Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism and Susceptibility to Osteoarthritis of the Knee: A Case-Control Study and Meta-Analysis.

• Main Authors: Chin Lin, Hsiang-Cheng Chen, Wen-Hui Fang, Chih-Chien Wang, Yi-Jen Peng, Herng-Sheng Lee, Hung Chang, Chi-Ming Chu, Guo-Shu Huang, Wei-Teing Chen, Yu-Jui Tsai, Hong-Ling Lin, Fu-Huang Lin, Sui-Lung Su
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2016-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC5033346?pdf=render

BACKGROUND:Studies of angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms and the risks of knee osteoarthritis (OA) have yielded conflicting results. OBJECTIVE:To determine the association between ACE I/D and knee OA, we conducted a combined case-control study and meta-analysis. METHODS:For the case-control study, 447 knee OA cases and 423 healthy controls were recruited between March 2010 and July 2011. Knee OA cases were defined using the Kellgren-Lawrence grading system, and the ACE I/D genotype was determined using a standard polymerase chain reaction. The association between ACE I/D and knee OA was detected using allele, genotype, dominant, and recessive models. For the meta-analysis, PubMed and Embase databases were systematically searched for prospective observational studies published up until August 2015. Studies of ACE I/D and knee OA with sufficient data were selected. Pooled results were expressed as odds ratios (ORs) with corresponding 95% confidence intervals (CI) for the D versus I allele with regard to knee OA risk. RESULTS:We found no significant association between the D allele and knee OA [OR: 1.09 (95% CI: 0.76-1.89)] in the present case-control study, and the results of other genetic models were also nonsignificant. Five current studies were included, and there were a total of six study populations after including our case-control study (1165 cases and 1029 controls). In the meta-analysis, the allele model also yielded nonsignificant results [OR: 1.37 (95% CI: 0.95-1.99)] and a high heterogeneity (I2: 87.2%). CONCLUSIONS:The association between ACE I/D and knee OA tended to yield negative results. High heterogeneity suggests a complex, multifactorial mechanism, and an epistasis analysis of ACE I/D and knee OA should therefore be conducted.