In 129 children, aged 12.6 +/- 3.8 years, affected by type 1 diabetes mellitus, the levels of dehydroepiandrosterone sulfate (DHEAS), cortisol, T3, fT3, T4, fT4, rT3, TSH, cholesterol, and triglycerides were evaluated and compared with those of a control group of 458 healthy age-matched children. The results were also correlated with hemoglobin HbA1C. The DHEAS-standard deviation score (DHEAS-SDS; -0.36 +/- 0.77) was significantly different from zero in diabetic children, while the cortisol serum level was higher than in control subjects (485 +/- 94 vs 359 +/- 132 nmol/l). Moreover, the DHEAS-SDS and DHEAS-SDS/cortisol ratio correlated negatively with HbA1c. Diabetic patients also showed lower T3 values (2.22 +/- 0.4 vs 2.32 +/- 0.3 nmol/l) and a higher rT3/T3 ratio (0.17 +/- 0.09 vs 0.15 +/- 0.05) than controls. There was a negative correlation between T3 and HbA1C. Cholesterol (4.77 +/- 1.08 vs 4.51 +/- 0.76 mmol/l) and triglycerides (0.82 +/- 0.53 vs 0.63 +/- 0.37 g/L) levels were higher in diabetic children and positively correlated with HbA1c, but not with DHEAS-SDS. We can therefore conclude that diabetes, particularly if poorly controlled, tends to induce a dissociation of cortisol and DHEAS secretion and a low T3 syndrome, similar to that seen in other illnesses.