Table 3.
Subgroup analysis for risk of T1DM.
| Subgroup | No. of studies | Risk of T1DMa | I2, % | Pwithinb | Pbetweenc | |
|---|---|---|---|---|---|---|
| OR | 95% CI | |||||
| Overall | 16 | 0.39 | (0.27, 0.57) | 76.70% | ||
| Age | ||||||
| Only children | 12 | 0.40 | (0.24, 0.64) | 81.1 | <0.001 | 0.77 |
| Other | 4 | 0.36 | (0.26, 0.50) | 0.0 | 0.53 | |
| Ethnicity | ||||||
| White | 2 | 0.42 | (0.25, 0.72) | 0.0 | 0.33 | 0.16 |
| Yellow | 2 | 0.29 | (0.19, 0.45) | 0.0 | 0.65 | |
| Mix | 6 | 0.65 | (0.4, 1.05) | 73.4 | 0.002 | |
| Latitude, °N | ||||||
| ≤30 | 5 | 0.29 | (0.16, 0.54) | 55.3 | 0.06 | 0.02 |
| 31–45 | 9 | 0.35 | (0.26, 0.47) | 36.4 | 0.13 | |
| >45 | 2 | 1.15 | (0.85, 1.57) | 0.0 | 0.75 | |
| Categories of 25(OH)D, nmol/L | ||||||
| ≤50 | 1 | 0.67 | (0.39, 1.15) | NA | NA | < 0.001 |
| 50–75 | 5 | 0.27 | (0.18, 0.41) | 16.8 | 0.31 | |
| 75–100 | 2 | 1.15 | (0.85, 1.57) | 0.0 | 0.75 | |
| >100 | 8 | 0.33 | (0.24, 0.45) | 26.3 | 0.22 | |
| Assay method of 25(OH)D | ||||||
| RIA | 2 | 0.39 | (0.17, 0.89) | 68.5 | 0.08 | 0.10 |
| HPLC | 3 | 0.24 | (0.13, 0.45) | 17.9 | 0.30 | |
| CPBA | 1 | 0.03 | (0.00, 0.48) | NA | NA | |
| CLIA | 3 | 0.38 | (0.26, 0.56) | 0.0 | 0.61 | |
| ELISA | 4 | 0.27 | (0.19, 0.38) | 0.0 | 0.62 | |
| LC-MS | 3 | 0.98 | (0.68, 1.42) | 33.6 | 0.22 | |
| Duration of T1DM | ||||||
| >1year | 3 | 0.25 | (0.13, 0.47) | 17.3 | 0.30 | 0.50 |
| <1year | 2 | 0.38 | (0.16, 0.89) | 0.0 | 0.64 | |
| Adjustment for ethnicity | ||||||
| Yes | 6 | 0.40 | (0.26, 0.60) | 58.1 | 0.04 | 0.98 |
| No | 10 | 0.38 | (0.22, 0.68) | 81.9 | <0.001 | |
| Adjustment for gender | ||||||
| Yes | 11 | 0.31 | (0.25, 0.39) | 17.3 | 0.28 | 0.001 |
| No | 5 | 0.80 | (0.46, 1.39) | 59.8 | 0.04 | |
T1DM type 1 diabetes, N number, OR odds ratio, 95% CI 95% confidential interval.
aSummary OR and 95%CI were calculated by random-effects models.
bPwithin was the P value for heterogeneity within each subgroup.
cPbetween calculated by meta-regression was the P value for heterogeneity between subgroups