Gluten-Free Diet Knowledge and Adherence in Adolescents with Celiac Disease: A Cross-Sectional Study.

Objectives: This study examined the relationship between knowledge of, and adherence to, the gluten-free diet (GFD) in a local population of adolescents with celiac disease (CD). The secondary objectives were to identify information sources used to learn about the GFD and to compare adolescents' and parents' knowledge of the GFD. Methods: Adolescents (12-17 years) with CD and their parents from pediatric gastroenterology clinics in Calgary, Alberta, completed an online survey containing a knowledge assessment (Gluten-Free Diet Quiz [GFD-Q]), an adherence scale, questions about GFD information sources, and demographic/clinical information. GFD-Q scores were deemed "sufficient knowledge" with correct identification of 3/3 gluten-containing foods, ≥4/7 gluten-free foods, and ≥ 4/7 foods that may contain gluten; otherwise, scores were termed "insufficient knowledge". Results: Of the 40 adolescent-parent pairs, 15 of 40 adolescents (37%) had sufficient knowledge, and 25 of 40 adolescents (63%) had insufficient knowledge. Within the insufficient knowledge group, 14 of 25 (56%) did not correctly identify enough allowed gluten-free foods. Parents scored higher on the GFD-Q (67% had sufficient knowledge). Adolescents reported overall adherence to the GFD (88%), with adherence being similar between the sufficient and insufficient knowledge groups (80% versus 92%). The most helpful information sources included physicians, another person with CD, parent(s), and Google; apps were infrequently used. Conclusion: Adolescents report good adherence; however, they struggle with GFD knowledge, particularly in identifying gluten-free foods. Further research is required to explore GFD educational tools, including mobile apps and dietician-led teaching sessions.

Review and Critical Appraisal of Clinical Practice Guidelines of Modalities Used in the Diagnosis of Celiac Disease.

Background: There is controversy over the recommendations for specific serological strategies implemented and the need for a biopsy to confirm celiac disease (CeD). We reviewed and appraised the current clinical practice guidelines (CPGs) to assess the quality and reliability of recommendations for CeD diagnosis in pediatric and adult populations. Methods: We searched databases, including MEDLINE, EMBASE, Web of Science, and CINAHL, between December 2010 and January 2021 for CPGs. Four independent reviewers extracted data. Appraisal of Guidelines Research and Evaluation (AGREE II) criteria were applied by two reviewers, and a standardized score was calculated for each of the six domains. A cut-off of 60% was used to identify high-quality guidelines. Results: A total of 654 records were identified, 10 of which were eligible for data extraction. Both adult and pediatric CPGs averaged above 70% for the domains of 'scope and purpose' and 'clarity and presentation'. For 'stakeholder involvement', the mean adult and pediatric CPG scores were below the cut-off. Only one adult-focused guideline exceeded the cut-off for the 'rigour of development' domain. 'Applicability' scores were most alarming, with adult CPGs averaging 21% and pediatric CPGs averaging 23%. Conclusion: Our review and appraisal of the CPGs for the diagnosis of CeD highlight significant discrepancies in clinical recommendations and some concerns regarding methodological rigour, particularly in stakeholder engagement, rigour, and applicability. Creating a Canadian guideline of high methodological quality that overcomes these weaknesses is critical to optimize patient care and ensuring accurate diagnoses in CeD.

Variation in Testing for and Incidence of Celiac Autoimmunity in Canada: A Population-Based Study.

