Losing weight sooner has best chance to reverse heart damage, mouse study shows

March 4, 2013

Johns Hopkins research on obese mice finds that the impact of dieting and losing weight benefits the heart health of the young, but not the older ones

In a study of the impact of weight loss on reversing from obesity, Johns Hopkins researchers found that poor heart function in young can be reversed when the animals lose weight from a low-calorie diet. However, older mice, who had been obese for a longer period of time, did not regain better heart function after they were on the same low-calorie diet.

"Our research indicates that the longer mice are obese, the greater the risk that their heart damage is irreversible," says Majd AlGhatrif, M.D., the first author of the study and an assistant professor of medicine at the Johns Hopkins University School of Medicine.

"We don't know whether the same principle would apply to humans as well, and if so, what the turning point would be. But the basic message is that losing weight sooner rather than later would be more beneficial," says Lili Barouch, M.D., the senior author of the study and a cardiologist and assistant professor of medicine at the Johns Hopkins University School of Medicine. "It certainly warrants further study to see if the findings would be similar in people," she says.

The results of the study, "Beneficial Cardiac Effects of are Lost with Age in a Murine Model of Obesity," have been published online ahead print by the Journal of Cardiovascular Translational Research.

Barouch says it's well-known that obesity increases the risk of cardiovascular disease in people, and some studies have shown that by cutting calories and , some of the detrimental effects of obesity on the heart can be reversed. But it has not been clear, she says,whether the duration of obesity in people—or their age— makes a difference in terms of the heart's ability to recover.

To shed light on that issue, the researchers studied the effects of in two groups of mice, one young and one old. The younger mice were 2 months old (young adults in mice years), while the older mice studied were between 6 and 7 months old (similar to middle age).

All of the mice were genetically engineered to be born without leptin, a hormone that triggers a sense of being full. Leptin deficiency causes overeating and obesity, so whenever food was available, they would overeat. Both groups had evidence of heart damage, including diastolic stiffness, which affects the heart's ability to relax and fill with blood and can lead to heart failure.

Both the young and old mice lost a similar amount of weight on the calorie-restricted diet after four weeks. However, in the younger mice, restricting calories had positive effects on the heart, including a return to normal diastolic function and a reduction in fat deposits in heart cells. In the older mice, remained impaired even though there was a reduction in oxidative stress that damages the heart.

While the researchers uncovered an age-dependent pathway leading to obesity-related heart dysfunction reversible only in younger animals, Barouch says more study is needed to determine what the findings may mean for altering heart disease in people. In the meantime, she says the study should encourage people who are obese to try to lose weight as early as possible in order to reduce their risk of disease later on.

Explore further: Timing is everything when it comes to weight loss, research shows

Related Stories

Timing is everything when it comes to weight loss, research shows

October 24, 2012
Joint research between the University of Michigan and the Argentina-based National Council of Science and Technology (CONICET) has shed light on one of the most frustrating mysteries of weight loss – why the weight inevitably ...

Yo-yo dieting vs. obesity? Dieters may be healthier, live longer, study finds

June 6, 2011
Yo-yo dieters may be healthier and live longer than those who stay obese, a new Ohio University study finds.

New research links obesity with heart rhythm disorder

August 16, 2011
University of Adelaide research has shown for the first time that obesity directly causes electrical abnormalities of the heart.

Recommended for you

Five vascular diseases linked to one common genetic variant

July 27, 2017
Genome-wide association studies have implicated a common genetic variant in chromosome 6p24 in coronary artery disease, as well as four other vascular diseases: migraine headache, cervical artery dissection, fibromuscular ...

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.