Palmitate-induced insulin hypersecretion and later secretory decline associated with changes in protein expression patterns in human pancreatic islets

In obese children with high circulating concentrations of free fatty acid palmitate we have observed that insulin levels at fasting and in response to a glucose challenge were several times higher than in obese children with low concentrations of the fatty acid as well as in lean controls. Declining and even insufficient insulin levels were observed in obese adolescents with high levels of the fatty acid. In isolated human islets exposed to palmitate we have observed insulin hypersecretion after 2 days exposure. In contrast, insulin secretion was reduced from the islets after 7 days culture in the presence of the fatty acid. This study aimed at identifying islet-related biological events potentially linked with the observed insulin hypersecretion and later secretory decline in these obese children and adolescents using the islet model. We analyzed protein expression data obtained from human islets exposed to elevated palmitate levels for 2 and 7 days by an improved methodology for statistical analysis of ...