Increased Incidence of Resistant Hypertension in Patients with Systemic Lupus Erythematosus: A Retrospective Cohort Study.

OBJECTIVES: To compare the risk of resistant hypertension (RHTN) in systemic lupus erythematosus (SLE) patients and controls without SLE; to define factors associated with RHTN in SLE patients.

METHODS: We studied 1,044 SLE patients and 5,241 control subjects using de-identified electronic health records from a tertiary care center. SLE was defined as ≥ 4 ICD codes for SLE and ANA ≥ 1:160. RHTN was defined as uncontrolled blood pressure on three anti-hypertensive medications or requiring four or more anti-hypertensives to attain control. First, we compared the risk of RHTN between groups. Second, we examined the association between RHTN and all-cause mortality in patients with SLE.

RESULTS: RHTN was nearly twice as prevalent in patients with SLE compared to control subjects (10.2% and 5.3%, respectively), with an incidence rate of 10.2 versus 6.1 cases/1,000 person-years of observation [Hazard Ratio (HR) = 1.72, 95% confidence interval: 1.28-2.30, p<0.001, adjusted for age, sex, race, baseline end-stage renal disease (ESRD), creatinine, and calendar year]. In patients with SLE, we found associations between RHTN and black race, lower renal function, hypercholesterolemia, and increased inflammatory markers. RHTN was associated with a significantly higher mortality risk (HR: 2.91, p=0.0005) after adjustment for age, sex, race, calendar year, creatinine, baseline ESRD, and number of visits.

CONCLUSIONS: Patients with SLE have a higher risk of RHTN compared to frequency-matched controls, independent of multiple covariates. RHTN is an important comorbidity for clinicians to recognize in SLE, as it is associated with a higher risk of mortality. This article is protected by copyright. All rights reserved.