Cytokines may promote or inhibit disease progression in type 1 diabetes. We investigated whether systemic proinflammatory, anti-inflammatory and regulatory cytokines associated differently with fasting and meal-stimulated beta cell function in patients with longer term type 1 diabetes. The beta cell function of 118 patients with type 1 diabetes of duration of 0.75-4.97 years was tested using a standardised liquid mixed meal test (MMT). Serum samples obtained at -5 to 120 min were analysed by multiplex bead-based technology for proinflammatory (IL-6, TNF-alpha), anti-inflammatory (IL-1 receptor antagonist [IL-1RA]) and regulatory (IL-10, TGF-beta(1-3)) cytokines, and by standard procedures for C-peptide. Differences in beta cell function between patient groups were assessed using stepwise multiple regression analysis adjusting for sex, age, duration of diabetes, BMI, HbA(1c) and fasting blood glucose. High fasting systemic concentrations of the proinflammatory cytokines IL-6 and TNF-alpha were associated with increased fasting and stimulated C-peptide concentrations even after adjustment for confounders (p < 0.03). Interestingly, increased concentrations of anti-inflammatory/regulatory IL-1RA, IL-10, TGF-beta(1) and TGF-beta(2) were associated with lower fasting and stimulated C-peptide levels (p < 0.04), losing significance on adjustment for anthropometric variables. During the MMT, circulating concentrations of IL-6 and TNF-alpha increased (p < 0.001) while those of IL-10 and TGF-beta(1) decreased (p < 0.02) and IL-1RA and TGF-beta(2) remained unchanged. The association between better preserved beta cell function in longer term type 1 diabetes and increased systemic proinflammatory cytokines and decreased anti-inflammatory and regulatory cytokines is suggestive of ongoing inflammatory disease activity that might be perpetuated by the remaining beta cells. These findings should be considered when designing immune intervention studies aimed at patients with longer term type 1 diabetes and residual beta cell function.
Fasting and meal-stimulated residual beta cell function is positively associated with serum concentrations of proinflammatory cytokines and negatively associated with anti-inflammatory and regulatory cytokines in patients with longer term type 1 diabetes
Pozzilli P;
2013-01-01
Abstract
Cytokines may promote or inhibit disease progression in type 1 diabetes. We investigated whether systemic proinflammatory, anti-inflammatory and regulatory cytokines associated differently with fasting and meal-stimulated beta cell function in patients with longer term type 1 diabetes. The beta cell function of 118 patients with type 1 diabetes of duration of 0.75-4.97 years was tested using a standardised liquid mixed meal test (MMT). Serum samples obtained at -5 to 120 min were analysed by multiplex bead-based technology for proinflammatory (IL-6, TNF-alpha), anti-inflammatory (IL-1 receptor antagonist [IL-1RA]) and regulatory (IL-10, TGF-beta(1-3)) cytokines, and by standard procedures for C-peptide. Differences in beta cell function between patient groups were assessed using stepwise multiple regression analysis adjusting for sex, age, duration of diabetes, BMI, HbA(1c) and fasting blood glucose. High fasting systemic concentrations of the proinflammatory cytokines IL-6 and TNF-alpha were associated with increased fasting and stimulated C-peptide concentrations even after adjustment for confounders (p < 0.03). Interestingly, increased concentrations of anti-inflammatory/regulatory IL-1RA, IL-10, TGF-beta(1) and TGF-beta(2) were associated with lower fasting and stimulated C-peptide levels (p < 0.04), losing significance on adjustment for anthropometric variables. During the MMT, circulating concentrations of IL-6 and TNF-alpha increased (p < 0.001) while those of IL-10 and TGF-beta(1) decreased (p < 0.02) and IL-1RA and TGF-beta(2) remained unchanged. The association between better preserved beta cell function in longer term type 1 diabetes and increased systemic proinflammatory cytokines and decreased anti-inflammatory and regulatory cytokines is suggestive of ongoing inflammatory disease activity that might be perpetuated by the remaining beta cells. These findings should be considered when designing immune intervention studies aimed at patients with longer term type 1 diabetes and residual beta cell function.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
