Fasting and post prandial pancreatic and enteroendocrine hormone levels in obese and non-obese participants.

Circulating insulin levels are known to be increased in people with higher body mass index (BMI) due to effects of adiposity on insulin resistance, whilst gut hormones have a more complex relationship, with fasting peptideYY (PYY) reported to be inversely related to BMI. This study aimed to further explore fasting and post prandial pancreatic and gut hormone concentrations in plasma samples from obese and non-obese participants. Participants with healthy BMI (n=15), overweight BMI (n=29) and obesity (n=161) had samples taken fasting and 30 min post mixed liquid meal for analysis of glucagon-like peptide-1 (GLP-1), PYY, glucose-dependent insulinotropic polypeptide (GIP), insulin and glucagon. Data visualiation used linear discriminant analysis for dimensionality reduction, to visualise the data and assess scaling of each hormone. Fasting levels of insulin, GIP and PYY were shown to be key classifiers between the 3 groups on ANCOVA analysis, with an observation of increased GIP levels in overweight, but not obese participants. In non-obese subjects, fasting GIP, PYY and insulin correlated with BMI, whereas in subjects with obesity only the pancreatic hormones glucagon and insulin correlated with BMI. Concentrations of total GLP-1 in the fasting state correlated strongly with glucagon levels, highlighting potential assay cross-reactivities. The study, which included a relatively large number of subjects with severe obesity, supported previous evidence of BMI correlating negatively with fasting PYY and positively with fasting insulin. The observation of increased fasting GIP levels in overweight but not obese participants deserves further validation and mechanistic investigation.

Motilin fluctuations in healthy volunteers determined by liquid chromatography mass spectrometry.

Introduction: Motilin is a hormone secreted by specialised enteroendocrine cells in the small intestine, and is known to modulate gastrointestinal motility in humans, regulating the migratory motor complex. It is understudied at least in part due to the lack of commercially available immunoassays. Method: A multiplexed liquid chromatography mass spectrometry (LC-MS/MS) method was optimised to measure motilin, insulin, C-peptide, GIP (1-42) and GIP (3-42). Corresponding active ghrelin concentrations were determined by immunoassay. Ten healthy volunteers with no prior history of gastroenterological or endocrine condition attended after overnight fast and had blood samples taken every 15 minutes for 4 hours whilst continuing to fast, and then further sampling for 2 hours following a liquid mixed meal. Hunger scores were taken at each time point using a visual analogue scale. Normal bowel habit was confirmed by 1 week stool diary. Results: Motilin levels fluctuated in the fasting state with an average period between peaks of 109.5 mins (SD:30.0), but with no evidence of a relationship with either ghrelin levels or hunger scores. The mixed meal interrupted cyclical motilin fluctuations, increased concentrations of motilin, insulin, C-peptide, GIP(1-42) and GIP(3-42), and suppressed ghrelin levels. Discussion: This study highlights the utility of LC-MS/MS for parallel measurement of motilin alongside other peptide hormones, and supports previous reports of the cyclical nature of motilin levels in the fasting state and interruption with feeding. This analytical method has utility for further clinical studies into motilin and gut hormone physiology in human volunteers.

Early Metabolic Benefits of Switching Hydrocortisone to Modified Release Hydrocortisone in Adult Adrenal Insufficiency.

Purpose: To compare metabolic effects of modified release hydrocortisone (MR-HC) with standard hydrocortisone (HC) therapies in adults with Adrenal Insufficiency (AI). Methods: Adult patients (n = 12) with AI, established on HC therapy, were recruited from Endocrinology clinics at University Hospitals Coventry and Warwickshire (UHCW), UK. Baseline (HC) metabolic assessments included fasting serum HbA1C, lipid and thyroid profiles, accurate measures of body composition (BodPod), and 24-h continuous measures of energy expenditure including Sleeping Metabolic Rate (SMR) using indirect calorimetry within the Human Metabolism Research Unit, UHCW. All participants then switched HC to MR-HC with repeat (MR-HC) metabolic assessments at 3 months. Paired-sample t-tests were used for data comparisons between HC and MR-HC assessments: P-value <0.05 was considered significant. Results: Following exclusion of 2 participants, analyses were based on 10 participants. Compared with baseline HC data, following 3 months of MR-HC therapy mean fat mass reduced significantly by -3.2 kg (95% CI: -6.0 to -0.4). Mean (SD) baseline HC fat mass vs repeat MR-HC fat mass: 31.9 kg (15.2) vs 28.7 kg (12.8) respectively, P = 0.03. Mean SMR increased significantly by +77 kcal/24 h (95% CI: 10-146). Mean (SD) baseline HC SMR vs repeat MR-HC SMR: 1,517 kcal/24 h (301) vs 1,594 kcal/24 h (344) respectively, P = 0.03. Mean body fat percentage reduced significantly by -3.4% (95% CI: -6.5 to -0.2). Other measures of body composition, energy expenditure, and biochemical analytes were equivalent between HC and MR-HC assessments. Conclusions: In adults with AI, switching from standard HC to MR-HC associates with early metabolic benefits of reduced fat mass and increased SMR.

