Burden of non-communicable diseases by Socio-demographic Index: a national and subnational analysis in Iran

Non-communicable diseases (NCDs) account for around four-fifths of deaths in Iran, yet their burden varies across provinces alongside differences in socio-demographic development. We assessed national and subnational trends in NCD burden in Iran and quantified associations between Socio-demographic Index (SDI) and burden metrics.

Age-standardized rates (ASRs) of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs) for NCDs and responsible risk factors were retrieved from Global Burden of Diseases 2021 study. Provinces were ranked into SDI quintiles. Generalized estimating equations (GEE) with clustering by province were used to estimate the link between SDI and burden indicators.

From 1990 to 2021, total NCD deaths in Iran increased by 83.4%, while ASRs of mortality, DALYs, and YLLs declined across all SDI strata and gaps narrowed. Per 0.1-unit higher SDI, ASRs of DALYs and mortality were lower, but ASRs of incidence and prevalence were significantly higher. ASR of mortality and DALY of cardiovascular diseases, chronic respiratory diseases, and neoplasms improved with SDI, whereas those for diabetes and kidney diseases worsened. In 2021, the top five risk factors for death and DALYs were high systolic blood pressure, high body mass index, elevated fasting plasma glucose, dietary risks, and air pollution, with only minor differences across SDI strata.

Despite reduced interprovincial SDI disparities, age-standardized NCD mortality and DALY rates remained lower at higher SDI levels; however, this pattern varied by cause. Stronger prevention and equitable NCD management in Iran remain critical.

The online version contains supplementary material available at 10.1007/s40200-026-01999-0.