ARISCAT and LAS VEGAS risk scores for predicting postoperative pulmonary complications after cardiac surgery: a cohort study.

Background: Postoperative pulmonary complications (PPCs) could lead to morbidity, mortality, and prolonged hospital stay. Different risk-scoring systems are used to predict the identification of patients at risk of developing PPCs. The diagnostic accuracies of the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) and Local Assessment of Ventilatory Management During General Anaesthesia for Surgery (LAS VEGAS) risk scores are compared in prediction of PPCs taking pulmonary complication as the gold standard in cardiac surgery. Materials and methods: A prospective cohort study with consecutive sampling technique. A total of 181 patients were included. Quantitative data is presented as simple descriptive statistics giving mean and standard deviation, and qualitative variables are presented as frequency and percentages. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies are also calculated. Results: Total 181 post-cardiac surgery patients were analyzed. The median [interquartile range] of age, height, weight, and BMI were 60.0 [52.0-67.0] years, 163.0 [156.0-168.0] cm, 71.0 [65.0-80.0] kg and 27.3 [24.2-30.4] kg/m2. 127 (70.2%) were male, and 54 (29.8%) were female. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of ARISCAT for the prediction of PPCs were (94.9%, 4.65%, 76.1%, 22.9% and 73.4%), whereas LAS VEGAS were (97.1%, 4.65%, 76.5%, 33.3% and 75.1%), respectively. Conclusion: Both the ARISCAT and LAS VEGAS risk scores are of limited value in cardiac surgery patients for the prediction of postoperative pulmonary complications, based on the predicted scores in this study.

Laparoscopic myomectomy videos on WebSurg and YouTube: does peer review process make a difference?

Objective: This study aimed to evaluate the quality of laparoscopic myomectomy videos on YouTube and WebSurg. Material and Methods: We searched using the keyword "laparoscopic myomectomy" on WebSurg and selected surgical interventions in the gynecology section. Eleven videos on WebSurg were enrolled. We selected the 22 most-relevant videos on YouTube to create a comparison group, with a ratio of 1:2. Sound in videos, number of subscribers, views, likes, and comments, number of days since videos were uploaded and durations of videos were recorded. View/day, like/view, like/subscriber, and view/subscriber ratios were calculated. The videos were evaluated with usefulness score (US), global quality scoring (GQS), modified discern score (mDS) and laparoscopic surgery video educational guidelines (LAP-VEGaS). Results: The view/day ratio was lower in WebSurg compared to YouTube [1.3 (1.9) vs. 7.5 (30.6), respectively; p=0.039]. No difference was found between WebSurg and YouTube in terms of US, GQS and mDS. On LAP-VEGaS assessment, WebSurg was found to be superior to YouTube in terms of intraoperative findings [2 (1-2) vs. 1 (0-2), p=0.001], additional materials [1 (0-2) vs. 1 (0-1), p=0.041], audio/written commentary [2 (2-2) vs. 2 (0-2), p=0.037], image quality [2 (2-2) vs. 2 (0-2), p=0.023], questions and total score [12 (11-13) vs. 10.5 (4-13), p=0.006]. The proportion of high-quality video was higher in WebSurg compared to YouTube, when the cut-off value of total score of 11 or 12 was used as 10 (100%) vs. 10 (50%), p=0.011 and 9 (90%) vs. 5 (25%), p=0.001, respectively. Conclusion: WebSurg was better compared to YouTube in terms of quality of laparoscopic myomectomy videos.

Evaluation of the educational quality of publicly available online videos on laparoscopic jejunostomy by utilizing the LAP-VEGaS guidelines.

