Four behaviours explain a majority of the socioeconomic disparities observed in the disease
Source: Wikimedia CC0
Lower socioeconomic status is associated with higher rates of death from coronary artery disease compared to higher socioeconomic status, and more than half of the disparities can be explained by four unhealthy behaviours. Dr Yachen Zhu of the Alcohol Research Group, US, and Dr Charlotte Probst of the Centre for Addiction and Mental Health, Canada, report these findings in a new study published September 17th in the open-access journal PLOS Medicine.
Coronary artery disease, also known as coronary heart disease or ischaemic heart disease, occurs when the arteries supplying the heart cannot deliver enough oxygen-rich blood due to plaque buildup, and is a major cause of death in the US. The condition poses a greater risk to people with lower socioeconomic status, but previous studies have reported conflicting results on whether certain unhealthy behaviours, like smoking, are primarily responsible for the observed disparities in deaths from the disease.
In the new study, researchers used data from 524 035 people aged 25 years and older whose mortality statuses were recorded in the National Death Index and who answered the National Health Interview Survey on demographics and health behaviours. The team used education as the primary indicator for socioeconomic status, and investigated four behavioural risk factors: smoking, alcohol use, physical inactivity and BMI. The four factors together explained 74% of the differences in mortality risk from coronary artery disease in men belonging to different socioeconomic levels and 61% in women.
The researchers conclude that their results highlight the need for effective public health policies and interventions that address each of these behaviours – both separately and together – because unhealthy behaviours often cluster among individuals from low socioeconomic backgrounds. They urge public health campaigns to raise awareness about heart health with messaging and outreach efforts customised for male and female audiences. The authors add, “These efforts are crucial to reducing the socioeconomic disparities in deaths from coronary artery disease in the US.”
The demands of the working week, often influenced by school or work schedules, can lead to sleep disruption and deprivation. Fortunately, new research presented at ESC Congress 2024 shows that people that ‘catch up’ on their sleep by sleeping in at weekends may see their risk of heart disease fall by one-fifth.
“Sufficient compensatory sleep is linked to a lower risk of heart disease,” said study co-author Mr Yanjun Song of the State Key Laboratory of Infectious Disease, Fuwai Hospital, National Centre for Cardiovascular Disease, Beijing, China. “The association becomes even more pronounced among individuals who regularly experience inadequate sleep on weekdays.”
It is well known that people who suffer sleep deprivation ‘sleep in’ on days off to mitigate the effects of sleep deprivation. However, there is a lack of research on whether this compensatory sleep helps heart health.
The authors used data from 90 903 subjects involved in the UK Biobank project, and to evaluate the relationship between compensated weekend sleep and heart disease, sleep data was recorded using accelerometers and grouped by quartiles (divided into four approximately equal groups from most compensated sleep to least). Q1 (n = 22 475 was the least compensated, having -16.05 hours to -0.26 hours (ie, having even less sleep); Q2 (n = 22 901) had -0.26 to +0.45 hours; Q3 (n=22 692) had +0.45 to +1.28 hours, and Q4 (n=22 695) had the most compensatory sleep (1.28 to 16.06 hours).
Sleep deprivation was self-reported, with those self-reporting less than 7 hours sleep per night defined as having sleep deprivation. A total of 19 816 (21.8%) of participants were defined as sleep deprived. The rest of the cohort may have experienced occasional inadequate sleep, but on average, their daily hours of sleep did not meet the criteria for sleep deprivation – the authors recognise this a limitation to their data.
Hospitalisation records and cause of death registry information were used to diagnose various cardiac diseases including ischaemic heart disease (IHD), heart failure (HF), atrial fibrillation (AF), and stroke.
With a median follow-up of almost 14 years, participants in the group with the most compensatory sleep (quartile 4) were 19% less likely to develop heart disease than those with the least (quartile 1). In the subgroup of patients with daily sleep deprivation those with the most compensatory sleep had a 20% lower risk of developing heart disease than those with the least. The analysis did not show any differences between men and women.
Co-author Mr Zechen Liu, also of State Key Laboratory of Infectious Disease, Fuwai Hospital, National Centre for Cardiovascular Disease, Beijing, China, added: “Our results show that for the significant proportion of the population in modern society that suffers from sleep deprivation, those who have the most ‘catch-up’ sleep at weekends have significantly lower rates of heart disease than those with the least.”
