Increased extracellular water measured by bioimpedance and by increased serum levels of atrial natriuretic peptide in RA patients-signs of volume overload.
The aim of the study is to investigate water compartments in patients with rheumatoid arthritis (RA). Acute inflammatory episodes such as infection stimulate water retention, chiefly implemented by the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism due to expected water loss (sweating etc.). Since SNS and HPA axis are activated in RA, inflammation might be accompanied by water retention. Using bioimpedance analysis, body composition was investigated in 429 controls and 156 treatment-naïve RA patients between January 2008 and December 2014. A group of 34 RA patients was tested before and after 10 days of intensified therapy. Levels of pro-atrial natriuretic peptide (proANP) and expression of atrial natriuretic peptide in synovial tissue were investigated in 15 controls and 14 RA patients. Extracellular water was higher in RA patients than controls (mean ± SEM: 49.5 ± 0.3 vs. 36.7 ± 0.1, % of total body water, p < 0.0001). Plasma levels of proANP were higher in RA than controls. RA patients expressed ANP in synovial tissue, but synovial fluid levels and synovial tissue superfusate levels were much lower than plasma levels indicating systemic origin. Systolic/diastolic blood pressure was higher in RA patients than controls. Extracellular water levels did not change in RA patients despite 10 days of intensified treatment. This study demonstrates signs of intravascular overload in RA patients. Short-term intensification of anti-inflammatory therapy induced no change of a longer-lasting imprinting of water retention indicating the requirement of additional treatment. The study can direct attention to the area of volume overload.
Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine, University Hospital Regensburg, 93042, Regensburg, Germany. rainer.straub@ukr.de.
Rainer H
RH
Straub
Department of Rheumatology and Clinical Immunology, Asklepios Medical Center Bad Abbach, Bad Abbach, Germany.
Boris
B
Ehrenstein
Department of Rheumatology and Clinical Immunology, Asklepios Medical Center Bad Abbach, Bad Abbach, Germany.
Florian
F
Günther
Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine, University Hospital Regensburg, 93042, Regensburg, Germany.
Luise
L
Rauch
Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine, University Hospital Regensburg, 93042, Regensburg, Germany.
Nadezhda
N
Trendafilova
BioTekna Biomedical Technologies, Marcon, Italy.
Dario
D
Boschiero
Department of Orthopedic Surgery, University Hospital Regensburg, Regensburg, Germany.
Joachim
J
Grifka
Laboratory of Experimental Rheumatology and Neuroendocrine Immunology, Department of Internal Medicine, University Hospital Regensburg, 93042, Regensburg, Germany.|Department of Rheumatology and Clinical Immunology, Asklepios Medical Center Bad Abbach, Bad Abbach, Germany.
Martin
M
Fleck
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001823:Body Composition; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D004797:Enzyme-Linked Immunosorbent Assay; D045604:Extracellular Fluid / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
D009320:Atrial Natriuretic Factor
Hypertension; Inflammation; Rheumatoid arthritis; Volume overload