Association between inflammation and systolic blood pressure in RA compared to patients without RA

Arthritis Res Ther. 2018 Jun 1;20(1):107. doi: 10.1186/s13075-018-1597-9.


Background: The relationship between inflammation and blood pressure (BP) has been studied mainly in the general population. In this study, we examined the association between inflammation and BP across a broader range of inflammation observed in rheumatoid arthritis (RA) and non-RA outpatients.

Methods: We studied subjects from a tertiary care outpatient population with C-reactive protein (CRP) and BP measured on the same date in 2009-2010; RA outpatients were identified using a validated algorithm. General population data were obtained from the National Health and Nutrition Examination Survey (NHANES) as comparison. To study the cross-sectional association between CRP and BP in the three groups, we constructed a generalized additive model. Longitudinal association between CRP and BP was examined using a repeated-measures linear mixed-effects model in RA outpatients with significant change in inflammation at two consecutive time points.

Results: We studied 24,325 subjects from the outpatient population, of whom 1811 had RA, and 5561 were from NHANES. In RA outpatients, we observed a positive relationship between CRP and systolic BP (SBP) at CRP < 6 mg/L and an inverse association at CRP ≥ 6 mg/L. A similar inverse U-shaped relationship was observed in non-RA outpatients. In NHANES, we observed a positive relationship between CRP and SBP as demonstrated by previous studies. Longitudinal analysis in RA showed that every 10 mg/L increase in CRP was associated with a 0.38 mmHg reduction in SBP.

Conclusions: Across a broad range of CRP observed in RA and non-RA outpatients, we found an inverse U-shaped relationship between CRP and SBP, highlighting a relationship not previously observed when studying the general population.

Keywords: Blood pressure; Inflammation; Rheumatoid arthritis.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / blood*
  • Arthritis, Rheumatoid / diagnosis
  • Arthritis, Rheumatoid / physiopathology*
  • Biomarkers / blood
  • Blood Pressure / physiology*
  • C-Reactive Protein / metabolism*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Inflammation / blood
  • Inflammation / diagnosis
  • Inflammation / physiopathology
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Nutrition Surveys / trends


  • Biomarkers
  • C-Reactive Protein