'Healthy obesity' is a myth, study suggests

A study by scientists at the University of Birmingham suggests that ‘healthy’ obese people are still at higher risk of heart failure or stroke than the general population.

The study, which was the largest of its kind to date, involving analysis of the GP records of 3.5 million people from across the UK from 1995 to 2015, was presented at the European Congress on Obesity in Porto, Portugal earlier this week.

The results raise questions around the concept of ‘healthy obesity’ – a condition characterised by having normal markers of metabolic health despite a body mass index (BMI) of 30 or more.

During the study, a team from the Institute of Applied Health Research at the University of Birmingham used electronic patient records to look for markers of being metabolically healthy, having normal blood pressure and cholesterol and no diabetes, while also being obese.

They then tracked how many people suffered one of four cardiovascular conditions: coronary heart disease (CHD), cerebrovascular disease (including stroke), heart failure and peripheral vascular disease (a disorder of blood circulation).

The results showed that, compared to healthy people of a normal weight, those regarded as healthy and obese had a 49% increased risk of coronary heart disease, a 7% higher risk of stroke, and a 96% increased risk of heart failure.

Lead author of the study, Dr Rishi Caleyachetty, said:

‘The idea of being healthily obese is a myth. Our work shows that so-called ‘metabolically healthy’ obese individuals are still at higher risk of coronary heart disease, cerebrovascular disease and heart failure than normal weight metabolically healthy individuals.

‘The priority of health professionals regarding these patients should be to promote and facilitate weight loss, as it is with any other obese patient.’

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For more information, contact Emma McKinney, Communications Manager for Health Sciences at the University of Birmingham, on +44 (0)121 414 6681.

Notes to editors

This press release is based on Oral Presentation OS2:OC54 at the European Congress on Obesity. The material has been peer reviewed by the congress selection committee. The authors are in the process of submitting their work to a medical journal for publication. The full paper is not available at this stage, however the authors are happy to answer your questions.

The researchers used linked electronic health records from 1995 to 2015 in The Health Improvement Network (THIN) to assemble a cohort of 3.5 million individuals aged 18 years or older and initially free from CVD. To determine metabolic health, they divided the population into groups according to BMI and the presence or absence of 3 metabolic abnormalities (diabetes, high blood pressure [hypertension], and abnormal blood fats [hyperlipidemia]) which were added together to create a metabolic abnormalities score (0, 1, 2 and 3). To be classified as MHO, individuals had to have none of these metabolic abnormalities.

In total, there were 165,302 adverse health events during an average 50-month follow-up of patients, with 61,546 cases of CHD, 54,705 of mini stroke and stroke, 25,254 cases of heart failure, and 23,797 cases of peripheral vascular disease.