: Diabetic kidney disease (DKD) is an increasing health problem and an extra burden to health services. Study of characteristic metabolic alterations of DKD is crucial for better understanding of pathogenesis to identify new potential biomarkers and drug targets. We hypothesised that metabolic profiling of amino acids, acylcarnitines, and organic acids are useful new biomarkers for the diagnosis of the early stages of DKD: The hypothesis was testing in a case-control study of 232 patients with type 2 diabetes mellitus and 150 healthy controls.