Individuals With Obesity More Likely to Have MGUS, A Multiple Myeloma Precursor

According to new research published in Blood Advances, individuals with obesity are more likely to have monoclonal gammopathy of undetermined significance (MGUS), a benign blood condition that often leads to multiple myeloma. The majority of patients with MGUS are often not immediately ill and show no symptoms of the condition. The presence of MGUS is often an indicator to monitor for the development of more severe conditions.

Image credit: Chinnapong | stock.adobe.com

In 2020, the CDC reported that approximately 42% of the US population has obesity (having a body mass index [BMI] of 30 or higher); however, there is little research that suggests how obesity influences cancer outcomes.

“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,” said David Lee, MD, MPH, MMSc, internal medicine resident at Massachusetts General Hospital, in a press release. “It's preceded by premalignant conditions including MGUS. 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.”

The investigators enrolled a total of 2628 patients who, based on self-reported race and family history of hematologic malignancies, were at an elevated risk of developing multiple myeloma. The patients were screened for MGUS, which was defined as the presence of monoclonal proteins at serum concentrations of 0.2/L or greater. Further, the investigators measured MGUS using mass spectrometry, which is a highly sensitive method of quantifying and identifying monoclonal proteins that are in the blood.

After adjusting for age, sex, race, education and income, the investigators determined that, compared to individuals with normal BMIs, having obesity was correlated with 73% higher odds of having MGUS. In addition, the association did not change when physical activity was accounted for; however, highly active individuals—those who engage in the equivalent of running or jogging 45 to 60 minutes per day or more—were less likely to have MGUS even after adjusting for BMI class. Further, those who reported heavy smoking and short sleep were also more likely to have detectable levels of MGUS.

The investigators note that limitations of the study include the cross-sectional study, and it only contains a “snapshot” of how certain variables or characteristics may relate to 1 another at a single point in time. Although the investigators found a strong association between MGUS, obesity, and lifestyle factors, there is still not enough evidence to assume causation.

Further, the American Medical Association recently voted to adopt a new policy that does not use BMI alone to assess whether an individual is of healthy weight due to the metric’s inability to distinguish between fat and lean mass. In addition, it does not account for how fat is distributed throughout the body. The BMI formula was created based on data from non-Hispanic White populations, meaning that Black, Asian, and Hispanic groups were not taken into consideration and that its implications cannot be accurately generalized across these populations.

The investigators note that future research will confirm these findings among other populations, such as those who are followed longitudinally, to further examine the mechanisms through which modifiable risk factors may impact MGUS’s development and progression.

"These results guide our future research in understanding the influence of modifiable risk factors, such as weight, exercise, and smoking, on cancer risk," said Lee in the press release. "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.”

References

American Society of Hematology. Obesity linked to detection of blood cancer precursor. News release. January 12, 2024. Accessed January 12, 2024. https://www.eurekalert.org/news-releases/1030816