Rheumatologists should not be falsely reassured by a normal mean blood pressure in lupus patients, according to a study from Johns Hopkins University that found age-related blood pressure patterns in systemic lupus erythematosus (SLE) differ from the general population and that increased diastolic blood pressure variability (BPV) is highly associated with cardiovascular events in SLE.1
“Patients with a high blood pressure variability should be more carefully assessed in order to minimize all potential secondary factors that might be driving [variability], like prednisone use, and to optimize blood pressure control in the long run,” says lead author of the study, George Stojan, MD, assistant professor of medicine in the Division of Rheumatology at the Johns Hopkins University School of Medicine, Baltimore, and co-director of the Johns Hopkins Lupus Center.
As a rheumatology fellow, when Dr. Stojan began seeing patients in the Hopkins Lupus Center, he was struck by the high BPV he saw in patients from visit to visit. He was aware of articles in The Lancet, by neurologist Peter Rothwell, that established blood pressure variability as an independent cardiovascular risk factor in patients with stroke, and
became interested in assessing the importance of this finding in patients with SLE. Increased atherosclerosis continues to be a major cause of illness and death in patients with lupus and other autoimmune diseases.2
“Accelerated atherosclerosis and its long-term sequelae are a major cause of late mortality among patients with systemic lupus erythematosus,” says Dr. Stojan. “The importance of mean blood pressure as a cardiovascular risk factor in this population has been well described.”
The Study
Dr. Stojan’s study looked at BPV from visit to visit and its relationship to age, demographics and clinical characteristics, as well as its potential for use as a cardiovascular risk factor in patients with SLE. The researchers used mixed-effects regression models to analyze systolic and diastolic blood pressure measures. From the models, they obtained estimates of the mean blood pressure, the visit-to-visit standard deviation and between-person standard deviation.
The researchers used data from National Health Statistics Reports from 2001–2008 to compare the general population to the estimated patient means and also examined the relationship between blood pressure, patient demographics, clinical characteristics and subsequent cardiovascular events.
The Hopkins Lupus Cohort is a prospective cohort study of predictors of lupus flare, atherosclerosis and health status in SLE. Ninety-five percent of patients in this cohort fulfilled four or more of the ACR’s 1982 revised classification criteria for SLE and the SLICC classification criteria for SLE.3-6 The patients were followed quarterly, or more if clinically needed, and patient data (including laboratory testing, clinical features and damage accrual) were recorded at the time of entry into the cohort and updated at each visit.