Systematic review and meta-analysis of the metabolic effects of modified-release hydrocortisone versus standard glucocorticoid replacement therapy in adults with adrenal insufficiency.

CONTEXT: Published studies exploring the metabolic effects of Modified-Release Hydrocortisone (MR-HC) replacement in patients with adrenal insufficiency (AI). OBJECTIVE: To compare metabolic effects of MR-HC with Standard Glucocorticoid (SG) replacement in adults with AI. Randomized control trials (RCTs) were meta-analysed; non-RCT studies described narratively with critical appraisal. DATA SOURCES: PubMed/Medline, EMBASE, CINAHL and CENTRAL were searched to identify relevant articles, published before Aug 2019. STUDY SELECTION: All study types that reported metabolic profile (including anthropometric, glucose and lipid-related parameters), on patients switched from SG to MR-HC replacement. Following independent screening from two reviewers, 390 studies were identified, of which 9 studies were included for review (RCT, n = 2; non-RCT, n = 7). DATA EXTRACTION: Two independent reviewers assessed each paper for bias and data extraction. RESULTS: Meta-analysis from RCTs (n = 2), 104 patients were switched from SG to MR-HC replacement. Combining treatment effects, at 3-months post-therapy switch there was significant reduction in body weight (-0.82 kg; 95% CI: -1.24 kg to -0.40 kg; P < .001) and HbA1c (-0.13%; 95% CI: -0.214% to -0.045%; P = .003). In the sub-group with Diabetes Mellitus (DM), reduction in HbA1C was more pronounced (-0.52%; 95% CI: -0.82% to -0.23%; P < .001). Non-RCT studies showed improved anthropometric measures and glucose metabolism up to 48-months following switch from SG to MR-HC replacement. CONCLUSIONS: In adults with AI, replacement with MR-HC associates with significant improvements in anthropometric measurements and HbA1c compared with SG replacement, particularly those with DM.

Overlap of endocrine hormone expression in the mouse intestine revealed by transcriptional profiling and flow cytometry.

The intestine secretes a range of hormones with important local and distant actions, including the control of insulin secretion and appetite. A number of enteroendocrine cell types have been described, each characterized by a distinct hormonal signature, such as K-cells producing glucose-dependent insulinotropic polypeptide (GIP), L-cells producing glucagon-like peptide-1 (GLP-1), and I-cells producing cholecystokinin (CCK). To evaluate similarities between L-, K-, and other enteroendocrine cells, primary murine L- and K-cells, and pancreatic α- and ß-cells, were purified and analyzed by flow cytometry and microarray-based transcriptomics. By microarray expression profiling, L cells from the upper small intestinal (SI) more closely resembled upper SI K-cells than colonic L-cells. Upper SI L-cell populations expressed message for hormones classically localized to different enteroendocrine cell types, including GIP, CCK, secretin, and neurotensin. By immunostaining and fluorescence-activated cell sorting analysis, most colonic L-cells contained GLP-1 and PeptideYY In the upper SI, most L-cells contained CCK, approximately 10% were GIP positive, and about 20% were PeptideYY positive. Upper SI K-cells exhibited approximately 10% overlap with GLP-1 and 6% overlap with somatostatin. Enteroendocrine-specific transcription factors were identified from the microarrays, of which very few differed between the enteroendocrine cell populations. Etv1, Prox1, and Pax4 were significantly enriched in L-cells vs. K cells by quantitative RT-PCR. In summary, our data indicate a strong overlap between upper SI L-, K-, and I-cells and suggest they may rather comprise a single cell type, within which individual cells exhibit a hormonal spectrum that may reflect factors such as location along the intestine and exposure to dietary nutrients.