles collect cholesterol throughout the body and transport it back to the liver for processing. Consider HDL particles as the cleanup crew whose mission it is to remove the LDL particles, sometimes known as the “bad” cholesterol, from the environment.
Higher HDL levels may provide more protection, according to some studies, although other research contradicts this. The opposite was demonstrated by another study which claimed that higher HDL levels don’t lower the frequency of cardiovascular events. In fact, some people’s atherosclerosis may worsen when HDL levels are quite high. There appears to be an optimal level of HDL cholesterol that lowers the risk of adverse cardiac events. There isn’t enough cleanup being done because there is too little.
According to Dr. Ni. Race, HDL, and cardiovascular health, too much could indicate that the cleaning crew is overworked and unable to complete their job of avoiding heart disease.
The Framingham Heart Study, conducted in the 1970s, demonstrated that low HDL levels were linked to a high risk of CVD and that HDL is inversely related to coronary heart disease (CHD). However, recent research co-funded by the National Institute on Aging and the National Institute on Neurological Disorders and Stroke and directed by Dr. Nathalie Pamir of the OHSU-PSU School of Public Health, challenges that theory. Low HDL levels among Black or African American adults were not associated with an increased risk of cardiovascular disease, according to a study published in the Journal of the American College of Cardiology. The study also found that “good” cholesterol was not a universal predictor of cardiovascular disease.
While the majority of risk variables have been “worked out” in cohorts that are primarily white and of European descent, Dr. Pamir said that it is unclear how these risk factors affect various racial groups.
The researchers evaluated the levels of the various lipoproteins and CHD in a national study to determine whether cholesterol levels could be used to predict CHD risk in all ethnic groups. In the prospective REGARDS trial, 23,901 people without coronary heart disease were tracked for more than 10 years. Of these, 57.8% were white and 58.4% were female. Participants were asked to specify as white or Black/African American during interviews on their demographics and medical history. At a home visit, blood pressure, an ECG, blood, and urine samples were all taken. Throughout the follow-up period, each participant underwent a six-monthly interview. 1,615 CHD-related incidents were noted throughout the trial, with 664 of those occurring in the Black/African American group.
Unsurprisingly, all subjects’ LDL and triglyceride levels were associated with higher CHD rates. Even more unexpectedly, the researchers discovered that while low HDL was not linked to an increased risk of CHD in Black or African American participants, it was in white people. Simply put, according to Dr. Pamir, “low HDL-C (good cholesterol) levels are only detrimental for White adults, with little risk prediction value in Black adults.”
According to Dr. Ni, there is no distinct HDL cholesterol sweet spot for African Americans when compared to the other two populations. African Americans generally had worse cardiovascular results than white Americans, he continued, suggesting that other factors may have a stronger impact on cardiovascular health, particularly in the context of other medical disorders like high blood pressure, diabetes, and obesity. Intriguingly, the researchers discovered that no participant group’s HDL level was connected to a lower risk of CHD occurrences.
According to Dr. Pamir, high levels of HDL-C in people of both races—White and Black—are not protective, despite what has been believed since the 1970s and the Framingham heart research. In the future, we must construct the risk algorithms more effectively. In addition, she added, those of us with high HDL-C may not get a “pat on the back” from our doctor since, despite what we had been led to believe for more than 60 years, high HDL-C may not actually be protective.
This study is helpful for comprehending population-based cardiovascular risk management, but practically, I don’t think it will change how I treat patients of African American heritage. According to Dr. Ni, HDL is just one of many risk factors for cardiovascular disease, and treating the whole person is frequently more effective.
Dr. Pamir came to the conclusion that risk factors can assist inform the actionable guidelines and that guidelines and risk factors need to apply to everyone. He noted that it is crucial to discover in future study if other recognised risk factors for CHD are also influenced by race.
Parvathy Sukumaran 
