Scientists from the University of Copenhagen have found an association between birth weight and the risk of health complications from childhood obesity, highlighting the need for preventive and treatment approaches for obese children born with low birth weight.
Obesity affects hundreds of millions of people, usually measured as a higher-than-ideal body mass index (BMI). According to the World Health Organization, an elevated BMI increases the risk of a variety of cardiometabolic diseases, which are responsible for around 5 million deaths per year, but not everyone is equally at risk.
Scientists from the University of Copenhagen have found that children born with low birth weight are at particularly high risk of health complications if they become obese later in life.
“Our study shows that the association between low birth weight and cardiometabolic disease risk can be detected already in childhood, and that this applies to both actual birth weight and the genetic determinants of birth weight.”
Sarah Stinson, postdoctoral researcher and lead author of the study
“This also supports the theory that people who are born with low birth weight, or who are genetically predisposed to low birth weight, are more vulnerable to adverse health outcomes, such as excess visceral fat storage, throughout their lives.”
Investigating the relationship between disease risk and birth weight
Scientists have already found that people born with a high birth weight are at higher risk of developing a suboptimal BMI later in life, while there is strong evidence that people born with a low birth weight or who have a genetic predisposition to low birth weight are at higher risk of cardiometabolic diseases such as type 2 diabetes.
What is less known is when and how individuals with these risk factors actually develop cardiometabolic disease in life, and how being overweight or obese may affect the development of cardiometabolic disease as a function of birth weight.
To learn more, the team of scientists analyzed the HOLBÆK study, a Danish cohort study of more than 4,000 children and adolescents with and without obesity. The cohort included a variety of health-related data, including birth weight, BMI, clinical assessments, blood samples, biomarkers, and a polygenic birth weight score (a calculation that combines the effects of many genetic variants associated with birth weight).
Lack of subcutaneous fat development increases the risk of disease
The scientists published their analysis in the journal eBiomedicine. They found that low birth weight can increase health risks if children develop obesity later in life. One example is sensitivity to insulin, a hormone that helps regulate blood sugar levels. Poor insulin sensitivity is a risk factor for type 2 diabetes.
“Looking at measures of insulin sensitivity, we see that being born with low birth weight does not have a negative effect on children of normal weight. But in obese children, children born with high birth weight have almost normal insulin sensitivity, while those with low birth weight have a significantly reduced insulin sensitivity,” says Pauline Croman-Raim, a doctoral student at the Novo Nordisk Foundation Centre for Basic Metabolic Research at the University of Copenhagen and the study's second author.
The reason may lie literally beneath the skin: The body normally stores fat in fat cells beneath the skin, called subcutaneous fat. But in babies who are born with low birth weight, these fat depots may be underdeveloped, so they can't expand as much as they need to to store more fat.
Instead, their bodies store fat around their organs, called visceral fat. Subcutaneous fat isn't dangerous to the body, but it's essential for the body to function properly. However, high levels of visceral fat have a variety of negative health effects, including an increased risk of type 2 diabetes.
The scientists also found an association between low birth weight and increased liver fat, which reduces insulin sensitivity and may explain why people with low birth weight are at higher risk of developing type 2 diabetes from an early age. Blood samples from people with low birth weight also had higher levels of obesity-related biomarkers in the blood.
Appropriate prevention and treatment are necessary for low birth weight babies
Based on these findings, Jens-Christian Holm, clinical associate professor at the Pediatric Obesity Clinic at Holbæk Hospital, University of Copenhagen and co-senior author of the paper, called for specific prevention and treatment approaches for obese children born with low birth weight.
“Such targeted strategies may reduce the risk of developing obesity-related cardiometabolic complications,” says Jens-Christian Holm.
“Early intervention and more precise decisions about who to treat and who not are key elements in the fight against cardiometabolic diseases,” adds Professor Torben Hansen from the Novo Nordisk Foundation Centre for Basic Metabolic Research at the University of Copenhagen, and co-first author of the paper.
sauce:
University of Copenhagen – Faculty of Health and Medicine
Journal References:
Stinson, SE, et al. (2024) Interactions of birth weight and obesity in determining childhood and adolescent cardiometabolic risk. eBioMedicine. doi.org/10.1016/j.ebiom.2024.105205​​.
