Browsing by Autor "M. Linda Sutherland"

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Brain volume, energy balance, and cardiovascular health in two nonindustrial South American populations
(National Academy of Sciences, 2023) Hillard Kaplan; Paul L. Hooper; Margaret Gatz; Wendy J. Mack; Emma Law; Helena C. Chui; M. Linda Sutherland; James D. Sutherland; Christopher J. Rowan; L. Samüel Wann
Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-income nations. With a sample of 1,165 individuals aged 40 to 94, we analyze population differences in cross-sectional rates of decline in BV with age. We also assess the relationships of BV with energy biomarkers and arterial disease and compare them against findings in industrialized contexts. The analyses test three hypotheses derived from an evolutionary model of brain health, which we call the embarrassment of riches (EOR). The model hypothesizes that food energy was positively associated with late life BV in the physically active, food-limited past, but excess body mass and adiposity are now associated with reduced BV in industrialized societies in middle and older ages. We find that the relationship of BV with both non-HDL cholesterol and body mass index is curvilinear, positive from the lowest values to 1.4 to 1.6 SDs above the mean, and negative from that value to the highest values. The more acculturated Moseten exhibit a steeper decrease in BV with age than Tsimane, but still shallower than US and European populations. Lastly, aortic arteriosclerosis is associated with lower BV. Complemented by findings from the United States and Europe, our results are consistent with the EOR model, with implications for interventions to improve brain health.
Coronary atherosclerosis in indigenous South American Tsimane: a cross-sectional cohort study
(Elsevier BV, 2017) Hillard Kaplan; Randall C. Thompson; Benjamin C. Trumble; L. Samüel Wann; Adel H. Allam; Bret Beheim; Bruno Frøhlich; M. Linda Sutherland; James D. Sutherland; Jonathan Stieglitz
High Prevalence of Cerebrovascular Calcifications and Clinical Correlates in Indigenous Bolivian Forager‐Horticulturalists: A Population‐Based Observational Study
(Wiley, 2026) Giuseppe Barisano; Bavrina Bigjahan; Grant D. Schleifer; Maria Ashna; Wendy J. Mack; M. Linda Sutherland; James D. Sutherland; Chui Hc; Meng Law; Thomas Fischbach
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.
Increases in regional brain volume across two native South American male populations
(Springer International Publishing, 2024) Nikhil N. Chaudhari; Phoebe Imms; Nahian F. Chowdhury; Margaret Gatz; Benjamin C. Trumble; Wendy J. Mack; Emma Law; M. Linda Sutherland; James D. Sutherland; Christopher J. Rowan
P2‐108: USING COMPUTED TOMOGRAPHY TO ASSESS BRAIN VOLUMETRICS IN AGING
(Wiley, 2019) Andrei Irimia; Hillard Kaplan; Ben C. Trumble; Juan J. Copajira Adrian; Alexander S. Maher; Kenneth A. Rostowsky; Nahian F. Chowdhury; M. Linda Sutherland; James D. Sutherland; Adel H. Allam
Although magnetic resonance imaging (MRI) remains the gold standard for the noninvasive evaluation of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) volumes in the aging brain, CT continues to be used widely for brain imaging, particularly when MRI is unavailable or contraindicated. In developing countries, CT is often the only imaging modality available for evaluation of brain atrophy in patients with mild cognitive impairment (MCI) or Alzheimer's disease (AD). This has renewed interest in the development of approaches to use head CT to estimate brain volumetrics. A brain segmentation approach was developed to delineate WM, GM and CSF from head CT using probabilistic, atlas-based classification. Feasibility and utility were evaluated by comparing MRI-only to CT-only segmentations in 10 older adults [mean (μ) ± standard deviation (σ) of age = 65 ± 7 yrs; 5 females] from whom both MRI and CT scans were acquired within an eight-week period. Segmentation similarity was quantified using the Dice coefficient (DC), a robust measure of inter-modality tissue classification agreement. Comparison of MRI vs. CT segmentations yielded normally-distributed DCs [μ ± σ across participants: 85.5% ± 4.6% (WM), 86.7% ± 5.6% (GM) and 91.3% ± 2.8% (CSF)], indicating satisfactory ability to calculate brain volumetrics from the CT scans of the participants, relative to MRI measurements. For this sample, bootstrapping suggests that the tissue classification method is sufficiently sensitive to estimate WM, GM and CSF volumes within ∼5%, ∼4% and ∼3% of their MRI-based values, respectively. Compared to MRI, volumes computed from CT displayed no evidence of systematic over- or under-estimation [t (9) = 0.89, p > 0.80]. Our contribution broadens the ability to integrate CT imaging findings with other research on brain aging in health and disease, and complements other methodologies for the study of brain volumetrics in neurodegenerative diseases, including AD.
