Table 1.
General characteristics of healthy controls and patients with knee osteoarthritis according to the vitamin D status.a
| Variables | Healthy controls (n = 65) | Knee OA patients | P-valueb | ||
|---|---|---|---|---|---|
| Vitamin D sufficient (n = 60) | Vitamin D insufficient (n = 64) | ||||
| Male, n (%) | 31 (47.7) | 26 (43.3) | 32 (50.0) | 0.753c | |
| Age (years) | 48.1 ± 7.8 | 47.8 ± 7.5 | 50.6 ± 8.6 | 0.091d | |
| Weight (kg) | 82.8 ± 13.3 | 83.4 ± 15.0 | 84.3 ± 12.4 | 0.823d | |
| BMI (kg/m2) | 27.6 ± 3.3 | 28.3 ± 3.2 | 28.8 ± 3.0 | 0.101d | |
| WC (cm) | 94.8 ± 12.3 | 93.4 ± 13.0 | 97.0 ± 12.5 | 0.269d | |
| Obesity, n (%) | 23 (35.4) | 22 (36.7) | 26 (40.6) | 0.816c | |
| Use of vitamin D supplement, n (%) | 26 (40.0) | 36 (60.0)* | 25 (39.1) | 0.031c | |
| Use of calcium supplement, n (%) | 20 (30.8) | 31 (51.7)* | 22 (34.4) | 0.039c | |
| Cigarette smoking, n (%) | 13 (20.0) | 11 (18.3) | 15 (23.4) | 0.772c | |
| Physical activity, n (%) | 0.915c | ||||
| Light | 49 (75.4) | 47 (78.3) | 52 (81.3) | ||
| MODERATE | 9 (13.8) | 8 (13.3) | 8 (12.5) | ||
| Heavy | 7 (10.8) | 5 (8.3) | 4 (6.3) | ||
| 25(OH)D levels (ng/mL) | 42.7 ± 9.6 | 41.8 ± 9.2 | 19.7 ± 5.5** | <0.0001d | |
| Parathyroid hormone (pg/mL) | 49.1 ± 8.3 | 47.8 ± 7.1 | 51.0 ± 9.8 | 0.110d | |
| Duration of disease (years) | 5.5 ± 2.7 | 5.9 ± 2.3 | 0.432e | ||
OA, osteoarthritis; BMI, body mass index; WC, waist circumference. 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.
a
Values are shown as means ± SD, unless otherwise indicated.
b
P < 0.05 was considered significant.
c
Obtained from Pearson chi-square test.
d
Obtained from one-way ANOVA test and Independent sample t-test.
e
Obtained from independent samples t-test.
*
Compared to the healthy controls and vitamin D insufficient group.
**
Compared to the healthy controls and vitamin D sufficient group.