3-Month Post-Operative Increase in FGF21 is Predictive of One-Year Weight Loss After Bariatric Surgery.

PURPOSE: The association between bariatric surgery outcome and blood levels of fibroblast growth factor 21 (FGF21) remains controversial. Many patients displayed stable or decreased FGF21 one year after bariatric surgery. Nevertheless, there is often an early increase FGF21 concentration in the post-surgery period. The aim of this study was to investigate the relationship between 3-month FGF21 response and percentage total weight loss at one year after bariatric surgery. MATERIALS AND METHODS: In this prospective monocentric study, a total of 144 patients with obesity grade 2-3 were included; 61% of them underwent a sleeve gastrectomy and 39% a Roux-en-Y gastric bypass. Data analysis was carried out to determine the relation between 3-month plasma FGF21 response and weight loss one year after bariatric surgery. Multiple adjustments were done including degree of weight loss after 3 months. RESULTS: FGF21 significantly increased between baseline and Month 3 (n = 144, p < 10-3), then decreased between Month 3 and Month 6 (n = 142, p = 0.047) and was not different from baseline at Month 12 (n = 142, p = 0.86). The 3-month-FGF21 response adjusted to body weight loss was not different between types of bariatric surgery. The 3-month-FGF21 response was associated to body weight loss at Month 6 (r = -0.19, p = 0.02) and Month 12 (r = -0.34, p < 10-4). After multiple regression analysis, only Month 12 body weight loss remained associated to 3-month FGF21 response (r = -0.3, p = 0.02). CONCLUSION: This study showed that the magnitude of changes in FGF21 at 3 months after bariatric surgery emerged as an independent predictor of one-year body weight loss irrespective of the type of surgery.

Newborn Screening of Primary Carnitine Deficiency: An Overview of Worldwide Practices and Pitfalls to Define an Algorithm before Expansion of Newborn Screening in France.

Primary Carnitine Deficiency (PCD) is a fatty acid oxidation disorder that will be included in the expansion of the French newborn screening (NBS) program at the beginning of 2023. This disease is of high complexity to screen, due to its pathophysiology and wide clinical spectrum. To date, few countries screen newborns for PCD and struggle with high false positive rates. Some have even removed PCD from their screening programs. To understand the risks and pitfalls of implementing PCD to the newborn screening program, we reviewed and analyzed the literature to identify hurdles and benefits from the experiences of countries already screening this inborn error of metabolism. In this study, we therefore, present the main pitfalls encountered and a worldwide overview of current practices in PCD newborn screening. In addition, we address the optimized screening algorithm that has been determined in France for the implementation of this new condition.

Validation of a global quantitative analysis methodology of tryptophan metabolites in mice using LC-MS.

In this study, we validated a method for quantifying 20 tryptophan (Trp) catabolites by liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) in 4 different matrices (urine, serum, intestinal contents and liver). The detection limit for all metabolites ranged between 0.015 and 11.25 nmol/L and the dynamic range of the calibration curves were adjusted to allow quantification of metabolites at endogenous levels. Matrix effects were evaluated using isotope labeled internal standards. Reproducibility in the 4 matrices was characterized by CV = 6.2% with an accuracy of 6.6%. Our method has been applied to the determination and quantification of 20 metabolites concentrations in 5 different mouse compartments (plus cecal contents). Our results show that our approach allows for a global exploration of the Trp metabolism by quantifying a large number of Trp metabolites, at the individual level by multi-matrix approach.