Socioeconomic development index (SDI) gradients and high BMI-Driven pan-cancer burden: a global burden of disease study on mortality, disability, and health inequities (2015–2021)

Abstract

Background: The rising prevalence of high body mass index (BMI) has become a critical driver of global oncologic morbidity and mortality, yet its pan-cancer burden remains poorly characterized across socioeconomic development strata. This study investigates the geographic, temporal, and sex-specific disparities in high BMI-attributable cancer burden, stratified by the Socioeconomic Development Index (SDI), to inform precision public health strategies. Methods: Leveraging the 2021 Global Burden of Disease (GBD) dataset, we analyzed age-standardized mortality, disability-adjusted life years (DALYs), and years of life lost (YLLs) for 17–23 countries across Asia and globally. SDI-stratified analyses evaluated temporal trends (2015–2021) and cancer-type contributions, while multivariable models assessed associations between income inequality (Gini coefficient), healthcare capacity, and metabolic risk exposure. Results: Marked disparities emerged across SDI gradients: high-SDI nations exhibited 6.7-fold higher mortality rates (e.g., Malaysia: 4.40 vs. Bangladesh: 0.65/100,000) and concentrated burdens in colorectal (40.5% DALYs) and breast cancers (27.0% DALYs), contrasting with distributed burdens in low-SDI regions (no cancer > 15.6% DALYs). Gender disparities highlighted male predominance in liver (+ 8.4 DALY difference) and colorectal cancers (+ 5.1), while female-specific malignancies (e.g., uterine cancer) retained consistent burdens across SDI levels. Temporal analyses revealed accelerated DALY reductions in middle-SDI regions (-4.5% annual percent change [APC]) but rising breast cancer burdens in low-SDI settings (+ 1.2% APC). Economic inequality (Gini > 0.40) correlated with elevated mortality (Turkey: 123.1/100,000), independent of GDP, underscoring synergistic impacts of BMI and sociodemographic inequities. Conclusion: High BMI-driven pan-cancer burden is profoundly shaped by SDI gradients, reflecting interactions between metabolic risk, healthcare access, and socioeconomic determinants. Tailored interventions—prioritizing colorectal and breast cancers in high-SDI regions and addressing systemic inequities in low-SDI settings—are critical to mitigating the dual burden of obesity and cancer in transitioning populations.