BACKGROUND & AIMS: The incidence of biopsy-confirmed celiac disease has increased. However, few studies have explored the incidence of celiac autoimmunity based on positive serology results. METHODS: A population-based cohort study assessed testing of tissue transglutaminase antibodies (tTG-IgA) in Alberta from 2012 to 2020. After excluding prevalent cases, incident celiac autoimmunity was defined as the first positive tTG-IgA result between 2015 and 2020. Testing and incidence rates for celiac autoimmunity were calculated per 1000 and 100,000 person-years, respectively. Incidence rate ratios (IRRs) were calculated to identify differences by demographic and regional factors. Average annual percent changes (AAPCs) assessed trends over time. RESULTS: The testing rate of tTG-IgA was 20.2 per 1000 person-years and remained stable from 2012 to 2020 (AAPC, 1.2%; 95% confidence interval [CI], -0.5 to 2.9). Testing was higher in female patients (IRR, 1.66; 95% CI, 1.65-1.66), those living in metropolitan areas (IRR, 1.39; 95% CI, 1.38-1.40), and in areas of lower socioeconomic deprivation (lowest compared to highest IRR, 1.24; 95% CI, 1.23-1.25). Incidence of celiac autoimmunity was 33.8 per 100,000 person-years and increased from 2015 to 2020 (AAPC, 6.2%; 95% CI, 3.1-9.5). Among those with tTG-IgA results ≥10 times the upper limit of normal, the incidence was 12.9 per 100,000 person-years. The incidence of celiac autoimmunity was higher in metropolitan settings (IRR, 1.28; 95% CI, 1.21-1.35) and in the least socioeconomically deprived areas compared to the highest (IRR, 1.22; 95% CI, 1.14-1.32). CONCLUSIONS: Incidence of celiac autoimmunity is high and increasing, despite stable testing rates. Variation in testing patterns may lead to underreporting the incidence of celiac autoimmunity in nonmetropolitan areas and more socioeconomically deprived neighborhoods.

Food Environment and Youth Intake May Influence Uptake of Gluten-Free Food Guide Recommendations in Celiac Disease.

A gluten-free (GF) food guide for children and youth (4-18 years) living with celiac disease (CD) has been developed and extensively evaluated by stakeholders, including registered dietitians. A case study analysis was conducted on data from 16 households of youth with CD to examine how factors related to parental food literacy, the home food environment, and food purchasing patterns may influence food guide uptake by Canadian youth with CD and their families. Households were of higher socioeconomic status, parents had good food literacy, and the home food availability of fruits, vegetables and GF grains was diverse. However, households also had a diverse supply of convenience foods and snack options. Youth reported consuming a larger proportion of these foods (>35% dietary intake) and had suboptimal diet quality. Dietary intake of fruits and vegetables were below GF plate model recommendations by over 30%. Despite limited economical barriers, good parental food literacy, and diverse food availability, meeting fruit and vegetable recommendations based on the pediatric GF food guide remains a major challenge. Findings inform that effective strategies and healthy public policies to support the uptake of GF food guide recommendations are needed to improve the health outcomes of youth with CD.

Association Between Celiac Disease and Autism Spectrum Disorder: A Systematic Review.

OBJECTIVE: The aim of the study was to perform a systematic review assessing the research investigating the association between celiac disease (CD) and autism spectrum disorder (ASD). METHODS: A literature search of MEDLINE and EMBASE was performed without limits placed on year or language. Observational studies reporting on the occurrence of CD among patients with ASD and/or the occurrence of ASD among patients with CD were included. Study design, characteristics, diagnostic criteria for ASD and CD, and the frequency of positive cases in the studied sample were recorded. Study quality was assessed using an adapted Newcastle-Ottawa Quality Assessment Scale. Due to substantial heterogeneity between studies, a meta-analysis was not performed. RESULTS: Of the 298 unique citations identified within our search strategy, 17 articles evaluating the association between CD and ASD were included. Of those articles, 13 observed samples of patients with ASD, and 6 observed samples of patients with CD. Overall, most studies had small sample sizes and reported no evidence for an association between the 2 conditions. However, a limited number of population-based studies of higher quality suggested a potential association between CD and ASD. CONCLUSIONS: Most studies assessing an association between CD and ASD are at risk for systematic and/or random error. A potential link has, however, been shown in a handful of high-quality studies, and, therefore, this comorbidity cannot be ruled out. Future studies should recruit larger sample sizes, include precise definitions of CD and ASD, and exclude patients with ASD on a gluten-free diet.

Survey of the initial management of celiac disease antibody tests by ordering physicians.