BACKGROUND: Despite its common nature, there is no data on the educational quality of publicly available laparoscopic jejunostomy training videos. The LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) video assessment tool, released in 2020, has been developed to ensure that teaching videos are of appropriate quality. This study applies the LAP-VEGaS tool to currently available laparoscopic jejunostomy videos. METHODS: A retrospective review of YouTube® videos was conducted for "laparoscopic jejunostomy." Included videos were rated by three independent investigators using LAP-VEGaS video assessment tool (0-18). Wilcoxon rank-sum test was used to evaluate differences in LAP-VEGaS scores between video categories and date of publication relative to 2020. Spearman's correlation test was performed to measure association between scores and length, number of views and likes. RESULTS: 27 unique videos met selection criteria. Academic and physician video walkthroughs did not demonstrate a significant difference in median scores (9.33 IQR 6.33, 14.33 vs. 7.67 IQR 4, 12.67, p = 0.3951). Videos published after 2020 demonstrated higher median scores than those published before 2020 (13 IQR 7.5, 14.67 vs. 5 IQR 3, 9.67, p = 0.0081). A majority of videos failed to provide patient position (52%), intraoperative findings (56%), operative time (63%), graphic aids (74%), and audio/written commentary (52%). A positive association was demonstrated between scores and number of likes (rs = 0.59, p = 0.0011) and video length (rs = 0.39, p = 0.0421), but not number of views (rs = 0.17, p = 0.3991). CONCLUSION: The majority of available YouTube® videos on laparoscopic jejunostomy fail to meet the basic educational needs of surgical trainees, and there is no difference between those produced by academic centers or independent physicians. However, there has been improvement in video quality following the release of the scoring tool. Standardization of laparoscopic jejunostomy training videos with the LAP-VEGaS score can ensure that videos are of appropriate educational value with logical structure.

Evaluation of YouTube videos addressing thoracoscopic sympathectomy using the LAP-VEGaS guidelines.

Introduction: The study aims to evaluate the quality of videos addressing thoracoscopic sympathectomy on YouTube® using the LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) criteria. Methods: YouTube was searched using the following keyword: "thoracoscopic sympathectomy" on August 22, 2021. The first 50 videos were analyzed and classified for baseline characteristics and conformity to the LAP-VEGaS checklist. Results: Duration ranged from 19 s to 22 min. The mean number of likes was 14.8 (range 0-80). The mean number of dislikes was 2.5 (range 0-14). The mean number of comments was 8.5 (range 0-67). Nineteen videos did not meet our criteria and were excluded. Regarding the remaining 31 videos, none contained all 16 points of the LAP-VEGaS essential checklist (mean 5.4 points, range 2-14 points), with almost all neglecting preoperative information and outcomes. The mean percentage of conformity was 37% (range 12%-93%). The most viewed videos were not associated with higher conformity to LAP-VEGaS criteria showing only 4/16 points (25%). Conclusions: The quality of videos addressing TS on YouTube®, based on the LAP-VEGaS checklist may be considered not acceptable. Experienced surgeons and surgeons in trainees should be aware of this when using it as a learning resource in their clinical practice.

Comparison of laparoscopic hysterectomy videos on YouTube and WebSurg platforms in terms of educational reliability and quality.

INTRODUCTION: This study aimed to compare the educational reliability of laparoscopic hysterectomy videos on YouTube and WebSurg platforms. MATERIALS AND METHODS: We performed an online search with the keyword "laparoscopic hysterectomy" on YouTube and WebSurg. On WebSurg, the surgical interventions in gynecology section were selected. On YouTube, the most relevant surgical videos according to algorithm of YouTube were included. 22 YouTube and 22 WebSurg videos were included in the study. Technical analysis were performed via calculation of ratios such as view/day, like/view, like/subscriber, view/subscriber, and Video Power Index. The videos were evaluated with usefulness and laparoscopic surgery video educational guidelines (LAP-VEGaS) scoring systems. RESULTS: View/day ratio was higher on YouTube than WebSurg [8.8 (42.1) and 2.5 (5.1), respectively; p = 0.02]. Like/view ratio was lower on YouTube than WebSurg [0.006 (0.01) and 0.01 (0.02), respectively; p = 0.001]. A significant difference was obtained only in the treatment section of usefulness scoring system [0 (0-2), and 0 (0-1) for YouTube and WebSurg, respectively; p = 0.04]. According to LAP-VEGaS, the scores of patient positioning, step-by-step approach, demonstration of intraoperative findings and anatomy, commentary in English parameters were significantly lower on YouTube compared to WebSurg [1(0-2) and 2(2-2), p < 0.001; 2 (0-2) and 2 (2-2), p = 0.004; 2(0-2) and 2(2-2), p < 0.001; 2(0-2) and 2(2-2), p = 0.009, respectively]. The total LAP-VEGaS score of YouTube was lower than WebSurg videos [10(4-16) and 13(10-15), respectively; p = 0.001). DISCUSSION: WebSurg was found to be more reliable platform in terms of educational value and quality of laparoscopic hysterectomy videos compared to YouTube.

