Table 2.
Oxidative stress markers in healthy controls and patients with knee osteoarthritis according to vitamin D status.
| Variables | Healthy controls (n = 65) | Knee OA patients | P-valuea | |
|---|---|---|---|---|
| Vitamin D sufficient (n = 60) | Vitamin D insufficient (n = 64) | |||
| MDA (nmol/mL) | 1.69 ± 0.36 | 1.87 ± 0.4*** | 2.18 ± 0.5*,** | <0.0001c |
| TOS (μmol H2O2 Equiv./L) | 9.1 (8.0, 10.1) | 10.3 (9.0, 16.6)* | 12.7 (9.8, 17.5)* | <0.0001b |
| TAC (mmol/L) | 2.1 ± 0.58 | 1.63 ± 0.47 * | 1.42 ± 0.38 *,** | <0.0001c |
| SOD (U/gHb) | 1,134 ± 179 | 1,156 ± 158 | 1,237 ± 189*,** | 0.003c |
| GPX (U/gHb) | 42.7 ± 12.5 | 44.9 ± 12.3 | 41.2 ± 11.4 | 0.217c |
| CAT (K/gHb) | 222 (199, 258) | 228 (207, 261) | 232 (213, 270) | 0.261b |
| PON-1 (U/mL) | 43.1 (36.2, 58.1) | 46.4 (35.3, 62.7) | 28.1 (28.0, 48.3)*,** | 0.003b |
| OSI | 0.54 ± 0.341 | 0.88 ± 0.53*** | 1.1 ± 0.77*,** | <0.0001c |
OA, osteoarthritis; MDA, malondialdehyde; TOS, total oxidant status; TAC, total antioxidant capacity; SOD, superoxide dismutase; GPx, glutathione peroxidase; CAT, catalase; PON-1, paraoxonase-1; OSI, oxidative stress index; MMP-1, matrix metalloproteinase-1; MMP-3, matrix metalloproteinase-3; MMP-13, matrix metalloproteinase-13; COMP, cartilage oligomeric matrix protein. Data are expressed as mean ± standard deviation for normally distributed data and median (25th and 75th percentiles) are presented for data not normally distributed (i.e., TOS, CAT, PON-1, MMP-1, MMP-3, MMP-13, and COMP). Vitamin D sufficient and insufficient was defined as serum 25(OH)D concentrations ≥ 30 ng/mL and serum 25(OH)D concentrations < 30 ng/mL, respectively.
P < 0.05 was considered significant.
Obtained from Kruskal-Wallis test.
Obtained from one-way analysis of variance (ANOVA).
Significantly different from the healthy controls (p < 0.0001).
Significantly different from the vitamin D sufficient patients (p < 0.001).
Significantly different from the healthy controls (p < 0.01).