Arterial Stiffness in Heart-Healthy Indigenous Tsimane Forager-Horticulturalists.

Abstract

BACKGROUND: Little is known about arterial stiffness in rural subsistence populations that experience few cardiovascular risk factors. We conducted a cross-sectional study comparing 3 arterial stiffness metrics among Tsimane forager-horticulturalists with 2 representative US cohorts. METHODS: Arterial elasticity (the inverse of stiffness) markers C1 (large artery elasticity) and C2 (small artery elasticity) were measured using a tonometry device among 490 Tsimane adults (mean age, 51.2±10.1 years; 55% women), and compared with 6294 multiethnic US adults (mean age, 62.0±10.2 years; 52% women) from MESA (Multi-Ethnic Study of Atherosclerosis). Carotid-femoral pulse wave velocity was assessed using the foot-to-foot method in a smaller Tsimane sample (n=94) and compared with 3086 predominantly White US adults (mean age, 46.1±8.7 years; 54% women) from the FHS Gen3 (Framingham Heart Study Third Generation). RESULTS: Tsimane participants exhibited superior arterial health compared with US cohorts, with higher elasticity (C1/C2) and lower stiffness (carotid-femoral pulse wave velocity). Their C1 (mean 22.8±12.2 mL/mm Hg×10) and C2 (mean 7.5±4.0 mL/mm Hg×100) were 47.3% and 35.7% higher than MESA participants by age 40 years, respectively, and differences remained sustained throughout adulthood. Compared with participants in FHS Gen3, the carotid-femoral pulse wave velocity in Tsimane participants (mean 6.2±1.2 m/s) was 33.9% lower and showed a minimal age-related increase, with carotid-femoral pulse wave velocity only higher by age 70+ (β=1.74±0.38; reference <40 years). Tsimane participants with ≥2 comorbidities (hypertension, obesity, and diabetes) had ≈25% higher arterial elasticity than healthy Americans with no comorbidities. CONCLUSIONS: Tsimane forager-farmers of the Bolivian Amazon demonstrate substantially lower arterial stiffness throughout adulthood than more urbanized and sedentary populations, and the differences are only partially explained by conventional cardiometabolic risk factors.