Effect of substance use on premature mortality among severely hypertensive African Americans

Low-income African Americans residing in impoverished neighborhoods confront myriad barriers to adhering to antihypertensive regimens. Substance use may thwart medication adherence and lifestyle modification efforts, which has implications for excess cardiovascular disease mortality. The Inner-City Hypertension and Body Organ Damage (ICHABOD) Study was a longitudinal cohort study that evaluated causes of mortality among African Americans who lived in urban areas, had severe, poorly controlled hypertension, and were admitted to a local hospital between 1999-2001 and 2002-2004. The authors employed Cox proportional hazards models to assess mortality associated with illicit substance use, including use of heroin and cocaine, as well as by use of tobacco and alcohol. Among192 participants with poorly controlled hypertension, 30% were active illicit substance users (specifically, 22.7% heroin users, 19.8% were cocaine users, and 30.7% were both cocaine and heroin users). The mean age among substance non-users was 52.3 years versus 48.7 years among those reporting current use. Mortality over 7.6 years of follow-up was 52.5% among substance users and 33.8% among nonusers (p-value, 0.01). After adjusting for potential confounders, the hazard ratio (HR) for cocaine use was 2.52 (95% confidence interval (CI) 1.38-4.59), while the HR for heroin use was 2.47 (95% CI 1.42-4.28) and the HR for both was 2.75 (95% CI 1.60-4.73). Substance use was associated with increased mortality among urban black Americans with poorly controlled hypertension. These data suggest the need for targeted interventions to support African Americans who have poorly controlled hypertension and use illicit substances, as a means of reducing excess mortality.