Disturbance of glucose metabolism and diabetes is an increasing complication in adult patients with cystic fibrosis (CF). The aim of the present study was to evaluate the impact of insulin and glucagon-like peptide-1 (GLP-1) secretion on early disturbance of glucose metabolism and clinical status in an unselected cohort of CF patients. 34 adult CF patients and 10 matched healthy subjects underwent an oral glucose tolerance test. Blood samples were taken to measure indices for insulin secretion and insulin sensitivity. Metabolic parameters were correlated with anthropometric and clinical data. In CF patients, there was a decrease in first phase insulin secretion (FPIR) with progressive delay of insulin peak, which was correlated with worsening glucose tolerance (Stumvoll index: normal glucose tolerance: 450±291; impaired fasting glucose: 252±203; impaired glucose tolerance: 309±254; CF related diabetes: 18±41; controls: 950±388) and high early post-challenge glucose peak (p<0.01 vs. controls). However, total insulin secretory capacity was not decreased in CF patients resulting to low glucose levels in the late phase (120-180 min). We found neither a difference in basal or maximal GLP-1 levels nor in insulin resistance between study groups. Maximum glucose levels correlated with impaired FEV1 (rs=-0.5, p=0.002). Our data demonstrate that alteration of FPIR, but not insulinopenia, insulin resistance, or disturbed GLP-1 secretion is present in the prediabetic state in CF patients. Correlation between high glucose levels and worse clinical status suggest that diabetes treatment should be initiated more early in the state of glucose intolerance.
For analysis of trace compounds, stable isotope dilution assays (SIDAs) have gained increasing importance in the past years. This methodology is based on the use of stable isotopically labelled analogues of the analytes as internal standards (IS). To take the mycotoxins patulin and ochratoxin A as examples, the benefits of SIDAs were demonstrated both for foods and for clinical analyses.Regarding PAT, an isotopomer labelled with(13)C was used as IS and enabled quantitation of the mycotoxin in tissues and blood. By applying this technology, a fast passive diffusion into tissue was proven with the model of the perfused rat stomach. Furthermore, rapid degradation of PAT was observed when it was reacted with blood, which was attributed to the formation of PAT-GSH adducts detected by LC-MS/MS.For OTA, a SIDA was based on the use of [(2)H5]-OTA as the IS and proved to be more accurate when compared to alternative methods such as HPLC-FD or ELISA. In contrast to PAT, OTA was detectable in human blood and urine samples. Under the assumption that the majority of OTA is circulating in blood, an urinary excretion rate of about 1% of the whole body content per day was calculated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.