South Africa has seen the quickest and most alarming rise of diabetes on the continent; from an estimated 1.9 million people living with the condition in 2011 to 4.2 million by 2021 – with 7.5 million predicted to be afflicted by 20451. South Africa also has the fastest rising prevalence on the continent with an estimated 20% of the adult population either diabetic or pre-diabetic1. Globally, diabetes prevalence is predicted to rise by 46% between 2019 and 20452. It currently stands at some 537 million people worldwide1.
This emerged at the recently held annual Sanofi medical meeting, the Cardio-Metabolic Axis Forum from April 19th–21st in Cape Town. This was a meeting of leading endocrinologists, specialist physicians, nephrologists, diabetes-treating doctors, academics and Patient Advocacy Groups (PAGs).
Speaking at the conference, specialist physician and endocrinologist, Dr Landi Lombard – former editor of the South Africa Journal of Diabetes and Vascular Disease – told delegates that the risk of death associated with diabetes in cardiovascular conditions is more than twice that of people with non-diabetes, while in all-cause mortality, it’s just under twice that of a person living without diabetes. Of the estimated 537 million people living with diabetes globally, only about half are diagnosed, of whom 25% receive care, 12.5% achieve treatment targets, and 6% live a life free of diabetes-related complications1.
Dr Lombard said that the pandemic is being driven by poor lifestyle choices and diet, lack of exercise and widespread obesity in the population, so better healthcare worker communication and education of patients is vital to stem the tide of diabetes.
Professor Robert Ritzel of the Department of Endocrinology, Diabetology and Angiology at Schwabing Hospital in Munich, said the Pacific Islands and the Middle East led the world with diabetes prevalence at between 25 % and 40 %. He said what precipitated a surge in diabetes was the speed at which a nation changed from a traditional to a modern lifestyle. When this happened within a few years, diabetes prevalence was likely to range between 20% and 40%. However, when change occurred over many generations, it gave epidemiologists and clinicians time to adapt.
Lombard said one of the biggest challenges was what diabetologists called ‘therapeutic inertia’ which contributes to a patient living with sub-optimal blood sugar control for many years. This term embraced physician, patient and healthcare system factors, patient injection related factors, time and resource constraints among physicians and the lack of a proper healthcare system plan. He said that in people with Type 2 diabetes, the median time it takes for the disease to intensify while taking one or more anti-diabetic drugs is 2.9 years. However, the use of an injectable slowed intensification down to 7.2 years or more.
Reasons for failure to intensify treatment or progress to injectable therapies varied between specialist and primary care physicians but were mainly because of a patient fear of injection, too many injections, perceptions of this being a ‘last resort’ treatment, fear of weight gain, fear of low blood sugar, and poor communication with patients.
Lombard said even 1 year of poor blood sugar control in people with Type 2 diabetes could result in an increase in the cumulative incidence of kidney disease of 18%, neuropathy of 8%, retinopathy of 7% and a significantly increased risk of heart attack (67%), heart failure (64%), stroke (51%) and composite cardiovascular events (62%).
Professor Naomi ‘Dinky’ Levitt, former Head of Endocrinology and Diabetic Medicine at the University of Cape Town and Groote Schuur Hospital and Director of the Chronic Disease Initiative for Africa, highlighted gestational diabetes as one of the greatest challenges.
Described as the “doyenne” of endocrinology in South Africa (SA), Levitt said one third of women who have gestational diabetes go on to develop diabetes within 6 years of giving birth, so post-partum intervention is crucial.
According to Levitt, lifestyle interventions had about a 20% positive effect, mainly because new mothers were pulled in all directions by family, the baby, husband, and domestic and work needs.
She said that with 31.4% of SA women estimated to have developed gestational diabetes, it would be ideal to screen all pregnant women at 24 and 28 weeks. However, this would collapse the healthcare system because of the healthcare staffing demands, so the alternative was to focus on risk factors such as being over 30 years old or being overweight.
She said that focusing on women with gestational diabetes would have the greatest impact on the pandemic, as treatment can help avoid pre-eclampsia and improve foetal development, resulting in fewer admissions to the neonatal ICU.
Speaking on behalf of Sanofi the conference sponsor, Dr Asafika Mbangata said: “Sanofi puts patients first and the aim of the conference was to empower stakeholders with the right information to help make critical care decisions for patients by sharing the latest data on advancements in treatments and technologies, along with insights into global and local policy changes impacting diabetes care.”
