This investigation examines the most important cardiovascular risk factors (e.g., metabolic parameters, body composition) and their changes in coeliac disease. The series of studies allow to assess body composition and cardiovascular risk-related metabolic parameters of newly diagnosed and treated coeliac patients in their complexity and to test if they change during therapy. The interventional part of the investigation aims to answer the question if a dietary intervention mitigates the unfavorable effects of unbalanced diet.

The global prevalence of coeliac disease (CD) is increasing, which contributes to the disease's significant public health care burden. Body composition and metabolic parameters of coeliac patients differ from the healthy population. Patients with non-classical CD are not necessarily lean; they usually have normal body weight but can be even overweight or obese. In coeliac patients, bodyweight tends to elevate, whereas the body composition changes unfavourably during a gluten-free diet (GFD). A reason for gaining weight is the improvement of malabsorption but an important contributor is the nutrient composition of the GFD, which generally has a high calorie density with high carbohydrate and fat content while being low in fibre. While terminating or mitigating the inflammatory process - if done without adequate dietary control - a GFD can readily lead to weight gain and unfavourably metabolic consequences (e.g., dyslipidemia, fatty liver disease, insulin resistance). The result can be an increase in cardiovascular risk in CD patients with a normal or high body weight at diagnosis. However, limited information is available on the cardiovascular (CV) risk in coeliac disease, and the data are controversial. This study examines the body composition and cardiovascular risk-related metabolic parameters at the diagnosis and on a gluten-free diet in a Hungarian cohort of CD patients. The randomised controlled trial (RCT) investigates the effect of structured, repeated, group-based dietary education on the examined metabolic parameters and body composition.

This study aims to draw attention to a new aspect of the management of CD patients: from a metabolic and cardiovascular point of view. Findings will help to identify which parameters are beneficial to optimize and re-assess during follow-up in CD.

Inclusion Criteria (applies to all subjects):

• Age should be over 18 years.
• Blood collection must be indicated with medical conditions.
• Signed informed consent.

Inclusion Criteria (applies to specific cohorts of patients):

• The diagnosis of CD should be set up according to the current guidelines (based on serology and histology in adults or as per the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) guideline in children).
• The newly diagnosed CD patients should be on a gluten-containing diet.
• Patients following a GFD for at least 1 year should exhibit good dietary adherence.
• In the randomized controlled trial (RCT), strict dietary adherence will be established based on CD-specific serology (normal level of antibodies), urine gluten immunogenic peptides (negative urine test), and dietary interview (convincing knowledge on the GFD and positive attitude towards strict adherence). Adherence to the mediterranean diet should be suboptimal (≤ 8 Medietrranean Diet Score). RCT-patients must have internet access and must be capable to attend the online sessions for 1 year.
• Control subjects should be free from CD according to the recent guidelines and should be on a gluten-containing diet.

Exclusion Criteria:

• Chronic conditions:

  • Estimated glomerular filtration rate calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula is <60mL/min/1.73m2 (CKD3 or more severe kidney failure).
  • Liver cirrhosis in Child-Pugh class B-C.
  • Heart failure (New York Heart Association (NYHA) III-IV).
  • Active malignant diseases.

• Any acute diseases or acute deterioration of underlying chronic conditions.

• Diseases that may be associated with clinically relevant malabsorption.

• Refractory CD.

• Pregnancy, lactation.

• Patients unable to understand the essentials of the informed consent.

• Lack of consent or withdrawal of consent.

Due to the nature of the study, the blinding of the participants is not possible. The blinding of the physicians, data managers and statisticians will be secured.