Epidemiology of stroke and transient ischemic attacks in the population of the territories adjacent to the former Semipalatinsk Nuclear Test Site, Kazakhstan

The issue of radiation exposure as a potential cause of cerebrovascular disease raises many concerns. The aim of the present study was to investigate the epidemiology of stroke and transient ischemic attacks (TIA) along with the associated risk factors among the population of East Kazakhstan exposed to ionising radiation from the former Semipalatinsk Nuclear Test Site (SNTS) in comparison with the unexposed population of the same region. This 5-year retrospective cross-sectional study included the data on 10,970 patients, of whom the majority (62.3%) suffered from ischemic stroke, 11.7% had hemorrhagic stroke and the remaining 26.0% had TIA. At the moment when stroke/TIA happened, exposed patients were younger than the unexposed (mean age 63 years versus 64 years, p < 0.001) and showed higher rates of nearly all associated comorbidities, which commonly were more severe. Besides, exposed patients showed a higher risk of stroke lethality in contrast with the unexposed. The observed features might indicate that people residing in the vicinity of the SNTS are vulnerable to cerebrovascular disease and thus, this study contributes to timely recognition of this public health problem. In addition, a longitudinal study has to be envisaged to clarify whether there is any cause-effect relationship between exposure to radiation from the SNTS and the development of stroke or transient ischemic attacks.