High Prevalence of Cerebrovascular Calcifications and Clinical Correlates in Indigenous Bolivian Forager‐Horticulturalists: A Population‐Based Observational Study

BACKGROUND: Intracranial arteriosclerosis (large- and small-vessel disease) is considered a risk factor for major neurological disorders, such as stroke, cognitive impairment, and dementia. While most studies investigating intracranial arteriosclerosis include individuals from industrialized populations, the prevalence and clinical meaning of intracranial vascular calcifications in populations with a subsistence lifestyle is unknown. METHODS: In this population-based study evaluating data collected between 2017 and 2019 from Tsimane and Moseten people, 2 indigenous populations of forager-horticulturalists living in the Bolivian Amazon, we used computed tomography to determine the prevalence of vascular calcifications in the intracranial internal carotid arteries, vertebral arteries, and lenticulostriate arteries within the basal ganglia, and their association with demographic characteristics, brain atrophy, cognitive performance, and clinical factors. RESULTS: Our analysis included 1232 individuals who underwent a head computed tomography scan. Intracranial vascular calcifications were found in most individuals (>90%) and their prevalence was higher than that reported for age-equivalent industrialized populations. These calcifications were significantly associated with higher age, brain atrophy, worse cognitive performance, and parkinsonian symptoms. CONCLUSIONS: Despite the physically active subsistence lifestyle and the low rates of typical cardiovascular risk factors and coronary artery disease, intracranial vascular calcifications are common in these Bolivian Amerindian people, suggesting that alternative factors may contribute to intracranial arteriosclerosis and a novel dementia phenotype.