Session Information
Date: Sunday, November 5, 2017
Title: Systemic Lupus Erythematosus – Clinical Aspects and Treatment Poster I: Biomarkers and Outcomes
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose:
Ambulatory 24-hour blood pressure and nocturnal blood pressure measurements are better predictors of cardiovascular risk than office blood pressure. Patients with systemic lupus erythematosus (SLE) have a high prevalence of hypertension and cardiovascular events. Recent findings indicate that sodium stored in the skin can be measured with 23Na+ magnetic resonance imaging (MRI) and plays an important role in both blood pressure and immune regulation. Little is known about ambulatory blood pressure in SLE and its relationship to skin Na+ is not known.
Methods:
Office blood pressure was measured at study enrollment using standard procedures and ambulatory 24-hour blood pressure measurements were recorded (Meditech, Budapest, Hungary) in 23 patients with SLE and 23 controls frequency-matched for age, race, and sex. Skin Na+ content in the lower leg was measured with a 3T 23Na+ knee-coil with a magnetic resonance imaging scanner (Philips Achieva 3T) in 13 patients with SLE. Phantoms containing aqueous solutions with 10, 20, 30, and 40 mmol/L NaCl were included for calibration. Blood pressure measurements in patients and control subjects were compared using Wilcoxon-rank sum tests and adjusted for age, race, and sex using a linear regression model. Spearman correlations were used to assess the correlation between blood pressure measurements and and skin sodium in SLE patients.
Results:
Results: Office blood pressure was not significantly different in patients with SLE and controls (Table). However, ambulatory blood pressure measurements, particularly nocturnal measurements, were higher in patients with SLE. In patients with SLE (n=13), skin Na+ concentrations were 15.0 (IQR 13.3 – 18.4) mmol/L and were significantly correlated with both office (rho= 0.67, P=0.023) and mean 24-hour systolic blood pressure (rho= 0.62, P= 0.04).
|
SLE (N=23) |
Controls (N=23) |
p-value |
p-value* |
|
|
Age, years |
35 (31-52) |
35 (26-50) |
0.73 |
|
|
BMI, kg/m2 |
25.9 (22.7-33.8) |
24.3 (22.7-26.8) |
0.22 |
|
|
Sex female |
19 (82.61%) |
20 (87.0%) |
1.0 |
|
|
Race white |
15 (65.2%) |
19 (82.6%) |
0.31 |
|
|
Smoker never |
17 (73.9%) |
17 (73.9%) |
1.0 |
|
|
24 hr Mean SBP, mmHg |
128.5 (113-139.1) |
115 (110.6-121) |
0.05 |
0.04 |
|
24 hr Mean DBP, mmHg |
78 (68.9-85.2) |
72.4 (66.8-74.9) |
0.02 |
0.04 |
|
Awake Mean SBP, mmHg |
130.2 (115-139.3) |
118.5 (114.7-124.7) |
0.07 |
0.07 |
|
Awake Mean DBP, mmHg |
82 (70.6-89) |
76.1 (70.2-78.6) |
0.07 |
0.07 |
|
Sleep Mean SBP, mmHg |
115 (104.7-129) |
107 (97.8-112.6) |
0.02 |
0.03 |
|
Sleep Mean DBP, mmHg |
68 (58-80) |
60.8 (53.6 – 66) |
0.008 |
0.02 |
|
Office SBP, mmHg |
126 (114-140) |
121 (115-127) |
0.37 |
0.43 |
|
Office DBP, mmHg |
83 (68-90) |
82 (73-90) |
0.76 |
0.84 |
|
Hypertension, Yes |
11 (47.8) |
2 (8.7) |
0.007 |
|
|
BMI= body mass index, SBP = systolic blood pressure, DBP = diastolic blood pressure, *Adjusted for age, sex, and race |
||||
|
** Continuous and categorical data expressed as median (interquartile range) and counts (percent) respectively |
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Conclusion:
Despite similar office blood pressure measurements, ambulatory blood pressure, particularly nocturnal blood pressure, was higher in patients with SLE than controls. Skin Na+ levels were correlated with systolic blood pressure in SLE. Studies to further assess the relationship between skin Na+ and disease activity, blood pressure, and cardiovascular disease in patients with SLE are needed.
To cite this abstract in AMA style:
Carranza Leon D, Chung CP, Ormseth MJ, Oeser AM, Wang P, Marton A, Titze J, Stein CM. Ambulatory Blood Pressure and Skin Sodium Concentrations in Patients with Systemic Lupus Erythematosus [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/ambulatory-blood-pressure-and-skin-sodium-concentrations-in-patients-with-systemic-lupus-erythematosus/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/ambulatory-blood-pressure-and-skin-sodium-concentrations-in-patients-with-systemic-lupus-erythematosus/