Being mildly overweight as a teenager raises the risk of heart failure in adulthood, scientists have once again found.
Scientists tracked 1.6million men for nearly five decades to examine the dangers of carrying extra weight in adolescence.
They found those who were even mildly overweight when they were 18 were more likely develop cardiomyopathy in later life.
The Swedish researchers warned the risk of the condition, which can lead to heart failure, was highest for the fattest teenagers.
The findings come amid a worldwide childhood obesity crisis, with figures showing there are 340million youngsters who are overweight or obese.
Being mildly overweight as a teenager raises the risk of heart failure in adulthood, scientists in Sweden find
Obesity is known to be a risk factor for a multitude of health problems including heart disease.
Researchers at the University of Gothenburg were looking mainly to see if teenage obesity raised the risk of cardiomyopathy.
It is the general term for diseases of the heart muscle, which can make it harder for the organ to pump blood around the body.
Men who enlisted in compulsory military service between 1969 and 2005, when they were 18 or 19 years old, were analysed.
Researchers recorded figures on their height, weight and overall fitness.
They also used two other national databases that track the causes of all deaths and hospitalisations to see if any men developed heart disease.
Among the men in the study, 4,477 were diagnosed with cardiomyopathy at an average age of 45.5.
The men who at age 18 had a body mass index (BMI) below 20 had a low risk of going on to develop cardiomyopathy.
But the risk steadily increased as weight increased, according to the findings that were published in the journal Circulation.
Men who had a BMI of 35 and over – considered obese – were eight times more likely to develop dilated cardiomyopathy as adults.
WHAT IS CARDIOMYOPATHY?
Cardiomyopathy is a disease of the heart muscle that affects its size, shape and structure.
The condition is usually inherited.
The three main types of cardiomyopathy are:
- Hypertrophic – heart wall is thickened
- Dilated – heart muscle becomes stretched and thin
- Arrhythmogenic right ventricular – heart muscle cells cannot be kept together
All of these types of cardiomyopathy affect the heart’s ability to pump blood around the body efficiently.
They can also impact the way electrical signals make the organ beat.
There is no cure, however, in most cases people’s quality or length of life is unaffected.
Therapies may include medication, treatment to normalise heart rhythm, pacemakers and, in rare cases, heart surgery or transplants.
Source: British Heart Foundation
Dilated cardiomyopathy is one form of the disease when the heart muscle becomes weak and can’t pump blood efficiently.
It wasn’t possible to estimate an increased risk of hypertrophic cardiomyopathy in men with a BMI of 35 or above because there were too few cases.
Hypertrophic cardiomyopathy is when the heart muscle becomes stiff and isn’t able to fill with blood properly.
The researchers expect the results to apply to men throughout the world, as levels of obesity are ‘disturbingly high’ in many high income countries.
The authors wrote: ‘Given the overall increase in body weight in young people globally, physicians need to be aware of an increased risk for cardiomyopathy.
‘The already marked importance of weight control in youth is further strengthened by these findings.’
But Professor Annika Rosengren, a cardiologist and author of the study, warned the findings may or may not translate to women.
She said: ‘The data on weight was gathered when males in Sweden register for compulsory military service.
‘Since women do not register for military service, data on women’s weight at around age 18 was not available to the researchers.’
Heart failure caused by cardiomyopathies doubled in Sweden between 1987 and 2006, the researchers noted.
Often the cause of the cardiomyopathy is unknown, however, in some people it’s the result of another condition or inherited.
Contributing factors include metabolic conditions, such as obesity, drug use, high blood pressure and drinking too much alcohol.
It affects around one in 500 people in the UK and US, according to charities.
Worldwide obesity has nearly tripled since 1975, according to the World Health Organization.
Health chiefs have long been trying to crack down on childhood obesity rates, considering children who are obese are put at a higher risk of heart conditions and diabetes.
Obese youngsters are likely to stay obese into adulthood, where long-term health problems include cancer.
WHAT IS OBESITY? AND WHAT ARE ITS HEALTH RISKS?
Obesity is defined as an adult having a BMI of 30 or over.
A healthy person’s BMI – calculated by dividing weight in kg by height in metres, and the answer by the height again – is between 18.5 and 24.9.
Among children, obesity is defined as being in the 95th percentile.
Percentiles compare youngsters to others their same age.
For example, if a three-month-old is in the 40th percentile for weight, that means that 40 per cent of three-month-olds weigh the same or less than that baby.
Around 58 per cent of women and 68 per cent of men in the UK are overweight or obese.
The condition costs the NHS around £6.1billion, out of its approximate £124.7 billion budget, every year.
This is due to obesity increasing a person’s risk of a number of life-threatening conditions.
Such conditions include type 2 diabetes, which can cause kidney disease, blindness and even limb amputations.
Research suggests that at least one in six hospital beds in the UK are taken up by a diabetes patient.
Obesity also raises the risk of heart disease, which kills 315,000 people every year in the UK – making it the number one cause of death.
Carrying dangerous amounts of weight has also been linked to 12 different cancers.
This includes breast, which affects one in eight women at some point in their lives.
Among children, research suggests that 70 per cent of obese youngsters have high blood pressure or raised cholesterol, which puts them at risk of heart disease.
Obese children are also significantly more likely to become obese adults.
And if children are overweight, their obesity in adulthood is often more severe.
As many as one in five children start school in the UK being overweight or obese, which rises to one in three by the time they turn 10.