Evaluation of YouTube laparoscopic hysterectomy videos as educational materials during the COVID-19 era using the LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) and LAP-VEGaS video assessment tool.

With increasing numbers of laparoscopic hysterectomies, surgical trainees are compelled to learn more about endoscopy. Owing to coronavirus disease-related social distancing requirements, online education has gained prominence. Here, we aimed to investigate the laparoscopic hysterectomy video quality on YouTube using the LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS). YouTube was searched on June 7, 2020 using 'laparoscopic hysterectomy'. Three examiners evaluated videos using Global Operative Assessment of Laparoscopic Skills (GOALS). Subsequently, videos were assessed for their conformity to the LAP-VEGaS and LAP-VEGaS Video Assessment Tool. Interobserver reliability was estimated using intraclass coefficients and Cronbach's alpha. Cochran's Q test was used to determine correlations among quantitative data. The median GOALS score was 21.50. The observers' GOALS scores were significantly correlated. The results showed low conformity to the LAP-VEGaS. YouTube is the most used platform among trainees. The low YouTube video educational quality highlights the necessity for peer review, as trainees increasingly seek such resources during the pandemic.IMPACT STATEMENTWhat is already known on this subject? YouTube is the most commonly used online resource for educational material among surgical trainees. Online videos usually do not undergo a peer-review process. The LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS) may be used to assess the educational quality of surgical videos.What do the results of this study add? To our knowledge, this is the first study on the quality of laparoscopic hysterectomy videos available on YouTube and the first study to evaluate YouTube laparoscopic surgery videos using the LAP-VEGaS Video Assessment Tool (VAT). Our study revealed the low educational quality of YouTube laparoscopic hysterectomy videos. The LAP-VEGaS VAT seems to be a valid and practical tool for assessing online laparoscopic hysterectomy videos.What are the implications of these findings for clinical practice and/or further research? Medical communities, especially tertiary care or academic centres, may upload educational peer-reviewed videos for trainees seeking this type of resource, especially during the coronavirus disease pandemic, as surgical education alternatives are limited.

Comprehensive assessment of the quality and reliability of the ten most-viewed YouTube videos on thoracoscopic lobectomy in children: a comparison from the available videos on a peer-reviewed platform.

BACKGROUND: Surgery residents often consider learning from the operative videos on YouTube, however, the quality of these videos is questionable. We aim to compare the quality and reliability of operative videos on thoracoscopic lobectomy (TL) in children available on YouTube (YT) and WebSurg (WS). METHODS: Using a defined search strategy, the most-viewed YT videos and all available WS videos on TL in children were identified. The quality and reliability of the two groups of videos were compared using the video popularity index (VPI), Journal of American Medical Association (JAMA) benchmark criteria, and LAP-VEGaS quality assessment tool. On the basis of the LAP-VEGaS score, the videos were divided into acceptable quality (score ≥ 11) or poor quality (score < 11). RESULTS: Ten most-viewed YT videos were compared with six relevant videos on WS. The median %VPI among the WS and YT videos were 83.3 (range 71.5-404.4) and 49.4 (range 0-270), respectively (p = 0.017). The median JAMA score of the WS videos was also significantly higher than the YT videos (p = 0.0003). In terms of the LAP-VEGaS scores, all WS videos versus only three YT had an acceptable quality. CONCLUSIONS: As compared to the WS videos, the quality and reliability of the YT videos on TL were significantly poorer.

Evaluation of YouTube Videos in Video-Assisted Thoracoscopic Pulmonary Lobectomy Education.