BACKGROUND: Appropriate interpretation of a positive celiac antibody test by an ordering physician is important in order to institute proper management. We evaluated why children with an initial positive celiac serology were not referred for diagnostic biopsy or followed with serial testing by the ordering physician. METHODS: Consecutive celiac serologies in all patients less than 18 years of age were evaluated over 3.5 years and 775 children with a positive tissue transglutaminase antibody (TTG) were identified. If no management of a positive TTG could be identified, a survey was sent to the ordering physician. Responses were categorized as appropriate or inappropriate management. RESULTS: Of the 775 patients with a positive TTG, 193 (24.9%, 95% CI 21.9-28.1%) received no follow-up management. We contacted 173 ordering physicians and 120 (69%) responded. Of the 120 responses, 55 patients (45.8%, 95% CI 36.8-55.1%) were managed appropriately and 46 (38.3%, 95% CI 29.7-47.7%) were considered to be inappropriately managed when no repeat TTG was obtained within 18 months. Reasons for inappropriate management included: screen considered to be false positive (44.7%), patient was not experiencing symptoms of celiac disease (31.6%), symptoms had resolved (15.8%), results were not indicative of celiac disease (26.3%) and patients started a gluten-free diet with no evaluation of response (15.8%). In 19 patients the TTG was not acted upon for technical reasons. CONCLUSIONS: Positive TTGs require appropriate interventions. These include: subspecialist referral for further evaluation and/or repeat testing to evaluate: 1) treatment response or 2) patients with minimal or no symptoms.

Normalization Time of Celiac Serology in Children on a Gluten-free Diet.

OBJECTIVES: Response to a gluten-free diet (GFD) in children with celiac disease is determined by symptom resolution and normalization of serology. We evaluated the rate of normalization of the transglutaminase (TTG) and antiendomysial (EMA) for children on a GFD after diagnosis. METHODS: Celiac serologies were obtained over 3.5 years after starting a GFD in 228 newly diagnosed children with biopsy-proven celiac disease. Patients were classified into categories based on serology (group A, TTG ≥10 × upper limit of normal [ULN] and EMA ≥ 1:80; group B, TTG ≥10 × ULN and EMA ≤ 1:40; and group C, TTG <10 × ULN) and by severity of histologic injury at diagnosis. RESULTS: In children with the highest serology at diagnosis (group A), 79.7% had an abnormal TTG at 12 months after diagnosis (mean TTG 12 months, 68.8 ±â€Š7.3, normal <20 kU/L). At 2 years, an abnormal TTG persisted in 41.7%. In contrast, only 35% of children with the lowest serology at diagnosis (group C) displayed an abnormal TTG at 12 months (mean TTG 14.3 ±â€Š1.9 kU/L). In those with the most severe mucosal injury, Marsh 3C, 74.2% and 33.2% had an abnormal TTG at 1 and 2 years. CONCLUSIONS: Normalization of celiac serology took >1 year in approximately 75% of GFD-compliant children with the highest celiac serology or most severe mucosal injury at diagnosis. Clinicians must consider serology and histology at diagnosis to properly evaluate response to GFD.

Evaluation of the ESPGHAN Celiac Guidelines in a North American Pediatric Population.

OBJECTIVES: We retrospectively examined the performance of the tissue transglutaminase (TTG), endomysial antibody (EMA) tests, and the ESPGHAN (European Society of Paediatric Gastroenterology, Hepatology and Nutrition) nonbiopsy criteria in a pediatric population. METHODS: Consecutive celiac serologies and corresponding intestinal biopsy results were obtained on children <18 years old over 3.5 years. Patients were classified into three categories: positive TTG, negative TTG, and IgA deficiency. RESULTS: Of the 17,505 patients with celiac serology performed, 775 had a positive TTG, 574 with a negative TTG were biopsied, and 25 were IgA deficient. Of the patients with a TTG ≥10 × upper limit of normal (ULN), positive EMA, and symptoms, 98.2% had biopsies consistent with celiac disease (CD). Four human leukocyte antigen (HLA) DQ2/DQ8-positive patients who met the ESPGHAN nonbiopsy criteria did not have CD. In the group with a TTG 3-10 × ULN, 75.7% EMA-positive patients and only 40% EMA-negative patients had CD (P<0.001). Of those with a TTG 1-3 × ULN, 52.2% EMA-positive patients vs. only 13.3% EMA-negative patients had CD (P<0.01). Of the patients with bulbar and duodenal biopsies, 9.8% had CD confined only in the bulb, especially those with a low titer TTG (P<0.01). CD prevalence in our cohort was 34.6%. Sensitivity, specificity, and positive predictive value of the TTG were 98.7%, 86.4%, and 79.4%, respectively. CONCLUSIONS: The TTG is a very sensitive screen for CD, but positive predictive value improves with a positive EMA titer. To apply the new ESPGHAN guidelines, clinicians must understand the performance of their celiac serology tests.

