The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) protocol: a randomised controlled study to evaluate treatment of asymptomatic coeliac disease in type 1 diabetes

Gluten-Free Diet and Metabolic Syndrome: Could Be a Not Benevolent Encounter?

Celiac disease is a rising disorder and is becoming frequently diagnosed in recent years. To date, the only available treatment is the gluten-free diet (GFD). The role of gluten on components of metabolic syndrome and on related inflammatory response is still unclear due to controversial results. In recent years, scientific focus on this topic has been growing up, in particular regarding the role of the GFD on glycometabolic parameters and diabetes. In addition, studies on the remaining components showed discordant results, which was likely due to heterogeneous and large celiac disease populations and to the lack of prospective studies. Furthermore, knowledge about the role of the GFD on inflammatory cytokines and the relationship among vitamin D and celiac disease, metabolic syndrome (MS) and GFD is needed. In this narrative review, we provided evidence regarding the role of the GFD on glycometabolic parameters, cholesterol, triglycerides, waist circumference, blood pressure and inflammatory cascade, also evaluating the role of vitamin D, trying to summarize whether this nutritional pattern may be a value-added for subjects with dysmetabolic conditions. Finally, due to the limited findings and very low-certainty evidence, predominantly based on observational studies, the real effects of a GFD on different components of MS, however, are unclear; nevertheless, an improvement in HDL levels has been reported, although data on glycemic levels are discordant.

Gastrointestinal Symptoms in Type 1 Diabetes: Relationship With Autoimmune and Microvascular Complications

PURPOSE

To assess reported rates of gastrointestinal (GI) symptoms and their association with autoimmune diseases and microvascular complications in adults and children with type 1 diabetes.

METHODS

The Gastrointestinal Symptom Scale was used to assess GI symptom type and severity in 2370 patients with type 1 diabetes aged 8 to 45 years evaluated as part of a clinical trial screening for celiac disease (CD). The presence and severity of GI symptoms and relationships with demographic, clinical, and other diabetes-related factors were evaluated.

RESULTS

Overall, 1368 adults (57.7%) aged 19 to 45 years and 1002 (42.3%) pediatric patients aged 8 to 18 years were studied. At least 1 GI symptom was reported in 34.1% of adults as compared with 21.7% of children (P < 0.0001). Common symptoms in children included upper and lower abdominal pain while adults more frequently reported lower GI symptoms. Participants with GI symptoms had higher hemoglobin A1c (HbA1c) levels (68 ± 14mmol/mol; 8.35 ± 1.37%) than those without symptoms (66 ± 15mmol/mol; 8.22 ± 1.40%; P = 0.041). Patients with microvascular complications (nephropathy, retinopathy, and/or neuropathy) were 1.8 times more likely to report GI symptoms (95% CI: 1.26-2.60; P < 0.01) after adjusting for age and sex. No association was observed between GI symptoms and the presence of autoimmune conditions, including thyroid and biopsy-confirmed CD (odds ratio = 1.1; 95% CI: 0.86-1.42; P = 0.45).

MAIN CONCLUSIONS

These results highlight that GI symptoms are an important clinical morbidity and are associated with increasing age, duration of type 1 diabetes, HbA1c, and microvascular complications but not with autoimmune comorbidities including CD.

The Association between Treatment Modality, Lipid Profile, Metabolic Control in Children with Type 1 Diabetes and Celiac Disease-Data from the International Sweet Registry

Background and Aims: A higher frequency of dyslipidemia is reported in children with type 1 diabetes (T1D) and celiac disease (CD). Recently, continuous subcutaneous insulin infusion (CSII) has been associated with better lipid profiles in patients with T1D. The aim of this study was to investigate the association between treatment modality and lipid profile, metabolic control, and body mass index (BMI)-SDS in children with both T1D and CD. Methods: Cross-sectional study in children registered in the international SWEET database in November 2020. Inclusion criteria were children (2–18 years) with T1D and CD with available data on treatment modality (CSII and injections therapy, IT), triglyceride, total cholesterol, HDL, LDL, dyslipidemia, HbA1c, and BMI-SDS. Overweight/obesity was defined as > +1 BMI-SDS for age. Data were analyzed by linear and logistical regression models with adjustment for age, gender, and diabetes duration. Results: In total 1009 children with T1D and CD (female 54%, CSII 54%, age 13.9 years ±3.6, diabetes duration 7.2 years ±4.1, HbA1c 7.9% ±1.4) were included. Significant differences between children treated with CSII vs. IT were respectively found; HDL 60.0 mg/dL vs. 57.8 mg/dL, LDL 89.4 mg/dL vs. 94.2 mg/dL, HbA1c 7.7 vs. 8.1%, BMI-SDS 0.4 vs. 0.6, overweight and obesity 17% vs. 26% (all p < 0.05). Conclusions: CSII is associated with higher HDL and lower LDL, HbA1c, BMI-SDS, and percentage of overweight and obesity compared with IT in this study. Further prospective studies are required to determine whether CSII improves lipid profile, metabolic control and normalize body weight in children with both T1D and CD.

