title: The role of smoking status and collagen IX polymorphisms in the susceptibility to cervical spondylotic myelopathy.
abstract: We investigated a possible association of collagen IX  tryptophan (Trp) alleles (Trp2 and Trp3) and smoking with cervical spondylotic  myelopathy (CSM) in 172 Chinese patients and 176 age- and gender-matched  controls. The smoking status was evaluated by smoking index (SI). The CSM cases  had a significantly higher prevalence of Trp2 alleles (Trp2+) than controls  (19.8 vs 6.2%, P = 0.002), but the prevalence of Trp3 alleles (Trp3+)  was similar between the two groups (23.3 vs 21.6%, P = 0.713). Logistic  regression analyses showed that the subjects with Trp2+ had a higher risk for  CSM. We thus analyzed whether smoking status influenced the association between  Trp2 alleles and CSM risk. Among Trp2+ subjects with an SI less than 100, the  smoking status did not influence the effect of risk for SCM [odds ratio (OR) =  1.34, 95% confidential interval (95%CI) = 0.85-2.18, P > 0.05]. When SI  increased from 101 to 300, the OR for CSM reached 3.34 (95%CI = 2.11-5.67, P =  0.011); when SI was more than 300, the OR for CSM reached 5.56 (95%CI =  3.62-7.36, P < 0.001). Among Trp2- subjects with SI more than 300, the OR  for CSM increased 2.14 (95%CI = 1.15-4.07, P = 0.024). We found a significant  association between the Trp2 alleles and CSM risk and smoking amplifies this  risk, suggesting that smoking abstinence is important for reducing CSM  occurrence in subjects with high genetic risk.
authors.affiliation: Department of Orthopedics, Xinhua Hospital (Chongming), Shanghai Jiaotong University, Shanghai, China.
authors.forename: Z C
authors.initials: ZC
authors.lastname: Wang
authors.forename: J G
authors.initials: JG
authors.lastname: Shi
authors.forename: X S
authors.initials: XS
authors.lastname: Chen
authors.forename: G H
authors.initials: GH
authors.lastname: Xu
authors.forename: L J
authors.initials: LJ
authors.lastname: Li
authors.forename: L S
authors.initials: LS
authors.lastname: Jia
mesh_terms: D000328:Adult; D024081:Collagen Type IX / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012907:Smoking; D013118:Spinal Cord Diseases / Q000235:genetics*; D055009:Spondylosis / Q000235:genetics*
chemical_list: D024081:Collagen Type IX