To compare the level and change of cortisol during the day of patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) with low and high erythrocyte sedimentation rate (ESR).
Saliva was collected in the real-life environment of 21 women with SLE, 16 women with pSS, and 30 age-matched healthy women at 9 fixed timepoints during 2 consecutive days. Repeated measures ANOVA was performed to examine whether cortisol levels during the day were different for the patients with low ESR (≤ 20 mm/h) versus those with high ESR (> 20 mm/h).
The groups with low and high ESR showed the characteristic change of cortisol during the day (time-of-day effect, F = 124.9, p < 0.001). The cortisol awakening level was lower for patients with high ESR than for patients with low ESR (group*time effect, F = 3.1, p = 0.02).
The cortisol awakening level differs for patients with low and high ESR, which indicates the usefulness of further studies of hypothalamic-pituitary-adrenal axis dynamics in patients with SLE and pSS.