P3‐134: APOE GENOTYPE AND COGNITIVE PERFORMANCE IN TSIMANE AND MOSETEN OF BOLIVIA
(Wiley, 2019) Margaret Gatz; Hillard Kaplan; Ben C. Trumble; Randall C. Thompson; Juan J. Copajira Adrian; M. Linda Sutherland; James D. Sutherland; Helena C. Chui; Daniel Eid Rodriguez; Raúl Quispe Gutierrez
The ε4 allele of the apolipoprotein gene (APOE) is an established risk factor for Alzheimer's disease (AD), with evidence predominantly from Caucasian populations. Results are mixed whether non-demented older adult ε4 carriers perform more poorly on cognitive tests. Some evidence indicates that APOE influences AD risk through episodic memory. We therefore hypothesized ε4 carriers would show lower episodic memory scores. Participants were indigenous lowland Bolivians practicing subsistence level horticulture (469 Tsimane; 86 Moseten) aged ≥55 (mean 66, range 55-96), with data from both cognitive testing and APOE genotyping from PCR. Culturally/linguistically adapted cognitive tests included episodic memory, digit span forward, semantic fluency, visual scan, and visuoconstructional ability. Episodic memory included immediate memory (average of 3 learning trials for an 8-word list), and delayed recall assessed after 10 minutes. General linear modelling evaluated whether memory scores were associated with carrying the ε4 allele. Distribution of APOE genotypes was not significantly different between Tsimane and Moseten populations: unadjusted 21% ε3/ε4 heterozygotes; 1% ε4/ε4 homozygotes. Controlling for population, age, gender, and education, there was a significant effect for delayed recall: those carrying an ε4 allele scored significantly lower, b = −0.705, SE = 0.203, p = .0006, ηP2 = 0.024. Neither immediate memory nor any other cognitive test showed a significant ε4 effect. There were no significant interactions between APOE and population, age, gender, or education. Within each population, controlling for age, gender, and education, the ε4 main effect was significant on delayed recall for both Tsimane, b = −0.527, SE = 0.212, p = .0131, ηP2 = 0.0132, and Moseten, b = −0.935, SE = 0.427, p = .0316, ηP2 = 0.0558, with a trend for Moseten on immediate memory, b = −0.589, SE = 0.240, p = .0163, ηP2 = 0.0692.
Physical activity mediates age differences in cognition among Tsimane forager-horticulturalists
(Oxford University Press, 2025) Phoebe Imms; Nikhil N. Chaudhari; Daniel K. Cummings; Daniel Eid Rodríguez; Giuseppe Barisano; Paul L. Hooper; M. Katherine Sayre; Edmond Seabright; Randall C. Thompson; M. Linda Sutherland
Among Tsimane males, who are more physically active than Tsimane females, the association between age and cognition via BV is significantly mediated by physical activity. Among Tsimane females, mediation occurs directly via physical activity, bypassing BV. These results suggest that mechanisms of cognitive differences across ages differ by sex and population. Studying the relationship between brain atrophy and lifestyle in nonindustrialized populations elucidates biological and environmental correlates of brain health.
