Prospective comparison of diagnostic tests for bile acid diarrhoea.

BACKGROUND: Bile acid diarrhoea is often missed because gold standard nuclear medicine tauroselcholic [75-Se] acid (SeHCAT) testing has limited availability. Empirical treatment effect has unknown diagnostic performance, whereas plasma 7α-hydroxy-4-cholesten-3-one (C4) is inexpensive but lacks sensitivity. AIMS: To determine diagnostic characteristics of empirical treatment and explore improvements in diagnostics with potential better availability than SeHCAT. METHODS: This diagnostic accuracy study was part of a randomised, placebo-controlled trial of colesevelam. Consecutive patients with chronic diarrhoea attending SeHCAT had blood and stool sampled. Key thresholds were C4 > 46 ng/mL and SeHCAT retention ≤10%. A questionnaire recorded patient-reported empirical treatment effect. We analysed receiver operating characteristics and explored machine learning applied logistic regression and decision tree modelling with internal validation. RESULTS: Ninety-six (38%) of 251 patients had SeHCAT retention ≤10%. The effect of empirical treatment assessed with test results for bile acid studies blinded had 63% (95% confidence interval 44%-79%) sensitivity and 65% (47%-80%) specificity; C4 > 46 ng/mL had 47% (37%-57%) and 92% (87%-96%), respectively. A decision tree combining C4 ≥ 31 ng/mL with ≥1.1 daily watery stools (Bristol type 6 and 7) had 70% (51%-85%) sensitivity and 95% (83%-99%) specificity. The logistic regression model, including C4, the sum of measured stool bile acids and daily watery stools, had 77% (58%-90%) sensitivity and 93% (80%-98%) specificity. CONCLUSIONS: Diagnosis of bile acid diarrhoea using empirical treatment was inadequate. Exploration suggested considerable improvements in the sensitivity of C4-based testing, offering potential widely available diagnostics. Further validation is warranted. CLINICALTRIALS: gov: NCT03876717.

Osteoporosis and bone fractures in patients with celiac disease: A nationwide cohort study.

Celiac disease (CD) is an autoimmune disease caused by an abnormal immune response triggered by ingestion of gluten. Treatment of CD is a lifelong gluten-free diet. Both diagnosed and undiagnosed CD has been found to be associated with reduced bone mineral density, which can lead to an increased risk of fractures. We therefore aimed to investigate the association of CD and the risk of fractures and osteoporosis in Denmark in a nationwide registry-based study. We identified all patients with CD (ICD-10 code K90.0) between 2000 and 2018 and included those with at least two contacts with a CD diagnosis. In total, 9397 CD patients and 93,964 randomly selected age- and sex-matched (1:10) references from the general population were identified. The overall hazard ratio (HR) of developing osteoporosis in CD patients compared with matches was 5.39 (95 % confidence interval (CI): 4.89, 5.95), however when excluding events of osteoporosis occurring within 12 months from the date of diagnosis the overall HR was reduced to 3.87 (95 % CI: 3.44, 4.33). The HR for major osteoporotic fractures was 1.37 (95 % CI: 1.25, 1.51) and for any fractures 1.27 (95 % CI: 1.18, 1.36). For osteoporosis, major osteoporotic fractures, and any fracture prior to diagnosis of CD the odds ratios comparing CD patients with matches were 4.32 (95 % CI: 3.64, 4.68), 1.29 (95 % CI: 1.21, 1.37) and 1.34 (95 % CI: 1.27, 1.41), respectively. Thus, this study showed an increased risk of osteoporosis and bone fractures among individuals with CD, both before and after diagnosis of CD. These results underline that the risk of osteoporosis should be considered in the clinical management of patients with CD and that early diagnosis and treatment could be important.

Celiac disease and risk of neuropsychiatric disorders: A nationwide cohort study.

