Clinicians are being warned not to ignore the increased cardiovascular health risks of those who are classed as either ‘healthy obese’ or deemed to be ‘normal weight’ but have metabolic abnormalities such as diabetes.
Academics at the University of Birmingham’s Institute of Applied Health Research carried out the largest study of its kind to date comparing weight and metabolic status to cardiovascular disease risks, published in the Journal of the American College of Cardiology.
The study showed that individuals who are ‘metabolically healthy obese’ (MHO) – those who are obese but do not suffer metabolic abnormalities 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 academics used electronic health records of 3.5 million British adults who were all initially free of cardiovascular disease (CVD). They then revisited each patient’s record, at an average of 5 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 (in particular strokes), heart failure, or peripheral vascular disease (PVD).
Patients were divided into four ‘body size phenotypes’ using Body Mass Index (BMI), which is calculated by dividing body weight (kg) by height (m) squared:
- Underweight (BMI less than 18.5)
- Normal weight (more than 18 but less than 25)
- Overweight (more than 25 but less than 30)
- Obese (more than 30).