'Healthy obese' people have higher heart disease risk: study

People who are obese but do not suffer metabolic disorders such as diabetes, high blood pressure and high cholesterol have an increased risk of cardiovascular diseases, a study warns.
Researchers at the University of Birmingham in the UK carried out the largest study of its kind to date comparing weight and metabolic status to cardiovascular disease risks.
The study showed that individuals who are metabolically healthy obese (MHO) - those who are obese but do not suffer from diseases such as diabetes, high blood pressure and high cholesterol - have an increased risk of cardiovascular disease events compared to those who are normal weight without metabolic abnormalities.

The researchers used electronic health records of 3.5 million British adults who were all initially free of cardiovascular disease (CVD).
They then revisited each patients record, at an average of five years and four months later, in order to assess whether they had gone on to develop each of four kinds of CVD events: coronary heart disease (CHD), cerebrovascular disease, heart failure, or peripheral vascular disease (PVD).
Patients were divided into four body size phenotypes using body mass index (BMI): Underweight (BMI less than 18.5), normal weight (more than 18 but less than 25), overweight (more than 25 but less than 30) and obese (more than 30).

The study showed that those who were MHO had a 49 per cent higher risk of coronary heart disease, seven per cent higher risk of cerebrovascular disease and a 96 per cent increased risk of heart failure than normal weight metabolically healthy individuals.

It also showed that normal weight individuals with one or more metabolic abnormalities had an increased risk of CHD, cerebrovascular disease, heart failure and PVD compared to normal weight individuals without metabolic abnormalities.
"We had unprecedented statistical power to examine body size phenotypes by the number of metabolic abnormalities, potentially reflecting several definitions of the metabolically healthy phenotype in relation to a range of CVD events," Rishi Caleyachetty from University of Birmingham said.

Obese individuals with no metabolic risk factors are still at a higher risk of coronary heart disease, cerebrovascular disease and heart failure than normal weight metabolically healthy individuals.
The so-called metabolically healthy obesity is clearly not a harmless condition and the term should no longer be used in order to prevent misleading individuals that obesity can be healthy, researchers said.
The finding that normal weight individuals with metabolic abnormalities also had similar risk of cardiovascular disease events than normal weight metabolically healthy individuals has important implications, said Professor Neil Thomas, also of the University of Birmingham.