Even for those with a healthy body mass index (BMI), a “fat belly” creates a two-fold higher long-term risk of heart problems. “Fat belly,” or central obesity, is a store of excess fat around the middle of the body, and this marker of abnormal fat distribution can induce heart problems, findings from the Mayo Clinic revealed. The study is the first of its kind to link normal weight and central obesity to non-fatal cardiovascular events, emphasizing the call to include central obesity measurements in cardiovascular health check-ups. The findings were presented at the EuroPrevent 2018, a European Society of Cardiology congress.

Dr. Jose Medina-Injosa, from the division of Preventive Cardiology at the Mayo Clinic, Minnesota, further detailed the findings, “They were shocking, as current knowledge and guidelines assume that if you have a normal weight, you are not at a greater risk [from heart problems], thus central obesity measurements are not recommended in this population [the US].”

The advice typically is: “See your doctor if your waist is bigger than your hips,” he asserts.

Significantly, the findings showed that people with normal weight and central obesity were more at risk from heart problems than all people without central obesity – whether they were of a healthy weight or obese. This could be due to the level of muscle in the body, explains Medina-Inojosa:

“The belly is usually the first place we deposit fat, so people classified as overweight BMI but without a fat belly probably have more muscle which is good for health. Muscle is like a metabolic storehouse and helps decrease lipid and sugar levels in the blood.”

The US study

The study tested the hypothesis that people at a normal weight, with central obesity, would have more significant heart problems than people at a normal weight and with normal fat distribution.

From 1996 to 2000, a total of 1,962 US participants, aged 45 years or older underwent clinical examinations. Measurements were taken of weight, height and waist circumference and hip circumference. Central obesity was defined as a ratio dividing the waist circumference by the hip circumference of 0.90 or above for men, and 0.85 or above for women.

Between the years of 2000 to 2016, the patients were then monitored regarding major adverse cardiovascular events (MACE), using linked medical records from the Rochester Epidemiology Project. MACE is defined as heart attack, surgical or percutaneous coronary revascularization to open blocked arteries, stroke, or death from cardiovascular causes.

Mostly, participants with a normal BMI (18.5-24.9kg/m2) and central obesity had an approximately two-fold higher long-term risk of MACE compared to participants without central obesity, regardless of their BMI.

Real-world implications

The implications of the study could be large, as “the current 2013 AHA/ACC/TOS recommendations for the management of obesity, cite lack of available data as the reason for not recommending waist/hip ratio assessment. This study supports further risk stratification, interventions and treatment interventions in those with increased waist/hip ratio,” Medina-Injosa tells.

Therefore, the findings demonstrate the importance for doctors not to assume that people with a normal BMI are not at risk of heart problems or that their fat distribution is normal. “Our study provides evidence that doctors should also measure central obesity to get a better picture of whether a patient is at risk,” Medina-Inojosa adds.

In terms of patient recommendations, he adds, “If you have fat around your belly and it’s greater than the size of your hips, visit your doctor to assess your cardiovascular health and fat distribution. If you have central obesity, the target will be waist loss rather than weight loss. Exercise more, decrease sedentary time by taking the stairs or getting off the train one stop early and walking, increase your muscle mass with strength and resistance training, and cut out refined carbohydrates.”

The study participants were a representative sample of the US population, which further enhances the implications of the findings on the greater public, “it is crucial to educate our patients on the importance of a good quality diet, increasing physical activity and having regular medical preventive check-ups as many in the population are unaware of the added risk.”

The team hopes to see interventions off the back of these results soon, preferably as a tool to implement community interventions, impact guidelines and as an initiation for a conversation with legislators.

Key factors contributing to central obesity are a diet high in refined carbs, and in combination with sedentarism. This leads to a greater accumulation of fat around the belly, which is linked to the molecular and hormonal mechanism that increases the cardiovascular risk.