Abstract 020: Age-Associated Rise in Arterial Stiffness Among Hunter-Gatherers

Introduction: Elevated blood pressure (BP) and arterial stiffness increase cardiovascular disease risk. While BP and arterial stiffness both increase with age in most westernized populations, BP does not rise with age in isolated hunter-gatherers, including Yanomami, where vascular disease is uncommon. No studies have examined if arterial stiffness rises with age among Yanomami or the geographically collocated Yekwana. Methods: In a pilot study conducted in February 2016, we sampled participants from 5 isolated Yanomami-Sanema villages and 3 Yekwana villages in the Upper Caura River Basin, a remote area of the Venezuelan Amazon. Trained staff measured cardio-ankle vascular index (CAVI) per standard protocols, and height and weight to determine body mass index (BMI). We used ANCOVA to compare the age-CAVI association between Yanomami and Yekwana, and further compared associations with data from US whites and Japanese female volunteers for physiological studies with CAVI measurement. Results: 80 participants (63 Yekwana; 17 Yanomami) age 11-72 years had data on CAVI. A 5-year increment in age was associated with a 0.24 unit (95% CI: 0.17, 0.31) and a 0.25 unit (95% CI: 0.14, 0.35) increase in CAVI in Yekwana and Yanomami, respectively (Figure). The age-CAVI slope did not differ in these two populations (p=0.95). Compared to Yanomami and Yekwana individuals, a 5-year increment in age was associated with a significantly greater increase in CAVI in US whites (0.12, 95% CI: 0.04, 0.20) and a non-significantly greater increase in Japanese females (0.08, 95% CI: -0.02, 0.18). Estimates did not markedly change after adjusting for BMI. Conclusion: In Yekwana and Yanomami individuals with hunter-gatherer lifestyles, arterial stiffness increased with age, in a manner similar to Japanese females but less steep than US whites. Taken together with our previous finding that BP does not rise with age in Yanomami and minimally in Yekwana, our preliminary findings suggest that rise in arterial stiffness with age might be independent of BP.