BACKGROUND: A dysregulation in the metabolism of lipids may be an early marker of autoimmunity in Type 1 Diabetes (T1D). It would be of general importance to identify metabolic patterns that would predict the risk for T1D later in life. The aim of this study was to perform a prospective evaluation of glutamine and phospholipids levels in Brazilian first degree relatives (FDR) of patients with T1D in a mean interval of 5 years.

FINDINGS: Brazilian FDR (n = 30) of patients with T1D were evaluated and blood was sampled to measure the levels of glutamine and phospholipids in the fasting serum by quantitative colorimetric method. The tests were repeated after a mean interval of 5 years and compared to a control group (n = 20). The FDR presented lower levels of phospholipids than controls (p = 0.028), but not of glutamine (p = 0.075). Phospholipids levels decreased over time (p = 0.028) in FDR and were associated with Glutamic acid decarboxylase autoantibody (GADA) titers (p = 0.045), autoantibody positivity (p = 0.008) and PTPN22 polymorphisms (p = 0.014).

CONCLUSIONS: In this Brazilian multiethnic population, there was a significant decrease in phospholipids levels in FDR in patients with T1D during a 5-year prospective follow-up, as well as a significant association between these metabolite, GADA and PTPN22 polymorphisms. For Glutamine no difference was found. These findings suggest that a dysregulation in the metabolism of lipids may precede the onset of the autoimmunity in T1D.