The aim of this study was to determine the impact of the routine use of serum C-peptide in an out-patient clinic setting on individuals with a cliniciandiagnosis of type 1 diabetes. Methods: In this single-centre study, individuals with type 1 diabetes of at least 3 years duration were offered random serum C-peptide testing at routine clinic review. A C-peptide ≥200 pmol/L prompted further evaluation of the individual using a diagnostic algorithm that included measurement of islet cell antibodies and genetic testing. Where appropriate, a trial of anti-diabetic co-therapies was considered. Results: Serum C-peptide testing was performed in 859 individuals (90% of the eligible cohort), of whom 114 (13.2%) had C-peptide ≥200 pmol/L. The cause of diabetes was reclassified in 58 individuals (6.8% of the tested cohort). The majority of reclassifications were to type 2 diabetes (44 individuals; 5.1%), with a smaller proportion of monogenic diabetes (14 individuals; 1.6%). Overall, 13 individuals (1.5%) successfully discontinued insulin, while a further 16 individuals (1.9%) had improved glycaemic control following the addition of co-therapies.The estimated total cost of the testing programme was £23,262 (~€26,053), that is, £27 (~€30) per individual tested. In current terms, the cost of prior insulin therapy in the individuals with monogenic diabetes who successfully stopped insulin was approximately £57,000 (~€64,000). Conclusions/interpretation: Serum C-peptide testing can easily be incorporated into an out-patient clinic setting and could be a cost-effective intervention. C-peptide testing should be strongly considered in individuals with a clinician-diagnosis of type 1 diabetes of at least 3 years duration. K E Y W O R D SC-peptide, misclassification, monogenic diabetes, reclassification, type 1 diabetes, type 2 diabetes, type 1 diabetes genetic risk score Click here to access the podcast for this paper. of 1|FOTEINOPOULOU ET aL. F I G U R E 2 Distribution of C-peptide levels by final diagnosis. Data are from the 114 individuals with C-peptide ≥200 pmol/L. Median C-peptide was highest in those reclassified to type 2 diabetes, but there was substantial overlap between the three groups.

Context: Computed tomography (CT) unenhanced attenuation value of !10 Hounsfield units (HU) has an excellent specificity (98%) to diagnose lipid-rich adrenocortical adenomas (ACAs) with a weaker sensitivity (71%). Objective: To determine from a routine clinical perspective if unenhanced attenuation value is influenced by cortisol secretion in ACAs. Design: This was a retrospective study of cases collected between 2009 and 2012. Setting: This study was conducted in a tertiary-care university hospital. Patients: Seventy-two patients operated on for an ACA (Weiss score %2) were analysed. Thirty-four patients had an ACA oversecreting cortisol (Cush-ACA). Thirty-eight patients had an ACA without cortisol oversecretion (Non Hyper-ACA). Main outcome measure: CT unenhanced attenuation value was correlated with the functional status. The Weiss score items were analysed. Results: Among the 34 patients with a Cush-ACA a minority (nZ7) had an unenhanced attenuation value under 10 HU. Among the high precontrast density (O10 HU) Cush-ACAs, washout analysis after contrast administration was consistent with the benign nature of the tumor in w60% of the cases. Less than 25% clear cells (lipid-rich cells), a Weiss score item, was present in 50% of the Cush-ACAs in favour of a lipid-poor content. Conclusions: Unenhanced attenuation value has a poor sensitivity to diagnose an ACA in case of cortisol oversecretion due to poor lipid content. Nevertheless, the accuracy of washout analysis was preserved in the group of Cush-ACAs.