Association between ACE polymorphisms and osteoarthritis susceptibility

The present study was designed to investigate the association of angiotensin-converting enzyme (ACE) rs4343 and rs4362 polymorphisms with the susceptibility to osteoarthritis (OA).

109 knee OA patients and 114 healthy people were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to perform the genotyping for two groups and the linkage disequilibrium and haplotype were analyzed using Haploview software. The differences of genotype and allele frequencies were analyzed by χ(2) test and Fisher's exact test. The relationship between ACE polymorphisms and OA susceptibility was represented by odds ratios (ORs) with 95% confidence intervals (95% CIs).

The genotypes distributions of ACE rs4343 and rs4362 polymorphisms in control groups were accordance with HWE. ACE rs4343 polymorphism was associated with the significantly increased risk of OA (AG vs. AA: OR=2.41, P=0.003; GG vs. AA: OR=5.35, P=0.015; G vs. A: OR=2.27, P<0.001). Similarly, rs4362 polymorphisms was also a risk factor for OA (CT vs. CC: OR=2.60, P=0.005; TT vs. CC: OR=3.15, P=0.003; T vs. C: OR=1.88, P=0.001). The result of haplotype analysis showed complete linkage disequilibrium in rs 4343 and rs 4362 polymorphisms. The G-T haplotype significantly increased OA susceptibility, but A-C is a protective factor for the occurrence of OA.

Significant correlation exists between ACE rs4343 and rs4362 polymorphisms and OA. In haplotype analysis, A-C haplotype may provide protection against OA, and G-T haplotype may be a risk factor for the development of OA.