Individuals with obesity are more likely to have a benign blood condition that often precedes multiple myeloma, according to new research to be published in Blood Advances. People who are physically active, meanwhile, are less likely to have this condition, even if they are obese. Smoking and too little sleep were also associated with risk of the condition.
Multiple myeloma is an incurable blood cancer of the plasma cells, and there are about 35,500 new cases in the U.S. each year. It is often preceded by a condition called monoclonal gammopathy of undetermined significance (MGUS).
“While significant advancements have been made in therapeutics for multiple myeloma, it remains an incurable disease, often diagnosed after patients have already experienced end-organ damage,” explains lead author David Lee, MD, an internal medicine resident at Massachusetts General Hospital.
“Our research group is focused on investigating risk factors and etiology of MGUS to better understand who may be at increased risk for developing MGUS and its progression to multiple myeloma,” he adds.
MGUS is characterized by an abnormal protein produced by plasma cells. Most people with MGUS exhibit no significant symptoms and are not immediately ill. Rather, the presence of MGUS serves as a warning to monitor for the potential development of more critical conditions, such as multiple myeloma, that MGUS can lead to.
As a result, there is great interest in whether there are other factors at work when people with MGUS go on to develop melanoma. Obesity is one of these possible factors, and very widespread. The Centers for Disease Control and Prevention reported in 2020 that nearly 42% of the US population is classified as obese, defined by a body mass index (BMI) of 30 or higher. Yet, little research exists to suggest how obesity may impact cancer outcomes.
The researchers write, “The emergence of mass spectrometry (MS) for the detection of MGUS has provided new opportunities to evaluate its risk factors.”
They enrolled 2,628 individuals from across the United States who were at elevated risk of developing multiple myeloma, based on self-identified race and family history of hematologic malignancies. Participants were screened for MGUS, defined by the presence of monoclonal proteins at serum concentrations of 0.2g/L or greater, as measured using mass spectrometry.
After controlling for age, sex, race, education, and income, the team found that obesity was associated with 73% higher likelihood of having MGUS. This association remained when accounting for physical activity. However, highly active individuals (defined as doing the equivalent of running or jogging 45-60 minutes per day or more) were less likely to have MGUS even after adjusting for BMI class, whereas those who reported heavy smoking and short sleep were more likely to also have detectable levels of MGUS.
Going forward, the team aims to validate these findings in other study cohorts, including individuals who are followed longitudinally, to further explore how obesity and other modifiable risk factors might influence the development and progression of MGUS.
“These results guide our future research in understanding the influence of modifiable risk factors, such as weight, exercise, and smoking, on cancer risk,” explains Lee. “Before we can develop effective preventative health strategies to lower the risk of serious diseases like multiple myeloma, we first need to better understand the relationship between MGUS and potentially modifiable risk factors like obesity.”
