AFTER decades of research showing the impossibly close link between obesity and heart problems, a Swedish study has finally proven what health experts long suspected: Excess weight does cause heart disease.
At last, the Karolinska Institute researchers used a method called Mendelian randomization to prove that high Body Mass Index (BMI) is a direct cause of heart disease.
Obesity alone - without other risk factors like high cholesterol, inactivity and diabetes - raises a person’s risks of heart disease by nearly a third, previous research has shown.
And that means that a third of the world’s population - the proportion of humans that are now overweight or obese - could be on a path toward the number one cause of death without lifestyle changes and medical interventions.
The Swedish researchers discovered that as BMI and fat mass increased so did the risk of many more than half a dozen conditions - especially aortic stenosis. This where the valve controlling the flow of blood from the heart to the body’s largest blood vessel, the aorta, narrows and fails to open fully.
They said if this condition is left untreated it can lead to serious problems - and even death.
Previous studies showed that the “fat but fit” theory suggests a bulging waistline is not harmful as long as other metabolic factors like blood pressure and glucose are within recommended levels.
But evidence is growing that this is wrong - an may be sending out the wrong message to millions of people.
Using data from 367,703 men and women aged 40 to 69 they identified 96 gene mutations linked to BMI and body fat mass to estimate their effect on 14 cardiovascular diseases.
Those with variants predicting higher BMI were at increased risk of aortic valve stenosis - as well as a host of other life threatening conditions. These included heart failure, deep vein thrombosis, high blood pressure, peripheral artery disease, coronary artery disease, atrial fibrillation and pulmonary embolism.
For every genetically-predicted one unit rise in BMI, the increased risk ranged from six percent for pulmonary embolism to 13 percent for aortic valve stenosis, researchers said.
Clogged arteries would later damage the valve and that would mean less blood leaves the heart and it has to work harder to pump enough blood out to circulate round the body. Blood can back up in other parts of the heart and sometimes the lungs. This can lead to shortness of breath, tiredness, fainting, chest pain and an irregular heart beat. This was followed by stroke, atrial fibrillation, heart failure, peripheral artery disease, deep vein thrombosis, high blood pressure and coronary artery disease.
These gene variants can all predispose people to be more likely to put on weight, said the researchers. (DailyMail)