Anger expression and lifestyle incongruity interactions on blood pressure in Samoan adults

Abstract

Prior research on psychosocial stress and blood pressure (BP) in adult Samoans identified the separate influences of lifestyle incongruity and anger expression within the context of societal modernization. The objective of this cross-sectional study was to determine the interactions between lifestyle incongruity and anger expression on BP in 376 men and women 25-65 years of age from Samoa. Participants were randomly selected from nine villages. Body mass index (BMI) and BP were measured by standard techniques. Anger expression was measured with an adapted version of the Spielberger Inventory. Material lifestyle was assessed by inventory of household items, exposure to news media, and off-island travel. Occupation and education lifestyle incongruities were calculated by subtracting the standardized lifestyle scale from the standardized occupation and education scales, respectively. Two-factor analysis of variance models with interactions were estimated within specific subgroups, with age- and BMI-adjusted BP as outcomes. In women <40 years of age with a material lifestyle relatively lower than their educational rank, anger suppression is associated with higher adjusted systolic BP. In young men whose material lifestyle is relatively lower than their occupational rank, those who report frequent experiences of Samoan culture-specific anger feelings have higher adjusted diastolic BP. We hypothesize that among young women, the higher BP may be due to stress arising from both a normative proscription against emotional expression, and a mismatch between their relatively higher educational level and lower material lifestyle. For young men, higher BP levels may be attributed to expected donations of earnings to the extended family that exceed their own material lifestyle, in combination with more frequent Samoan-specific feelings of anger.