“As we chase the miracles of science to improve people’s lives, we know we cannot shape the future of diabetes management without partnerships with healthcare professionals and other stakeholders. Collaboration across all medical disciplines is essential if we are to overcome this pandemic, and we’re hopeful the conference opened the door to future robust collaborative actions that improve patient outcomes,” concluded Dr Mbangata.
References
Adapted from IDF Diabetes Atlas (10th edition). International Diabetes Federation. 2022. http://www.diabetesatlas.org/. Accessed 23 April, 2024.
People with a rare longevity condition known as growth hormone receptor deficiency (GHRD) may also have possible cardiovascular health advantages. Also called Laron syndrome, GHRD, which is characterised by the body’s impaired ability to use its own growth hormone and results in stunted growth, has been linked in mice to a record 40% longevity extension and lower risks for various age-related diseases.
The risk of cardiovascular disease in individuals with GHRD has remained unclear until now, leading to the speculation that in people, this mouse longevity mutation may actually increase cardiovascular disease. In humans, unlike mice, GHRD is not associated with an extended lifespan.
The study, appearing in Med, is the latest product of an international collaboration spanning nearly 20 years between Valter Longo, professor of gerontology at the USC Leonard Davis School of Gerontology, and endocrinologist Jaime Guevara-Aguirre of the Universidad San Francisco de Quito, Ecuador.
Over the past two decades, Longo, Guevara-Aguirre and colleagues have examined the health and aging of people with the gene mutation that causes GHRD. This rare mutation, found in just 400 to 500 people worldwide, was identified in a group of Ecuadorians whose ancestors had fled Spain during the Inquisition more than three centuries ago. The mutation leaves them with ineffective growth hormone receptors and results in a type of dwarfism.
The team’s previous research has indicated that while GHRD/Laron syndrome reduces growth, it also appears to reduce the risk of several age-related diseases. Although the Ecuadorians with GHRD have a higher rate of obesity, they have a very low risk of cancer and Type 2 diabetes. They also appear to have healthier brains and better performance on tests of cognition and memory.
For the current study, the research team examined cardiovascular function, damage, and risk factors in GHRD subjects and their relatives. Researchers conducted two phases of measurements in Los Angeles and Ecuador, involving a total of 51 individuals, with 24 diagnosed with GHRD and 27 relatives without GHRD serving as controls.
Key findings from the study included:
GHRD subjects displayed lower blood sugar, insulin resistance, and blood pressure compared to the control group.
They also had smaller heart dimensions and similar pulse wave velocity (a measure of stiffness in the arteries) but had lower carotid artery thickness compared to control subjects.
Despite elevated low-density lipoprotein (LDL) levels, GHRD subjects showed a trend for lower carotid artery atherosclerotic plaques compared to controls (7% vs 36%).
“These findings suggest that individuals with GHRD have normal or improved levels of cardiovascular disease risk factors compared to their relatives,” said Longo, senior author of the new study. “Although the population tested is small, together with studies in mice and other organisms this human data provide valuable insights into the health effects of growth hormone receptor deficiency and suggest that drugs or dietary interventions that cause similar effects could reduce disease incidence and possibly extend longevity.”
A study in more than 3000 US counties, with 315 million residents, has suggested that air pollution is linked with stress and depression, putting under-65-year-olds at increased risk of dying from cardiovascular disease. The research was presented at ESC Preventive Cardiology 2024, a scientific congress of the European Society of Cardiology (ESC).1
“Our study indicates that the air we breathe affects our mental well-being, which in turn impacts heart health,” said study lead author Dr Shady Abohashemof Harvard Medical School, Boston, US.
According to the World Health Organization, air pollution is estimated to have caused 4.2 million premature deaths worldwide in 2019.2 Mental illness has also been linked with premature death.3 This study examined whether air pollution and poor mental health are interrelated and have a joint impact on death from cardiovascular disease.
