More than a high BMI, an obese heart is a silent risk: New research shows that fat tissue around the heart releases molecules that alter heart rhythm, identifying potential new targets for preventative therapies for heart disease By Professor Lea Delbridge, University of Melbourne and Dr James Bell, La Trobe University and University of Melbourne.
More than two thirds of Australians are now overweight or obese.
More than just a statistic, this figure is concerning because obesity is associated with a number of long-term health issues including diabetes, cardiovascular disease, some cancers, musculoskeletal disease, disability and has recently emerged as a risk factor in COVID-19 morbidity.
Of these, heart disease is Australias biggest killer. And irregular heart rhythms, known as atrial fibrillation (AF), are an early phase of heart disease, which can lead to stroke, heart failure and, eventually, death.
AF is also associated with accelerated dementia and depression.
In Australia, one in 11 deaths are linked to atrial fibrillation with an economic cost of more than $A1.25 billion per year. Described as a silent killer, many people with AF have no symptoms and it is often difficult to diagnose.
It has been known for some time that obesity is a critical risk factor for AF. Each unit increase in body mass index (BMI) increases AF risk by four to five per cent.
So, developing new preventative therapies for treating AF is crucial to reducing the public health and economic burden of this disease.
Our latest study published in the Journal of the American College of Cardiology has highlighted that the build-up of fat around the heart is especially dangerous for heart health showing a link between the fat deposit on the surface of the heart muscle with atrial fibrillation.
The Framingham Heart Study first identified an important, but poorly understood link between accumulation of fat around the heart and the risk of the most common form of irregular heart rhythms atrial fibrillation.
This then culminated in a new collaboration, between pre-clinical researchers and clinical cardiologists at the University of Melbourne and Melbourne Biomedical Precinct.
Our group has been researching the role of cardiac adipose (fat tissue) in regulating heart muscle contraction and heart pump function for a number of years.
And our partners, Drs Jon Kalman and Chrishan Nalliahs team from the Department of Medicine at the Royal Melbourne Hospital, have been investigating the effects of patient obesity on the electrical abnormalities which provoke AF.
During the project, while patients were still undergoing surgery, we could rush heart tissue fragments (removed as part of the surgical process) into the research lab and work on them immediately.
The most common irregular rhythms of the upper chambers of the heart atrial fibrillation are more prevalent in aged and obese populations. One in three people will develop AF beyond the age of 55 and the risk accelerates with increasing age.
People are often unaware they have AF and the first sign could be tragic: a stroke due to blood clot traveling to the brain or the danger of a sudden blackout with dire consequences.
Silent progression to heart failure is common, with AF only detected when the symptoms of heart failure emerge.
Changes in heart rhythms
Most people dont realise that there is a lot of fat adipose tissue around the heart muscle. In extreme cases the amount of fat has been found to be up to 50 per cent of the entire heart weight.
Our research has shown that the adipose tissue around the heart produces biochemical factors which changes the way electrical signals move through the heart muscle tissue to generate the heartbeat.
The cell-to-cell communication is disrupted, and the transfer of the electrical signal between cells (which creates the heart beat) is delayed. These factors have a potentially major role in causing disruption of electrical activity which underlies atrial fibrillation.
And although BMI increases the risk of AF, it is the cardiac adipose burden (and not BMI) that is most important in electrical and structural disruption.
There are no general screening processes, no preventative treatments and AF and AF complications are associated with hospitalisation rates of up to 40 per cent.
It is also likely that AF is under-diagnosed in women.
Men often undergo cardiac surgery to unblock coronary arteries where AF is then often detected. Heart disease with major artery involvement is much less common in women, so AF often remains undetected until the disease is dangerously advanced.
Potential new treatments
Understanding the basic causes, early intervention and developing new preventative therapies is crucial.
Current treatments for those diagnosed with AF are limited and lack effectiveness. They are designed to abolish the irregular heart rhythms without addressing the underlying cellular causes.
Drug therapies can actually make arrhythmias worse and the common atrial ablation catheter procedure only works for a limited time and repeat procedures are common.
By showing that the fat around the heart drives these rhythm irregularities, our study identifies potential new targets for developing preventative therapies that may reduce the catastrophic health consequences.
Our research suggests that more proactive management to measure the heart adipose load should be undertaken as part of a risk assessment.
It also raises the possibility that a surgical approach to reduce cardiac adipose (fat) tissue could be an intervention to consider in future and identifies molecular signalling which may potentially pave the way for targeted drug treatment.
A link to living in a time of Covid?
Obesity has emerged as a major risk factor for morbidity in COVID-19 patients, with cardiovascular complications a major underlying cause of death.
The causes underlying this are poorly understood. It is possible that the fat surrounding the heart is implicated.
Our study shows that factors released from the heart can have potentially catastrophic effects on how the heart muscle functions but the extent to which this underlies the cardiovascular component of COVID-19 mortality or morbidity has yet to be further explored.
