Duration Of Rheumatoid Arthritis Changes Blood Levels Of Angiotensin And Aldosterone

Abstract

The article presents data on the influence of rheumatoid arthritis (RA) duration on changes in blood levels of angiotensin (ATII) and aldosterone (ALD). Objective — To examine the changes in the activity of the renin-angiotensin-aldosterone system (RAAS) depending on the time elapsed from the onset of RA (i.e., on the stage of the disease development). Methods – We examined 184 patients diagnosed with RA (sensu the ACR/EULAR 2010 criteria) without concomitant pathology. The control group (CG) consisted of 34 virtually healthy individuals. The serum concentrations of ATII and ALD were determined by the enzyme-linked immunosorbent assay (ELISA). Results — When assessing the studied parameters of the RAAS, we discovered that in all examined RA patients, the level of ATII and ALD in the blood was more than twice as high as that in the CG (p<0.001; p<0.010). ATII concentration decreased unevenly with increasing disease duration. The differences of the group of patients with a duration of RA less than 6 months were not statistically significant with the groups of patients of 0.6-1.0 and 2.1-3.0 years (p>0.050), while the differences with patients with a disease duration of 1.1-2.0, 3.1-4.0, and >5 years were statistically significant (p<0.050). Further comparative analysis of the indicators revealed statistically significant differences between the group of patients of 0.6-1.0 years and patients with RA duration of 3.1-4.0 and >5 years (p<0.050), as well between patients with RA duration of 1.1-2.0 and 4.1-5.0 years (p<0.050). The blood content of ALD increased unevenly in patients: from the minimum to the maximum disease duration. In individuals with a duration of RA<0.5 years, the differences were significant (p<0.05), with the exception of the group of 0.6-1.0 years (p>0.05). In patients with a disease duration of 0.6-1.0 and 1.1-2.0 years, the differences were statistically significant with all subsequent groups of RA duration (p<0.05). Further mathematical processing of data using multiple regression analysis and determination of correlations showed the presence of a linear inverse relationship between the ATII level and the duration of the disease (R=-0.44, p<0.001; F=10.98, p=0.001). Data processing also revealed strong direct correlations between the level of ALD in the blood and the duration of the disease (R=0.4999, p<0.001; F=58.27, p<0.001). Conclusion — The RAAS is heterogeneous and its integration into a single system is ambiguous. The significance of various components of the RAAS in RA is determined by the pathophysiological processes in the patient’s body. Blocking of various components of the RAAS should be differentiated and either correspond to some specific levels of indicators for each patient, or match to the stages of RA associated with the duration of the disease.