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Obesity linked to increased risk of blood cancer precursors, study finds health news


According to a recent study, monoclonal gammopathy of unknown significance (MGUS), a benign blood disorder, often precedes multiple myeloma in obese individuals. The study results are published in Blood Advances. Multiple myeloma is a blood cancer of plasma cells, a type of white blood cell that makes antibodies to fight infection. MGUS, characterized by an abnormal protein produced by plasma cells, is a known precursor to multiple myeloma. Most people with MGUS have no significant symptoms and do not become ill immediately. Rather, the presence of MGUS serves as a warning to monitor for the potential development of more complex conditions, such as multiple myeloma, that MGUS may develop into.

The Centers for Disease Control and Prevention reported in 2020 that approximately 42% of the US population is classified as obese, defined by a body mass index (BMI) of 30 or higher. However, little research exists to suggest how obesity may affect cancer outcomes. “Although significant advances have been made in the treatment of multiple myeloma, it remains an incurable disease, often diagnosed after patients have already suffered organ damage,” explained David Lee, MD, MPH, MMSC, an internal medicine resident in Massachusetts. Southern Hospital. “It is preceded by pre-malignant conditions, including MGUS. Our research group is focused on investigating the risk factors and etiology of MGUS to better understand who is at risk for MGUS and its progression to multiple myeloma.”

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Between February 2019 and March 2022, investigators enrolled 2,628 individuals across the United States who were at high risk for developing multiple myeloma based on self-identified race and family history of hematologic malignancy. Participants were screened for MGUS, defined by the presence of a monoclonal protein at a serum concentration of 0.2g/L or greater. The investigators measured MGUS using mass spectrometry—a novel, highly sensitive method of detecting and quantifying monoclonal proteins in blood.

After controlling for age, sex, race, education and income, the team found that being obese was associated with a 73% higher chance of developing MGUS, compared to people of normal weight. This association remained unchanged when accounting for physical activity. However, highly active individuals (defined as running or jogging the equivalent of 45–60 minutes or more per day) were less likely to have MGUS even after adjusting for BMI class, whereas those who reported heavy smoking and little sleep were more likely. There are also detectable levels of MGUS.

Limitations include that this was a cross-sectional study – a snapshot of how specific variables or characteristics may relate to each other at one point in time. Although the investigators found a strong association between MGUS, obesity, and lifestyle factors, they did not have enough evidence to infer causation. In addition, the American Medical Association recently voted to adopt a new policy that no longer uses BMI alone to determine whether someone is at a healthy weight, as previous research suggests that metric does not effectively distinguish between fat and lean mass and how no Fat is distributed throughout the body. The formula was based on data from non-Hispanic white populations, suggesting that its effects may not accurately generalize to black, Asian, and Hispanic groups.
Going forward, the researchers aim to validate these findings in other study cohorts, including those followed longitudinally, to further explore the mechanisms by which obesity and other modifiable risk factors may influence the development and progression of MGUS.

“These findings guide our future research to understand the impact of modifiable risk factors such as weight, exercise and smoking on cancer risk,” explained Dr. Ltd. “Before we can develop effective preventive health strategies to reduce 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.”