Clinical and laboratory data of RA patients and healthy control group are demonstrated in table (1). There was no significant difference between RA cases and healthy controls as regard age (36.7 vs 39 years, P 0.3) or gender (males 16.3% versus 20%, P 0.7). The median DAS ESR-28 and median DAS28 CRP were 3.8 and 3.2 respectively. Among studied cases: 47.5% were in remission, 38.8% were in moderate activity, 11.3% were in high activity and 2.5% were in low activity as shown in figure (1). Hemoglobin level was significantly higher among control than RA group (13.5 ± 1.1 gm/dl versus 11 ± 1.3 gm/dl, P < 0.001). No statistically significant difference was detected between serum vitamin D among RA cases and control group (23.5ng/ml versus 25ng/ml, P 0.9).
Table (2) shows clinical and laboratory data of rheumatoid arthritis patients with active disease and those in remission. There was no statistically significant difference between both groups as regard all laboratory parameters except ESR (40 versus 14 mm/hour, P < 0.001) and CRP (19.5 versus 3.5 mg/dl, P < 0.001). Serum calcium and vitamin D level were not significantly different between active RA patients and patients in remission (serum calcium 8.6 mg/dl versus 8.9mg/dl, P 0.06) (serum vitamin D 25ng/ml versus 20 ng/ml, P 0.09).
Normal vitamin D level (sufficiency) was found in 23 patients (28.75%). Vitamin D deficiency was detected in 11 patients (13.75%) and insufficiency was detected in 46 patients (57.5%) as shown in figure (2). There was no statistically significant difference between patients with different levels of vitamin D as regard clinical and laboratory data except ESR which was significantly higher in patients with sufficient vitamin D level (p 0.035) as demonstrated in table (3). Table (4) showed that serum vitamin D level was significantly correlated with CRP in active RA group (R = 0.32, P = 0.04) and serum Calcium in remission group (R = 0.4, P = 0.02). Otherwise, there was no significant correlation between vitamin D level and other clinical or laboratory parameters.
Table (1): clinical and laboratory data of RA patients and healthy control:
| Rheumatoid cases n = 80 | Control n = 40 | P value |
Age, years, Mean ± SD | 36.7 ± 8.8 | 39 ± 10.3 | 0.3 |
Gender, Female n (%) | 67 (83.8%) | 16 (80%) | 0.4 |
Number of tender joints, median (IQR) | 3 (0.25–6) | | |
Number of swollen joints, median (IQR) | 0 (0–3) | | |
PGA, median (IQR) | 1 (0–5) | | |
DAS28 ESR, mm/h, median (IQR) | 3.8 (2.4–5) | | |
DAS28 CRP, mg/dl, Median (IQR) | 3.2 (1.6–4.5) | | |
WBCs, mean ± SD | 6.7 ± 2.2 | 7.2 ± 1.1 | 0.8 |
Hemoglobin, gm/dl, mean ± SD | 11 ± 1.3 | 13.5 ± 1.1 | < 0.001* |
Platelets, mean ± SD | 263 ± 64 | 290 ± 56 | 0.003* |
ESR, mm/h, median (IQR) | 27 (14–41.5) | 20 (15.3–24.5) | 0.1 |
CRP, mg/dl, median (IQR) | 6 (3.25–21.75) | 4 (3–4) | 0.001* |
RF, Positive n(%) | 69 (86.3%) | | |
Anti CCP, Positive n(%) | 72 (90%) | | |
Serum Calcium, mg/dl, mean ± SD | 8.7 ± 0.7 | 8.6 ± 0.8 | 0.6 |
Serum vitamin D, ng/ml, median (IQR) | 23.5 (18–35) | 25 (16.3–28.8) | 0.9 |
PGA; patient global assessment, DAS 28; disease activity score 28, ESR; erythrocyte sedimentation rate, CRP; C reactive protein, RF; rheumatoid factor, anti CCP; anti cyclic citrullinated peptide.
P value < 0.05 is considered statistically significant.
Table (2): difference in clinical and laboratory data between RA patients with active disease and those in remission:
| Active rheumatoid cases n = 40 | Rheumatoid cases in remission n = 40 | P value |
Age, years, mean ± SD | 36 ± 8.7 | 36.7 ± 8.9 | 0.7 |
Gender, female n (%) | 32 (80%) | 35 (87.5%) | 0.3 |
WBCs, mean ± SD | 7 ± 2.3 | 6.3 ± 2 | 0.15 |
Hemoglobin, gm/dl, mean ± SD | 10.7 ± 1.2 | 11.1 ± 1.3 | 0.3 |
Platelets, mean ± SD | 271 ± 68 | 255 ± 61 | 0.3 |
ESR, mm/h, median (IQR) | 40 (34–50.75) | 14 (10–20) | < 0.001 |
CRP, mg/dl, median (IQR) | 19.5 (12–24) | 3.5 (3–6) | < 0.001 |
RF, positive n(%) | 34 (85%) | 35 (87.5%) | 0.5 |
Anti CCP, positive n(%) | 35 (87.5%) | 37 (92.5%) | 0.3 |
Serum calcium, mg/dl, mean ± SD | 8.6 ± 0.7 | 8.9 ± 0.9 | 0.06 |
Serum vitamin D, ng/ml, median (IQR) | 25 (19.3–38.7) | 20.1 (15.4–29) | 0.09 |
WBCs; white blood cells, ESR; erythrocyte sedimentation rate, CRP; C reactive protein, RF; rheumatoid factor, anti CCP; anti cyclic citrullinated peptide.