The study focused on particles less than 2.5 micrometres in diameter, also referred to as fine particles or PM2.5. They come from vehicle exhaust fumes, power plant combustion, and burning wood, and present the highest health risk. To conduct the study, county-level data on annual PM2.5 levels were obtained from the Centers for Disease Control and Prevention (CDC).4 PM2.5 exposure was categorised as high or low according to World Health Organization (WHO) standards. The researchers gathered data on the average number of days (age-standardised) that county residents experienced mental health issues – including stress, depression, and emotional problems – from the CDC.5 Each county was then categorised into three groups based on these numbers. Counties in the top third reported the most days of poor mental health (PMH).4 Age-adjusted premature cardiovascular mortality rates (under 65 years of age) per county, were obtained from the CDC.6 County characteristics were sourced from the County Health Rankings project.
The study included 3047 US counties, representing 315 720 938 residents (with over 207 million aged 20 to 64 years and 50% females) in 2013. Between 2013 and 2019, some 1 079 656 (0.34%) participants died from cardiovascular disease before the age of 65 years. The researchers analysed the associations between pollution, mental health, and premature cardiovascular mortality after adjusting for factors that could influence the relationships.7
Counties with dirty air (high PM2.5 concentrations) were 10% more likely to report high levels of PMH days compared to counties with clean air (low PM2.5 concentrations). That risk was markedly greater in counties with a high prevalence of minority groups or poverty. The link between PMH and premature cardiovascular mortality was strongest in counties with higher levels (above WHO recommended levels: ≥10 µm2) of air pollution. In these counties, higher levels of PMH were associated with a three-fold increase in premature cardiovascular mortality compared to lower PMH levels. Further, one-third of the pollution-related risk of premature cardiovascular deaths was explained by increased burden of PMH.
Dr Abohashem said: “Our results reveal a dual threat from air pollution: it not only worsens mental health but also significantly amplifies the risk of heart-related deaths associated with poor mental health. Public health strategies are urgently needed to address both air quality and mental wellbeing in order to preserve cardiovascular health.”
1The abstract ‘Air pollution associates with poor mental health and amplifies the premature cardiovascular death in the United States: longitudinal nationwide analysis’ will be presented during the session ‘Young Investigators Award – Population Science and Public Health’ which takes place on 26 April 2024.
2World Health Organization: Ambient (outdoor) air pollution.
3Byrne P. Meeting the challenges of rising premature mortality in people with severe mental illness. Future Healthc J. 2023;10(2):98-102.
4CDC PLACES databases.
5CDC Behavioral Risk Factor Surveillance System.
6CDC WONDER databases.
7The analyses were adjusted for calendar year and county characteristics such as demographics, median household income, unemployment rates, violent crime rates, education level, food environment index, rates of health insurance, level of mental health provision, level of primary care provision.
Many people hesitate to eat eggs amid concerns that they may raise cholesterol levels, with negative cardiovascular consequences. However, results from a prospective, controlled trial presented at the American College of Cardiology’s Annual Scientific Session show that over a four-month period cholesterol levels and other cardiovascular markers were similar among people who ate fortified eggs most days of the week compared with a non-egg eating control group.
A total of 140 patients with or at high risk for cardiovascular disease were enrolled in the PROSPERITY trial, which aimed to assess the effects of eating 12 or more fortified eggs a week versus a non-egg diet (consuming less than two eggs a week) on HDL- and LDL-cholesterol, as well as other key markers of cardiovascular health over a four-month study period.
“We know that cardiovascular disease is, to some extent, mediated through risk factors like high blood pressure, high cholesterol and increased BMI and diabetes. Dietary patterns and habits can have a notable influence on these and there’s been a lot of conflicting information about whether or not eggs are safe to eat, especially for people who have or are at risk for heart disease,” said Nina Nouhravesh, MD, a research fellow at the Duke Clinical Research Institute in Durham, North Carolina, and the study’s lead author. “This is a small study, but it gives us reassurance that eating fortified eggs is OK with regard to lipid effects over four months, even among a more high-risk population.”
Eggs are a common and relatively inexpensive source of protein and dietary cholesterol. Nouhravesh and her team wanted to look specifically at fortified eggs as they contain less saturated fat and additional vitamins and minerals, such as iodine, vitamin D, selenium, vitamin B2, 5 and 12, and omega-3 fatty acids.
