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 frequency-matched controls without SLE; to define factors associated with RHTN in SLE patients.

Methods In this retrospective cohort study, 1,044 SLE patients and 5,241 control subjects were analyzed via de-identified electronic health records at a tertiary care center. SLE was defined as $\gt 4$ ICD codes for SLE and ANA $\gt 1:160$. RHTN was defined as uncontrolled blood pressure on 3 anti-hypertensives or requiring $\gt 4$ to attain control. We used logistic regression and Cox proportional hazards models to compare risk of RHTN between groups. In an exploratory analysis, risk of mortality was assessed in patients with SLE.

Results The prevalence of RHTN was higher in patients with SLE than in control subjects ($10.2\%$ and $5.3\%$, respectively), with an incidence rate of 14.7 versus 7.4 cases/1,000 person-years of observation [$\mathrm{Hazard\ Ratio\ (HR)} = 1.50$, $\mathrm{95\%\ C.I.\ (confidence\ interval):\ } 1.12–2.00$, $p=0.006$, adjusted for age, sex, race, end-stage renal disease, creatinine, year]. In patients with SLE, RHTN was associated with black race, lower renal function, hypercholesterolemia, increased inflammatory markers. It was also associated with a significantly higher mortality risk ($\mathrm{HR:\ } 3.89$, $\mathrm{CI:\ } 2.32–6.54$, $p\lt0.0001$).

Conclusions Patients with SLE have a higher risk of RHTN compared to frequency-matched controls independent of age, sex, race, and end-stage renal disease. RHTN is an important comorbidity for clinicians to recognize in SLE, as it is associated with a 3.9-fold higher risk of mortality.