Obesity is a complex condition that may have up to 11 different forms, each caused by distinct biological pathways, according to a recent study conducted by researchers at the Broad Institute in Cambridge, Massachusetts. This new insight challenges the traditional view of obesity solely based on body mass index (BMI) and body appearance.
The World Health Organization defines obesity as having excess fat that poses a risk to health, with BMI being a common measure to determine if someone has the condition. However, not everyone with obesity experiences health complications, leading some researchers to propose the concept of “preclinical” obesity to categorize individuals with and without symptoms caused by excess fat.
In the study, the researchers conducted a genome-wide association study on over 2 million people with obesity from diverse ancestries worldwide. They identified 743 genetic regions linked to obesity, including 86 previously unreported regions. By analyzing the effects of gene variations in these regions on various tissues, such as insulin production, the researchers identified 11 clusters of obesity endotypes, each characterized by distinct biological pathways.
These endotypes include metabolically unhealthy and healthy obesity, types related to insulin production, immune system dysregulation, hormonal control of appetite, and lipid metabolism. The researchers emphasize that endotypes are not mutually exclusive, and individuals may exhibit multiple endotypes with varying degrees of influence.
The validation of these endotypes using data from the Mass General Brigham Biobank suggests a more nuanced understanding of obesity that could lead to personalized treatments and interventions. By recognizing the diversity of obesity forms, healthcare providers may better target therapies to address the underlying biological mechanisms driving the condition.
The study also has implications for future research on obesity and its interaction with genes and lifestyle factors. Understanding the different endotypes may reshape how studies are conducted and how interventions are developed in the future. While the study identified 11 endotypes, researchers believe there may be more undiscovered variations that could further refine our understanding of obesity clusters.
Overall, this research sheds light on the complexity of obesity and highlights the need for personalized approaches to treatment. By unraveling the diverse biological pathways contributing to obesity, healthcare professionals may be able to tailor interventions more effectively and improve outcomes for individuals with the condition.
