A new study has found that “metabolically healthy” obese people are still at higher risk of cardiovascular disease. The investigation, which will be presented at this year’s European Congress on Obesity (ECO) in Porto, Portugal, found that obese but so-called healthy people have higher risks of suffering from heart failure or strokes.
Researchers from the Institute of Applied Health Research in the College of Medical and Dental Sciences at the University of Birmingham looked at the health records of 3.5 million people over ten years and found the risk is still higher for healthy obese people than for people with healthy weights.
Researchers analyzed 3.5 million ‘healthy obese’ people
According to the researchers, people with metabolically healthy obesity are clinically obese regarding their body mass index but are considered healthier than regular obese people because they do not suffer from metabolic complications like abnormal blood fats, poor blood sugar control, diabetes, or high blood pressure. Researchers noted that it is not established whether metabolically healthy obesity is associated with excess risk of cardiovascular disease.
The study found limitations in the evidence to link MHO with cardiovascular diseases, such as inconsistent definitions of metabolic health, inconsistent control for other factors, and small sample sizes. The researchers addressed those limitations in a large contemporary cohort, which was completely based on linked primary care electronic health data.
The researchers from the University of Birmingham in the U.K used linked electronic medical records from 1995 through 2015 in The Health Improvement Network (THIN), which is a large U.K. database of general practice records. Using the THIN data, they put together a cohort of 3.5 million individuals aged 18 years or older who were initially free from cardiovascular disease.
To determine metabolic health, the researchers divided the population into groups according to their BMI and the absence or presence of metabolic abnormalities, such as diabetes, high blood pressure (hypertension), and abnormal blood fats (hyperlipidemia). The data was then used to create a metabolic abnormalities score (0, 1, 2 and 3), and researchers decided that to be classified with metabolically healthy obesity, individuals had to have none of the metabolic abnormalities.
The study focused on examining whether the risk of developing four cardiovascular conditions was different for normal weight people that have no metabolic conditions or people with metabolically healthy obesity. They analyzed the risk of developing coronary heart disease, cerebrovascular disease –which could be a stroke or a transient ischemic attack-, heart failure or peripheral vascular disease.
“This is the largest prospective study of the association between metabolically health obesity and cardiovascular disease events,” said Dr. Rishi Caleyachetty, from the University of Birmingham. “Metabolically healthy obese individuals are at higher risk of coronary heart disease, cerebrovascular disease and heart failure than normal weight metabolically healthy individuals.”
‘Healthy obese’ people still face a high risk of developing heart disease
The researchers found that compared to normal weight individuals without metabolic abnormalities, people with metabolically healthy obesity had a 50 percent increased risk of coronary heart disease, a 7 percent increased risk of cerebrovascular disease and twice the risk of heart failure. The results also took into account demographics and smoking behavior. They found that metabolically healthy obese individuals had a 9 percent lower risk of peripheral vascular disease (PVD), but when they analyzed the numbers further and excluded cigarette smokers, healthy obese people had an 11 percent increased the risk of developing PVD.
The results also took into account demographics and smoking behavior. They found that metabolically healthy obese individuals had a 9 percent lower risk of peripheral vascular disease (PVD), but when they analyzed the numbers further and excluded cigarette smokers, healthy obese people had an 11 percent increased risk of developing PVD.
Caleyachetty believes the results show that metabolically healthy obese individuals should still seek to lose weight to lower their risk of cardiovascular disease.
‘Weight loss should be promoted and facilitated among obese people’
The researchers also found that the risk of cardiovascular disease events in obese individuals increased if the individuals had more metabolic abnormalities present. They noted that compared to a normal weight person without metabolic abnormalities, an obese individual with three metabolic abnormalities had a 2.6 times increased risk of coronary heart disease, a 58 percent increased risk of cerebrovascular disease, including strokes, a 3.8 times increased risk of heart failure as well as a 2.2 times increased risk of PVD.
The British Heart Foundation recommends some heart health advice to obese people, such as not smoking, eating a balanced diet, exercising regularly and limiting the amount of alcohol. According to Caleyachetty, at the population level, the so-called metabolically healthy obesity is not a harmless condition. He noted that perhaps it is better not to use that term to describe an obese person, regardless of how many metabolic complications they have.