Background: YouTube® (YouTube, San Bruno, CA) is the most popular, public domain, free access video source. The educational value of the videos is difficult to determine. This study aimed to determine the evaluation of video-assisted thoracoscopic surgery (VATS) lobectomy videos as an educational source on the YouTube platform. Materials and Methods: VATS lobectomy, as a keyword, was searched on YouTube and sorted by the number of visualizations. The top 25 most viewed VATS lobectomy videos uploaded to YouTube were analyzed. The videos were evaluated for critical view of safety (CVS) and LAParoscopic surgery Video Educational GuidelineS (LAP-VEGaS). Results: There were ∼1670 videos for the search term "VATS lobectomy." There were 16 primary surgeons from 8 different countries. Most of the videos (n = 19) were affiliated to an academic institution. There was a positive significant correlation between author's h-index and number of likes. Videos showed conformity to CVS assessment with a rate of 56.5%. LAP-VEGaS conformity to educational content (e.g., audio or written commentary) and case presentation was very low. Conclusions: Using videos of VATS lobectomy in training may have great potential to improve surgical opinion. YouTube is user driven and these videos are not peer reviewed. This article showed issues concerning safety violations. We believe that professional societies should focus on promoting and disseminating valuable educational videos.

Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients: post-hoc analysis of LAS VEGAS study.

BACKGROUND: Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. METHODS: Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. RESULTS: Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (VT) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH20. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. CONCLUSIONS: Neurosurgical patients are ventilated with low VT and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs.

A Novel Approach for Pathway Analysis of GWAS Data Highlights Role of BMP Signaling and Muscle Cell Differentiation in Colorectal Cancer Susceptibility.

Genome-wide association studies (GWAS) have revolutionized the field of gene mapping. As the GWAS field matures, it is becoming clear that for many complex traits, a proportion of the missing heritability is attributable to common variants of individually small effect. Detecting these small effects individually can be difficult, and statistical power would be increased if relevant variants could be grouped together for testing. Here, we propose a VEGAS2Pathway approach that aggregates association strength of individual markers into pre-specified biological pathways. It accounts for gene size and linkage disequilibrium between markers using simulations from the multivariate normal distribution. Pathway size is taken into account via a resampling approach. Importantly, since the approach only requires summary data, the method can easily be applied in all GWASs, including meta-analysis, singleton-based, family-based, and DNA-pooling-based designs. This approach is implemented in a user-friendly web page https://vegas2.qimrberghofer.edu.au and a command line tool. The web implementation uses gene-sets from the gene ontology (GO), curated gene-sets from MSigDB (containing canonical pathways and gene-sets from BIOCARTA, REACTOME, KEGG databases), PANTHER, and pathway commons databases, enabling analysis of a wide range of complex traits. We applied this method on a colorectal cancer GWAS meta-analysis data set (10,934 cases, 12,328 controls) from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). We report statistically significant enrichment of association signal for the 'BMP signaling' and 'muscle cell differentiation' pathways, suggesting a possible role for these pathways onto the risk of colorectal cancer.

Vegas (Verruciform Genital-Associated) Xanthoma: A Comprehensive Literature Review.

INTRODUCTION: Verruciform xanthoma is a wart-like benign lesion. The classic histologic appearance consists of foamy histiocytes within elongated dermal papillae and epithelial acanthosis. The lesion most commonly occurs in the oral cavity, but has been reported in extra-oral sites such as the penis, scrotum, and vulva. The clinical and histologic characteristics of verruciform genital-associated (Vegas) xanthomas of the penis, scrotum, and vulva are reviewed. METHODS: PubMed was used to search the following term: verruciform xanthoma. The relevant papers were obtained and reviewed. RESULTS: There have been 193 cases of genital-associated verruciform xanthomas. There were 164 in men and 29 in women. Similar to verruciform xanthomas of the oral mucosa, they presented as asymptomatic lesions, demonstrated foam cells in the dermal papillae, and were typically managed successfully with surgical excision. CONCLUSION: Verruciform xanthoma is a benign lesion characterized by a wart-like growth that is most commonly seen in the oral mucosa. Verruciform xanthomas of the genital region have been coined Vegas xanthomas. Vegas xanthomas have been reported in association with a variety of diseases, as well as in healthy individuals. Biopsy is required for diagnosis, and complete surgical excision is typically curative.

Gene-based analysis of regulatory variants identifies 4 putative novel asthma risk genes related to nucleotide synthesis and signaling.