Accuracy of Screening Tests for Celiac Disease in Asymptomatic Patients With Type 1 Diabetes

INTRODUCTION

To evaluate the diagnostic performance of celiac serologic tests in asymptomatic patients with type 1 diabetes (T1D).

METHODS

Patients with T1D asymptomatic for celiac disease were prospectively screened with immunoglobulin A anti-tissue transglutaminase. Test characteristics were calculated and optimal cutoffs for a positive screen determined.

RESULTS

Two thousand three hundred fifty-three patients were screened and 101 proceeded to biopsy. The positive predictive value of immunoglobulin A anti-tissue transglutaminase at the assay referenced upper limit of normal (30CU) was 85.9%, and the sensitivity and specificity were 100% and 38%, respectively.

DISCUSSION

Thresholds extrapolated from the general population for the diagnostic evaluation of celiac disease are not suitable for use in asymptomatic T1D patients. Population-specific screening cutoffs are required.

Coeliac disease is associated with depression in children and young adults with type 1 diabetes: results from a multicentre diabetes registry

AIMS

To analyse the association between coeliac disease (CD) and depression in children, adolescents, and young adults with type 1 diabetes (T1D).

METHODS

We included 79,067 T1D patients aged 6-20 years, with at least six months of diabetes duration, and treatment data between 1995 and 2019 were documented in the diabetes patient follow-up registry. We categorized patients into four groups: T1D only (n = 73,699), T1 + CD (n = 3379), T1D + depression (n = 1877), or T1D + CD + depression (n = 112).

RESULTS

CD and depression were significantly associated (adjusted OR: 1.25 [1.03-1.53]). Females were more frequent in both the depression and the CD group compared with the T1D only group. Insulin pumps were used more frequently in T1D + CD and T1D + depression compared with T1D only (both p < .001). HbA1c was higher in T1D + depression (9.0% [8.9-9.0]), T1D + CD + depression (8.9% [8.6-9.2]), both compared with T1D only (8.2% [8.2-8.2], all p < .001). We found comorbid autism, attention deficit hyperactivity disorder, anxiety, schizophrenia, and eating disorders more frequently in the T1D + CD + depression group compared with T1D only (all p < .001).

CONCLUSIONS

CD and depression are associated in young T1D patients. The double load of T1D and CD may lead to an increased risk for depression. Depression was associated with additional psychological and neurological comorbidities. Aside from imperative CD screening after T1D diagnosis and regular intervals, depression screening might be helpful in routine care, especially in patients with diagnosed CD.

Impact of a Gluten-Free Diet on Quality of Life and Health Perception in Patients With Type 1 Diabetes and Asymptomatic Celiac Disease

CONTEXT

Celiac disease (CD) is a common comorbidity seen in patients with type 1 diabetes (T1D) and is frequently asymptomatic. As chronic conditions requiring significant lifestyle changes, there are limited reports assessing changes in health-related quality of life (HRQoL) during transition to a gluten-free diet (GFD) in patients with T1D who are asymptomatic for CD.

OBJECTIVE

This work aims to prospectively assess HRQoL and health perception in children and adults with T1D and asymptomatic CD after random assignment to GFD vs usual diet.

METHODS

Patients with T1D aged 8 to 45 years without CD symptoms were serologically screened for CD, with positive results confirmed with intestinal biopsy. Participants were randomly assigned in an open-label fashion to a GFD or gluten-containing diet (GCD) for 12 months. Generic and diabetes-specific HRQoL and self-perceived wellness (SPW) were assessed longitudinally.

