Retrospective cohort study of association of cumulative excess body mass index and MGUS progression to myeloma

Obesity is a risk factor for multiple myeloma (MM) and its precursor, monoclonal gammopathy of unknown significance (MGUS). However, it is unclear how cumulative exposure to obesity affects the risk ok MGUS progression to MM. A cohort study using the US Veterans Health Administration database from October 1, 1999, to December 31, 2021, included 22,429 patient with MGUS. Among the patients with BMI of 18.5 to less than 25 at MGUS diagnosis, each 1-unit increase of excess BMI (ie; >25) per year was associated with a statistically significant 21% higher risk of progression to MM (aHR 1.21; 95% CI 1.04-1,40). However, among patients with BMI 25 or greater at MGUS diagnosis, the incremental risk associated with cumulative excess BMI exposure was not statistically significant. The authors conclude that for patients with healthy weight at MGUS diagnosis, maintaining a healthy weight may prevent progression to MM.