Does a gluten-free diet increase body mass index and lipid profile in celiac patients? A systematic review and meta-analysis

Impact of Gluten-free Diet on Anthropometric Indicators in Individuals With and Without Celiac Disease: A Systematic Review and Meta-analysis

PURPOSE

Previous studies have found that a gluten-free diet (GFD) may have improve obesity-related factors. For this reason, we conducted a systematic review and meta-analysis to investigate the effect of a GFD on anthropometric indicators.

METHODS

We performed a systematic search in databases from inception until July 12, 2022. We included all relevant articles that evaluate efficacy of a GFD on anthropometric indicators in patients with and without celiac disease (CD). Random-effects models were applied to combine the data. The main outcomes were then analyzed using weight mean differences (WMDs) and 95% CIs.

FINDINGS

A total of 27 articles met the eligible criteria and were included. Pooled results from the random-effects model indicated that the GFD has no significant effect on any of the factors of anthropometry, including weight (WMD, 1.20 kg; 95% CI, -1.16 to 3.55 kg; P = 0.319), body mass index (WMD, 0.70 kg/m2; 95% CI, -0.45 to 1.84 kg/m2; P = 0.233), waist circumference (WMD, 0.92 cm; 95% CI, -1.34 to 3.17 cm; P = 0.497), and body fat (WMD, 1.02%; 95% CI, -0.38% to 2.42%; P = 0.153). The subgroup results indicated that after implementation of a GFD significant increased weight and body fat occurred in patients with compared with without CD. In addition, the effect of this diet on the increase of BMI and body fat in the intervention of more than 48 weeks was significantly higher.

IMPLICATIONS

The results of the present study indicate that a GFD can have a significant and beneficial effect on weight and body fat in patients with CD.

Risk of obesity during a gluten-free diet in pediatric and adult patients with celiac disease: a systematic review with meta-analysis

CONTEXT

Obesity is a significant risk factor for many pathological conditions. Whether a gluten-free diet (GFD) is a risk factor for overweight or obesity remains controversial.

OBJECTIVE

The primary aim of this study was to assess the prevalence of body mass index (BMI) categories at disease presentation and the variation in BMI category from underweight/normal to overweight/obese and vice versa during a GFD.

DATA SOURCES

PubMed, Scopus, and Web of Science databases were searched through February 2021 for retrospective, cross-sectional, and prospective studies reporting BMI categories at disease diagnosis and during a GFD.

DATA EXTRACTION

Data were extracted by 2 reviewers independently. Disagreements were resolved by consensus; a third reviewer was consulted, if necessary. Risk of bias was assessed with the Cochrane ROBINS-I tool.

DATA ANALYSIS

Subgroup analysis based on age (pediatric/adult patients), study design (prospective, cross-sectional, retrospective), and duration of GFD was performed.. Forty-five studies were selected (7959 patients with celiac disease and 20 524 healthy controls). The mean BMI of celiac patients at presentation was significantly lower than that of controls (P < 0.001). During a GFD, the mean BMI increased significantly (mean difference = 1.14 kg/m2 [95%CI, 0.68-1.60 kg/m2]; I2 = 82.8%; P < 0.001), but only 9% of patients (95%CI, 7%-12%; I2 = 80.0%) changed from the underweight/normal BMI category to the overweight/obese category, while 20% (95%CI, 11%-29%; I2 = 85.8%) moved into a lower BMI category.

CONCLUSION

Most celiac patients had a normal BMI at presentation, although the mean BMI was significantly lower than that of controls. A GFD does not increase the risk of becoming overweight/obese, especially in children. The quality of several studies was suboptimal, with moderate or high overall risk of bias and heterogeneity.

A systematic review and meta-analysis of the prevalence and odds of eating disorders in patients with celiac disease and vice-versa

OBJECTIVES

In the present systematic review and meta-analysis study, we aimed to review studies that assessed the prevalence and risk of eating disorders (EDs) in patients with celiac disease (CD) and vice-versa.

METHOD

We conducted a systematic search in PubMed, Embase, Scopus, and Web of Science for studies that assessed the prevalence and risk of AN in patients with CD and vice-versa. Joanna Briggs Institute tools were used for critical appraisal. The STATA software was used for the meta-analysis of the random-effect model.

RESULTS

In this study, 23 observational studies were included. The results of the meta-analysis indicated that the pooled prevalence of EDs and bulimia nervosa in patients with CD was 8.88% [95% CI: 6.4, 11.7] and 7.26% [95% CI: 0.23, 21.57], respectively. Moreover, the risk of anorexia nervosa in patients with CD was significantly higher than in the healthy population (relative risk [RR]: 1.48 [95% CI: 1.32, 1.64]). The rates of CD in patients with AN and EDs were 0.96% [95% CI: 0.15, 2.31] and 0.90% [95% CI: 0.56, 1.31], respectively. Moreover, the overall risk of CD in patients with AN was significantly higher compared with healthy adults (RR: 2.35 [95% CI: 1.27-3.44]).