RESULTS

A total of 2387 T1D patients were serologically screened. CD was biopsy-confirmed in 82 patients and 51 participants were randomly assigned to a GFD (N = 27) or GCD (N = 24). Excellent adherence to the assigned diets was observed. Overall, no changes in generic (P = .73) or diabetes-specific HRQoL (P = .30), or SPW (P = .41) were observed between groups over 12 months. Hemoglobin A1c (HbA1c) and gastrointestinal symptoms were consistent predictors of HRQoL and SPW.

CONCLUSION

HRQoL and SPW were not significantly affected by the adoption of a GFD over 12 months, but worsened with symptom onset and increased HbA1c. Our findings indicate that transition to a GFD can be made successfully in this population without adversely affecting quality of life.

Epidemiology, Presentation, and Diagnosis of Celiac Disease

The incidence of celiac disease is increasing, partly because of improved recognition of, and testing for, the disease. The rise in incidence is also due to a real increase of this immune-based disorder, independent of disease detection. The reasons for this true rise in recent decades are unknown but may be related to environmental factors that may promote loss of tolerance to dietary gluten. Strategies to reduce the development of celiac disease have not been proven successful in randomized trials, but the quantity of early-life gluten exposure has been a major focus of prevention efforts. The criteria for the diagnosis of celiac disease are changing, but in adults, diagnosis still depends on the presence of duodenal villous atrophy while the patient is on a gluten-containing diet, along with findings from serology analysis. Although guidelines in the United States continue to mandate a biopsy at all ages, some children receive a diagnosis of celiac disease without a biopsy. If proven accurate and scalable, assays that detect gluten-HLA tetramer complexes might be used in diagnosis to be made in the context of a gluten-free diet without intestinal biopsy.

Gluten-free diet impact on dynamics of pancreatic islet-specific autoimmunity detected at celiac disease diagnosis

OBJECTIVE

Almost 6% of celiac disease (CD) patients at diagnosis are positive for at least one of the main pancreatic islet autoantibodies that characterize type 1 diabetes (T1D). Few information, dated back to almost two decades ago, exist as to whether a gluten-free diet (GFD) could reduce the islet-specific autoimmunity detected in patients at CD diagnosis. Aim of the study was to evaluate the impact of GFD on 31 patients who presented islet-specific autoimmunity at CD diagnosis.

METHODS

CD patient sera collected at diagnosis and throughout the GFD were analyzed for the main humoral autoantibodies so far identified in T1D, directed against one or more among insulin, glutamic-acid decarboxylase, tyrosine-phosphatase 2, and zinc cation-efflux transporter autoantigens.

RESULTS

GFD (median duration 39 months) was associated to a decrease or disappearance of the islet-specific autoantibodies in 71% of CD patients. Almost 80% of the patients who became autoantibody-negative during the GFD were positive for only one of the islet-specific autoimmune markers at CD diagnosis, with none of them developing diabetes. Conversely, 80% of the CD patients positive at diagnosis for ≥2 islet-specific autoantibodies were still positive after more than two years of GFD, with 25% of them developing T1D.

CONCLUSIONS

Various factors appear to influence, individually or in combination, the effects of the GFD on pancreatic islet-specific autoimmune response detected at CD diagnosis. These factors include the number of diabetes autoantibodies found at CD diagnosis, the adherence to the GFD, its duration and an asymptomatic clinical presentation of CD.

Screening and Treatment Outcomes in Adults and Children With Type 1 Diabetes and Asymptomatic Celiac Disease: The CD-DIET Study

OBJECTIVE

To describe celiac disease (CD) screening rates and glycemic outcomes of a gluten-free diet (GFD) in patients with type 1 diabetes who are asymptomatic for CD.

RESEARCH DESIGN AND METHODS

Asymptomatic patients (8-45 years) were screened for CD. Biopsy-confirmed CD participants were randomized to GFD or gluten-containing diet (GCD) to assess changes in HbA_1c and continuous glucose monitoring over 12 months.

