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Risks of ‘metabolically healthy obesity’ assessed

By Nicole MacKee
People who are obese but metabolically healthy are at increased risk of heart failure (HF) and atrial fibrillation (AF) compared with people of a healthy weight and metabolism, but are at no greater risk of heart attack, stroke or cardiovascular death, researchers say.

In a cohort study of almost three million people discharged from French hospitals – reported in Diabetes, Obesity and Metabolism – those with ‘metabolically healthy obesity’ (defined as obesity without hypertension, dyslipidaemia and diabetes) were found to be at a 34% increased risk of new-onset HF and a 33% increased risk of new-onset AF.

However, people with metabolically healthy obesity did not have an increased risk of myocardial infarction (hazard ratio [HR], 0.92), ischaemic stroke (HR, 0.93) or cardiovascular death (HR, 0.99), compared with metabolically healthy people without obesity. Study participants were followed up for an average of five years.

Professor John Dixon of Swinburne University of Technology’s Iversen Health Innovation Research Institute said there was growing understanding of the role of obesity in AF.

‘It is interesting that, independent of those very narrow-focused metabolic changes, the risk of AF and cardiac failure is there. We understand the very strong link between cardiac failure and body mass index, but AF has been a far more recent discovery,’ he said.

The researchers also reported that there was a higher risk of clinical events in metabolically healthy men with obesity compared with those of normal weight, but a lower risk for most events in metabolically healthy women with obesity compared with those in the healthy weight range.

Professor Dixon said: ‘Women tend to wear their weight around the hips and thighs, while men have an abdominal distribution which is associated with metabolic and other problems, including heart failure.’

He said it was also important to note that study participants with metabolically healthy obesity tended to be younger.

‘People who don’t have metabolic obesity at the age of 30, may not have it by 34 or 35, but by the time they reach their 50s, they are at very high risk,’ he said.

And, he said, the list of serious complications associated with obesity was growing.

‘We must address weight stigma and stop blaming and shaming people with obesity,’ he said. ‘We must look after people with obesity like we look after anyone with a chronic disease and that doesn’t happen in Australia today,’ said Professor Dixon, noting that more than 90% of bariatric procedures occurred in the private health system, and weight loss drugs were still not available on the PBS.
Diabetes Obes Metab 2021; doi: 10.1111/dom.14492.