Abstract
Objectives: Ambulatory blood pressure monitoring measures 24-hour blood pressure, night-time blood pressure, and impaired dipping of nocturnal blood pressure, parameters that better predict cardiovascular risk than standard office blood pressure measurements. Systemic lupus erythematosus is characterized by immune system hyperactivity, elevated cardiovascular risk and high prevalence of hypertension; however, little is known about ambulatory blood pressure in lupus patients and its relationship to immune activation. Methods: We studied 26 patients with lupus and 26 control subjects. We obtained ambulatory 24-hour blood pressure measurements and report plasma concentrations of 77 markers of immune activation using a multiplex immunoassay and assessed their association with blood pressure measurements. Results: Despite similar office blood pressure measurements in patients with lupus and controls, lupus patients had higher 24-hour systolic [median (interquartile range) 129 (113 - 140) vs. 116 (111 - 121) mmHg, p = 0.03] and diastolic blood pressure [80 (69 - 86) vs. 72 (64 - 75) mmHg, p = 0.006] as well as less nocturnal dipping [7.8% (5.1 - 14.2%) vs. 12.0% (8.1 20.0%)] p = 0.03], compared to controls. In patients with lupus, markers of the innate (monocyte chemotactic protein-3) and adaptive immune systems [CUB domain-containing protein-1 and Interleukin-15 receptor subunit-α,] were associated with nocturnal blood pressure measurements and attenuated nocturnal dipping. In conclusion, 24-hour systolic and diastolic blood pressure was higher and nocturnal blood pressure dipping was attenuated in patients with lupus compared to control subjects. Conclusion: In patients with SLE, nocturnal blood pressure and attenuated nocturnal blood pressure dipping were significantly associated with several innate and adaptive immune system biomarkers.