RESULTS

Adults had higher CD-seropositivity rates than children (6.8% [95% CI 4.9-8.2%, N = 1,298] vs. 4.7% [95% CI 3.4-5.9%, N = 1,089], P = 0.035) with lower rates of prior CD screening (6.9% vs. 44.2%, P < 0.0001). Fifty-one participants were randomized to a GFD (N = 27) or GCD (N = 24). No HbA_1c differences were seen between the groups (+0.14%, 1.5 mmol/mol; 95% CI -0.79 to 1.08; P = 0.76), although greater postprandial glucose increases (4-h +1.5 mmol/L; 95% CI 0.4-2.7; P = 0.014) emerged with a GFD.

CONCLUSIONS

CD is frequently observed in asymptomatic patients with type 1 diabetes, and clinical vigilance is warranted with initiation of a GFD.

Online education for gluten-free diet teaching: Development and usability testing of an e-learning module for children with concurrent celiac disease and type 1 diabetes

BACKGROUND AND OBJECTIVE

Celiac disease (CD), the most common genetically-based food intolerance, affects 3% to 16% of children with type 1 diabetes (T1D). Treatment involves lifelong adherence to a gluten-free diet (GFD). Individualized dietary education is resource-intensive. We, therefore, sought to develop and test the usability of an e-learning module aimed at educating patients and caregivers regarding implementation of the GFD in children with concurrent CD and T1D.

METHODS

An interactive e-learning module was developed based on extensive review of CD, T1D, and educational literature. A mixed-methods usability testing approach was used to refine and evaluate the module, using qualitative semi-structured interviews, observations, and satisfaction and knowledge questionnaires in two iterative cycles. The module was refined based on themes identified from each usability cycle.

RESULTS

Eighteen patients (8 in cycle 1, 10 in cycle 2) and 15 caregivers (7 in cycle 1, 8 in cycle 2) participated. Patient participants had CD and T1D for a mean (SD) of 6.1 ± 5.1 and 8.3 ± 5.5 years, respectively. Their mean age was 13.5 ± 4.5 years. Thematic analysis of usability interviews showed the module to be appealing and resulted in minor module revisions after each cycle to improve usability. Mean satisfaction scores post-module completion were high (4.67 ± 0.54), indicating participants were "very satisfied" with the education. Knowledge test scores increased significantly from pre- to post-module completion (P = 0.001).

CONCLUSION

A multifaceted user-centered usability approach demonstrated that an innovative, interactive e-learning module is effective in knowledge retention and can provide comprehensive and accessible information in the implementation of the GFD teaching in children with CD and T1D.

Prevalence and characteristics of celiac disease in South African patients with type 1 diabetes mellitus: Results from the Durban Diabetes and Celiac Disease Study

BACKGROUND AND AIM

The aim of this study was to assess the prevalence and characteristics of celiac disease (CD) in all patients with type 1 diabetes mellitus attending a tertiary adult diabetes clinic in Durban, South Africa.

METHODS

This was a cross-sectional observational study that screened 202 patients; of these, 56.4% were African (Black), 31.7% Asian Indian, 4.5% White, and 7.4% mixed race. Demographic data, symptoms, and anthropometry were documented. Blood tests included anti-tissue transglutaminase antibody (tTG), anti-endomysial antibody (EMA), and anti-gliadin antibody (AGA). Endoscopy and duodenal biopsy were performed in patients with celiac antibodies. Diagnosis of CD was based on the modified Marsh classification.

RESULTS

Mean age and mean duration of diabetes were 26.4 ± 11.4 and 10.7 ± 9.1 years, respectively. Celiac antibodies were found in 65 (32.2%) patients: EMA 7.4%, tTG immunoglobulin A (IgA) 8.4%, tTG immunoglobulin G 1.9%, AGA IgA 18.3%, and AGA immunoglobulin G 21.8%. Histological evidence of CD was found in 5.9% (n = 12/202): 2.5% were classed as definite CD (Marsh 3) and 3.4% as potential CD (Marsh 1). None of the patients with CD were symptomatic. The sensitivity of AGA IgA, EMA, and tTG IgA antibodies for detecting histologically proven CD was 66.7%, 50.0%, and 41.7%, respectively.

CONCLUSION

The prevalence of CD was similar to reports from western countries. No ethnic specific differences were noted. CD was silent in all patients in this study. The sensitivity of EMA and tTG antibodies was poor and merits further evaluation as screening tools for CD in South African patients with type 1 diabetes mellitus.

