Overweight as a child is not necessarily a risk factor for heart attack later in life. If weight is normalized before adulthood, the heart seems unaffected by the higher childhood BMI, according to a study conducted at the University of Gothenburg.
“This study is important because it underlines the importance of reversing unhealthy weight early on,” says Rebecka Bramsved, researcher, specialist physician, and one of the co-authors.
It is well known that children with overweight or obesity generally have an increased risk of heart attack later in life. However, it has been unclear to what extent this risk can be mitigated by normalizing weight before adulthood.
Childhood BMI not determinant
The concerned study, published in the journal JAMA Pediatrics, included over 103,000 people born between 1945 and 1968. Height and weight data were collected from school health services in the city of Gothenburg and then linked to Swedish register data on heart attacks.
The results show that overweight in both childhood and young adulthood is associated with an increased risk of heart attack. However, a heightened risk was not found among those who had overweight at age 7–8 but of normal weight in young adulthood. For this group, the risk of heart attack was the same as for those of normal weight in both childhood and young adulthood.
However, an increased risk of heart attack was seen among individuals withhad overweight at age 20, in both the group with overweight throughout childhood and the group with normal weight during childhood but became overweight during puberty.
Age during weight gain matters
When comparing the risk of heart attack for these two groups, the researchers found that the group with onset of overweight during puberty had a higher risk than the group with overweight throughout childhood.
“This study doesn’t explain why overweight with onset during puberty seems to carry a greater risk, but we’re working on the hypothesis that puberty, and the changes in sex hormones that occur during puberty, influence matters,” says Claes Ohlsson, professor and senior physician.
The researchers argue that the study results support the importance of early detection and treatment of overweight and obesity. In addition to Rebecka Bramsved and Claes Ohlsson, professor and senior physician Jenny Kindblom is another of the co-authors.
“Our results provide further support for the idea that prevention of adult cardiovascular disease should actually start during childhood,” says Jenny Kindblom.