INTRODUCTION: Previous studies have indicated that patients with celiac disease (CD) may have an increased risk of developing neuropsychiatric disorders. However, large-scale epidemiologic studies on the topic are still scarce. We aimed to examine the association between CD and development of neuropsychiatric disorders during an 18-year follow-up period. METHODS: We conducted a prospective cohort study. All Danish patients with an incident diagnosis of CD (ICD-10 K90.0) from 2000 to 2018 were identified in nationwide registries and compared with birthdate- and sex-matched controls (variable 1:10 ratio) for the development of a neuropsychiatric disease. Individual neuropsychiatric diseases were also examined. The absolute risk was calculated by the cumulative incidence, and the relative risk was estimated in Cox regression models. RESULTS: We identified a cohort of 6329 patients with CD diagnosed from 2000 to 2018 and 63,287 matches at risk for developing incident neuropsychiatric disorders. The cumulative incidence of development of any neuropsychiatric disorder was 3.9%, 14.9%, 24.8%, 35.9% after 1, 5, 10, and 15 years of follow-up, respectively, in patients with CD compared with 1.8%, 9.3%, 18.3%, and 27.0% in controls. Gray's test for equality p < 0.001. The relative risk was HR = 1.58 (95% confidence interval: 1.49-1.68) in CD patients compared with matches. For the individual outcomes, CD was associated with an increased relative risk of developing anxiety, depression, eating disorders, epilepsy, migraine, and stress. We also found indications of an increased relative risk of ADHD, alcoholism, bipolar disorders, and drug abuse, although the associations were less clear. No associations were found between CD and dementia, Parkinson's disease, and schizophrenia. CONCLUSIONS: In this nationwide study including more than 6000 patients with CD, we found an increased risk of development of a neuropsychiatric disorder compared with age- and sex-matched controls. The causes and the clinical relevance of these associations remain to be elucidated.

Efficacy and safety of colesevelam for the treatment of bile acid diarrhoea: a double-blind, randomised, placebo-controlled, phase 4 clinical trial.

BACKGROUND: Bile acid diarrhoea is a common but overlooked cause of chronic watery diarrhoea. Plasma 7α-hydroxy-4-cholesten-3-one (C4) is an alternative to the gold standard tauroselcholic [75Se] acid (SeHCAT) test. Low-certainty evidence supports sequestrant treatment, including colesevelam. We aimed to determine the efficacy and safety of colesevelam in bile acid diarrhoea. METHODS: In this randomised, double-blind, placebo-controlled, investigator-initiated phase 4 trial of the sequestrant colesevelam in bile acid diarrhoea (SINBAD), we enrolled consecutive patients aged 18-79 years without inflammatory bowel disease attending SeHCAT testing for suspected bile acid diarrhoea at four Danish secondary care centres. Participants were randomly allocated 1:1 to receive 12 days of treatment with colesevelam (overencapsulated tablets of 625 mg) or placebo, with the starting dose of two capsules twice daily and titrated to effect during the first 5 days of treatment. A pharmacist independent of the clinical investigators generated a randomisation list on the web page randomization.com using block randomisation (randomisation was not stratified). C4 and SeHCAT diagnostic results were blinded during treatment. We treated all patients with diarrhoea, with a daily mean of 3·0 or more bowel movements or 1·0 or more watery bowel movements (Bristol stool scale type 6 and 7). Remission was defined as the absence of both these criteria during treatment days 6-12. The primary outcome was the intention-to-treat remission rate in bile acid diarrhoea diagnosed by C4 concentration greater than 46 ng/mL. A secondary outcome was the intention-to-treat remission rate in bile acid diarrhoea diagnosed by SeHCAT retention of 10% or less. This trial is registered with ClinicalTrials.gov, NCT03876717. FINDINGS: Between Oct 25, 2018, and July 1, 2021, 168 patients were randomly assigned to receive colesevelam (n=84) or placebo (n=84). 41 patients had C4 concentration greater than 46 ng/mL (22 assigned to the colesevelam group and 19 to the placebo group). For the C4-defined primary outcome, 14 (64%) of 22 participants receiving colesevelam versus three (16%) of 19 participants receiving placebo achieved remission (adjusted odds ratio 9·1, 95% CI 1·9-62·8; p=0·011). For the SeHCAT-defined secondary outcome, 75 of the 168 participants had retention of less than 10% (37 assigned to the colesevelam group and 38 assigned to the placebo group); 22 (59%) of 37 participants receiving colesevelam achieved remission versus five (13%) of 38 participants receiving placebo (adjusted odds ratio 11·1, 95% CI 3·4-45·6; p=0·00020). There were no serious adverse events. Common adverse events were transient. For patients receiving colesevelam within the primary outcome population, five had abdominal pain, nine had bloating, and four had nausea. For patients receiving placebo, four had abdominal pain, four had bloating, and one had nausea. No participants with bile acid diarrhoea withdrew due to adverse events. INTERPRETATION: Colesevelam was superior to placebo at inducing remission of bile acid diarrhoea diagnosed with C4 concentration greater than 46 ng/mL. Secondary outcome data suggest similar efficacy treating SeHCAT-defined bile acid diarrhoea. Colesevelam was safe during the treatment. FUNDING: Fabrikant Vilhelm Pedersen og hustrus mindelegat; recommended by the Novo Nordisk Foundation.

