Table 1. Characteristics and IL1-RN VNTR polymorphism genotype distributions in studies included in the meta-analysis.
| Author, year | Ethnicity | Quality scorea | Control | Case | P HWE | ||||||||
| LL | 2L | 22 | L | 2 | LL | 2L | 22 | L | 2 | ||||
| Tsai 2006 [10] | Taiwan(Asian) | 6 | – | – | – | 142 | 6 | – | – | – | 198 | 10 | – |
| Lee 2004 [11] | Korean(Asian) | 7 | 109 | 18 | 0 | 236 | 18 | 83 | 10 | 0 | 176 | 10 | 0.39 |
| Parks 2004 [12] | United States(Caucasian) | 7 | 169 | 18 | 15 | 356 | 48 | 66 | 12 | 8 | 144 | 28 | <0.01 |
| Parks 2004 [12] | United States(African-American) | 7 | 69 | 3 | 0 | 141 | 3 | 137 | 6 | 1 | 280 | 8 | 0. 86 |
| Jonsen2004 [21] | Sweden(Caucasian) | 6 | 111 | 75 | 14 | 297 | 103 | 86 | 38 | 14 | 210 | 66 | 0.78 |
| Huang 2002 [22] | Taiwan(Asian) | 7 | 96 | 6 | 1 | 198 | 8 | 43 | 8 | 1 | 94 | 10 | 0.03 |
| Zhu 2000 [23] | China(Asian) | 5 | 15 | 31 | 4 | 61 | 39 | 26 | 52 | 2 | 104 | 56 | 0.03 |
| Tjernstrom 1999 [24] | Sweden(Caucasian) | 7 | – | – | – | 339 | 39 | – | – | – | 130 | 32 | – |
| Heward 1999 [25] | Caucasian(Caucasian) | 4 | 312 | 7 | 19 | 631 | 45 | 106 | 4 | 6 | 216 | 16 | <0.01 |
| Suzuki 1997 [26] | Japan(Asian) | 4 | – | – | – | 418 | 18 | – | – | – | 354 | 38 | – |
| Blakemore 1994 [9] | England(Caucasian) | 7 | 152 | 92 | 17 | 396 | 126 | 39 | 31 | 11 | 109 | 53 | 0.54 |
a
The quality score was determinded by using the Newcastle-Ottawa quality assessment scale.
IL1-RN: Interleukin-1 receptor antagonist gene; VNTR: variable number of tandem repeats; HWE: Hardy-Weinberg equilibrium.