Counter-regulatory responses to postprandial hypoglycaemia in patients with post-bariatric hypoglycaemia vs surgical and non-surgical control individuals

Aims/hypothesis Post-bariatric hypoglycaemia is an increasingly recognised complication of bariatric surgery, manifesting particularly after Roux-en-Y gastric bypass. While hyperinsulinaemia is an established pathophysiological feature, the role of counter-regulation remains unclear. We aimed to assess counter-regulatory hormones and glucose fluxes during insulin-induced postprandial hypoglycaemia in patients with post-bariatric hypoglycaemia after Roux-en-Y gastric bypass vs surgical and non-surgical control individuals. Methods In this case–control study, 32 adults belonging to four groups with comparable age, sex and BMI (patients with post-bariatric hypoglycaemia, Roux-en-Y gastric bypass, sleeve gastrectomy and non-surgical control individuals) underwent a postprandial hypoglycaemic clamp in our clinical research unit to reach the glycaemic target of 2.5 mmol/l 150–170 min after ingesting 15 g of glucose. Glucose fluxes were assessed during the postprandial and hypoglycaemic period using a dual-tracer approach. The primary outcome was the incremental AUC of glucagon during hypoglycaemia. Catecholamines, cortisol, growth hormone, pancreatic polypeptide and endogenous glucose production were also analysed during hypoglycaemia. Results The rate of glucose appearance after oral administration, as well as the rates of total glucose appearance and glucose disappearance, were higher in both Roux-en-Y gastric bypass groups vs the non-surgical control group in the early postprandial period (all p<0.05). During hypoglycaemia, glucagon exposure was significantly lower in all surgical groups vs the non-surgical control group (all p<0.01). Pancreatic polypeptide levels were significantly lower in patients with post-bariatric hypoglycaemia vs the non-surgical control group (median [IQR]: 24.7 [10.9, 38.7] pmol/l vs 238.7 [186.3, 288.9] pmol/l) (p=0.005). Other hormonal responses to hypoglycaemia and endogenous glucose production did not significantly differ between the groups. Conclusions/interpretation The glucagon response to insulin-induced postprandial hypoglycaemia is lower in post-bariatric surgery individuals compared with non-surgical control individuals, irrespective of the surgical modality. No significant differences were found between patients with post-bariatric hypoglycaemia and surgical control individuals, suggesting that impaired counter-regulation is not a root cause of post-bariatric hypoglycaemia

Comparison of high-temperature conversion and equilibration methods for the determination of d31-palmitic acid oxidation in man using continuous-flow isotope ratio mass spectrometry

International audienceDuring nutritional interventions, the ingestion of d31-palmitic acid and H218O allows assessment of dietary fatty acid oxidation from cumulative 2H recovery in urine and estimation of the total body water pool (TBW) from 18O dilution. Continuous flow – isotope ratio mass spectrometry (CF-IRMS) coupled to either equilibration or high temperature conversion techniques (HTC) permits 2H and 18O enrichment measurements in biologicalfluids. Thus it was of great interest to compare these methods applied to the determination of dietary fatty acid oxidation. Linearity, accuracy and correlation between CF-equilibration and CF-HTC were first checked using 2H- and 18O- enriched water and urine samples. Urine samples from 14 subjects were then measured with both methods. 2H- and 18O- raw data were normalised against calibration lines. The final aim was to study the impact of normalised raw results on physiological data (i.e. TBW and d31-palmitate recovery). No significant difference was observed between δ18O‰ and δ2H‰ enrichment measurements depending on the analytical method used. Volumes of TBW calculated from δ18O‰ enrichments measured either with CF-equilibration or CF-HTC were not significantly different with respectively 45.2±1.0L or 45.7±1.0L (mean±sem, p=0.09). Palmitic acidoxidation results obtained from δ2H‰ enrichment measurements and TBW from CFequilibration vs CF-HTC were not significantly different (p≥0.26) with respectively 16.2±1.6% vs 16.2±1.1% at 8h, 18.7±2.0% vs 17.6±1.3% at 12h and 21.7±1.9% vs 21.5±1.3% at 3 days post-dose (mean ± sem).Thus, even if CF-HTC was preferred because it was more practical to carry out, both methods allow study of dietary lipid oxidation in man and generate similar result

Effect of postprandial modulation of glucose availability: short- and long-term analysis

International audienceLow glycaemic index (LGI) foods have been proposed as potential means to decrease postprandial glucose excursions and thus to improve diabetes management. We modulated glucose availability of cereal products and thus their glycaemic index to study the metabolic effect of LGI foods on daylong glucose control acutely and in the long term following a 5-week GI intervention diet in free-living subjects. In this randomised, parallel trial, two groups of nineteen overweight subjects followed an ad libitum 5-week intervention diet in which usual starch was replaced by either LGI or high GI (HGI) starch. During the exploration days (days 1 and 36), subjects ate their assigned 13 C-labelled test breakfast (LGI or HGI), and total and exogenous glucose kinetics (using stable isotopes), postprandial concentrations of glucose, insulin, lipid profile and nutrient oxidation were assessed after the test breakfast and a standardised lunch. At day 1, LGI breakfast significantly decreased post-breakfast glycaemic response with a parallel decrease in exogenous and total glucose appearance (P, 0·05). Post-lunch and post-breakfast glycaemic responses were positively correlated (r 0·79, P,0·0001). Following the 5-week diet, difference between the groups in terms of glucose kinetics and response was maintained (no significant interaction group £ time) but tended to decrease over time for the post-breakfast glycaemic response. Post-lunch and post-breakfast glycaemic responses remained positively correlated (r 0·47, P¼ 0·004). Modulation of postprandial glucose availability at breakfast decreased plasma exogenous glucose appearance and improved glucose control at the subsequent lunch. After 5 weeks, these effects were maintained in healthy subjects but remained to be confirmed in the longer term. Glucose availability: Glucose kinetics: Stable isotope analysis: Second-meal effect: Short-and long-term analysis Rising postprandial glucose excursions are associated with greater risk of developing metabolic disorders, CVD and diabetes (1

