Housing Instability and Incident Hypertension in the CARDIA Cohort

Abstract

Housing instability, a growing public health problem, may be an independent environmental risk factor for hypertension, but limited prospective data exist. We sought to determine the independent association of housing instability in early adulthood (year 5, 1990-1991) and incident hypertension over the subsequent 15 years of follow-up (years 7, 10, 15, and 20) in the Coronary Artery Risk Development in Young Adults (CARDIA) study (N=5,115). Because causes of inadequate housing and its effects on health are thought to vary by race and sex, we hypothesized that housing instability would exert a differential effect on incident hypertension by race and sex. At year 5, all CARDIA participants were asked about housing and those free of hypertension were analyzed (N=4,342). We defined housing instability as living in overcrowded housing, moving frequently, or living doubled up. Of the 4,342 participants, 8.5 % were living in unstable housing. Across all participants, housing instability was not associated with incident hypertension (incidence rate ratio (IRR), 1.1; 95 % CI, 0.9-1.5) after adjusting for demographics, socioeconomic status, substance use, social factors, body mass index, and study site. However, the association varied by race and sex (p value for interaction, G0.001). Unstably housed white women had a hypertension incidence rate 4.7 times (IRR, 4.7; 95 % CI, 2.4-9.2) that of stably housed white women in adjusted analysis. There was no association among white men, black women, or black men. These findings suggest that housing instability may be a more important risk factor among white women, and may act independently or as a marker for other psychosocial stressors (e.g., stress from intimate partner violence) leading to development of hypertension. Studies that examine the role of these psychosocial stressors in development of hypertension risk among unstably housed white women are needed.

Household crowding is associated with higher allostatic load among the Inuit

“…Chronic stress was measured using the AL framework applied for the first time to a representative sample of Inuit. Previous studies reported that living in overcrowded dwellings is associated with increased blood pressure,11 12 cardiovascular reactivity,10 and with increased AL13 14 among younger age groups. Extending upon these findings, we observed positive associations between household size and overcrowding and AL among Inuit adults.…”

“…An American study found that the association between more people per room and poor health leading to school absence among six-grade boys was mediated by cardiovascular reactivity sensitive to stressful circumstances 10. Household crowding was associated with increased blood pressure among boys from India11 and with the incidence of hypertension among Caucasian women in the USA 12. Work by Evans et al has demonstrated that as early as age 9, increased stress is associated with a cumulative risk model that combines factors like household crowding, noise, violence and single parenthood into an index representing early adversity 13.…”

Psychosocial Risk Factors for Hypertension: an Update of the Literature

“…[36, 37, 39–45, 48, 51–54] Seven studies used a combination of assessments (i.e., BP measurement, ICD codes, patient report of taking an antihypertensive medication)[37–41, 48, 51] while three studies solely used patient self-report of a HTN diagnosis. [46, 50, 55] Six categories of psychosocial stressors were examined across the 21 studies: six studies examined the effects of mental health (i.e., depression, anxiety, PTSD);[37, 41, 42, 44, 54, 55] two examined personality factors;[48, 50] three examined social support/isolation;[36, 43, 53] six examined occupational stress;[45–47, 49, 52, 56] one examined housing instability;[51] and three examined the role of sleep quality. [38–40] The definition of psychosocial stressors within each category varied widely, with only two studies using the same assessment tool (i.e., CES-D to assess depression).…”

“…[51] Housing instability was assessed as the frequency of moving, house crowding, and currently occupying a residence without paying rent or money among young men and women (ages 18–30 years) participating in the CARDIA study. After adjusting for confounding variables, there was no difference in incidence rate of HTN among those in stable housing as compared to unstable house situations in the overall study population (Incidence rate ratio (IRR): 1.1, 95CI: 2.4–9.2).…”

“…After adjusting for confounding variables, there was no difference in incidence rate of HTN among those in stable housing as compared to unstable house situations in the overall study population (Incidence rate ratio (IRR): 1.1, 95CI: 2.4–9.2). [51] However, there were significant variations by participant race and gender. White women with unstable housing had four times the rate of incident HTN than white women with stable housing (IRR: 4.7, 95CI:2.4–9.2).…”