Research support for this work was provided by the National Health and Medical Research Council.
This article first appeared in Pursuit.
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- The kids aren't all right: COVID-19-fueled stress eating, inequities, lack of fitness expected to boost obesity, experts say - USA TODAY - October 18th, 2020
- Hispanics live longer than most Americans, but will the US obesity epidemic change things? - The Conversation US - October 18th, 2020
- Obesity in children on the rise due to remote learning, study shows - WWLTV.com - October 18th, 2020
- How the pandemic is boosting the risk of childhood obesity WHYY - WHYY - October 18th, 2020
- Risk of severe Covid-19 high for obese people, regardless of other factors - Health24 - October 18th, 2020
- The COVID-19 pandemic emphasizes the need to manage patient obesity - Medical Economics - October 18th, 2020
- Learn About the Advice From FIGO on Obesity | Figo - International Federation of Gynecology and Obstetrics - October 18th, 2020
- Bariatric Surgery Associated with 3-Year Increase in Life Expectancy for Obese Patients - Endocrinology Network - October 18th, 2020
- funded study links adolescent brain differences to increased waist circumference - National Institutes of Health - October 18th, 2020
- National Pet Obesity Awareness Day puts spotlight on keeping furry friends at a healthy weight - KING5.com - October 18th, 2020
- Studies Begin to Untangle Obesitys Role in Covid-19 - The New York Times - September 29th, 2020
- Covid-19 has killed more people than obesity in the UK this year - Full Fact - September 29th, 2020
- Relation found between AMI and obesity < Hospital < - KBR - Korea Biomedical Review - September 29th, 2020
- Long-term impact of obesity on patient-reported outcomes and patient satisfaction after lumbar spine surgery: an observational study. - Physician's... - September 29th, 2020
- Recovered Covid patients just cant stop eating - The New Indian Express - September 29th, 2020
- Wellness Expert James Hill Says Healthy Is More Than Weight Loss - Healthline - September 29th, 2020
- Weight Gain Linked to Later Life Incident VTE - MD Magazine - September 29th, 2020
- 18 Percent Of Americans Don't Have Enough To Eat, Which Makes Them...Obese? - Science 2.0 - September 29th, 2020
- Food insecurity in the US increasingly linked to obesity - Medical News Today - September 28th, 2020
- U.S. Adult Obesity Rate Hits Highest Rate Ever Recorded - Club Industry - September 28th, 2020
- Mission: Readiness ties obesity to national security - News - Times Record - September 28th, 2020
- The Intersection Of Obesity, COVID-19, Social Justice And Mental Health - Club Industry - September 28th, 2020
- Experience of Polish Patients with Obesity in Contacts with Medical Pr | PPA - Dove Medical Press - September 28th, 2020
- Cleveland Clinic Study Identifies Weight-Loss Threshold for Cardiovascular and Survival Benefits in Patients with Obesity and Diabetes - Health... - September 28th, 2020
- Coronavirus pandemic could impact cancer rates and care in the future - WKTV - September 28th, 2020
- Nonalcoholic Fatty Liver Disease and Heart Failure: Is There a Connection? - Michigan Medicine - September 28th, 2020
- Should India adopt NOVA classification of food? - The Sunday Guardian - September 28th, 2020
- Obesity and the Bitter Pill of Truth - Medscape - September 23rd, 2020
- Obesity and COVID-19: A renewed call to address a growing crisis - World Bank Group - September 23rd, 2020
- Negative pressure wound therapy does not cut infection risk in obese women after cesarean delivery - National Institutes of Health - September 23rd, 2020
- Obesity linked to hospitalisation and ICUs for Covid-19 patients - The Irish Times - September 23rd, 2020
- New Research Shows Potential Utility of Growth Standards to Monitor Healthy Weight in Puppies and May Help Identify Puppies at Risk for Obesity -... - September 23rd, 2020
- SCOTUS, Sallys economic effects and obesity - AL.com - September 23rd, 2020
- Obesity can cause and be consequence of poor sleep - Westside Eagle Observer - September 23rd, 2020
- Health Education Week 2020: Opportunities and Advancements in Obesity Medicine - Medical Economics - September 23rd, 2020
- COVID-19 Recovery Analysis: Assisted Reproductive Technology Market | Increase in Rate of Infertility and Obesity-Related Cases to Boost the Market... - September 23rd, 2020
- Stephanie Yeboah: 'Obesity is a disgusting word... it's just used to scare people' - Telegraph.co.uk - September 23rd, 2020
- Diabetes, Obesity and other five risk factors that can lead to heart failure - India TV News - September 23rd, 2020
- Research finds out a new phenomenon of obesity with the multiple burden of malnutrition in India - Eastern Eye - September 23rd, 2020
