Interarm Blood Pressure Difference in Patients With Systemic Lupus Erythematosus.

Objectives: This study was performed to determine the relationship between systemic lupus erythematosus (SLE) and the interarm blood pressure difference (IAD) and to elucidate the role of the IAD as a surrogate marker for early detection of peripheral artery disease (PAD) in patients with SLE.

Methods: In total, 135 patients with SLE and 135 age- and gender-matched subjects were enrolled. The IAD and risk of an abnormal IAD were compared between the SLE and control groups, and logistic regression analysis was performed to determine the relationship between SLE and an abnormal IAD. The specificity and sensitivity of an IAD of 10 mm Hg or greater for diagnosis of PAD (ankle brachial index of <0.90) were calculated.

Results: Both the systolic and diastolic IADs were significantly higher in the SLE group than in the control group (P < 0.001). After adjustment for confounding factors, SLE remained significantly associated with an abnormal IAD (P = 0.039). Both the systolic and diastolic IADs were negatively associated with the ankle brachial index. Using a systolic IAD of 10 mm Hg or greater as the cutoff point, the specificity and sensitivity for PAD were 90% and 41%, respectively. A diastolic IAD of 10 mm Hg or greater exhibited higher specificity (92%), but lower sensitivity (30%).

Conclusions: Systemic lupus erythematosus is independently associated with an abnormal IAD, and an IAD of 10 mm Hg or greater predicts PAD with high specificity but low sensitivity. Blood pressure should be measured at least once in both arms in patients with SLE for early detection of asymptomatic PAD.