Glycemic control and microvascular complications in adults with type 1 diabetes and long-lasting treated celiac disease: A case-control study

AIMS

To investigate whether in type 1 diabetes (T1DM) patients the concomitance of long-lasting celiac disease (CD) treated with a gluten free diet (GFD) impacts glycaemic control and the prevalence/severity of microvascular complications.

METHODS

A case-control, observational study was performed in 34 patients with T1DM and GFD-treated CD and 66 patients with T1DM alone matched for age, gender, and T1DM duration. Anthropometric parameters, glucose control (HbA1_c), status of chronic complications and concomitant autoimmune diseases were evaluated.

RESULTS

HbA1_c level was similar in T1DM + CD and T1DM alone (7.8 ± 1.0 vs 7.7 ± 1.1%, P = 0.57); insulin requirement was significantly higher in T1DM + CD compared with T1DM (P = 0.04). There were no differences in systolic blood pressure while diastolic blood pressure was significantly lower in T1DM + CD (P = 0.003). The prevalence/severity of microvascular complications was similar between the two groups. Glomerular filtration rate (eGFR) was significantly lower in T1DM + CD (100 ± 20 vs 110 ± 16 ml/min/1.73 m², P = 0.007).

CONCLUSIONS

In patients with T1DM, the co-occurrence of long-term GFD-treated CD neither worsens glycemic control nor negatively impacts chronic microvascular complications. However, patients with T1DM + CD have lower eGFR values than those with T1DM alone.

Coeliac disease

Coeliac disease occurs in about 1% of people in most populations. Diagnosis rates are increasing, and this seems to be due to a true rise in incidence rather than increased awareness and detection. Coeliac disease develops in genetically susceptible individuals who, in response to unknown environmental factors, develop an immune response that is subsequently triggered by the ingestion of gluten. The disease has many clinical manifestations, ranging from severe malabsorption to minimally symptomatic or non-symptomatic presentations. Diagnosis requires the presence of duodenal villous atrophy, and most patients have circulating antibodies against tissue transglutaminase; in children, European guidelines allow a diagnosis without a duodenal biopsy provided that strict symptomatic and serological criteria are met. Although a gluten-free diet is an effective treatment in most individuals, a substantial minority develop persistent or recurrent symptoms. Difficulties adhering to a gluten-free diet have led to the development of non-dietary therapies, several of which are undergoing trials in human beings.

Celiac Disease Prevention

Celiac disease (CD) is a common autoimmune disorder induced by ingestion of gluten in genetically susceptible individuals. Despite the prerequisite for a genetic predisposition, only a minority of the 40% of the Caucasian population that has this genetic predisposition develops the disease. Thus, environmental and/or lifestyle factors play a causal role in the development of CD. The incidence of CD has increased over the last half-century, resulting in rising interest in identifying risk factors for CD to enable primary prevention. Early infant feeding practices have been suggested as one of the factors influencing the risk of CD in genetically susceptible individuals. However, recent large prospective studies have shown that neither the timing of gluten introduction nor the duration or maintenance of breastfeeding influence the risk of CD. Also, other environmental influences have been investigated as potential risk factors, but have not led to primary prevention strategies. Secondary prevention is possible through early diagnosis and treatment. Since CD is significantly underdiagnosed and a large proportion of CD patients are asymptomatic at the time of diagnosis, secondary prevention will not identify all CD patients, as long as mass screening has not been introduced. As following a gluten-free diet is a major challenge, tertiary prevention strategies are discussed as well.

Celiac Disease and Diabetes: When to Test and Treat

Prevalence studies from around the world have established a substantial increase in the prevalence of celiac disease (CD) in patients with type 1 diabetes mellitus (T1DM). Approximately two-thirds of patients with T1DM and CD are asymptomatic for CD at diagnosis. We aim to provide an up-to-date state-of-the-art summary of the recommendations for serologic testing for CD in patients with T1DM and to clarify the debate on the need for screening and interventions. We searched Medline and Cochrane databases for studies of celiac autoimmunity and biopsy-proven CD in people with T1DM between January 1, 2000 and December 1, 2015. CD was found to be an independent risk factor for micro- and macrovascular complications, as well as for increased morbidity in patients with T1DM. Publications, however, reveal controversy regarding the benefits of a gluten-free diet (GFD) on glycemic control, bone health, and quality of life in individuals with T1DM and asymptomatic CD. A multicenter, prospective randomized controlled trial aimed to investigate this issue is currently ongoing. Until resolution of the pros and cons of screening for CD, and of the benefit versus burden of GFD treatment in T1DM patients with asymptomatic CD, we recommend repeated screening for CD during childhood and adulthood, and treatment with GFD for those with biopsy-proven CD, even if asymptomatic.

