Five year hypertension incidence in African Americans: the contribution of socioeconomic status, perceived stress, and John Henryism.

The two-fold objectives of this study were to determine if hypertension incidence (HI) was greatest for low socioeconomic status (SES) individuals; and, if so, test the hypothesis that the elevated risk is explained by the joint contribution of perceived stress (PS) and John Henryism (JH) i.e. high effort coping with stress. In 1993, blood pressure (BP) was remeasured in a community based cohort of African Americans free of HI in 1988. Covariates in sex-specific regression models included weight change and baseline BP, age, weight, height, waist:hip ratio, exercise, and alcohol consumption. Primary predictors included SES, baseline PS and JH (and their interaction) and changes in PS and JH (and their interaction). Participants included 1,407 (507 men, 900 women) African Americans in Pitt County, NC, ages 25-50 in 1988. All had untreated, mean DBP < 95 mmHg at baseline. 415 men (82%) and 780 women (87%) were reexamined. Analyses were restricted to the 327 men and 674 women with baseline BP < mmHg. HI was defined by BP ≥ , or treated, in 1993. Baseline SES was not associated with HI; nor were baseline PS and JH. PS change, however, predicted HI and, for men, significant interactions between PS change and JH change were observed. When HI for men with zero PS change (the referent) was compared to men with −2, −1, +1, and +2 sd unit PS changes, the RRʹs and 95% CIʹs were, respectively: 0.39 (0.16, 0.94), 0.63 (0.40, 0.97), 1.60 (1.03, 2.47), and 2.55 (1.06, 6.12). A +2 sd unit increase in JH magnified 4 fold (RR=10.63, 95% CI=1.43, 78.84) the effects of a +2 sd unit increase in PS. For women, RRʹs for PS change also followed a dose response pattern, but none was statistically significant and no interactions with increased JH were observed. When mean change in BP was the outcome, the findings paralleled those for HI for both sexes. We conclude that low SES was not associated with HI in this African American cohort; however, adverse changes in PS was an important risk factor; and for men, increased JH strongly potentiated the PS change effects.