P value < 0.05 is considered statistically significant.
Table (3): difference in clinical and laboratory data between RA patients with different levels of vitamin D:
| Vitamin D deficiency n = 11 | Vitamin D insufficiency n = 46 | Vitamin D sufficiency n = 23 | P value |
Age, years, mean ± SD | 34.5 ± 8.6 | 37.8 ± 8 | 35.6 ± 10.1 | 0.23 |
Gender, female n (%) | 10 (90.9%) | 39 (84.8%) | 18 (78.3%) | 0.6 |
Number of tender joints, median (IQR) | 2 (1–5) | 2.5 (0–6) | 4 (0–7) | 0.5 |
Number of swollen joints, median (IQR) | 0 (0–3) | 0 (0–3) | 3 (0–4) | 0.3 |
PGA, median (IQR) | 1 (1–3) | 1 (0–5) | 3 (0–6) | 0.4 |
DAS28 ESR, median IQR | 3 (2–4.7) | 3.4 (1.9–4.8) | 4.7 (2.5–5.6) | 0.2 |
DAS28 CRP, median (IQR) | 2.6 (1.6 -4) | 2.9 (0.9–4.3) | 3.7 (1.7–5) | 0.3 |
WBCs, mean ± SD | 7.4 ± 2.4 | 6.9 ± 2.4 | 6 ± 1.5 | 0.2 |
Hemoglobin, gm/dl, mean ± SD | 10.5 ± 0.9 | 11.1 ± 1.3 | 10.8 ± 1.4 | 0.3 |
Platelets, mean ± SD | 263 ± 73 | 260 ± 58.6 | 268 ± 74.6 | 0.9 |
ESR, mm/h, median (IQR) | 20 (20–40) | 19.5 (10–35) | 39 (16–51) | 0.035* |
CRP, mg/dl, median (IQR) | 6 (3–12) | 6 (4–13) | 10 (4–24) | 0.35 |
RF, positive n(%) | 11 (100%) | 38 (82.6%) | 20 (87%) | 0.3 |
Anti CCP, positive n(%) | 10 (90.9%) | 40 (87%) | 22 (95.7%) | 0.5 |
Serum calcium, mg/dl, mean ± SD | 8.4 ± 0.8 | 8.8 ± 0.7 | 8.8 ± 0.7 | 0.15 |
PGA; patient global assessment, DAS 28; disease activity score 28, WBCs; white blood cells, ESR; erythrocyte sedimentation rate, CRP; C reactive protein, RF; rheumatoid factor, anti CCP; anti cyclic citrullinated peptide.
P value < 0.05 is considered statistically significant.
Table (4): Correlation between vitamin D level and clinical and laboratory data of all patients included in the study:
| Active rheumatoid cases | Rheumatoid cases in remission | Control |
Character | Rho | P | Rho | P | Rho | P |
Age | -0.12 | 0.9 | 0.04 | 0.8 | -0.95 | 0.7 |
DAS28 ESR | 0.2 | 0.27 | -0.2 | 0.2 | | |
DAS28 CRP | 0.11 | 0.5 | -0.13 | 0.44 | | |
ESR | 0.3 | 0.053 | -0.85 | 0.16 | -0.17 | 0.5 |
CRP | 0.32 | 0.04* | -0.24 | 0.9 | -0.28 | 0.22 |
Hemoglobin | 0.09 | 0.6 | -0.24 | 0.9 | -0.28 | 0.22 |
WBCs | -0.13 | 0.4 | -0.2 | 0.26 | -0.3 | 0.18 |
Platelets | -0.03 | 0.9 | 0.02 | 0.9 | 0.17 | 0.5 |
RF | -0.01 | 0.5 | -0.12 | 0.5 | | |
Anti CCP | 0.08 | 0.6 | -0.3 | 0.8 | | |
Serum calcium | 0.1 | 0.5 | 0.4 | 0.02* | | |
DAS 28; disease activity score 28, WBCs; white blood cells, ESR; erythrocyte sedimentation rate, CRP; C reactive protein, RF; rheumatoid factor, anti CCP; anti cyclic citrullinated peptide.
P value < 0.05 is considered statistically significant.