DISCUSSION

The result of the present meta-analysis showed the high prevalence of EDs in patients with CD. Moreover, there was a significant bidirectional association between CD and EDs.

Determinants of health-related quality of life in patients with celiac disease: a structural equation modeling

Background

We aimed to investigate the determinants of Health-related quality of life (HRQOL) in Iranian patients with celiac disease (CD) using the structural equation modeling (SEM).

Methods

In the present cross-sectional study, a total of 170 adult patients with CD were recruited. The information regarding adherence to diet, symptom severity, and HRQOL were collected using the celiac disease adherence test (CDAT), gastrointestinal symptom rating scale (GSRS), and SF-36 questionnaire respectively. Association between various studied variables and HRQOL was assessed using SEM. The standardized regression weights were used to assess total, direct and indirect effects. The model fit indices were used to assess the “goodness of fit” between the hypothesized models.

Results

The mean age of participants was 37.57 ± 9.59 years. The results of SEM indicated that the overall fit of our model was acceptable. Adherence to the diet, GSRS score, occupation, and education level was significantly related to PCS of SF-36; and adherence to the diet, GSRS score, and education level were significantly correlated with MCS of SF-36. The analysis of indirect associations indicated that only adherence to diet indirectly via GSRS score was significantly associated with PCS and MCS of SF-36.

Conclusion

In adult patients with celiac disease, HRQOL was associated with age, education, adherence to GFD, and GSRS score. Additionally, occupation and disease duration were associated with HRQOL only in women and men respectively.

The Healthy Gluten-Free Diet: Practical Tips to Prevent Metabolic Disorders and Nutritional Deficiencies in Celiac Patients

The gluten-free diet (GFD) is the cornerstone treatment for coeliac disease (CD). However, a healthy GFD is more complex than the only exclusion of gluten-containing foods. Most celiac patients do not receive nutritional advice and tend to consume industrial gluten-free products (GFPs), which often lack fiber, vitamins, and other micronutrients while being rich in saturated fats and refined sugars. This review focuses on the main potential metabolic disorders and nutritional deficiencies in CD patients at diagnosis and dissects the main nutritional and metabolic issues due to a non-balanced GFD. Nutritional tips to achieve an adequate dietary approach in CD are provided. We also compared the main nutritional components of naturally gluten-free cereals (including pseudocereals) to give an exhaustive overview of the possible healthy alternatives to processed GFPs. Clinicians and dietitians should be systematically involved in the diagnosis of CD to monitor the appropriateness of GFD and the patient’s nutritional status over time.

Psychometric properties of the Persian version of the celiac disease adherence test questionnaire

BACKGROUND

A gluten-free diet (GFD) is the only effective treatment for celiac patients and assessing adherence to this diet is important. Celiac disease Adherence Test (CDAT) is a valid English-language questionnaire that is used for assessing the adherence to the GFD. In the present study, we aimed to translate the CDAT questionnaire in Persian and evaluate its validity and reliability.

METHODS

In the present cross-sectional study, CDAT was translated and back-translated by three bilingual professional translators. Content validity was evaluated by 12 gastroenterologists and nutritionists. To assess the construct validity, 230 patients with celiac disease were randomly selected from the national celiac disease registry database. Internal consistency of the items and test-retest reliability were assessed by Cronbach's alpha and Intraclass Correlation Coefficient (ICC). To assess the convergent validity of the questionnaire, the correlation coefficient between the CDAT score and anti-tissue transglutaminase immunoglobulin A (anti-t-TG-IgA) titer was assessed.

RESULTS

The content validity index, content validity ratio, and impact score of the Persian version of CDAT (Pv-CDAT) were 0.97, 0.95, and 4.61 respectively. Three significant factors were extracted and according to the confirmatory factor analysis the three-factor model had adequate fitness (chi-square p-value of 0.74, root mean error of approximation: 0.001 [95% CI: 0.001-0.083], comparative fit index: 1, standardized root mean squared residual: 0.04, and coefficient of determination: 0.78). The questionnaire had good feasibility with the floor effect of 3.1% and the ceiling effect of 0.4%. Moreover, it has high internal consistency (Cronbach-alpha: 0.71) and test-retest reliability (ICC: 0.78). The correlations between CDAT categories and anti-tTG-IgA categories showed a significant correlation between the two tests (r = 0.53; P < 0.001).

CONCLUSIONS

The results of the present study showed that the Pv-CDAT questionnaire with high validity, reliability, and internal consistency can be used for assessing adherence to the GFD in adult celiac patients in Iran.