'Beer bellies' linked to dangerous heart remodelling — especially in men

While it’s been acknowledged for some time that visceral fat — belly fat —that wraps around internal organs is a health hazard, new research suggests it’s particularly dangerous to the male heart.

Researchers who studied advanced cardiovascular MRI (magnetic resonance imaging) scans of 2,244 adults aged 46 to 78 without known heart disease found that abdominal obesity — an unhealthy hip-to-waist ratio —  is associated with worrisome patterns of “cardiac remodelling,” more so than overall weight alone.

The findings “highlight the need for personalized risk assessment in obesity-related cardiovascular disease,” the authors wrote in research presented at this week’s annual meeting of the Radiological Society of North America in Chicago.

Canadians are experiencing “high and growing levels” of fat stored around the waist and stomach, Statistics Canada reports. From 2022 to 2024, nearly half (49 per cent) of adults aged 18 to 79 had a waist circumference above the threshold for abdominal obesity, meaning greater than 102 centimetres for males and greater than 88 cm for females).

The National Post reached out to the study’s lead author, Dr. Jennifer Erley, a radiology resident at University Medical Center Hamburg-Eppendorf, Germany to break the findings down. The conversation, via email, has been edited for clarity and length.

What made you interested in exploring abdominal obesity’s effect on the heart?

Obesity is very common in our modern society, about to replace smoking in terms of costs and health-care consequences. However, we still don’t really know if obesity has independent effects on the heart, because obese people often also suffer from other cardiovascular risk factors, such as diabetes and high blood pressure.

We also don’t really know if the effect of obesity on the heart is different for men and women, although men and women suffer from different types of obesity. Males generally tend to be more obese and tend to have more visceral obesity, which is sometimes described as ‘beer belly.’

I wanted to find an answer to these questions using a population-based trial, which is based here in Germany, the Hamburg City Health Study.

What was known before your study about obesity’s impact on the heart’s anatomy?

The effect of obesity on the heart has been studied previously, also in population-based studies. However, there have been discrepancies in the results.

Most studies predominately classified obesity according to BMI and they found that a high BMI is associated with cardiac dilatation.

Fewer studies investigated ‘visceral’ obesity according to WHR (waist-to-hip ratio), and some did not find a different effect of visceral obesity compared to general obesity.

Moreover, many studies used echocardiography (an ultrasound test that checks the heart’s structure and function) to investigate how obesity impacts the heart’s anatomy, which is broadly available but does not allow for further tissue characterization.

What did you find on MRI scans in people with a high BMI versus those with abdominal (high waist-to-hip-ratio) obesity?

Similar to previous studies, we found a high BMI is associated with bigger heart chambers, indicated by increased cardiac volumes (the amount of blood the heart holds and pumps) and an accompanying hypertrophy (thickening of the heart muscle).

Abdominal or visceral obesity, on the other hand, was associated with a proportionally greater hypertrophy but smaller heart chambers.

This form of remodelling, where the heart muscle thickens but does not enlarge, is called ‘concentric remodelling’ and we know from previous studies that this form of remodelling is prone to lead to heart failure. (In a release, Erley explained how, when the inner chambers become smaller, “the heart holds and pumps less blood,” messing with the ability of the heart muscle to properly relax.)

This association was more prominent in males than in females in our study.

What might explain the gender difference?

Males tend to suffer from obesity at a younger age than females due to the protective effect of estrogen on the female metabolism. Therefore, the male heart is exposed to the effects of obesity longer than the female heart.

What is important is to detect this type of remodelling before any symptoms occur, such as shortness of breath, in order to radically intervene.

As a radiologist, I think that it is important to consider the effect of abdominal obesity when we see concentric remodelling in cardiac magnetic resonance scans.

Nowadays, we have a broad variety of therapeutic strategies to tackle visceral obesity and it’s important to address obesity as a ‘pathology,’ just like arterial hypertension and diabetes.

Patients and clinicians should take obesity (particularly the accumulation of abdominal fat) just as seriously as those other pathologies.

National Post

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