For this study, patients were randomly assigned to eat 12 fortified eggs a week (cooked in whatever manner they chose) or to eat fewer than two eggs of any kind (fortified or not) per week. All patients were 50 years of age or older (the average age was 66 years), half were female and 27% were Black. All patients had experienced one prior cardiovascular event or had two cardiovascular risk factors, such as high blood pressure, high cholesterol, increased BMI or diabetes. The co-primary endpoint was LDL and HDL cholesterol at four months. Secondary endpoints included lipid, cardiometabolic and inflammatory biomarkers and levels of vitamin and minerals.
Patients had in-person clinic visits at the start of the study and visits at one and four months to take vital signs and have bloodwork done. Phone check-ins occurred at two and three months and patients in the fortified egg group were asked about their weekly egg consumption. Those with low adherence were provided additional education materials.
Results showed a -0.64mg/dL and a -3.14mg/dL reduction in HDL-cholesterol and LDL cholesterol, respectively, in the fortified egg group. While these differences weren’t statistically significant, the researchers said the differences suggest that eating 12 fortified eggs each week had no adverse effect on blood cholesterol. In terms of secondary endpoints, researchers observed a numerical reduction in total cholesterol, LDL particle number, another lipid biomarker called apoB, high-sensitivity troponin (a marker of heart damage), and insulin resistance scores in the fortified egg group, while vitamin B increased.
“While this is a neutral study, we did not observe adverse effects on biomarkers of cardiovascular health and there were signals of potential benefits of eating fortified eggs that warrant further investigation in larger studies as they are more hypothesis generating here,” Nouhravesh said, explaining that subgroup analyses revealed numerical increases in HDL cholesterol and reductions in LDL cholesterol in patients 65 years or older and those with diabetes in the fortified egg group compared with those eating fewer than two eggs.
So why have eggs gotten a bad rap? Some of the confusion stems from the fact that egg yolks contain cholesterol. Experts said a more important consideration, especially in the context of these findings, might be what people are eating alongside their eggs, such as buttered toast, bacon and other processed meats, which are not heart healthy choices. As always, Nouhravesh said it’s a good idea for people with heart disease to talk with their doctor about a heart healthy diet.
This single-centre study is limited by its small size and reliance on patients’ self-reporting of their egg consumption and other dietary patterns. It was also an unblinded study, which means patients knew what study group they were in, which can influence their health behaviours.
A new study from the Smidt Heart Institute at Cedars-Sinai shows there is a gender gap between women and men when it comes to exercise. The findings, published in the Journal of the American College of Cardiology (JACC), show that women can exercise less often than men, yet receive greater cardiovascular gains.
“Women have historically and statistically lagged behind men in engaging in meaningful exercise,” said Martha Gulati, MD, director of Preventive Cardiology in the Department of Cardiology in the Smidt Heart Institute at Cedars-Sinai, the Anita Dann Friedman Chair in Women’s Cardiovascular Medicine and Research and co-lead author of the study.
“The beauty of this study is learning that women can get more out of each minute of moderate to vigorous activity than men do. It’s an incentivising notion that we hope women will take to heart.”
Investigators analysed data from 412 413 US adults utilising the National Health Interview Survey database. Participants between the time frame of 1997 to 2019 – 55% of whom were female – provided survey data on leisure-time physical activity.
Investigators examined gender-specific outcomes in relation to frequency, duration, intensity and type of physical activity.
“For all adults engaging in any regular physical activity, compared to being inactive, mortality risk was expectedly lower,” said Susan Cheng, MD, MPH, the Erika J. Glazer Chair in Women’s Cardiovascular Health and Population Science, director of the Institute for Research on Healthy Aging in the Department of Cardiology in the Smidt Heart Institute, and senior author of the study.
“Intriguingly, though, mortality risk was reduced by 24% in women and 15% in men.”
The research team then studied moderate to vigorous aerobic physical activity, such as brisk walking or cycling, and found that men reached their maximal survival benefit from doing this level of exercise for about five hours per week, whereas women achieved the same degree of survival benefit from exercising just under about 2 ½ hours per week.
Similarly, when it came to muscle-strengthening activity, such as weightlifting or core body exercises, men reached their peak benefit from doing three sessions per week and women gained the same amount of benefit from about one session per week.
Cheng said that women had even greater gains if they engaged in more than 2 ½ hours per week of moderate to vigorous aerobic activity, or in two or more sessions per week of muscle-strengthening activities.
The investigators note their findings help to translate a longstanding recognition of sex-specific physiology seen in the exercise lab to a now-expanded view of sex differences in exercise-related clinical outcomes.