A systematic review and meta-analysis of the nutrient content of preterm and term breast milk.

BACKGROUND: Breast milk nutrient content varies with prematurity and postnatal age. Our aims were to conduct a meta-analysis of preterm and term breast milk nutrient content (energy, protein, lactose, oligosaccharides, fat, calcium, and phosphorus); and to assess the influence of gestational and postnatal age. Additionally we assessed for differences by laboratory methods for: energy (measured vs. calculated estimates) and protein (true protein measurement vs. the total nitrogen estimates). METHODS: Systematic review results were summarized graphically to illustrate the changes in composition over time for term and preterm milk. Since breast milk fat content varies within feeds and diurnally, to obtain accurate estimates we limited the meta-analyses for fat and energy to 24-hour breast milk collections. RESULTS: Forty-one studies met the inclusion criteria: 26 (843 mothers) preterm studies and 30 (2299 mothers) term studies of breast milk composition. Preterm milk was higher in true protein than term milk, with differences up to 35% (0.7 g/dL) in colostrum, however, after postnatal day 3, most of the differences in true protein between preterm and term milk were within 0.2 g/dL, and the week 10-12 estimates suggested that term milk may be the same as preterm milk by that age. Colostrum was higher than mature milk for protein, and lower than mature milk for energy, fat and lactose for both preterm and term milk. Breast milk composition was relatively stable between 2 and 12 weeks. With milk maturation, there was a narrowing of the protein variance. Energy estimates differed whether measured or calculated, from -9 to 13%; true protein measurement vs. the total nitrogen estimates differed by 1 to 37%. CONCLUSIONS: Although breast milk is highly variable between individuals, postnatal age and gestational stage (preterm versus term) were found to be important predictors of breast milk content. Energy content of breast milk calculated from the macronutrients provides poor estimates of measured energy, and protein estimated from the nitrogen over-estimates the protein milk content. When breast milk energy, macronutrient and mineral content cannot be directly measured the average values from these meta-analyses may provide useful estimates of mother's milk energy and nutrient content.

Impact of radial artery cannulation for coronary angiography and angioplasty on radial artery function.

The radial artery is commonly used as a conduit in coronary artery bypass grafting. No data exist on the effects of radial sheath insertion on radial artery function. Because many patients considered for coronary artery bypass grafting have had previous radial procedures, it is important to understand any effects radial sheath insertion may have on radial artery function. Twenty-two patients who underwent elective coronary angiography or angioplasty with a 6Fr sheath through the right radial artery were studied. Radial artery function was assessed using ultrasound to measure flow-mediated dilation (FMD). Reactive hyperemia was produced by 5-minute cuff inflation on the arm to suprasystolic pressures. Radial artery diameter was measured at rest and 1 minute after cuff deflation. FMD was expressed as percent change in radial diameter compared with at rest. In all cases, the left radial artery was studied as a control. Patients were studied before sheath insertion, immediately after sheath insertion, and 6 weeks after sheath insertion. The FMD of the cannulated arm was 13.2% before sheath insertion versus 3.6% immediately after sheath insertion (p <0.01) and 0.2% (p <0.01) 9 weeks after sheath insertion. In contrast, there were no significant changes in the noncannulated arm at either time point. In conclusion, radial artery sheath insertion for coronary angiography or angioplasty results in immediate and persistent blunting of FMD, suggesting severe vasomotor dysfunction. Radial artery sheath insertion has important effects on radial artery function that must be considered when selecting radial conduits for coronary artery bypass grafting.

Cardiac sarcoplasmic reticulum calcium release and load are enhanced by subcellular cAMP elevations in PI3Kgamma-deficient mice.

