Socioeconomic Status, John Henryism and Hypertension Risk in Blacks

BACKGROUND:

Socioeconomic status as measured by education, income and/or occupation is generally inversely associated with hypertension-risk. John Henryism research is designed to test the psychosocial stress hypothesis that low SES Blacks who are strongly predisposed to overcome difficult life circumstances through effortful active coping might have higher blood pressure than their more relaxed neighbors and that John Henryism and anger suppression are positively correlated in Blacks.

The first two years of the project analyzed data collected on 1,548 Black and white men and women in Edgecombe County, North Carolina. The Edgecombe County data were collected in 1983 to provide data for a representative sample of households to be used in evaluating the effectiveness of a community high blood pressure control program. Approximately 50 percent of the sample was Black and 56 percent women. In the first year, measurements were made in all four race-sex groups of the effect-modifying role of John Henryism on education and on alternative measures of SES. In the second year, analyses were conducted on the degree to which job security, marriage, and socioeconomic mobility predict blood pressure in each race-sex group.

DESIGN NARRATIVE:

A survey was conducted of 2,017 Black men and women in Pitt County, North Carolina. Study variables included age, sex, marital status, socioeconomic status (SES), John Henryism (behavioral predisposition to cope actively with psychosocial environmental stressors), social support, anger-coping style, social desirability, dietary variables including sodium, potassium, calcium and alcohol, blood pressure, height, weight, and pregnancy. In the cross-sectional study, blood pressure was the continuous outcome as measured by linear regression. Three years after baseline all normotensive persons were re-examined in order to measure changes in blood pressure from baseline after exposure to selected psychosocial and dietary factors. The study provided an estimate of the degree to which John Henryism, social support, anger-coping and dietary factors modify the association between SES and blood pressure in Blacks.

The study was renewed in 1993 to re-examine the 1,429 respondents (571 men, 912 women) with untreated, mean diastolic blood pressure < 95 mmHg at baseline, and again at follow-up, on changes in blood pressure during the intervening four to five years (1988-1992/93). The social variables included socioeconomic status, John Henryism, stress, and social support; the dietary variables included alcohol, sodium, potassium, and calcium; and the anthropometric variables included body mass index (BMI) and waist/hip ratio (WHR). With an emphasis on SES, physical activity, dietary habits, and cigarette smoking, the predictors of weight gain, and changes in patterning of body fat were also examined. Multiple linear regression was the primary analytic tool used to study these longitudinal relationships. In cross-sectional analyses which controlled for physical activity and other important variables, the roles of insulin resistance in mediating associations between obesity and blood pressure, and stress and blood pressure, were also examined.