With all types of exercise and variables accounted for, Gulati says there’s power in recommendations based on the study’s findings.
“Men get a maximal survival benefit when performing 300 minutes of moderate to vigorous activity per week, whereas women get the same benefit from 140 minutes per week,” Gulati said.
“Nonetheless, women continue to get further benefit for up to 300 minutes a week.”
Christine M. Albert, MD, MPH, chair of the Department of Cardiology in the Smidt Heart Institute and the Lee and Harold Kapelovitz Distinguished Chair in Cardiology, says concrete, novel studies like this don’t happen often.
“I am hopeful that this pioneering research will motivate women who are not currently engaged in regular physical activity to understand that they are in a position to gain tremendous benefit for each increment of regular exercise they are able to invest in their longer-term health,” said Albert, professor of Cardiology.
Atherosclerosis, caused by arterial wall plaque build-up, is a leading cause of death globally, particularly in the developed countries. Although the mortality rates for this condition fell dramatically during the 20th century, the incidence is now ever increasing. Unfortunately, despite the widespread impact of atherosclerosis – and efforts to curb it – data on the global and national trends of the disease is quite limited.
In a recent effort to address this knowledge gap, a research team from China led by Professor Rongchong Huang decided to conduct a detailed statistical analysis on the impact of atherosclerosis at the global and national levels by using GBD data. The study was published in the Chinese Medical Journal.
“It is unknown how global changes in pertinent controllable variables in recent years have affected the burden of atherosclerosis,” remarks Prof Huang.
The researchers analysed publicly available data from the Global Burden of Disease Study 2019 related to the three main clinical presentations of atherosclerosis, ischaemic heart disease (IHD), ischaemic stroke (IS), and peripheral arterial disease (PAD). The data collected, which spanned the period from 1990 to 2019, included participants of all ages with similar epidemiologic characteristics and in relative proximity, from 21 countries.
Overall, the study had four main goals. The first was to determine the global trends in terms of prevalence, mortality, and disability of the three conditions. The second goal was to identify the years that had the biggest shift in the trends of these indicators. Finally, the third and fourth goals were to analyze global trends based on age, gender, and socioeconomic factors and report global and national patterns, respectively.
According to the results, there was an overall increasing trend in the global incidence of the three clinical manifestations of atherosclerosis from 1990 to 2019. Notably, the main drivers for this rising incidence were adults aged 20–54. The researchers found this very concerning, given that atherosclerosis with such an early onset is usually caused by preventable factors, such as lack of exercise, dietary habits, and environmental pollution. However, the mortality rates and disability-adjusted life years for IHD and IS declined during this period across all age groups. This could indicate greater awareness regarding these conditions and their early symptoms, as well as advancements in clinical management.
Nonetheless, the global rise in the incidence of atherosclerosis over the past three decades is a serious problem that warrants special attention towards its root causes. In this regard, Prof Huang explains: “This rise can be attributed to a variety of factors. Firstly, global aging trends have led to a higher prevalence of the disease, given that age is a significant risk factor for atherosclerosis. Secondly, modern lifestyle habits, including high-fat diets, lack of exercise, smoking, and excessive alcohol consumption, have increased atherosclerosis risk. Lastly, there has been a rise in chronic diseases such as diabetes and hypertension, which are significant risk factors for atherosclerosis.”
The researchers also pointed out that the burden posed by atherosclerosis is increasing significantly in low- or middle-income countries, summarising key social and economic development indicators. China, which has the world’s greatest number of deaths due to cardiovascular diseases, is a prime example of this issue.
Taken together, the study paints a grim picture of global cardiovascular health, which is very concerning. “Overall, the burden of atherosclerosis-related disease is still not significantly decreasing and is even trending upward, especially in low- and middle-income countries and in younger populations,” says Prof Huang, “There is an urgent need for more targeted treatment and management in younger populations and in low-middle and middle-income countries.”
Hopefully, the results of these analyses will prompt decision makers, scientists, and medical professionals alike to increase their efforts towards fighting against atherosclerosis and its devastating consequences.
