Table 1.
Main characteristics of included studies in this meta-analysis.
| Mean age | Total | |||||||
| Studies | Country | Ethnicity | Cases | Control | Case/Controls | Genotyping methods | Polymorphisms | Quality scores |
| Awasthi 2011 | Indian | Asian | 74.39 ± 45.7m (1–15y) | 73.61 ± 42.56m (1–15y) | 211/137 | PCR-RFLP | ADAM33 F+1, V4, ST+4, S2 | 7 |
| Qu 2011 | China | Asian | 7.74 ± 2.78(8–13) | 7.52 ± 2.95(8–13) | 412/397 | PCR-RFLP | ADAM33 F+1, T+1, T2, T1, V4 | 8 |
| Wang 2017 | China | Asian | 3–15 | 3–15 | 197/120 | PCR-RFLP | ADAM 33 F+1 | 7 |
| Yu 2011 | China | Asian | 3.9 ± 3.1 | 3.3 ± 2.7 | 123/136 | PCR-RFLP | ADAM33 S2 | 7 |
| Fan 2015 | China | Asian | 5.27–1.93(2–10) | 5.68–2.17(3–12) | 120/105 | PCR-RFLP | ADAM 33 F+1, T1, S2 | 8 |
| Shalaby 2015 | Egypt | African | 8.5 (±3.6)(3–14) | 8.8 (±2.6)(4–13) | 400/200 | PCR-RFLP | ADAM33 F+1, ST+4 | 6 |
| Li 2014 | China | Asian | 10.4 ± 2.9(3.1–14.6) | 3.1–14.6 | 299/311 | PCR-RFLP | ADAM33 V4, T2, S2, S1, T1 | 6 |
| Zihlif 2014 | Jordan | Asian | 5.96–4.63 | 7.53–4.83 | 107/115 | PCR-RFLP | ADAM33 T1, T2, V4, S2 | 6 |
| Zhao 2012 | China | Asian | 14.2 ± 3.4(3.1–14.8) | 14.5 ± 3.5(3.3–14.9) | 110/144 | PCR-RFLP | ADAM33 T2, V4 | 6 |
| Yu 2018 | China | Asian | 6.26 ± 2.06(5–12) | 6.19 ± 2.03 | 105/98 | Sequencing | ADAM33 ST+4 | 7 |
| Long 2018 | China | Asian | 22.98 ± 20.67y | 22.51 ± 20.32 | 101/117 | SNaPshot | ADAM33 S2,IL13+2044G/AIL-13-1112C /T IL-4 -590C/TADRB2-46G /A | 8 |
| Ding 2013 | China | Asian | 6.62 ± 1.90(1–14) | 5.86 ± 2.11(0.78–14) | 90/82 | PCR-RFLP | IL-13+2044G/A | 7 |
| Guo 2017 | China | Asian | 5.4 ± 1.8(1–13) | 6.3 ± 2.1(3–14) | 80/112 | PCR-RFLP | IL-13+2044G/A IL-13-1112C /T | 8 |
| Zhang 2016 | China | Asian | 5. 68 ± 3. 33 | 4. 85 ± 3. 69 | 153/103 | Mass Array | IL-13+2044G/A | 7 |
| Narozna 2016 | Poland | European | 11.5 ± 3.6 | 12.1 ± 33.4 | 177/194 | TaqMan | IL-13+2044G/AIL-4 -590C/T | 6 |
| Martínez 2015 | Mexico | Mestizo | 10.8 ± 2.9 | NA | 421/430 | TaqMan | IL-13-1112C /TADRB2-46G /A | 6 |
| Alghobashy 2018 | Egypt | African | 6–12 | 6–11 | 104/52 | PCR-RFLP | ADRB2-46G /AADRB2 -79G/C | 8 |
| Dixit 2014 | India | Asian | 6.29 ± 3.28(1–15) | 6.08 ± 3.22(1–15) | 275/275 | PCR-RFLP | IL-13-1112C /TIL-4 -590C /T | 7 |
| Liao 2014 | China | Asian | 6.30 ± 3.39 | 4.96 ± 3.61 | 300/200 | PCR-RFLP | IL-13 -1112C /TIL-4-590C/T | 7 |
| Huang 2013 | China | Asian | 48.6 ± 43.2m | 40.9 ± 41.5 | 168/188 | Mass Array | ORMDL3 rs7216389 | 7 |
| Yang 2012 | China | Asian | 5.872 ± 2.543 | 6.038 ± 2.526 | 152/190 | Mass Array | ORMDL3 rs7216389 | 6 |
| Sun 2010 | China | Asian | 6–14 | 6–14 | 178/129 | PCR-RFLP | ORMDL3 rs7216389 | 7 |
| Wei 2016 | China | Asian | 6.02 ± 1.98 | 6.31 ± 2.04 | 128/100 | Mass Array | ORMDL3 rs7216389 | 7 |
| Jia 2013 | China | Asian | 4.27 ± 2.52 | 4.15 ± 2.91 | 77/50 | PCR-RFLP | IL-13 +1923 | 7 |
| Pu 2013 | China | Asian | 5.8 ± 2.9 (3–12) | 5.6 ± 2.6 | 96/96 | PCR-RFLP | IL-13 +1923 | 7 |
| Ramphul 2014 | Mixed | African/Asian | 3–12 | 18–22 | M:193/189C:192/192 | PCR-RFLP | IL-13 +1923IL-4 -590C/TADRB2-46G /A | 7 |
