Salivary cortisol levels, but not salivary α-amylase levels, are elevated in patients with rheumatoid arthritis irrespective of depression.
OBJECTIVE
Stress is recognized as an important factor in the etiology of rheumatoid arthritis (RA). Therefore, we explored multiple aspects of stress in RA patients.


METHODS
Salivary cortisol and α-amylase levels were measured as markers of the hypothalamic-pituitary-adrenal axis activity and sympatho-adrenomedullary system activity, respectively. Depression was assessed by the Beck Depression Inventory (BDI) and short-term analysis of the heart rate variability (HRV) was performed to evaluate the autonomic nervous system.


RESULTS
The salivary cortisol levels of the RA patients were significantly higher than those of the normal controls (NC; 0.12 ± 0.162 μg/dL vs. 0.068 ± 0.052 μg/dL, P = 0.006). There was no difference in salivary α-amylase levels between the RA and the NC. The BDI levels of the RA patients were significantly higher than the NC (13.7 ± 8.9 vs. 6.4 ± 6.9, P < 0.001). Depression was more prevalent in RA patients than in the NC. The salivary cortisol levels were still significantly higher in the RA than the NC after controlling BDI by logistic regression analysis (P = 0.002). There was no significant difference in the HRV of RA patients and the NC. The evaluation of relationship between stress measures and disease activity markers of RA revealed that only BDI was positively correlated with the visual analogue pain scale.


CONCLUSIONS
Salivary cortisol levels and the BDI of RA patients were higher than those of the NC, and elevated salivary cortisol levels were independent of depression. However, the level of stress may not be correlated with disease activity in RA.
Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea.|BK21 Division of Cell Transformation and Restoration, Ajou University School of Medicine, Suwon, Korea.
Hyoun-Ah
HA
Kim
Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea.|BK21 Division of Cell Transformation and Restoration, Ajou University School of Medicine, Suwon, Korea.
Ja-Young
JY
Jeon
Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea.|BK21 Division of Cell Transformation and Restoration, Ajou University School of Medicine, Suwon, Korea.
Bo-Ram
BR
Koh
BK21 Division of Cell Transformation and Restoration, Ajou University School of Medicine, Suwon, Korea.|Department of Family Practice, Ajou University School of Medicine, Suwon, Korea.
Sat-Byul
SB
Park
Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea.|BK21 Division of Cell Transformation and Restoration, Ajou University School of Medicine, Suwon, Korea.
Chang-Hee
CH
Suh
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000201:enzymology* / Q000209:etiology / Q000503:physiopathology; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003863:Depression / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012463:Saliva / Q000201:enzymology*; D015854:Up-Regulation; D000516:alpha-Amylases / Q000032:analysis*
D015415:Biomarkers; D000516:alpha-Amylases; D006854:Hydrocortisone
alpha amylase; cortisol; depression; rheumatoid arthritis; saliva; stress