Long-Term Trends and Prognosis in Cardiovascular Mortality in the Kazakhstani Population Living Around the...

Background: The purpose of the study is the assessment of mortality from cardiovascular diseases (CVDs) and their dose-response relationships and the calculation of the number of years of life lost (YLL) in Kazakhstani residents living in territories around the Semipalatinsk nuclear test site. Materials and Methods: The study is based on the State Scientific Automated Medical Registry (SSAMR) database. The study included 3482 residents of the Abay and Beskaragai districts exposed to radiation and 1886 residents of the Kokpekty district (control group). The median equivalent radiation dose for the exposed group was 864.0 mSv, compared to 64.4 mSv in the control group. The study period was from 1949 to 2024. Results: Mortality rates in the exposed group exceeded those of the comparison group throughout the study. The relative risk (RR) of mortality was 1.41 for all CVDs, 2.0 for stroke, 7.88 for chronic cerebrovascular disease (CCVD), and 2.39 for congenital heart disease (CHD). Age-standardized mortality rates were higher in the radiation-exposed population, with the highest excess risk recorded in 1960-1964 (RR = 5.31; 95% CI 4.32-6.53). The number of YLL from acute myocardial infarction (AMI) was 6097.0 in the exposed group versus 5893.0 in the comparison group, 3857.5 from hemorrhagic stroke versus 1996.9, and 2696.6 from CHD versus 957.7. An increase in radiation dose by 1 cSv was associated with an 8.5% increase in the odds of death from CVDs (OR = 1.085; 95% CI 1.075-1.094; p < 0.001). Radiation dose demonstrated good predictive ability for mortality from cardiovascular diseases (AUC = 0.700). Conclusions: The results indicate an increased risk of CVD mortality among residents of radiation-contaminated areas of Kazakhstan throughout the study period.