Obesity a Risk Factor for Myeloma in African Americans

A new study has found an association between body mass index (BMI) and the risk for multiple myeloma among African Americans in the United States.

The study, published in the Journal of the National Cancer Institute, showed that those in the highest BMI categories had as much as a 43% increased risk of dying from multiple myeloma compared to those with normal weight.

“While causal inferences cannot be made from observational studies like ours, evidence is becoming convincing that obesity is associated with multiple myeloma among major population groups,” wrote researcher Jennifer S. Sonderman, of the International Epidemiology Institute, and colleagues. “The findings thus continue to suggest that additional research into potential biologic mechanisms, as well as into means of prevention, of BMI-associated multiple myeloma is warranted.”

The researchers combined data from seven prospective cohorts tracking mortality in a group of 239,597 African American adults and calculated risk for death from multiple myeloma according to BMI. Among all participants in the study, 36% were overweight with a BMI of 25 to < 30 kg/m², and 33% were obese with a BMI of 30 or greater.

With a median follow-up of 11.6 years, 496 deaths from multiple myeloma were observed. Compared to those patients with a normal BMI, hazard ratios [HR] were increased for all other BMI groups: 1.07 (95% CI, 0.86–1.33) for BMIs of 25 to less than 30, 1.14 (95% CI, 0.87–1.49) for BMIs of 30 to less than 35, and 1.43 (95% CI, 1.03–1.97) for BMIs of 35 to less than 60 (P = .04 for trend).

These trends remained even after adjustment for education, marital status, alcohol consumption, physical activity, and cigarette smoking intensity.

“Our data suggest that the patterns and magnitudes of BMI-associated risk are similar among African Americans and that strategies aimed at obesity prevention and reduction may have benefit with respect to multiple myeloma mortality,” the researchers wrote.