Genetic variations in the fat mass and obesity-associated (FTO) gene are strongly associated with obesity in both children and adults in the Chinese population, a study reports.
The study, “FTO gene polymorphisms and obesity risk in Chinese population: a meta-analysis,” was published in the World Journal of Pediatrics.
The World Health Organization estimates that 1.1 million adults and 124 million children and adolescents are overweight. Following this global trend, China is facing a fast rise in childhood obesity, with particular incidence in rural areas.
Obese people are at higher risk for other diseases, such as type 2 diabetes, hypertension, cardiovascular diseases, and cancer, making obesity a critical issue worldwide.
Many genes have been associated with obesity, the FTO gene being the one with the strongest association. This gene plays an important role in regulating brain circuits controlling appetite, feeding behaviors, and energy balance.
Supporting its key role, studies in European populations have described genetic variations in FTO as strongly associated with obesity. However, this association has been controversial in Asian populations.
Aiming to investigate the association of FTO gene polymorphisms — genetic variants that differ from the original gene in a single nucleotide, the building block of DNA — with obesity in the Chinese population, researchers conducted a meta-analysis of published studies.
The analysis included 26 studies that examined four FTO genetic variants — rs9939609, rs6499640, rs8050136, and rs1558902 — and their correlation with obesity. Obesity was defined as a body mass index (BMI) of 28 kilograms per square meter (kg/m2) or more.
Overall, people with any of these FTO genetic variants were 30% more likely to be obese than people without them. But the association was stronger if patients had the rs1558902, rs9939609, or rs8050136 variants, which resulted in a 48%, 45%, and 43% higher risk for obesity, respectively.
When the team considered children and adolescents separately from adults, they found similar associations in both groups, where FTO variants increased the risk for obesity by 30% and 41%, respectively.
“Further large sample perspective studies should be performed to define the association of FTO gene with overweight/obesity, and illuminate the specific mechanism of such association,” the study concluded.