- WHO launches guide to boost children's health and well-being in Russian-speaking countries - Russian Federation - ReliefWeb - September 23rd, 2020
- For teens with severe obesity, bariatric surgery works, but is rarely used. Experts say that needs to change - The Detroit News - September 20th, 2020
- Obesity associated with a higher risk for dementia, new study finds - National Institute on Aging - September 20th, 2020
- Your Health First: Top underlying health conditions in North Dakota? Obesity and Type 2 diabetes - KX NEWS - September 20th, 2020
- US adult obesity at highest level ever recorded; Arkansas and Oklahoma rank in top five - 5newsonline.com - September 20th, 2020
- Coronavirus science | Week in review: 'Long Covid', obesity, and will the virus become seasonal? - Health24 - September 20th, 2020
- Mediterranean diet helps offset the health impacts of obesity - Earth.com - September 20th, 2020
- Obese people 70% more at risk of severe COVID-19: Assocham - The Indian Express - September 20th, 2020
- Could interaction between Covid-19 and pre-existing bacteria explain severity in the obese? - Health24 - September 20th, 2020
- Despicable to blame Government for Covid-19 death rate given obesity, says Tory peer - Evening Standard - September 20th, 2020
- If a heavyweight is morbidly obese why is he also fit to box? - Boxing News Online - September 20th, 2020
- Cancer Is on the Rise Among Young People - Discover Magazine - September 20th, 2020
- Letters to the Editor: Sept. 20 - Canon City Daily Record - September 20th, 2020
- Good nutrition can contribute to keeping COVID-19 and other diseases away - Kiowa County Press - September 20th, 2020
- Why COVID-19 is more deadly in people with obesityeven if they're young - Science Magazine - September 8th, 2020
- Higher obesity rates appear to contribute to higher bankruptcy rates in the United States - PsyPost - September 8th, 2020
- Worldwide Non-Invasive Fat Reduction Industry to 2025 - Increasing Prevalence of Obesity Presents Opportunities - ResearchAndMarkets.com - Business... - September 8th, 2020
- New evidence testosterone therapy is effective obesity treatment in men - New Atlas - September 8th, 2020
- Obesity is tied to greater risk of complications from COVID-19 - WWLTV.com - September 8th, 2020
- Pregnancy, Obesity and Nutrition Initiative (PONI): FIGO releases new Supplement - International Federation of Gynecology and Obstetrics - September 7th, 2020
- High Pleural Pressure Prevents Alveolar Overdistension and Hemodynamic Collapse in ARDS with Class III Obesity. - Physician's Weekly - September 7th, 2020
- Global Intragastric Balloon Market (2019 to 2028) - Rise in Government Initiatives Regarding Obesity Presents Opportunities - ResearchAndMarkets.com -... - September 7th, 2020
- Drugs That Fight Diabetes and Obesity May Treat Covid-19 - Bloomberg - September 6th, 2020
- COVID-19 Patients With Obesity Have Higher Viral Load, for Longer - Medscape - September 6th, 2020
- Even half a glass of alcohol increases risk of obesity, study shows - Study Finds - September 6th, 2020
- America's Obesity Epidemic Threatens Effectiveness of Any COVID Vaccine - POZ - September 6th, 2020
- 'Fat-Shaming' Drops in US but UK Public Still Apportion Blame - Medscape - September 6th, 2020
- Calls for tougher regulation to fight obesity - Newsroom - September 6th, 2020
- Consumption of alcohol even in small amounts can result in obesity and metabolic syndrome, suggests study - Firstpost - September 6th, 2020
- World's richest countries grappling with children's reading and math skills, mental well-being and obesity - UNICEF - September 6th, 2020
- Definition of Chronic disease - MedicineNet - August 31st, 2020
- America's Move to Raise A Healthier Generation of Kids ... - August 31st, 2020
- Controlled obesity status: a rarely used concept, but with particular importance in the COVID-19 pandemic and beyond - DocWire News - August 31st, 2020
- Groningen University Hospital to investigate role of obesity in patients with COVID-19 - Innovation Origins - August 31st, 2020
- Obesity and COVID-19: How weight tips the scales to severe COVID-19 illness - The Stanford Daily - August 31st, 2020
- Study finds obese people at higher risk of COVID-19 complications - Times of India - August 31st, 2020
- Childhood obesity could increase the risk of multiple sclerosis in later life - The Conversation UK - August 31st, 2020
- Peter Rhodes on an Indian romance, the risks of obesity and standing up for nice things - expressandstar.com - August 31st, 2020
- Joint Pain Injections Market: Investments by key players is driving the global market - BioSpace - August 31st, 2020
- Why your doctor will not talk to you about obesity - The Standard - August 31st, 2020
- EDITORIAL: We haven't tackled obesity - and now it's proving our downfall - Bahamas Tribune - August 31st, 2020