Association of eNOS polymorphisms with susceptibility to osteonecrosis of the femur head : A meta-analysis.
OBJECTIVE
The aim of the present study was to determine whether polymorphisms of the endothelial nitric oxide synthase (eNOS) gene are associated with susceptibility to osteonecrosis of the femoral head (ONFH).


METHODS
We conducted a meta-analysis to assess the association between the 4b/a, G894T, and T786C polymorphisms of eNOS and the susceptibility to ONFH.


RESULTS
A total of five studies, which included 566 cases and 833 controls, were included in the meta-analysis. Meta-analysis revealed a significant association between allele a of the 4b/a polymorphism and ONFH in all study subjects (odds ratio, OR 3.237; 95 % confidence interval, CI 2.036-5.148; P = 6.9 × 10-7); stratification by ethnicity indicated an association between this allele and ONFH in Caucasians and Asians (OR 2.985; 95 % CI 1.592-5.597; P = 0.001 and OR 3.567; 95 % CI 1.793-7.095; P = 2.9 × 10-4, respectively). Meta-analysis stratified by ONFH type showed a significant association between allele a of the 4b/a polymorphism and idiopathic and secondary ONFH (OR 3.411; 95 % CI 2.049-5.679; P = 2.4 × 10-6and OR 3.163; 95 % CI 1.781-5.619, P = 8.6 × 10-5, respectively). However, the meta-analysis did not show any allelic association between the G894T and T786C polymorphisms and ONFH (OR 1.718; 95 % CI 0.796-3.707; P = 0.168 and OR 1.027; 95 % CI 0.191-5.517; P = 0.976, respectively).


CONCLUSIONS
Our meta-analysis of published studies shows that the 4b/a polymorphism is associated with the development of idiopathic and secondary ONFH in Caucasians and Asians.
Division of Rheumatology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, 73, Inchon-ro, Seongbuk-gu, 02841, Seoul, Korea.
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GG
Song
Division of Rheumatology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, 73, Inchon-ro, Seongbuk-gu, 02841, Seoul, Korea. lyhcgh@korea.ac.kr.
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YH
Lee
D005260:Female; D005271:Femur Head Necrosis / Q000453:epidemiology* / Q000235:genetics*; D056726:Genetic Association Studies; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D008297:Male; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity
D005819:Genetic Markers; D052250:Nitric Oxide Synthase Type III
Confidence Interval; Endothelial nitric oxide synthase; Meta-analysis; Osteonecrosis; Polymorphism