Impact of type 1 diabetes mellitus and celiac disease on nutrition and quality of life

Objective:

Type 1 diabetes mellitus (T1DM) and celiac disease (CD) are autoimmune diseases and have similar genetic patterns. T1DM treatment is based on diet, physical activity and insulin therapy, whereas CD depends on dietary changes with restriction of wheat, rye and barley. The aim of the study was to evaluate the quality of life (QoL) of individuals with the association of T1DM and CD, to characterize their nutritional status and to compare it with those with only one disease and healthier controls.

Subjects/Methods:

Sixty patients controlled by sex, age and body mass index (BMI) were stratified by previous diagnosis in: T1DM and CD (DMCD group); T1DM (DM group); CD (CD group); or healthy participants (HC). The SF-36 questionnaire was applied to assess psychological well being and results were compared with glycemic control and presence of complications related to diabetes, adhesion to gluten-free diet (GFD). Nutritional status and body mass composition were determined by BMI, waist circumference, bioimpedance, general laboratory tests and whole-body densitometry.

Results:

The time of diagnosis of T1DM was similar between DMCD and DM groups; however, the duration of CD was significantly higher in the CD group compared with DMCD. The SF-36 analysis revealed statistically significant differences between DM and HC groups in two domains: general health (P=0.042) and energy/vitality (P=0.012). QoL was also correlated with compliance to a GFD, and scores were similar in both groups: DMCD and CD. Forty percent of individuals in the CD group had visceral fat area above 100 cm², as opposed to 20% in the other groups.

Conclusions:

Individuals of DMCD group had similar scores to DM, CD and HC on QoL, as well as on their nutritional status and bone metabolism. Thereby, we should conclude that the association of T1DM and CD did not deteriorate their health status.

Screening for coeliac disease in adult patients with type 1 diabetes mellitus: myths, facts and controversy

This review aims at summarizing the present knowledge on the clinical consequences of concomitant coeliac disease (CD) in adult patients with type 1 diabetes mellitus (T1DM). The cause of the increased prevalence of CD in T1DM patients is a combination of genetic and environmental factors. Current screening guidelines for CD in adult T1DM patients are not uniform. Based on the current evidence of effects of CD on bone mineral density, diabetic complications, quality of life, morbidity and mortality in patients with T1DM, we advise periodic screening for CD in adult T1DM patients to prevent delay in CD diagnosis and subsequent CD and/or T1DM related complications.

Design of a dietary intervention to assess the impact of a gluten-free diet in a population with type 1 Diabetes and Celiac Disease

Background

Celiac Disease occurs at a 5–10 fold greater prevalence in patients with type-1 diabetes (T1D), despite this increased risk, there is limited objective evidence regarding the impact of a Gluten-Free Diet (GFD) in the large proportion of asymptomatic (30–70 %) patients with both autoimmune diseases. Given the requirements and intricacies inherent to each condition, we describe the rationale and design a dietary curriculum specifically addressing the educational requirements for children and adults with CD and diabetes as part of the CD-DIET Study.

Methods and design

The CD-DIET Study (Celiac Disease and Diabetes - Dietary Intervention and Evaluation Trial) is a multicenter randomized controlled trial aimed at evaluating the safety and efficacy of a GFD in patients with asymptomatic celiac disease and T1D on key diabetes and patient-centered outcomes.

Discussion

Key dietary components of the trial include a description and evaluation of food consumption patterns including glycemic index and glycemic load, novel assessments of gluten quantification, and objective and subjective measures of GFD adherence. This dietary curriculum will establish rigorous guidelines to assess adherence and facilitate evaluation of a GFD on metabolic control, bone health and patient quality of life in patients with CD and diabetes.

Trial registration Number

NCT01566110. Date of Registration: March, 2012.