International variations in body mass index within the CASiRe global cohort of sickle cell disease patients

Although SCD has traditionally been associated with underweight status, body mass index (BMI) status is shifting globally. As disease-modifying therapies have become available, BMI status has increased. Our aim was to determine the prevalence and risk factors of underweight, overweight, and obese statuses in SCD patients in low-middle and high-income countries.

The CASiRe research consortium cross-sectionally analyzed the association of BMI status (underweight, normal weight, overweight, and obesity) to age, genotype, treatment status, and associated clinical outcomes of 532 SCD patients from Italy, United States, and Ghana.

Overall, BMI status varied significantly between countries (underweight P < .001, obesity P < .001, overweight P = .038). Underweight (9.5%-17.2%) and overweight/obesity (14%-27.8%) statuses increased from pediatrics to adults. Hemoglobin (Hgb) SC represented the highest percentage of overweight/obese patients (Hgb SC 49% vs SS/SB0Thal 16%, P < .001). Hydroxyurea use (HgbSS/SB0Thal [-]Hydroxyurea 11% vs [+]Hydroxyurea 32% overweight/obese, P < .001), higher hemoglobin levels (Adults, R = 0.396 P < .001), and genotype (HgbSS/SB0Thal vs SC, P < .001) correlated with overweight/obesity status. Lower hemoglobin (OR 0.77, P < .001) and male sex (OR 0.41 P < .001) were predictors of underweight status while higher hemoglobin (OR 1.38, P < .001) and older age (OR 1.01, P = .031) were predictors of obesity. Underweight status was associated with Ghanian site, male gender, leg ulcers, and microalbuminuria showing that it remains a significant clinical issue.

As access to disease-modifying therapy improves for SCD, monitoring for overweight and obesity and their comorbid conditions may be necessary. Underweight SCD patients should be carefully evaluated for end-organ complications, especially in low-resource settings.