Accelerating Burden of Hypertensive Heart Disease in Low- and Lower-Middle-SDI Countries, 1990-2023: The Contribution...

Background: Low- and lower-middle-socio-demographic index (SDI) countries face a rapidly growing burden of hypertensive heart disease (HHD). However, the contribution of non-optimal temperature, particularly cold exposure, remains poorly characterised in these populations. Methods: Using Global Burden of Disease Study 2023 data, we analysed HHD deaths, disability-adjusted life years (DALYs), and age-standardised rates in 79 low- and lower-middle-SDI countries from 1990 to 2023. Temporal trends were assessed using estimated annual percentage change (EAPC), socioeconomic inequality using slope index of inequality (SII) and concentration index, and temperature-attributable burden using the GBD comparative risk assessment framework. Bayesian age-period-cohort models projected burden to 2050. Results: From 1990 to 2023, deaths from HHD in low- and low-middle-SDI countries combined increased by approximately 192% (from 157,950 to 461,110), with corresponding DALYs rising by approximately 171% across these countries. Across all SDI strata, the age-standardizsed mortality rate increased significantly in low-SDI countries (EAPC+ 0.58%; 95% CI: 0.53%-0.63%), whereas the increase in low-middle-SDI countries was not statistically significant (EAPC+ 0.06%; 95% CI: 0.00%-0.12%), with Central Sub-Saharan Africa recording the highest 2023 rate (44.6 per 100,000). Cold temperature consistently contributed a greater temperature-attributable HHD burden than high temperature throughout the study period. Despite the overall increase in HHD burden, the absolute cold-attributable burden increased only modestly, whereas age-standardised cold-attributable rates remained largely stable, particularly in low-SDI settings. Cross-country absolute inequality widened substantially (SII -18.93 to -20.66). Projections indicate that HHD deaths and DALYs will increase markedly by 2050, driven mainly by population ageing among women. Conclusion: Low- and lower-middle-SDI countries face a growing HHD burden, with cold exposure representing an important environmental contributor. Its impact should be considered alongside population ageing, hypertension control, healthcare accessibility, and other cardiovascular determinants. Strengthening hypertension management and implementing low-cost, winter-specific cardiovascular protection strategies may help mitigate projected burden.