The Indigenous South American Tsimane Exhibit Relatively Modest Decrease in Brain Volume With Age Despite High Systemic Inflammation
Year: 2021
Type: article
Study design: Observational Study
Abstract: Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infections and therefore inflammation. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane and (b) compares this association to that of 3 industrialized populations in the United States and Europe. This cohort-based panel study enrolled 746 participants aged 40-94 (396 males), from whom computed tomography (CT) head scans were acquired. BV and intracranial volume (ICV) were calculated from automatic head CT segmentations. The linear regression coefficient estimate β^T of the Tsimane (T), describing the relationship between age (predictor) and BV (response, as a percentage of ICV), was calculated for the pooled sample (including both sexes) and for each sex. β^T was compared to the corresponding regression coefficient estimate β^R of samples from the industrialized reference (R) countries. For all comparisons, the null hypothesis β T = β R was rejected both for the combined samples of males and females, as well as separately for each sex. Our results indicate that the Tsimane exhibit a significantly slower decrease in BV with age than populations in the United States and Europe. Such reduced rates of BV decrease, together with a subsistence lifestyle and low CVD risk, may protect brain health despite considerable chronic inflammation related to infectious burden.
Authors: Andrei Irimia, Nikhil N Chaudhari, David J Robles, Kenneth A Rostowsky, Alexander S Maher, Nahian F Chowdhury, Maria Calvillo, Van Ngo, Margaret Gatz, Wendy J Mack, E Meng Law, M Linda Sutherland, James D Sutherland, Christopher J Rowan, L Samuel Wann, Adel H Allam, Randall C Thompson, David E Michalik, Daniel K Cummings, Edmond Seabright, Sarah Alami, Angela R Garcia, Paul L Hooper, Jonathan Stieglitz, Benjamin C Trumble, Michael D Gurven, Gregory S Thomas, Caleb E Finch, Hillard Kaplan
Institutions: University of Southern California, The Alfred Hospital, Alfred Health, Monash University, MemorialCare Health System, University of Nevada, Reno, Renown Health, Ascension, Al-Azhar University, University of Missouri–Kansas City, University of California, Irvine, MemorialCare Long Beach Medical Center, Long Beach Medical Center, Miller Children's & Women's Hospital, University of New Mexico, Chapman University, University of California, Santa Barbara, Arizona State University, Université Toulouse-I-Capitole, Institute for Advanced Study in Toulouse
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3165669339