Coronary atherosclerosis in indigenous South American Tsimane: a cross-sectional cohort study.
Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden.



We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with non-contrast CT in Tsimane adults. We assessed the difference between the Tsimane and 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). CAC scores higher than 100 were considered representative of significant atherosclerotic disease. Tsimane blood lipid and inflammatory biomarkers were obtained at the time of scanning, and in some patients, longitudinally.



Between July 2, 2014, and Sept 10, 2015, 705 individuals, who had data available for analysis, were included in this study. 596 (85%) of 705 Tsimane had no CAC, 89 (13%) had CAC scores of 1-100, and 20 (3%) had CAC scores higher than 100. For individuals older than age 75 years, 31 (65%) Tsimane presented with a CAC score of 0, and only four (8%) had CAC scores of 100 or more, a five-fold lower prevalence than industrialised populations (p≤0·0001 for all age categories of MESA). Mean LDL and HDL cholesterol concentrations were 2·35 mmol/L (91 mg/dL) and 1·0 mmol/L (39·5 mg/dL), respectively; obesity, hypertension, high blood sugar, and regular cigarette smoking were rare. High-sensitivity C-reactive protein was elevated beyond the clinical cutoff of 3·0 mg/dL in 360 (51%) Tsimane participants.



Despite a high infectious inflammatory burden, the Tsimane, a forager-horticulturalist population of the Bolivian Amazon with few coronary artery disease risk factors, have the lowest reported levels of coronary artery disease of any population recorded to date. These findings suggest that coronary atherosclerosis can be avoided in most people by achieving a lifetime with very low LDL, low blood pressure, low glucose, normal body-mass index, no smoking, and plenty of physical activity. The relative contributions of each are still to be determined.



National Institute on Aging, National Institutes of Health; St Luke's Hospital of Kansas City; and Paleocardiology Foundation.
Department of Anthropology, University of New Mexico, Albuquerque, NM, USA. Electronic address: hkaplan@unm.edu.
Hillard
H
Kaplan
Saint Luke's Mid America Heart Institute, University of Missouri-Kansas City, Kansas City, MO, USA.
Randall C
RC
Thompson
School of Human Evolution and Social Change, and Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA.
Benjamin C
BC
Trumble
Ascension Healthcare, Milwaukee, WI, USA.
L Samuel
LS
Wann
Al Azhar University, Cairo, Egypt.
Adel H
AH
Allam
Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Bret
B
Beheim
National Museum of Natural History, Smithsonian Institution, Washington, DC, USA; Dartmouth College, Hanover, NH, USA.
Bruno
B
Frohlich
Newport Diagnostic Center, Newport Beach, CA, USA.
M Linda
ML
Sutherland
South Coast Radiological Medical Group, Laguna Hills, CA, USA.
James D
JD
Sutherland
Institute for Advanced Study in Toulouse, Toulouse, France; Department of Anthropology, University of New Mexico, Albuquerque, NM, USA.
Jonathan
J
Stieglitz
Department of Medicine, Universidad de San Simón, Cochabamba, Bolivia.
Daniel Eid
DE
Rodriguez
University of California, Irvine School of Medicine, Irvine, CA, USA; Miller Women's and Children's Hospital Long Beach, CA, USA.
David E
DE
Michalik
Renown Institute for Heart and Vascular Health, Reno, NV, USA; University of Nevada, Reno, NV, USA.
Chris J
CJ
Rowan
Laboratorio de Paleopatologia, Catedra Pedro Weiss, Universidad Peruana Cayetano Heredia, Lima, Peru.
Guido P
GP
Lombardi
Department of Bioengineering, University of Washington, Seattle WA, USA.
Ram
R
Bedi
Department of Anthropology University of California Santa Barbara, Santa Barbara, CA, USA.
Angela R
AR
Garcia
Weill Cornell Medical College and the NewYork-Presbyterian Hospital, NY, USA.
James K
JK
Min
Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Jagat
J
Narula
University of Southern California Leonard Davis School of Gerontology, Los Angeles, CA, USA; Dornsife College, University of Southern California, Los Angeles, CA, USA.
Caleb E
CE
Finch
Department of Anthropology University of California Santa Barbara, Santa Barbara, CA, USA; Long Beach Memorial, Long Beach, CA, USA.
Michael
M
Gurven
University of California Irvine, Orange, CA, USA.
Gregory S
GS
Thomas
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry / Q000379:methods; D050197:Atherosclerosis / Q000097:blood / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000209:etiology; D001838:Bolivia / Q000453:epidemiology; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000208:ethnology* / Q000209:etiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D008019:Life Style; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed
D018836:Inflammation Mediators; D008055:Lipids