BACKGROUND: Hundreds of genetic variants are thought to contribute to variation in asthma risk by modulating gene expression. Methods that increase the power of genome-wide association studies (GWASs) to identify risk-associated variants are needed. OBJECTIVE: We sought to develop a method that aggregates the evidence for association with disease risk across expression quantitative trait loci (eQTLs) of a gene and use this approach to identify asthma risk genes. METHODS: We developed a gene-based test and software package called EUGENE that (1) is applicable to GWAS summary statistics; (2) considers both cis- and trans-eQTLs; (3) incorporates eQTLs identified in different tissues; and (4) uses simulations to account for multiple testing. We applied this approach to 2 published asthma GWASs (combined n = 46,044) and used mouse studies to provide initial functional insights into 2 genes with novel genetic associations. RESULTS: We tested the association between asthma and 17,190 genes that were found to have cis- and/or trans-eQTLs across 16 published eQTL studies. At an empirical FDR of 5%, 48 genes were associated with asthma risk. Of these, for 37, the association was driven by eQTLs located in established risk loci for allergic disease, including 6 genes not previously implicated in disease cause (eg, LIMS1, TINF2, and SAFB). The remaining 11 significant genes represent potential novel genetic associations with asthma. The association with 4 of these replicated in an independent GWAS: B4GALT3, USMG5, P2RY13, and P2RY14, which are genes involved in nucleotide synthesis or nucleotide-dependent cell activation. In mouse studies, P2ry13 and P2ry14-purinergic receptors activated by adenosine 5-diphosphate and UDP-sugars, respectively-were upregulated after allergen challenge, notably in airway epithelial cells, eosinophils, and neutrophils. Intranasal exposure with receptor agonists induced the release of IL-33 and subsequent eosinophil infiltration into the lungs. CONCLUSION: We identified novel associations between asthma and eQTLs for 4 genes related to nucleotide synthesis/signaling and demonstrated the power of gene-based analyses of GWASs.

Patrones espaciales en comunidades de macroinvertebrados acuáticos de la Puna Argentina / Spatial patterns in communities of aquatic macroinvertebrates of Argentinean Puna

ResumenLos macroinvertebrados son un componente vital en los ecosistemas acuáticos, procesan materia orgánica y sirven de alimento para otros organismos como los peces o anfibios. En los sistemas altoandinos, y más específicamente en las vegas o bofedales de Argentina, el conocimiento de la diversidad acuática es escaso o nulo, lo que ha dificultado la interpretación de patrones espaciales a escalas regionales. Típicamente estos ecosistemas se sitúan entre los 3 200 y 5 200 m.s.n.m. en zonas con precipitaciones por debajo de los 300 mm anuales. En este trabajo se realizó la primera descripción cuantitativa de los patrones espaciales de diversidad y composición de macroinvertebrados acuáticos en siete vegas de la Puna Argentina, y su relación con las características del ambiente, de la vegetación circundante y las características físico-químicas del agua. Se recolectaron 3 131 individuos de macroinvertebrados acuáticos, los cuales fueron identificados en 25 taxa que pertenecen a 22 familias y 24 géneros. Entre las plantas vasculares se registraron un total de 62 especies, correspondiente a 20 familias, las graminoides cespitosas fueron la forma de vida más abundante seguida por plantas en cojín o tapete. A partir de un análisis estadístico de ordenamiento NMDS (Non-Metrical Multidimensional Scaling) se segregaron los sitios de muestreo de cada vega. Las vegas ubicadas más al oeste y al sur y con mayor temperatura del agua se agruparon sobre el eje 1, mientras que las vegas con mayor conductividad, sólidos totales disueltos, y concentración de sales en el agua lo hicieron sobre el eje 2. La temperatura del agua fue siempre mayor que la del aire, y no mostró un patrón claro de disminución con la altitud. La altitud no se correlacionó con la abundancia de los macroinvertebrados ni con la riqueza de las plantas. Las formas de vida de plantas como gramíneas dispersas, hierbas rastreras y postradas (que en muchos casos ingresan al cauce de agua) y plantas acuáticas fueron más abundantes en las vegas 4, 5 y 7 y estuvieron asociadas con ciertos taxa de macroinvertebrados que pertenecen a distintos grupos funcionales tróficos como colectores- filtradores, colectores- recolectores y raspadores. Finalmente, las variables de conductividad, sólidos totales disueltos y concentración de sales fueron más elevadas en la vega 6, asociadas a Bivalvia (colector-filtrador) y Hyalella (colector-recolector). A partir de estos resultados se evidencia que los macroinvertebrados presentaron patrones espaciales de diversidad y composición, siendo en primer lugar más importante su relación con la vegetación circundante y en segundo término con las características físico-químicas del agua en siete vegas de la Puna argentina.

