Children who develop type 1 diabetes early in life show low levels of carnitine and amino acids at birth: does this finding shed light on the etiopathogenesis of the disease?

BACKGROUND: Children and adolescents with overt type 1 diabetes (T1D) have been found to show an altered carnitine profile. This pattern has not previously been analysed in neonates before onset of the disease. MATERIALS AND METHODS: Fifty children who developed T1D during the first 6 years of life, born and living in the Tuscany and Umbria Regions of Italy, were identified and 200 controls were recruited into the study. All newborns were subjected to extended neonatal screening by mass spectrometry at 48-72 hours of life. Four controls for each of the 50 index cases were taken randomly and blinded in the same analytical batch. The panel used for neonatal screening consists of 13 amino acids, free carnitine, 33 acyl-carnitines and 21 ratios. All Guthrie cards are analyzed within two days of collection. RESULTS: Total and free carnitine were found to be significantly lower in neonates who later developed T1D compared to controls. Moreover, the concentrations of the acyl-carnitines - acetyl- L-carnitine (C2), proprionylcarnitine (C3), 3-hydroxyisovalerylcarnitine (C5OH), miristoylcarnitine (C4), palmitoylcarnitine (C16) and stearoylcarnitine (C18) - were also significantly low in the cases vs controls. Furthermore, total amino acid concentrations, expressed as the algebraic sum of all amino acids tested, showed a trend toward lower levels in cases vs controls.