A study published in The Lancet Healthy Longevity shows that brain metabolism, detected with advanced imaging techniques, declines more sharply in middle-aged people with a sustained high cardiovascular risk over 5 years
Cardiovascular disease and dementia frequently occur together in elderly people. Nevertheless, few longitudinal studies have examined how atherosclerosis and its associated risk factors affect brain health from middle age. Now, a new study by scientists at the Centro Nacional de Investigaciones Cardiovasculares (CNIC) in Madrid provides new data on this relationship; the results confirm the importance of controlling traditional cardiovascular risk factors, such as hypertension, cholesterol, diabetes, smoking, and a sedentary lifestyle, not only to preserve cardiovascular health, but also to prevent Alzheimer’s disease and other dementias.
The CNIC study shows that atherosclerosis (accumulation of fatty deposits in the arteries) and its associated risk factors, in addition to being the main cause of cardiovascular disease, are also implicated in the cerebral alterations typically found in Alzheimer’s disease, the most frequent cause of dementia.
According to study author Dr Valentín Fuster, CNIC General Director, the new findings are important because they open up the possibility of treating a modifiable disorder, ie cardiovascular disease, to prevent the development a presently untreatable disease – dementia. “The sooner we act to control cardiovascular risk factors, the better it is for our brain health,” said Dr. Fuster.
“Everybody knows that a healthy lifestyle and controlling cardiovascular risk factors are important for preventing a heart attack,” continued Dr Fuster. “Nevertheless, the additional information linking the same risk factors to a decline in brain health could further increase awareness of the need to acquire healthy habits from the earliest life stages.”
In 2021, CNIC scientists discovered that the presence of cardiovascular risk factors and subclinical (presymptomatic) atherosclerosis in the carotid arteries (the arteries that supply the brain) was associated with lower glucose metabolism in the brains of apparently healthy 50-year-old participants in the PESA-CNIC-Santander study. Glucose metabolism in the brain is considered an indicator of brain health.
The PESA-CNIC-Santander study directed by Dr Fuster is a prospective study that includes more than 4000 asymptomatic middle-aged participants who have been exhaustively assessed for the presence and progression of subclinical atherosclerosis since 2010.
Dr Fuster’s team, led by Drs Marta Cortés Canteli and Juan Domingo Gispert, have continued to monitor the cerebral health of these participants over 5 years. Their research shows that individuals who maintained a high cardiovascular risk throughout this period had a more pronounced reduction in cerebral glucose metabolism, detected using imaging techniques such as positron emission tomography (PET).
“In participants with a sustained high cardiovascular risk, the decline in cerebral metabolism was three times greater than in participants who maintained a low cardiovascular risk,” commented Catarina Tristão-Pereira, first author on the study and INPhINIT fellow.
Glucose is the main energy source for neurons and other brain cells. “If there is a sustained decline in cerebral glucose consumption over several years, this may limit the brain ability to withstand neurodegenerative or cerebrovascular diseases in the future,” explained Dr Gispert, an expert in neuroimaging at the CNIC and Barcelonaβeta Research Center.
Through a collaboration with Drs Henrik Zetterberg and Kaj Blennow, world experts in the identification of new blood biomarkers at the University of Gothenburg in Sweden, the CNIC team discovered that the individuals showing this metabolic decline already show signs of neuronal injury. “This is a particularly important finding because neuronal death is irreversible”, said Dr. Cortés Canteli, a neuroscientist at the CNIC and a Miguel Servet fellow at the Fundación Jiménez Díaz Health Research Institute.
The CNIC team also discovered that the progression of subclinical atherosclerosis in the carotid arteries over five years is linked to a metabolic decline in brain regions vulnerable to Alzheimer’s disease, in addition to the effect of cardiovascular risk factors. “These results provide yet another demonstration that the detection of subclinical atherosclerosis with imaging techniques provides highly relevant information,” said Dr Fuster, who is the principal investigator on the PESA study. “The interaction between the brain and the heart is a fascinating topic, and with this study we have seen that this relationship begins much earlier than was thought.”
The scientists conclude that, “carotid screening has great potential to identify individuals at risk of cerebral alterations and cognitive decline in the future.” In the published article they write, “this work could have important implications for clinical practice since it supports the implementation of primary cardiovascular prevention strategies early in life as a valuable approach for a healthy cerebral longevity.”
“Although we still don’t know what impact this decline in cerebral metabolism has on cognitive function, the detection of neuronal injury in these individuals shows that the earlier we start to control cardiovascular risk factors, the better it will be for our brain,” concluded Dr Cortés Canteli.