Biochemical abnormalities among patients referred for celiac disease antibody blood testing in a primary health care setting.

To investigate possible biochemical abnormalities associated with celiac disease (CD) antibody positivity in a primary health care setting and thereby identify predictors that could potentially reduce diagnostic delay and underdiagnosis of CD. This observational cohort study included measurements of CD antibodies in the Copenhagen Primary Care Laboratory (CopLab) database from 2000 to 2015; CD antibody positivity was defined as tissue transglutaminase antibody IgA or IgG ≥ 7 kU/L and/or deamidated gliadin peptide antibody IgG ≥ 10 kU/L. Individuals with a prior diagnosis of CD were excluded. We examined differences between individuals with positive and negative CD antibody tests regarding the results of biochemical tests performed six months before and one month after the date of the CD antibody test. We identified 76,265 measurements of CD antibodies during 2000-2015, and 57,061 individuals met the inclusion criteria (706 antibody-positive and 56,355 antibody-negative). We found lower ferritin, hemoglobin, cobalamin and folic acid levels and higher levels of transferrin, ALAT (alanine transaminase), and alkaline phosphate among individuals with a positive CD antibody test. Furthermore, we illustrated more measurements below the sex-specific reference intervals for hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), ferritin, cobalamin and folic acid among individuals with a positive CD antibody test. This study identified several biochemical abnormalities associated with CD antibody positivity among individuals referred to CD antibody testing. The pattern of abnormalities suggested that micronutrient deficiencies were prevalent among CD antibody-positive individuals, confirming malabsorption as a sign of CD. These findings illustrate the possibility of reducing diagnostic delay and underdiagnosis of CD.

Newly Diagnosed Celiac Disease and Bone Health in Young Adults: A Systematic Literature Review.

Celiac disease (CD), a gluten-induced autoimmune disease, is associated with low bone mineral density (BMD) among children. Unfortunately, it is often diagnosed in adulthood, which may lead to an increased risk of fragile bones. The aim of this systematic review was to report on BMD status among young adults newly diagnosed with CD, and to examine the effect of a gluten-free diet (GFD), nutritional supplements, such as vitamin D, or antiresorptive medications on BMD recovery. Databases searched were Medline, Embase, and Cochrane Library up to July 2nd, 2020. Both observational studies and clinical trials were considered, if patients were newly diagnosed and between 20 and 35 years of age and reported on BMD. We critically appraised the identified studies using ROBINS-I and summarized the findings narratively. Out of 3991 references, we identified 3 eligible studies: one cross-sectional study and two longitudinal studies. In total, 188 patients were included, and the study population consisted primarily of women with an age range between 29 and 37 years old. Compared to healthy controls, our target population had lower BMD. Moreover, a strict GFD may increase BMD during a follow-up period of up to 5 years. Newly diagnosed CD patients aged 20-35 years are at risk of lower BMD. Therefore, it may be crucial to assess BMD at time of diagnosis in young women. Whether the results can be extrapolated to young men is unknown. While strict GFD may improve BMD over time, there is a lack of robust evidence to demonstrate that nutritional supplements or antiresorptive agents are beneficial in the prevention of fragile bones in this age group.

