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- Boursier, Jerome, et al.
(författare)
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Non-invasive tests accurately stratify patients with NAFLD based on their risk of liver-related events
- 2022
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Ingår i: Journal of Hepatology. - : ELSEVIER. - 0168-8278 .- 1600-0641. ; 76:5, s. 1013-1020
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Previous studies on the prognostic significance of non-invasive liver fibrosis tests in non-alcoholic fatty liver disease (NAFLD) lack direct comparison to liver biopsy. We aimed to evaluate the prognostic accuracy of fibrosis-4 (FIB4) and vibration-controlled transient elastography (VCTE), compared to liver biopsy, for the prediction of liver-related events (LREs) in NAFLD. Methods: A total of 1,057 patients with NAFLD and baseline FIB4 and VCTE were included in a multicenter cohort. Of these patients, 594 also had a baseline liver biopsy. The main study outcome during follow-up was occurrence of LREs, a composite endpoint combining cirrhosis complications and/or hepatocellular carcinoma. Discriminative ability was evaluated using Harrells C-index. Results: FIB4 and VCTE showed good accuracy for the prediction of LREs, with Harrells C-indexes >0.80 (0.817 [0.768-0.866] vs. 0.878 [0.835-0.921], respectively, p = 0.059). In the biopsy subgroup, Harrells C-indexes of histological fibrosis staging and VCTE were not significantly different (0.932 [0.910-0.955] vs. 0.881 [0.832-0.931], respectively, p = 0.164), while both significantly outperformed FIB4 for the prediction of LREs. FIB4 and VCTE were independent predictors of LREs in the whole study cohort. The stepwise FIB4-VCTE algorithm accurately stratified the risk of LREs: compared to patients with "FIB4 <1.30", those with "FIB4 >- 1.30 then VCTE <8.0 kPa" had similar risk of LREs (adjusted hazard ratio [aHR] 1.3; 95% CI 0.3-6.8), whereas the risk of LREs significantly increased in patients with "FIB4 >1.30 then VCTE 8.0-12.0 kPa" (aHR 3.8; 95% CI 1.3-10.9), and even more for those with "FIB4 >-1.30 then VCTE >12.0 kPa" (aHR 12.4; 95% CI 5.1- 30.2). Conclusion: VCTE and FIB4 accurately stratify patients with NAFLD based on their risk of LREs. These non-invasive tests are alternatives to liver biopsy for the identification of patients in need of specialized management. Lay summary: The amount of fibrosis in the liver is closely associated with the risk of liver-related complications in nonalcoholic fatty liver disease (NAFLD). Liver biopsy currently remains the reference standard for the evaluation of fibrosis, but its application is limited by its invasiveness. Therefore, we evaluated the ability of non-invasive liver fibrosis tests to predict liver-related complications in NAFLD. Our results show that the blood test FIB4 and transient elastography stratify the risk of liver-related complications in NAFLD, and that transient elastography has similar prognostic accuracy as liver biopsy. These results support the use of non-invasive liver fibrosis tests instead of liver biopsy for the management of patients with NAFLD.(C) 2022 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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- Meyer, Nicolas, et al.
(författare)
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Behavioural responses of breeding arctic sandpipers to ground-surface temperature and primary productivity
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 755
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Tidskriftsartikel (refereegranskat)abstract
- Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success.
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- Meyer, Nicolas, et al.
(författare)
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Nest attentiveness drives nest predation in arctic sandpipers
- 2020
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129:10, s. 1481-1492
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Tidskriftsartikel (refereegranskat)abstract
- Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this tradeoff or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models to investigate parental care evolution as they may use several parental care strategies. The three main incubation strategies include both parents sharing incubation duties ('biparental'), one parent incubating alone ('uniparental'), or a flexible strategy with both uniparental and biparental incubation within a population ('mixed'). By monitoring the incubation behaviour in 714 nests of seven sandpiper species across 12 arctic sites, we studied the relationship between incubation strategy and nest predation. First, we described how the frequency of incubation recesses (NR), their mean duration (MDR), and the daily total duration of recesses (TDR) vary among strategies. Then, we examined how the relationship between the daily predation rate and these components of incubation behaviour varies across strategies using two complementary survival analysis. For uniparental and biparental species, the daily predation rate increased with the daily total duration of recesses and with the mean duration of recesses. In contrast, daily predation rate increased with the daily number of recesses for biparental species only. These patterns may be attributed to two independent mechanisms: cryptic incubating adults are more difficult to locate than unattended nests and adults departing the nest or feeding close to the nest can draw predators' attention. Our results demonstrate that incubation behaviour as mediated by incubation strategy has important consequences for sandpipers' reproductive success.
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