Published literature from PubMed, EMBASE, and ISI web of science databases were retrieved. The studies evaluating the association of ENPP1/PC1 gene K121Q polymorphism with obesity were included, in which sufficient data were presented to calculate the odds ratio (OR) with 95 % confidence intervals (CIs).
Ten case-control studies meeting the inclusion criteria identified a total of 24,324 subjects including 11,372 obese and 12,952 control subjects. The meta-analysis results showed a statistically significant association of K121Q with obesity [OR (95 % CI): 1.25 (1.04-1.52) P=0.021] under a recessive model of inheritance (QQ vs. KK+KQ) without heterogeneity or publication bias.
The results from the present study have indicated that ENPP1/PC1 Q121 variant may increase the risk of obesity and that more well-designed studies based on a larger population will be required to further evaluate the role of ENPP1/PC1 gene K121Q polymorphism in obesity and other related metabolic syndromes.