Prevalence of cerebrovascular calcifications in indigenous Bolivian Tsimane and Moseten
(Wiley, 2023) Giuseppe Barisano; M. Linda Sutherland; James D. Sutherland; Margaret Gatz; Wendy J. Mack; Helena C. Chui; Meng Law; Daniel Eid Rodríguez; Raúl Quispe Gutierrez; Andrei Irimia
Abstract Background Intracranial arteriosclerosis has been increasingly recognized as an etiological factor contributing to cognitive impairment. Indigenous Tsimane and Moseten, Amerindians of the Bolivian Amazon with physically‐active subsistence lifestyle, are reported to have lower prevalence of dementia (Gatz et al., Alzheimer’s Dement, In press) and coronary artery disease (Kaplan et al.,Lancet,2017) than Western populations. We assessed the prevalence of intracranial arteriosclerosis, cerebrovascular calcifications, and leukoaraiosis in these populations and investigated their relationship with brain atrophy and cognition. Method 155 participants aged ≥60 (60.6% females) underwent a non‐contrast computed tomography scan and cognitive testing. Visual rating scales were used to evaluate global cortical atrophy (GCA, simplified Pasquier), medial temporal atrophy (MTA, Scheltens), internal carotid artery (ICA) calcifications extent and morphology (Babiarz/Kockelkoren), lenticulostriate arteries (LSA) calcifications (de Brouwer), deep and periventricular leukoaraiosis (Fazekas). The maximum density (Hounsfield units) of LSA calcifications and the presence of infarcts and vertebral arteries (VA) calcifications were also evaluated. Result Virtually all participants presented vascular calcifications in ICA (99.3%), LSA (87.4%), and VA (98.5%) ( Fig.1,2 ). ICA calcification morphology was continuous in 58.7% and irregular/patchy in 40.5%, indicating medial and intimal pathology, respectively ( Fig.3 ). In 13.2% of cases, the LSA calcifications were surrounded by parenchymal calcifications in the basal ganglia ( Fig.4 ). Most cases showed no radiological sign of infarcts or leukoaraiosis. ICA calcifications correlated with age (P<.0001) while other calcification locations showed little association with age. LSA calcifications were greater in men than women (P<.01) with sex differences minimal for other calcification locations. After controlling for age and sex, ICA, LSA, basal ganglia and VA calcifications were related to greater GCA (all P<.05). LSA calcification density was significantly related to greater GCA and MTA, and to poorer visuo‐constructional ability (all P<.01). Prevalence of ICA and VA calcifications were higher compared to those reported in a population‐based European sample (79% and 16.9%, respectively; Vinke et al.,Neurobiol.Aging,2021). ( Fig.5 ) Conclusion Despite the low prevalence of dementia and coronary artery disease, cerebrovascular calcifications are commonly observed in this indigenous Bolivian population, and are associated with greater brain atrophy. Their underlying pathogenetic mechanisms remain unclear, but the high prevalence of infectious and inflammatory disorders might play a role.
Prevalence of dementia and mild cognitive impairment in indigenous Bolivian forager‐horticulturalists
(Wiley, 2022) Margaret Gatz; Wendy J. Mack; Helena C. Chui; Emma Law; Giuseppe Barisano; M. Linda Sutherland; James D. Sutherland; Daniel Eid Rodriguez; Raúl Quispe Gutierrez; Juan Copajira Adrian
The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer's disease (AD) dementia phenotype.
Testosterone is positively associated with coronary artery calcium in a low cardiovascular disease risk population
(University of Oxford, 2023) Benjamin C. Trumble; Jacob D. Negrey; Stephanie V. Koebele; Randall C. Thompson; L. Samüel Wann; Adel H. Allam; Bret Beheim; M. Linda Sutherland; James D. Sutherland; Daniel Eid Rodríguez
Among Tsimane, testosterone is positively associated with coronary artery calcium despite generally low normal testosterone levels, minimal atherosclerosis and rare cardiovascular disease (CVD) events. Associations between low testosterone and CVD events in industrialized populations are likely confounded by obesity and other lifestyle factors.