Diagnostic Delay in Coeliac Disease: A Survey among Danish Patients.

Background: Coeliac disease affects around 1% of the population, although many cases remain undiagnosed. Underdiagnosis and diagnostic delay in coeliac disease may cause health complications and be a burden for both the patient and society. Casuistic reports indicate that the diagnostic delay may be significant in Danish patients. Aim: To investigate the diagnostic delay among Danish patients with coeliac disease. Methods: We performed a survey among coeliac disease patients to investigate the diagnostic delay. A web-based questionnaire was sent to all members of The Danish Coeliac Society. Results: The questionnaire was completed by 1,392 individuals with a diagnosis of coeliac disease (78.1% women; mean age: 42.8 years). The mean delay was 1.8 (SD 5.0) years from the first symptom to the first health care contact and 5.8 (SD 9.5) years from the first symptom to diagnosis; 18.6% of the participants reported a total diagnostic delay of more than 10 years. Among the patient-reported reasons for delay were misunderstandings, unspecific symptoms, and a lack of knowledge or focus on coeliac disease among the doctors. In total, 52.7% rated the time to diagnosis to have been "too long," and 20.1% were not satisfied with the diagnostic process. However, the majority were "to some extent" or "very" satisfied with the diagnostic process. Conclusion: We found evidence of a significant diagnostic delay among Danish patients with coeliac disease. This was primarily due to the delay from the time of first health care contact to the time of diagnosis. This study highlights the importance of raising awareness of coeliac disease among health care professionals.

Symptoms and biomarkers associated with undiagnosed celiac seropositivity.

BACKGROUND: Studies have indicated that underdiagnosis and diagnostic delay are common in celiac disease. Therefore, it is important to increase our knowledge of what symptoms and biomarkers could identify undiagnosed cases of celiac disease. METHODS: We screened for celiac disease antibodies in stored blood samples from 16,776 participants in eight population-based studies examined during 1976-2012. Undiagnosed celiac seropositivity was defined as celiac disease antibody positivity (IgG-deamidated gliadin peptide above 10.0 U/mL and/or IgA-tissue transglutaminase (TTG) or IgG-TTG above 7.0 U/mL) without a known diagnosis of celiac disease in the National Patient Register. In all studies general health symptoms were recorded by participant-completed questionnaire, including self-perceived health, tiredness, headache and gastrointestinal symptoms. Furthermore, blood samples were drawn for analyses of biomarkers e.g. hemoglobin, blood glucose, cholesterol, liver parameters and vitamins. The participants with undiagnosed celiac seropositivity were matched by sex, age and study with four controls among the celiac disease antibody negative participants. RESULTS: We excluded, five participants with known celiac disease, resulting in a population of 16,771 participants. In this population 1% (169/16,771) had undiagnosed celiac seropositivity. There were no statistically significant differences in symptoms between cases and controls. Undiagnosed celiac seropositivity was associated with low blood cholesterol (< 5 mmol/L) and low hemoglobin (< 7.3 mmol/L for women and < 8.3 mmol/L for men). CONCLUSION: In this general population study, undiagnosed cases of celiac seropositivity did not have more symptoms than controls, confirming the diagnostic difficulties of celiac disease and the low prognostic value of symptoms for a diagnosis of celiac disease. Furthermore, decreased levels of cholesterol and/or hemoglobin in the blood were associated with undiagnosed celiac seropositivity.

