Sex differences in the association of childhood socioeconomic status with adult blood pressure change: the CARDIA study

Abstract

Objective: To examine sex differences in the relation of childhood socioeconomic status (CSES) to systolic (SBP) and diastolic blood pressure (DBP) trajectories during 15 years, spanning young (mean [M] [standard deviation {SD}] = 30 [3] years) and middle (M [SD] = 45 [3] years) adulthood, independent of adult SES.

Methods: A total of 4077 adult participants reported father's and mother's educational attainments at study enrollment (Year 0) and own educational attainment at enrollment and at all follow-up examinations. Resting BP also was measured at all examinations. Data from examination Years 5 (when participant M [SD] age = 30 [3] years), 7, 10, 15, and 20 are examined here. Associations of own adult (Year 5), mother's, and father's educations with 15-year BP trajectories were examined in separate multilevel models. Fully controlled models included time-invariant covariates (age, sex, race, recruitment center) and time-varying covariates that were measured at each examination (marital status, body mass, cholesterol, oral contraceptives/hormones, and antihypertensive drugs). Analyses of parental education controlled for own education.

Results: When examined without covariates, higher education - own (SBP γ = -0.03, DBP γ = -0.03), mother's (SBP γ = -0.02, DBP γ = -0.02), and father's (SBP γ = -0.02, DBP γ = -0.01) - were associated with attenuated 15-year increases in BP (p < .001). Associations of own (but not either parent's) education with BP trajectories remained independent of standard controls. Sex moderated the apparent null effects of parental education, such that higher parental education-especially mother's, predicted attenuated BP trajectories independent of standard covariates among women (SBP γ = -0.02, p = .02; DBP γ = -0.01, p = .04) but not men (SBP γ = 0.02, p = .06; DBP γ = 0.005, p = .47; p interaction SBP < .001, p interaction DBP = .01).

Conclusions: Childhood socioeconomic status may influence women's health independent of their own adult status.

Figure 1

Modifying effect of sex on the association of mother’s education with 15-year change in adult SBP. Data points represent predicted SBP values obtained from Model 3 (with addition of the sex-X-mother’s education and sex-X-mother’s education-X-time interaction terms) by CARDIA exam year. Filled squares represent men and open circles represent women.

Figure 2

Modifying effect of sex on the association of mother’s education with 15-year change in adult DBP. Data points represent predicted DBP values obtained from Model 3 (with addition of the sex-X-mother’s education and sex-X-mother’s education-X-time interaction terms) by CARDIA exam year. Filled squares represent men and open circles represent women.