AbstractThe macroinvertebrates are a vital component of freshwater ecosystems as they contribute to the process of organic matter while serving as food for other organisms such as fish and amphibians. Unfortunately, the knowledge of the aquatic diversity is poor in the high Andean systems (between 3 200 and 5 200 m.a.s.l. and rainfall below 300 mm per year), especially in the Argentinean peatbogs, a fact which has made difficult the interpretation of spatial patterns on a regional scale. The present study aimed to describe the composition of aquatic macroinvertebrates in seven peatbogs in the Argentinean Puna, and to analyze for the first time their spatial patterns. For this, we studied the relationship of these organisms with the environment, and obtained information about the surrounding vegetation and water physico-chemical characteristics. A total of 3 131 specimens of aquatic macroinvertebrates were collected, representing 25 taxa belonging to 22 families and 24 genera. In addition, 62 species of vascular plants were recorded, belonging to 20 families. The most abundant life form were the tufted grasses, followed by cushions. By using an NMDS (Non-Metrical Multidimensional Scaling) statistical analysis, the sampling sites were ordered in each peatbog as follows. The peatbogs located furthest West and South with higher water temperature were grouped on axis 1, whereas those with higher conductivity, whole water dissolved solids and salt concentration were grouped on axis 2. The water temperature was higher than air temperature at all times, and we found no association between temperature and altitude. The altitude had no correlation with the abundance of macroinvertebrates or with plant richness. Life forms such as scattered graminoids, trailing and prostrate herbs (in many cases they get into the channel) and aquatic plants were more abundant in peatbogs 4, 5 and 7 and they had a correlation with some macroinvertebrates belonging to functional trophic groups such as filter-collectors, collectors and scrapers. Finally, conductivity, whole dissolved solids and salt concentration had their highest value in peatbog 6, where Bivalvia (filter-collector) and Hyalella (collector) were also found. The results obtained attest that these macroinvertebrates displayed diversity and composition spatial patterns, the most important feature being their relationship with the surrounding vegetation, and to a lesser extent, with the physical and chemical traits of water in seven fertile lowlands in the Argentinean Puna. Rev. Biol. Trop. 64 (2): 747-762. Epub 2016 June 01.

The association between LRP-1 variants and chylomicron uptake after a high fat meal.

BACKGROUND AND AIMS: In vitro studies suggest that low density lipoprotein receptor-related protein 1 (LRP1) plays a role in the secondary uptake of chylomicrons. In addition, in vivo studies using LRP-1 knockout mice show these animals exhibit delayed chylomicron clearance. Whether this is true in humans is unknown. We aimed to determine whether genetic variants in LRP-1 are associated with postprandial chylomicron uptake in humans given an oral fat challenge. METHODS AND RESULTS: As many as 817 men and women (mean age +/- standard deviation = 48.4 +/- 16.4 years) forming the study population for the Genetics of Lipid Lowering Drugs Network (GOLDN) study ingested an oral fat load of 700 kilocalories per m² of body surface area at 83% fat, after an 8-h fast. Chylomicrons were measured by nuclear resonance spectroscopy (NMR) at fasting, and 3.5 and 6 h after the meal. 26 Single nucleotide polymorphisms (SNPs) in the LRP-1 gene were genotyped on the Affymetrix 6.0 array. Chylomicrons were, as expected, zero at fasting. Mixed linear models adjusted for age, sex, study site and pedigree tested for associations between LRP-1 SNPs and changes in chylomicron concentrations 3.5-6 h. A gene-based test across all 26 SNPs was conducted which corrected for the linkage disequilibrium (LD) between SNPs. 11 LRP-1 SNPs were significantly associated with the change in chylomicron concentration correction for multiple testing (Q < 0.05). The subsequent gene-based test, was also significant (P = 0.01). CONCLUSION: These results require replication but strongly indicate the role of LRP1 in postprandial lipoprotein uptake and/or clearance.