Biochemical Diagnosis of Bile Acid Diarrhea: Prospective Comparison With the 75Seleno-Taurohomocholic Acid Test.

INTRODUCTION: The diagnosis of bile acid diarrhea is often missed because the availability of the seleno-taurohomocholic acid (SeHCAT) test is limited. We aimed to compare the biomarkers 7α-hydroxy-4-cholesten-3-one (C4) and fibroblast growth factor 19 (FGF19) with the SeHCAT test. METHODS: Patients with chronic diarrhea without intestinal resection referred for SeHCAT were prospectively recruited for this diagnostic accuracy study. Blood was sampled at fasting and after a stimulation meal with chenodeoxycholic acid. SeHCAT retention ≤10% defined bile acid diarrhea and >10% defined miscellaneous diarrhea. Receiver operating characteristics (ROC) were analyzed with SeHCAT as the gold standard. www.clinicaltrials.gov (NCT03059537). RESULTS: Patients with bile acid diarrhea (n = 26) had mean C4 of 30 ng/mL (95% confidence interval: 19-46) vs 8 (7-11; P < 0.001) in the miscellaneous diarrhea group (n = 45). Area under the ROC curve (ROCAUC) for C4 was 0.83 (0.72-0.93). C4 < 15 ng/mL had 85% (74%-96%) negative predictive value; C4 > 48 ng/mL had 82% (59%-100%) positive predictive value. Twenty patients had C4 values 15-48 ng/mL, of whom 11/20 had SeHCAT ≤10%. Median fasting FGF19 was 72 pg/mL (interquartile range: 53-146) vs 119 (84-240) (P = 0.004); ROCAUC was 0.71 (0.58-0.83). Stimulated FGF19 responses did not differ (P = 0.54). DISCUSSION: We identified C4 thresholds with clinically useful predictive values for the diagnosis of and screening for bile acid diarrhea in patients with chronic watery diarrhea. Further validation of the cutoff values with the placebo-controlled effect of sequestrant therapy is warranted (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/AJG/B603).

Long-term Consequences of Undiagnosed Celiac Seropositivity.

INTRODUCTION: Diagnosed celiac disease (CD) is associated with lymphoproliferative malignancy and gastrointestinal cancer, but little is known about the long-term consequences of undiagnosed CD. We aimed to investigate long-term consequences of undiagnosed CD for mortality and incidence of cancer and other chronic diseases. METHODS: We screened biobank serum samples for immunoglobulin (Ig) A and IgG tissue transglutaminase (TTG) and IgG deamidated gliadin peptide in a study of 8 population-based cohort studies comprising 16,776 participants examined during 1976-2012 and followed with >99% complete follow-up in Danish nationwide registries until December 31, 2017, regarding vital status and incidence of diseases. Undiagnosed CD was defined as antibody positivity (IgA-TTG or IgG-TTG ≥ 7 U/mL and/or IgG deamidated gliadin peptide ≥ 10 U/mL) in individuals without a diagnosis of CD recorded in the National Patient Register. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated by Cox regression analyses with age as the underlying time scale. RESULTS: The prevalence of undiagnosed CD was 1.0% with no statistically significant increase over time. Undiagnosed CD was associated with increased risk of cancer overall (HR, 1.57; 95% CI, 1.16-2.11), gastrointestinal cancer (HR, 2.33; 95% CI, 1.35-4.04), cancer of the uterus (HR, 3.95; 95% CI, 1.46-10.69), breast cancer (HR, 1.98; 95% CI, 1.02-3.82), head and neck cancer (HR, 3.12; 95% CI, 1.15-8.43), and cardiovascular disease (HR, 1.37; 95% CI, 1.01-1.85). We found no statistically significant association between undiagnosed CD and mortality (HR, 1.19; 95% CI, 0.87-1.61). DISCUSSION: Undiagnosed CD was associated with increased risk of cardiovascular disease and cancer suggesting that untreated CD has serious long-term health consequences not only affecting the gastrointestinal tract (see Visual Abstract, Supplementary Digital Content, http://links.lww.com/AJG/B566).

