Human regulatory T cells (Treg cells) that develop from conventional T cells (Tconv cells) following suboptimal stimulation via the T cell antigen receptor (TCR) (induced Treg cells (iTreg cells)) express the transcription factor Foxp3, are suppressive, and display an active proliferative and metabolic state. Here we found that the induction and suppressive function of iTreg cells tightly depended on glycolysis, which controlled Foxp3 splicing variants containing exon 2 (Foxp3-E2) through the glycolytic enzyme enolase-1. The Foxp3-E2–related suppressive activity of iTreg cells was altered in human autoimmune diseases, including multiple sclerosis and type 1 diabetes, and was associated with impaired glycolysis and signaling via interleukin 2. This link between glycolysis and Foxp3-E2 variants via enolase-1 shows a previously unknown mechanism for controlling the induction and function of Treg cells in health and in autoimmunity.

Aim: To analyze whether bone mineral density (BMD) and bone resorption status are influenced by long-term metabolic control and duration of disease in adolescents with long-standing type 1 diabetes mellitus. Methods: Twenty-seven adolescents (age 13.1 ± 1.7 years, duration of diabetes 6.9 ± 3.0 years) were studied. The BMD, expressed as z score, was measured at the lumbar spine (L1–L4) using dual-energy X-ray absorptiometry, while the urinary excretion of total deoxypiridinoline (Dpyd), a marker of bone resorption, was measured by immunoassay and was corrected by creatinine (Cr). Linear and multivariate correlations between lumbar BMD z score or Dpyd/Cr excretion and age and disease variables [short-term (Hb A_1clatest) or long-term (Hb A_{1cwholeduration}) metabolic control, duration, ‘diabetes impact index’ (mean Hb A_{1cwholeduration} x duration of disease in months)] were sought. Results: In diabetic subjects the mean BMD z score was –0.44 ± (SD) 1.02 (95% CI: –0.03; –0.84), and the Dpyd/Cr excretion was not increased. A negative correlation was found between lumbar BMD z score and age (r –0.59; p = 0.001), duration (r –0.39; p = 0.04), and the diabetes impact index (r –0.4; p = 0.04). The Dpyd/Cr ratio correlated negatively with age (r –0.40; p = 0.04) and positively with height velocity (r 0.42; p = 0.04). By using multiple linear regression, age showed a significant inverse correlation with lumbar BMD z score (β = –0.39; p = 0.0005). A negative correlation was found between lumbar BMD z score and Hb A_{1cwholeduration} (β = –0.40; p = 0.02) or diabetes impact index (β = –0.001; p = 0.01). Conclusions: Poor metabolic control may expose adolescents with long-standing type 1 diabetes to the risk of developing osteopenia in adult age. Optimization of metabolic control in growing diabetic children may prevent osteoporosis in later life.

Celiac Disease (CD) occurs in patients with Type 1 Diabetes (T1D) ranging the prevalence of 4.4-11.1% versus 0.5% of the general population. The mechanism of association of these two diseases involves a shared genetic background: HLA genotype DR3-DQ2 and DR4-DQ8 are strongly associated with T1D, DR3-DQ2 with CD. The classical severe presentation of CD rarely occurs in T1D patients, but more often patients have few/mild symptoms of CD or are completely asymptomatic (silent CD). In fact diagnosis of CD is regularly performed by means of the screening in T1D patients. The effects of gluten-free diet (GFD) on the growth and T1D metabolic control in CD/T1D patient are controversial. Regarding of the GFD composition, there is a debate on the higher glycaemic index of gluten-free foods respect to gluten-containing foods; furthermore GFD could be poorer of fibers and richer of fat. The adherence to GFD by children with CD-T1D has been reported generally below 50%, lower respect to the 73% of CD patients, a lower compliance being more frequent among asymptomatic patients. The more severe problems of GFD adherence usually occur during adolescence when in GFD non compliant subjects the lowest quality of life is reported. A psychological and educational support should be provided for these patients.

Glargine could represent an innovative strategy to prevent lung disease progression in CF patients with early glucose derangements. Larger controlled trials are needed to better clarify the effects of insulin on clinical status in CF patients with early glucose derangements.