Table 1 Characteristics of the individual studies included in the meta-analysis
First author, yearPopulation (ethnicity)CaseControlGenotyping methodsAssociationP (HWE)NOS score
P value (allele contrast)
Yucesoy 2001 [1]American (C)325164PCR-RFLPTNF −308A/GP>0.050.0038
TNF −238A/GP<0.050.127
Crobett 2002 [30]South African (AF)121120PCR-RFLPTNF −308A/GP>0.050.0548
TNF −238A/GP<0.050.152
Li 2004 [18]Chinese (A)259341PCR-RFLPTNF −308A/GP>0.050.5548
Wang 2005 [15]Chinese (A)96116PCR-RFLPTNF −308A/GP<0.050.1617
TNF −238A/GP<0.050.888
Qu 2007 [19]Chinese (A)184111PCR-RFLPTNF −308A/GP>0.050.1058
Wang 2005 [16]Chinese (A)75137PCR-RFLPTNF −308A/GP<0.010.1767
TNF −238A/GP<0.010.897
Wu 2007 [20]Chinese (A)183111PCR-RFLPTNF −308A/GP>0.050.1068
TNF −238A/GP>0.050.619
Yu 2009 [29]Chinese (A)259341PCR-RFLPTNF −238A/GP>0.050.3798
Rad 2012 [28]Iranian (C)4545PCRTNF −308A/GP>0.050.5848
Wang 2012 [17]Chinese (A)6868PCR-RFLPTNF −308A/GP<0.050.9458
TNF −238A/GP<0.050.951
Kurniawidjaja 2014 [24]Indonesian (A)171165PCR-RFLPTNF −308A/GP<0.050.7198
Mai 2014 [23]Chinese (A)6444PCR-RFLPTNF −308A/GP>0.050.4508
TNF −238A/GP>0.050.877
  • C: Caucasian, A: Asian, AF: African.