The association of celiac disease and allergic disease in a general adult population.

Background: The relationship between allergy and celiac disease (CD) is not clear. Objective: The objective of this article is to investigate the association of CD and CD antibody positivity with hay fever, asthma and immunoglobulin (Ig)E sensitization in a general adult population. Methods: A total of 2297 individuals were screened for CD antibodies and underwent allergy testing. CD antibody-positive participants were invited to undergo clinical evaluation including biopsies. Additionally, biobank blood samples from four population-based studies (6423, 973, 1718 and 1101 participants) with data on IgE sensitization to inhalant allergens were screened for CD antibodies. CD antibody-positive participants were screened for serum IgE against food allergens in three biobank studies. CD-antibody positivity was defined as IgA or IgG tissue transglutaminase ≥7 U/ml and/or IgG deamidated gliadin peptide ≥10 U/ml. Results: The nine participants (0.4%) diagnosed with CD had significantly higher prevalence of IgE sensitization to wheat and dust mites. The prevalence of CD antibody positivity was 0.8% (18/2297), and these participants had a significantly higher prevalence of IgE sensitization to food allergens (Fx5), egg, dust mites and mugwort. In the biobank studies, the prevalence of CD antibody positivity was 0.8% to 1.2%. One study showed a positive association between CD antibody positivity and IgE sensitization for dog, horse and food allergens. Conclusion: We found a possible association of CD and IgE sensitization to some food and inhalant allergens in the Health2006 study. In further studies, however, we could not consistently replicate these associations.

Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial.

OBJECTIVE: To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. DESIGN: 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. RESULTS: 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. CONCLUSION: Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation. TRIAL REGISTRATION NUMBER: NCT01731366; Results.

A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults.

Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.

The distribution of HLA DQ2 and DQ8 haplotypes and their association with health indicators in a general Danish population.

BACKGROUND: Human leukocyte antigen (HLA) DQ2 and DQ8 are important risk factors for some autoimmune diseases such as celiac disease (CD), but their possible role in other diseases and health conditions is not fully explored. OBJECTIVES: The objective of this article is to examine the distribution of HLA DQ2 and HLA DQ8 in an adult general population, and their association with health indicators (diseases, symptoms and biomarkers). METHODS: In this cross-sectional, population-based study, 2293 individuals were screened for HLA DQ2 and DQ8; CD-associated alleles (DQA*0201*03*05/DQB*02*0301/0304*0302/0305) and DQB1*02 homozygosity were determined for screen-positive participants. The National Patient Registry provided diagnosis information. RESULTS: A total of 47.7% (1093/2293) individuals were positive for DQ2 and/or DQ8: 31.2% (716/2293) only DQ2, 11.9% (273/2293) only DQ8, 4.1% (93/2293) both DQ2 and DQ8. Among nine individuals diagnosed with CD, 89.9% (8/9) had DQ2.5cis, 22.2% (2/9) DQ8 and 22.2% (2/9) DQ2.2 (two both DQ2 and DQ8). HLA DQ2.5 was associated with higher thyroid-stimulating hormone levels, while DQ2/DQ8-positive participants had significantly lower prevalence of irritable bowel syndrome (IBS). DQ2/DQ8 were strongly associated with CD, but no other registry-based diagnoses. CONCLUSION: In this general Danish population, 47.7% were HLA DQ2/DQ8 positive and thus potentially at risk for CD. All individuals with CD were DQ2/DQ8 positive; the majority DQ2.5. Surprisingly, DQ2/DQ8-positivity was associated with lower IBS prevalence.

Plasma Alkylresorcinols Reflect Gluten Intake and Distinguish between Gluten-Rich and Gluten-Poor Diets in a Population at Risk of Metabolic Syndrome.

