Demographic, psychiatric, fatigue and biomarker characteristics across the participant groups
| Variable | SLE (n=36) | HC (n=30) | P value |
| Mean (SD), Median (LQ, UQ) or n (%) | |||
| Demographic | |||
| Age (years) | 40 (32, 48.75) | 32 (27, 46.5) | P=0.14 |
| Gender (% female) | 34 (94) | 30 (100) | P=0.19 |
| Handedness (% right-handed) | 30 (83) | 28 (93) | P=0.34 |
| Years in education | 16.11 (3.51) | 17.97 (3.40) | P= 0.034 |
| WTAR (IQ) | 102.5 (98.25, 108) | 111 (105, 114) | p= 0.001 |
| Ethnic origin | P=0.132 | ||
| Caucasian | 24 (66.7) | 24 (80) | |
| Black Caribbean | 4 (11.1) | 0 | |
| Black African | 3 (8.3) | 0 | |
| Indian | 1 (2.8) | 0 | |
| Bangladeshi | 0 | 1 (3.3) | |
| Chinese | 1 (2.8) | 1 (3.3) | |
| Other | 3 (8.3) | 4 (13.3) | |
| Depression | |||
| MADRS | 4 (1, 8) | 1 (0, 3) | P= 0.012 |
| HADS - D | 4 (1, 9) | 1 (0, 2) | P< 0.001 |
| BDI - II | 10 (4, 20.25) | 3 (0.75, 8) | P= 0.002 |
| Anxiety | |||
| HADS – A | 6 (3, 10.5) | 5 (2, 7) | P=0.08 |
| Fatigue | |||
| FSMC – Motor score | 36 (22, 40.5) | 14 (11.5, 18.5) | P< 0.001 |
| FSMC – Cognitive score | 31 (22, 40) | 14 (11.5, 18.5) | P< 0.001 |
| FSMC – total score | 67.5 (44.75, 80.5) | 27 (23, 37) | P< 0.001 |
| Biomarkers of inflammation and endothelial activation | |||
| hsCRP (mg/L)1 | 1.44 (0.66, 5.06) | 0.88 (0.39, 1.39) | P= 0.013 |
| IL-6 (pg/mL)1 | 1.67 (0.50, 5.33) | 0.50 (0.50, 1.32) | P= 0.003 |
| VCAM-1 (ng/mL)2 | 474.93 (194.30) | 345.66 (53.79) | P= 0.001 |
| VEGF (pg/mL)1 | 66.04 (13.93, 139.60) | 45.42 (6.04, 114.93) | P=0.275 |
| BLyS (ng/mL)1 | 0.51 (0.35, 0.71) | 0.34 (0.27, 0.39) | P< 0.001 |
Missing data: WTAR not included for 3 HCs, and 4 SLEs, these participants’ first language was not English and/or they had dyslexia, as such it was felt that the scale would not accurately measure IQ in these participants. MADRS–5 SLE, 2 HC; FSMC–2 SLE, 1 HC hsCRP, IL-6, VEGF, BLyS-2 HC, 2 SLE; VCAM-1–2 SLE.
P-values in bold are significant at <0.05.
BDI-II, Becks Depression Inventory - II; BLyS, B lymphocyte stimulator; FSMC, Fatigue Scale for Motor and Cognitive Functions; HADS-A, Hospital Anxiety and Depression Scale–Anxiety score; HADS-D, Hospital Anxiety and Depression Scale–Depression score; IL-6, Interleukin 6; MADRS, Montgomery Asberg Depression Rating Scale; VCAM-1, vascular cell adhesion molecule-1; VEGF, vascular endothelial growth factor;WTAR, Weschler Test of Adult Reading; hsCRP, high sensitivity C reactive protein;.