Endurance Training with or without Glucose-Fructose Ingestion: Effects on Lactate Metabolism Assessed in a Randomized Clinical Trial on Sedentary Men

Glucose-fructose ingestion increases glucose and lactate oxidation during exercise. We hypothesized that training with glucose-fructose would induce key adaptations in lactate metabolism. Two groups of eight sedentary males were endurance-trained for three weeks while ingesting either glucose-fructose (GF) or water (C). Effects of glucose-fructose on lactate appearance, oxidation, and clearance were measured at rest and during exercise, pre-training, and post-training. Pre-training, resting lactate appearance was 3.6 ± 0.5 vs. 3.6 ± 0.4 mg·kg−1·min−1 in GF and C, and was increased to 11.2 ± 1.4 vs. 8.8 ± 0.7 mg·kg−1·min−1 by exercise (Exercise: p &lt; 0.01). Lactate oxidation represented 20.6% ± 1.0% and 17.5% ± 1.7% of lactate appearance at rest, and 86.3% ± 3.8% and 86.8% ± 6.6% during exercise (Exercise: p &lt; 0.01) in GF and C, respectively. Training with GF increased resting lactate appearance and oxidation (Training × Intervention: both p &lt; 0.05), but not during exercise (Training × Intervention: both p &gt; 0.05). Training with GF and C had similar effects to increase lactate clearance during exercise (+15.5 ± 9.2 and +10.1 ± 5.9 mL·kg−1·min−1; Training: p &lt; 0.01; Training × Intervention: p = 0.97). The findings of this study show that in sedentary participants, glucose-fructose ingestion leads to high systemic lactate appearance, most of which is disposed non-oxidatively at rest and is oxidized during exercise. Training with or without glucose-fructose increases lactate clearance, without altering lactate appearance and oxidation during exercise

Vitamin A Deficiency during the Perinatal Period and First Weeks of Life Modifies Vitamin A and Lipid Postprandial Metabolism in Both Female and Male Young Rats

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3D Chemical Shift-Encoded MRI for Volume and Composition Quantification of Abdominal Adipose Tissue During an Overfeeding Protocol in Healthy Volunteers.

International audienceThe aim of this work was to assess chemical shift-encoded MRI (CSE-MRI) method to quantify content and composition changes of fat storage in healthy volunteers during a 31 days overfeeding protocol while comparing CSE-MRI results with DEXA, MRS and Gas chromatography measurements. A total of 21 volunteers underwent a NMR protocol at 3T with an axial 3D CSE-MRI on abdominal region and spectroscopy acquired on subcutaneous adipose tissue, visceral adipose tissue and liver. The NMR protocol was used to analyze the volume and the fatty acid composition of abdominal adipose tissues, and the fat content in the liver.Abstract available: https://index.mirasmart.com/ISMRM2019/PDFfiles/0108.htm

Docosahexaenoic Acid (DHA) Bioavailability in Humans after Oral Intake of DHA-Containing Triacylglycerol or the Structured Phospholipid AceDoPC®

International audienceAceDoPC((R)) is a structured glycerophospholipid that targets the brain with docosahexaenoic acid (DHA) and is neuroprotective in the experimental ischemic stroke. AceDoPC((R)) is a stabilized form of the physiological 2-DHA-LysoPC with an acetyl group at the sn1 position; preventing the migration of DHA from the sn2 to sn1 position. In this study we aimed to know the bioavailability of C-13-labeled DHA after oral intake of a single dose of C-13-AceDoPC((R)), in comparison with C-13-DHA in triglycerides (TAG), using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to assess the C-13 enrichment of DHA-containing lipids. C-13-DHA enrichment in plasma phospholipids was significantly higher after intake of AceDoPC((R)) compared with TAG-DHA, peaking after 24 h in both cases. In red cells, C-13-DHA enrichment in choline phospholipids was comparable from both sources of DHA, with a maximum after 72 h, whereas the C-13-DHA enrichment in ethanolamine phospholipids was higher from AceDoPC((R)) compared to TAG-DHA, and continued to increase after 144 h. Overall, our study indicates that DHA from AceDoPC((R)) is more efficient than from TAG-DHA for a sustained accumulation in red cell ethanolamine phospholipids, which has been associated with increased brain accretion

Visceral Fat Accumulation During Lipid Overfeeding Is Related to Subcutaneous Adipose Tissue Characteristics in Healthy Men

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Visceral Fat Accumulation During Lipid Overfeeding Is Related to Subcutaneous Adipose Tissue Characteristics in Healthy Men

International audienc

Visceral Fat Accumulation During Lipid Overfeeding Is Related to Subcutaneous Adipose Tissue Characteristics in Healthy Men

International audienc