BACKGROUND: Many patients with celiac disease experience difficulties in adherence to a gluten-free diet. Methods for testing compliance to a gluten-free diet are costly and cumbersome. Thus, a simple biomarker of gluten intake is needed in a clinical setting and will be useful for epidemiologic studies investigating wider effects of gluten intake. OBJECTIVE: The aim was to evaluate plasma total alkylresorcinol concentrations as a measure of gluten intake. METHODS: In this randomized, controlled, crossover intervention study in 52 Danish adults with features of the metabolic syndrome, we compared 8 wk of a gluten-rich and gluten-poor diet separated by a washout period of ≥6 wk. We measured fasting plasma concentrations of alkylresorcinols to determine if they reflected differences in gluten intake as a secondary outcome of the original study. In addition, we investigated in 118 Danish adults the cross-sectional association between self-reported gluten intake and plasma alkylresorcinols in the same and a similar study at baseline. We used mixed-model ANCOVA for examining treatment effects, a classification tree to determine compliance to the gluten-poor diet, and linear regression models for examining baseline correlation between plasma alkylresorcinol concentrations and gluten intake. RESULTS: Plasma total alkylresorcinols decreased more during the gluten-poor period (geometric mean: -124.8 nmol/L; 95% CI: -156.5, -93.0 nmol/L) than in the gluten-rich period (geometric mean: -31.8 nmol/L; 95% CI: -63.1, -0.4 nmol/L) (P < 0.001). On the basis of the plasma alkylresorcinol profile, we built a classification tree to objectively determine compliance and found an overall participant misclassification error of 3.9%. In the cross-sectional study we found a 5.6% (95% CI: 2.4%, 8.9%) increase in plasma total alkylresorcinols per 1-g increase in reported gluten intake (P < 0.001). CONCLUSION: We propose the use of plasma alkylresorcinols to monitor compliance to a gluten-free diet as well as to help investigations into the possible effects of gluten in the wider population. This trial was registered at www.clinicaltrials.gov as NCT017119913 and NCT01731366.

Symptoms and biomarkers associated with celiac disease: evaluation of a population-based screening program in adults.

OBJECTIVES: To identify possible early predictors (symptoms and biomarkers) of celiac disease, compare symptoms before and after screening, and evaluate the diagnostic efficacy of serologic screening for celiac disease in an adult Danish population. METHODS: This cross-sectional population-based study was based on the 5-year follow-up of the Health2006 cohort, where 2297 individuals were screened for celiac disease; 56 were antibody positive and thus invited to clinical evaluation. Eight were diagnosed with biopsy-verified celiac disease. A follow-up questionnaire was sent to antibody-positive individuals 19 months after the clinical evaluation to obtain information on their symptoms and their experience with participation in the screening. RESULTS: Before screening, participants subsequently diagnosed with celiac disease did not differ from the rest of the population with respect to symptoms, but had significantly lower total cholesterol. Tissue transglutaminase IgA antibodies with a cut-off of 10 U/ml had a positive predictive value of 88%. The majority of participants were satisfied with their participation in the screening program. Individuals with celiac disease were generally satisfied with having been diagnosed and 71% felt better on a gluten-free diet. CONCLUSION: There were no differences in the prevalence of symptoms between participants with and without screening-detected celiac disease, confirming that risk stratification in a general population by symptoms is difficult. The majority of participants diagnosed with celiac disease felt better on a gluten-free diet despite not reporting abdominal symptoms before diagnosis and participants in the clinical evaluation were generally satisfied with participation in the screening program.

Diagnosis of bile acid diarrhoea by fasting and postprandial measurements of fibroblast growth factor 19.