We recently showed that phosphoinositide-3-kinase-gamma-deficient (PI3Kgamma-/-) mice have increased cardiac contractility without changes in heart size compared with control mice (ie, PI3Kgamma+/+ or PI3Kgamma+/-). In this study, we show that PI3Kgamma-/- cardiomyocytes have elevated Ca2+ transient amplitudes with abbreviated decay kinetics compared with control under field-stimulation and voltage-clamp conditions. When Ca2+ transients were eliminated with high Ca2+ buffering, L-type Ca2+ currents (I(Ca,L)), K+ currents, and action potential duration (APD) were not different between the groups, whereas, in the presence of Ca2+ transients, Ca2+-dependent phase of I(Ca,L) inactivation was abbreviated and APD at 90% repolarization was prolonged in PI3Kgamma-/- mice. Excitation-contraction coupling (ECC) gain, sarcoplasmic reticulum (SR) Ca2+ load, and SR Ca(2+) release fluxes measured as Ca2+ spikes, were also increased in PI3Kgamma-/- cardiomyocytes without detectable changes in Ca2+ spikes kinetics. The cAMP inhibitor Rp-cAMP eliminated enhanced ECC and SR Ca2+ load in PI3Kgamma-/- without effects in control myocytes. On the other hand, the beta-adrenergic receptor agonist isoproterenol increased I(Ca,L) and Ca2+ transient equally by approximately 2-fold in both PI3Kgamma-/- and PI3Kgamma+/- cardiomyocytes. Our results establish that PI3Kgamma reduces cardiac contractility in a highly compartmentalized manner by inhibiting cAMP-mediated SR Ca2+ loading without directly affecting other major modulators of ECC, such as AP and I(Ca,L).

Phosphoinositide 3-kinase gamma-deficient mice are protected from isoproterenol-induced heart failure.

BACKGROUND: We have recently shown that genetic inactivation of phosphoinositide 3-kinase gamma (PI3Kgamma), the isoform linked to G-protein-coupled receptors, results in increased cardiac contractility with no effect on basal cell size. Signaling via the G-protein-coupled beta-adrenergic receptors has been implicated in cardiac hypertrophy and heart failure, suggesting that PI3Kgamma might play a role in the pathogenesis of heart disease. METHODS AND RESULTS: To determine the role for PI3Kgamma in hypertrophy induced by G-protein-coupled receptors and cardiomyopathy, we infused isoproterenol, a beta-adrenergic receptor agonist, into PI3Kgamma-deficient mice. Compared with controls, isoproterenol infusion in PI3Kgamma-deficient mice resulted in an attenuated cardiac hypertrophic response and markedly reduced interstitial fibrosis. Intriguingly, chronic beta-adrenergic receptor stimulation triggered impaired heart functions in wild-type mice, whereas PI3Kgamma-deficient mice retained their increased heart function and did not develop heart failure. The lack of PI3Kgamma attenuated the activation of Akt/protein kinase B and extracellular signal-regulated kinase 1/2 signaling pathways in cardiac myocytes in response to isoproterenol. beta1- and beta2-adrenergic receptor densities were decreased by similar amounts in PI3Kgamma-deficient and control mice, suggesting that PI3Kgamma isoform plays no role in the downregulation of beta-adrenergic receptors after chronic beta-adrenergic stimulation. CONCLUSIONS: Our data show that PI3Kgamma is critical for the induction of hypertrophy, fibrosis, and cardiac dysfunction function in response to beta-adrenergic receptor stimulation in vivo. Thus, PI3Kgamma may represent a novel therapeutic target for the treatment of decreased cardiac function in heart failure.

Regulation of cardiac excitation-contraction coupling by action potential repolarization: role of the transient outward potassium current (I(to)).

The cardiac action potential (AP) is critical for initiating and coordinating myocyte contraction. In particular, the early repolarization period of the AP (phase 1) strongly influences the time course and magnitude of the whole-cell intracellular Ca(2+) transient by modulating trans-sarcolemmal Ca(2+) influx through L-type Ca(2+) channels (I(Ca,L)) and Na-Ca exchangers (I(Ca,NCX)). The transient outward potassium current (I(to)) has kinetic properties that make it especially effective in modulating the trajectory of phase 1 repolarization and thereby cardiac excitation-contraction coupling (ECC). The magnitude of I(to) varies greatly during cardiac development, between different regions of the heart, and is invariably reduced as a result of heart disease, leading to corresponding variations in ECC. In this article, we review evidence supporting a modulatory role of I(to) in ECC through its influence on I(Ca,L), and possibly I(Ca,NCX). We also discuss differential effects of I(to) on ECC between different species, between different regions of the heart and in heart disease.