| Zeng 2015 | China | Asian | 6. 60 ± 3. 40 | 4. 91 ± 3. 73 | 250/200 | PCR-RFLP | IL-4-590C/T | 7 |
| Smolnikova 2013 | Russians | European | 13.3 ± 2.24 | 14.8 ± 0.68 | 64/50 | PCR | IL-4-590C/T | 8 |
| Zhang 2010 | China | Asian | 10. 3 ± 1. 5(6–13) | 10. 1 ± 1. 5(6–13) | 291/668 | PCR-RFLP | IL-4 -590C/T | 7 |
| Wu 2019 | China | Asian | 6.8 ± 2.7(3–12) | 6.6 ± 2.5(3–12) | 160/160 | PCR-RFLP | IL-13-1112C /TIL-4 -590C/T | 6 |
| Li 2014 | China | Asian | 8.4 ± 2.7(3–12) | 7.9 ± 3.2(3–12) | 500/523 | PCR-RFLP | IL-13-1112C /TIL-4 -590C/T | 7 |
| Lin 2012 | China | Asian | 4.4 ± 2.3(1.4 -13) | 7.7 ± 2.5(3–14) | 72/102 | PCR-RFLP | IL-4-590C/T | 8 |
| Huang 2010 | China | Asian | 6. 57 ± 2. 76(2–13) | 7. 46 ± 2. 94(3–14) | 100/122 | PCR-RFLP | IL-4 -590C/T | 6 |
| Yan 2015 | China | Asian | 6 ± 2. 8(6m-14y) | 7 ± 2. 1(4–14) | 34/30 | PCR-RFLP | IL-4 - 590C/T | 7 |
| Karam 2013 | Egypt | African | 10.3 ± 2.4 | 9.8 ± 2.8 | 90/110 | AS-PCR | ADRB2-46G /AADRB2 -79G/C | 6 |
| Abdullah 2011 | Saudi Arabia | Asian | 10.4 ± 4.6 | 12.6 ± 4.2 | 73/85 | PCR-RFLP | ADRB2 -46G/AADRB2 -79G/C | 7 |
| Yang 2012 | China | Asian | 7.66 ± 2.59 | 7.69 ± 2.55 | 212/52 | Sequencing | ADRB2-46G /A | 7 |
| Zheng 2012 | China | Asian | 3.5 | 3.8 | 198/110 | StepOnePlus/TaqMan | ADRB2-46G /A | 7 |
| Feng 2018 | China | Asian | 5.8 ± 2.8(2–12) | 6.3 ± 3.1(2–12) | 173/166 | Taqman | ADRB2-46G /AADRB2 -79G/C | 8 |
| Isaza 2012 | Colombia | Mestizo | (6–17) | (6–17) | 109/137 | Sequencing | ADRB2 -46G/AADRB2 -79G/C | 8 |
| Qi 2014 | China | Asian | 1.1–14 | 2–14 | 120/117 | PCR-RFLP | ADRB2 -79G/C | 7 |
| Tian 2016 | China | Asian | 5.6 ± 10.3(0.75–16) | 5.2 ± 9.8(2–14) | 298/304 | TaqMan | ADRB2 -46G/AADRB2 -79G/C | 7 |
| Yang 2017 | China | Asian | N/A | N/A | 74/110 | PCR-RFLP | ADRB2 -46G/A | 6 |
| Kilic 2019 | Turkey | European | 9.5 ± 2.8(5–16) | 9.5 ± 2.5(5–14) | 80/100 | StepOnePlus/TaqMan | VDR ApaI, TaqI, FokI | 8 |
| Maalmi 2013 | Tunisia | African | 9.1 (4–16) | 9.5 (2–16) | 155/225 | PCR-RFLP | VDR ApaI, TaqI, FokI, BsmI | 7 |
| Mo 2015 | China | Asian | NA | NA | 71/71 | PCR-RFLP | VDR ApaI, BsmI | 7 |
| Zhu 2019 | China | Asian | 8.76 ± 1.22 | 8.60 ± 1.16 | 97/100 | Sequencing | VDR FokI, BsmI | 8 |
| Ismail 2013 | Egypt | African | 8.6 ± 2.7 | 7.8 ± 2.6 | 51/33 | TaqMan | VDR FokI | 6 |
| Zhao 2015 | China | Asian | 3.14 ± 1.07(2–6) | 3.37 ± 1.04(2–6) | 40/40 | Sequencing | VDR ApaI, TaqI, FokI, BsmI | 7 |
| Ma 2014 | China | Asian | 11 | 10.6 | 60/60 | PCR-RFLP | VDR ApaI, TaqI, FokI, BsmI | 7 |
| Einisman 2015 | Chile | American | 6-15 | 2-18 | 75/227 | PCR-RFLP | VDR ApaI, TaqI, FokI | 7 |
| Hou 2018 | China | Asian | 8.84 ± 3.2 | 8.04 ± 3.01 | 70/70 | PCR-RFLP | VDR ApaI, BsmI | 6 |
| Zhang 2010 | China | Asian | 7.1 ± 2.3 | 7.1 ± 1.6 | 118/160 | PCR-RFLP | CTLA-4+49A/G | 7 |
| Wang 2014 | China | Asian | 8m–10y | 9m–10y | 40/40 | Sequencing | CTLA-4+49 A/G | 7 |
| Zhang 2012 | China | Asian | 1–10 | 3–7 | 26/30 | PCR-RFLP | CTLA-4+49 A/G | 6 |