Stratification by ethnicity showed that, when assuming an allele contrast model, the UCP3 -55T allele was associated with T2DM in Asians (REM OR = 1.22, 95% CI 1.04–1.44) but not in Europeans (REM OR = 1.12, 95% CI 0.91–1.38). This evidence concerns the gene UCP3 and type 2 diabetes mellitus.