Why do some people lose substantial weight with GLP-1-based medications while others see more modest results?
An American study offers a potential answer by identifying a distinct biological subtype of obesity that responds especially well to tirzepatide, moving the field closer to precision medicine for obesity
Tirzepatide is a glucagon-like peptide 1 (GLP-1) drug that mimics two naturally occurring hormones involved in appetite and blood sugar regulation
The research, published in the journal Gastroenterology, identified a subgroup of patients with obesity who produce lower levels of natural appetite-regulating hormones, experience faster stomach emptying and report greater hunger after meals
This is a subtype of the “hungry gut” obesity phenotype, characterised by an abnormal duration of fullness
People with “hungry-gut” obesity may eat normal portion sizes, but snack more frequently
These patients lost nearly twice as much weight after six months of tirzepatide treatment as patients with other obesity subtypes
“Obesity is a complex disease driven by different biological mechanisms,” says study senior author and Mayo Clinic gastroenterologist and obesity researcher Dr Andres Acosta
“Our findings suggest that we can begin identifying which patients are most likely to respond to specific therapies rather than treating obesity as a single disease.”
The researchers studied 483 adults with obesity and found three different biological types of the disease
About one in four participants produced lower levels of GLP-1 and other hormones that help people feel full after eating
Patients in this group lost an average of 21.5% of their body weight after six months of treatment with tirzepatide, compared with 11.7% for patients in the other groups
The findings support growing efforts to personalise obesity treatment using an individual’s underlying biology, rather than relying on a one-size-fits-all approach
Because obesity increases the risk of diabetes, heart disease, certain cancers and many other serious chronic conditions, identifying the right therapy sooner could improve long-term health outcomes
The researchers also found that the reduced hormone levels were associated with decreased hormone production in the intestine, rather than differences in the gut microbiome, providing new insight into the biology underlying this subtype of obesity
They caution that prospective studies are needed before this approach can be incorporated into routine clinical practice, but that these findings represent an important step toward more precise, individualised treatment for obesity
