From: Association of homocysteine with ankylosing spondylitis: a systematic review and meta-analysis
Subgroups | Â | N | SMD (95% CI) | Z | P | Heterogeneity test | |
---|---|---|---|---|---|---|---|
 |  |  |  |  | P | I2 (%) | |
Region | Asia | 4 | 0.974 (−0.573, 2.521) | 1.23 | 0.217 | < 0.001 | 98.1% |
Asia + Europe (Turkey) | 3 | 0.018 (− 0.661, 0.698) | 0.05 | 0.958 | < 0.001 | 91.4% | |
Europe/America | 2 | 0.148 (−0.484, 0.780) | 0.46 | 0.646 | 0.055 | 73.0% | |
Combined | 9 | 0.463 (−0.300, 1.226) | 1.19 | 0.234 | < 0.001 | 97.3% | |
Sample size | ≥ 50 | 6 | 0.708 (−0.283, 1.700) | 1.40 | 0.162 | < 0.001 | 98.1% |
<  50 | 2 | −0.269 (− 0.632, 0.093) | 1.46 | 0.145 | 0.891 | 0.0% | |
Combined | 8 | 0.471 (−0.355, 1.298) | 1.12 | 0.264 | < 0.001 | 97.6% | |
Disease activity | active | 3 | 0.048 (−0.904, 1.000) | 0.10 | 0.921 | < 0.001 | 92.0% |
inactive | 3 | 0.078 (−0.733, 0.889) | 0.19 | 0.851 | < 0.001 | 89.0% | |
Combined | 6 | 0.059 (−0.488, 0.606) | 0.21 | 0.833 | < 0.001 | 88.5% | |
Smoking | Smoker | 1 | 0.497 (−0.066, 1.060) | 1.73 | 0.084 | NA | NA |
Non-smoker | 1 | 0.201 (−0.355, 0.757) | 0.71 | 0.478 | NA | NA | |
Combined | 2 | 0.347 (−0.048, 0.743) | 1.72 | 0.085 | 0.464 | 0.0% | |
MTHFR C677T genotype | CC | 2 | 1.599 (−0.864, 4.062) | 1.27 | 0.203 | < 0.001 | 98.1% |
CT | 2 | 1.693(−1.256, 4.642) | 1.13 | 0.260 | < 0.001 | 97.7% | |
TT | 2 | 2.771(−1.141, 6.682) | 1.39 | 0.165 | < 0.001 | 92.2% | |
Combined | 6 | 1.992 (0.663, 3.320) | 2.94 | 0.003 | < 0.001 | 95.7% | |
Treatment | NSAIDs | 2 | −0.365(− 1.020, 0.291) | 1.09 | 0.275 | 0.092 | 64.8% |
SSZ | 2 | 0.024 (−0.872, 0.920) | 0.05 | 0.958 | 0.003 | 88.7% | |
SSZ + MTX | 1 | 0.915 (0.312, 1.518) | 2.97 | 0.003 | NA | NA | |
Anti-TNF-α | 1 | −0.774 (−1.163, − 0.385) | 3.90 | < 0.001 | NA | NA | |
Combined | 6 | −0.094 (− 0.634, 0.445) | 0.34 | 0.732 | 0.000 | 87.7% |