High BMI in Early Adulthood Increases Multiple Myeloma Risk Among Black Women

High body mass index (BMI) in early adulthood associated with increased risk for multiple myeloma (MM) among Black women, according to results published in the British Journal of Cancer.

The incidence of MM is more than 2-times higher for Black persons. Male gender, age, and African ancestry are established MM risk factors.

To assess the relationship between body size and MM risk among Black women, data were sourced from 55,276 participants in the Black Women’s Health Study (BWHS), which was a prospective cohort study that recruited Black women across the United States in 1995. Early adult BMI was defined as BMI at age 18 years.

The women had BMIs of <25 (21,310 women), 25 to 29.9 (17,358 women), 30 to 34.9 (9076 women), and ≥35 (7532 women) kg/m² at baseline. In general, women with lower BMI had higher educational attainment, engaged in more physical activity, and fewer had type 2 diabetes than those with higher BMI.

Incident diagnoses of MM were confirmed during follow-up in a total of 292 women.

Risk for MM was associated with early adult BMI of 25 to <30 kg/m² (adjusted hazard ratio [aHR], 1.38) and 30 to <35 kg/m² (aHR, 1.57), compared with <25 kg/m². Risk for MM increased 19% for every 5 kg/m² in early adult BMI (aHR, 1.19).

HR for usual adult BMI ≥35 kg/m² was 1.38, compared with women with a usual adult BMI <25 kg/m²; the HR per 5 kg/m² was 1.09 (95% CI, 1.00-1.20).

Additional predictors for MM included higher BMI in both early and usual adulthood (early adult BMI of ≥25 kg/m² and usual adult BMI of ≥35 kg/m²; aHR, 1.60) and height (aHR, 1.21 per 10 cm). 

This study was limited by relying on self-reported measures.

“The results of the present study extend the prior literature by showing an association in Black women, who have both a higher risk of MM and a greater prevalence of obesity compared to [non-Hispanic Whites],” the study authors concluded.