Somatic Symptoms Are Associated With Elevated Blood Pressure and Epstein-Barr Virus Antibodies Among Shuar of the Ecuadorian Amazon.

Introduction: This study tests the hypothesis that self-reported somatic symptoms are associated with biomarkers of stress, including elevated blood pressure and suppressed immune function, among Shuar adults living in the Ecuadorian Amazon.

Methods: Research was conducted in three Shuar communities in the Upano Valley of the Ecuadorian Amazon and included the collection of biomarkers and a structured morbidity interview. Participants self-reported somatic symptoms such as headaches, body pain, fatigue, and other bodily symptoms. We examined whether the number of somatic symptoms reported was associated with measures of immune (Epstein-Barr virus [EBV] antibodies) and cardiovascular (blood pressure) functioning in 97 Shuar adults (37 women, 60 men; ages 18-65 years). Multivariate linear regression analyses were used to examine the relationships among somatic symptoms and stress biomarkers, controlling for age, sex, body mass index (BMI), active infection, level of education, and income.

Results: Controlling for relevant covariates, Shuar adults reporting the highest level of somatic symptoms (three symptoms) were more likely to exhibit elevated systolic (β = 0.20, p = 0.04) and diastolic blood pressure (β = 0.23, p = 0.03), in comparison to adults reporting no symptoms. Shuar adults reporting two symptoms, compared to no symptoms, were more likely to exhibit elevated EBV antibody concentrations (β = 0.34, p = < 0.01).

Conclusions: These preliminary findings demonstrate that somatic symptoms reported by Shuar men and women are associated with physiological measures widely associated with chronic psychosocial stress. These findings complement the cross-cultural literature in medical anthropology documenting the close connection between the expression of somatic symptoms and stressful life circumstances and highlight the important role that human biologists can play in exploring biocultural phenomena.