Arterial stiffness, not systolic blood pressure, increases with age in native Papuan populations

Systolic blood pressure (SBP) and arterial stiffness are closely related and may behave reciprocally as cause or effect, interacting in a vicious cycle. Both SBP and arterial stiffness increase with age in populations in most developed countries. However, the age-related increase in SBP appears to be absent in indigenous populations, partially because of their lifelong low-sodium and high-potassium diets, whereas age-related arterial stiffening in these populations remains to be determined. We performed a field survey of the indigenous population of Soroba, a small village located in the central highlands of Papua, Indonesia. Blood pressure levels and brachial-ankle pulse wave velocity (baPWV) were measured using an automatic device. A total of 125 native Papuans 16-75 years of age (59% women) were included in this study. SBP and pulse pressure were not correlated with age. However, diastolic and mean arterial pressure levels increased with age. The prevalence of hypertension was 5% (n = 6; all women), and baPWV significantly increased with age. Compared with participants 45 years of age and older, those younger than 45 years had a higher body mass index (BMI) and spot urine sodium-to-potassium ratio but lower baPWV; however, SBP was not different between these age groups. Multivariate linear regression analysis revealed that SBP was independently associated with baPWV, sex and BMI but not with age; baPWV was independently associated with SBP, age, BMI, sex and heart rate. SBP and baPWV were closely related, but the age-related changes in these measurements differed in this highland Papuan population.