The plasma metabolic fingerprinting of weight/age-matched diabetes/non-diabetic African-American women with/without uncoupling protein 3 (UCP3) (missense polymorphism, g/g or g/a), that reduced the oxidation of LCFA, revealed two acylcarnitines namely glutamate and 2-oxoglutarate (α-ketoglutarate) were found to be substantially increased in diabetic women with a g/g allele. This evidence concerns the gene UCP3 and diabetes mellitus.