Human serum acylcarnitine profiles in different glucose tolerance states

AimsTo understand the relationship between serum acylcarnitine profiles and glucose tolerance status.MethodsWe analyzed 61 subjects who were divided into three groups based on their glucose tolerance status: normal glucose tolerance (NGT; n = 20, M/F = 9/11, mean age 48 years), pre-diabetes (Pre-DM; n = 20, M/F = 11/9, mean age 51 years), or newly diagnosed type 2 diabetes mellitus (T2DM; n = 21, M/F = 8/13, mean age 49 years). Fasting serum free carnitine and acylcarnitine concentrations were determined using isotope dilution electrospray ionization mass spectrometry coupled with high performance liquid chromatography.ResultsIn comparison with NGT subjects, Pre-DM and type 2 diabetes subjects showed serum metabonomic changes highlighted by dysregulation of mitochondrial fatty acid combustion. Of the long-chain carnitine esters, significantly higher palmitoylcarnitine (C16), 3-OH-hexadecanoylcarnitine (C16-OH), carnitine C20, carnitine C22, and carnitine C24 concentrations (all P < 0.05) were noted in the newly diagnosed type 2 diabetes group, and even the pre-diabetes group.ConclusionsThis research provides further evidence of alterations in serum acylcarnitine profiles being associated with worse glucoseintolerance. The findings may suggest different degrees of involvement of dysregulated mitochondrial function and incomplete long-chain fatty acid oxidation pathways in the natural course of type 2 diabetes.