BACKGROUND: A deficiency in the ileal hormone fibroblast growth factor 19 (FGF19) has been described in patients with bile acid diarrhoea (BAD), but fasting FGF19 levels have insufficient diagnostic power. We assess whether single postprandial sampling of FGF19 has greater discriminative value than fasting FGF19 for detection of BAD and we evaluate the reproducibility of fasting FGF19. MATERIALS AND METHODS: Twenty-six patients consecutively referred to Se homocholic acid retention test (SeHCAT) were included. Serum FGF19 was measured after an overnight fast and again 1 h postprandially and again in the fasting state 1 week later. RESULTS: Nine of 26 patients had SeHCAT less than 10% and fasting FGF19 was lower [median 62 pg/ml, interquartile range (IQR): 47-67] than in the 17 diarrhoea controls with SeHCAT at least 10% (median 103 pg/ml, IQR: 77-135, P=0.006). Postprandial FGF19 in BAD patients (61 pg/ml, IQR: 48-69) was similar to fasting values (P=0.59) and increased insignificantly in diarrhoea controls (137 pg/ml, IQR: 88-182; P=0.25). The difference in postprandial FGF19 between patients with BAD and diarrhoea controls was highly significant (P<0.001). CONCLUSION: The difference in serum FGF19 between groups of patients with BAD and diarrhoea controls is amplified postprandially. Within each group, the difference between fasting and postprandial FGF19 was not statistically significant. Further investigations are warranted on stimulated FGF19 response to elucidate its role in BAD.

Celiac disease: diagnosis and treatment.

This national clinical guideline approved by the Danish Society for Gastroenterology and Hepatology describes the diagnosis and treatment of celiac disease (CD) in adults. CD is a chronic immune-mediated enteropathy of the small intestine triggered by the ingestion of gluten-containing proteins, which are found in wheat, rye, and barley. The disease prevalence is 0.5-1.0%, but CD remains under-diagnosed. The diagnosis relies on the demonstration of lymphocyte infiltration, crypt hyperplasia, and villous atrophy in duodenal biopsies. Serology, malabsorption, biochemical markers, and identification of specific HLA haplotypes may contribute to CD diagnosis. Classical CD presents with diarrhoea and weight loss, but non-classical CD with vague or extraintestinal symptoms is common. The treatment for CD is a lifelong gluten-free diet (GFD), which, in the majority of patients, normalises the small intestinal mucosa and absorption. Adherence to a GFD usually requires dietary advice from a clinical dietician. The monitoring of antibody levels and malabsorption markers is crucial during follow-up and allows for early treatment of disease complications. Important complications include osteoporosis, iron and vitamin deficiencies, and enteropathy-associated T-cell lymphoma.

Screening for celiac disease in Danish adults.

OBJECTIVE: The prevalence of celiac disease (CD) as recorded in the Danish National Patient Registry is ∼50/100,000 persons. This is much lower than the reported prevalence of CD in other Nordic countries and underdiagnosis is suspected. Our aim was to estimate the prevalence of CD in a population-based study of Danish adults. METHODS: A total of 2297 adults aged 24-76 years living in the southwestern part of Copenhagen were screened for CD by immunoglobulin (Ig)A and IgG antibodies to transglutaminases and deamidated gliadin. IgA/IgG-positive participants were invited to a clinical evaluation, including biopsies, by a gastroenterologist. RESULTS: Of the invited 56 participants, 40 underwent a full clinical evaluation and 8 persons were diagnosed with CD; 2 of the 16 persons, who did not complete the clinical evaluation, were considered by experts to have probable CD. None of the above 56 participants had a known history of CD or a recorded diagnosis of CD in National Patient Registry. By combining cases of biopsy-proven CD (n = 8), probable CD (n = 2), and registry-recorded CD (n = 1), the prevalence of CD was estimated to be 479/100,000 (11/2297) persons (95% CI: 197-761). CONCLUSION: In this general adult population, the prevalence of CD as estimated by screening and clinical evaluation was 10 times higher than the registry-based prevalence of CD. Of 11 participants diagnosed with CD in our screening study, 10 were unaware of the diagnosis prior to the study. Thus, our study suggests that CD is markedly underdiagnosed in Danish adults.