Table 1 Sociodemographic characteristics, 25(OH)D levels and clinical characteristics of the population included in the study
Rheumatoid arthritis | Ankylosing spondylitis | Psoriatic arthritis | Controls | |
|---|---|---|---|---|
(n = 775) | (n = 738) | (n = 721) | (n = 677) | |
Age at inclusion, years, mean (SD) | 57.1 (12.3) | 48.1 (11.7) | 51.8 (12.0) | 54.0 (12.4) |
Age at the beginning of disease, years, mean (SD) | 45.8 (13.4) | 29.7 (11.8) | 39.5 (13.3) | 48.5 (12.4) |
Female sex, n (%) | 581 (75.0) | 200 (27.1) | 327 (45.4) | 437 (64.5) |
Educational level, n (%) | ||||
Elementary | 467 (60.9) | 318 (43.3) | 331 (46.3) | 229 (34.1) |
University /secondary | 300 (39.1) | 416 (56.7) | 383 (53.7) | 443 (65.9) |
Caucasian Race, n (%) | 747 (96.6) | 723 (98.0) | 712 (98.9) | 668 (98.7) |
Others | 26 (3.4) | 15 (2.0) | 8 (1.1) | 9 (1.3) |
Main activity, n (%) | ||||
Sedentary | 236 (35.0) | 263 (39.3) | 253 (38.9) | 291 (46.3) |
Moderate | 290 (43.0) | 238 (35.5) | 241 (37.1) | 207 (32.9) |
Active with displacement | 148 (22.0) | 169 (25.2) | 156 (24.0) | 131 (20.8) |
BMI, kg/m2, mean (SD) | 26.9 (4.8) | 27.4 (4.4) | 28.2 (4.7) | 26.7 (4.4) |
Obesity (BMI ≥30), n (%) | 180 (23.2) | 186 (25.2) | 209 (29.1) | 147 (21.8) |
Smoking status, n (%) | ||||
Current smokers | 189 (24.4) | 254 (34.4) | 157 (21.8) | 143 (21.2) |
Past smokers | 202 (26.1) | 240 (32.5) | 227 (31.5) | 176 (26.0) |
Never smokers | 384 (49.5) | 244 (33.1) | 337 (46.7) | 357 (52.8) |
25 (OH) D | ||||
25(OH)D (ng/ml), median (p25 − p75) | 20.4 (14.4–29.2) | 20.9 (13.1–29.0) | 20.0 (14.0–28.8) | 24.8 (18.4–32.6) |
25(OH)D deficiency, n (%) | 314 (40.5) | 293 (39.7) | 295 (40.9) | 181 (26.7) |
Sunshine hours/month*, median (p25 − p75) | 162 (122–219) | 165 (136–233) | 178 (128–235) | 301 (202–345) |
Disease duration, years, median (p25 − p75) | 8.0 (3.0–14.0) | 15.0 (8.0–26.0) | 9.0 (4.0–16.0) | 2.0 (0.0–6.0) |
RF-positive, n (%) | 528 (68.1) | -- | -- | -- |
ACPA-positive, n (%) | 482 (62.2) | -- | -- | -- |
DAS28-ESR, mean (SD) | 3.2 (1.2) | -- | 3.0 (1.3) | -- |
HAQ (0–3), median (p25 − p75) | 0.5 (0.1–1.1) | -- | 0.4 (0.0–0.9) | -- |
ESR (mm/h), median (p25 − p75) | 17.0 (9.0–29.0) | 10.0 (6.0–21.0) | 12.0 (6.0–21.0) | 10.0 (5.0–18) |
CRP (mg/l), median (p25 − p75) | 3.1 (1.2–8.0) | 3.6 (1.6–8.9) | 2.9 (1.4–6.1) | 1.9 (1.3–3.3) |
BASDAI (0–10), median (p25 − p75) | -- | 3.5 (1.7–5.3) | -- | -- |
BASFI (0–10), median (p25 − p75) | -- | 3.1 (1.3–5.2) | -- | -- |
HLA-B27, n (%) | -- | 561 (76) | -- | -- |
Erosions (RA), n (%) | 352 (45.4) | -- | -- | -- |
Biologic therapy (% ever treated), n (%) | 313 (40.4) | 349 (47.4) | 300 (41.7) | -- |
Vitamin D, n (%) | 325 (41.9) | 82 (11.1) | 114 (15.8) | 138 (20.4) |
Calcium supplements, n (%) | 328 (42.3) | 68 (9.2) | 105 (14.6) | 122 (18.0) |