Obestatin Levels Are Associated With C-Peptide and Antiinsulin Antibodies at the Onset, Whereas Unacylated and Acylated Ghrelin Levels Are Not Predictive of Long-Term Metabolic Control in Children With Type 1 Diabetes

Abstract

Ghrelin secretion is altered at the onset and after the start of insulin therapy in children with type 1 diabetes. Contemporary regulation of acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (OBST) remains undefined in this disease. It is unknown as to whether they could be good predictors of changes in glucose and metabolic control. This was a longitudinal study conducted in a tertiary care center. AG, UAG, and OBST were measured at baseline and after 2 years of follow-up in 51 children and adolescents with a history of type 1 diabetes extending beyond 1 year. A total of 33 healthy matched subjects were used as controls. Age-, puberty-, and body mass index-adjusted UAG levels were lower (P < .005) and OBST levels were higher (P < .009) in children with type 1 diabetes, with respect to controls. AG levels were similar to controls, but all ratios of the three peptides are altered in diabetic patients. OBST (P < .05) was negatively correlated with C-peptide (P < .05) and insulin antibodies (P < .008) at the onset of diabetes. In diabetic patients, baseline AG and UAG levels were negatively correlated with insulin dosage in the short and long term (P < .001). AG, but not OBST, was positively correlated with C-peptide levels 2 years after diagnosis (P < .05). Overall, the peptides were not predictive of glucose and metabolic control. UAG, AG, OBST, and their ratios are differently regulated in children with type 1 diabetes, suggesting a role in the metabolic balance of the disease, with insulin a likely regulator of AG and UAG. The peptides do not appear to be good long-term predictors of glucose control, with further investigations needed to explain whether OBST could be a precocious predictor of islet dysfunction.