Cartilage Intermediate Layer Protein Gene is Associated with Lumbar Disc Degeneration in Male, but Not Female, Collegiate Athletes

Abstract

Background The authors previously identified a significant association between lumbar disc degeneration (LDDG) and cartilage intermediate layer protein (CILP) single nucleotide polymorphism (SNP) in collegiate male judokas. Hypothesis A significant association between LDDG and the CILP SNP is observed in Japanese collegiate athletes. Study Design Cross-sectional study; Level of evidence, 3. Methods The participants were 601 trained collegiate athletes (male, 403; female, 198) from 7 different sports. Lumbar disc degeneration was evaluated using T2-weighted magnetic resonance imaging. Genotyping of the CILP gene (1184T/C) was performed by using DNA sequencing. Results Among the 601 collegiate athletes, the odds ratio (OR) for the occurrence of LDDG with the CILP C allele was 1.4 (95% confidence interval [CI], 1.05-1.86). By using logistic regression analysis concomitant with the interaction term and the Wald test, the authors found that weight (OR, 1.04; 95% CI, 1.02-1.06), CILP genotype (CT: OR, 2.0; 95% CI, 1.24-3.15; CC: OR, 2.9; 95% CI, 1.09-7.74), and gender (OR, 2.1; 95% CI, 1.21-3.67) were significant risk factors for LDDG. These analyses also indicated that there was no effect of the CILP genotype on LDDG in female athletes. Conclusion The CILP SNP 1184T/C is a risk factor for male collegiate athletes. Information regarding the CILP gene polymorphism may be important for preventing and managing lumbar disc diseases, especially in male athletes.