EAL

CD: Nutritional Adequacy (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate body composition by DEXA and by bioelectrical impedance in celiac adolescents on a gluten-free diet to investigate whether impedance may provide an accurate and reliable alternative method to assess nutritional status in these patients.

Inclusion Criteria:

Diagnosis of celiac disease made according to the European Society of Pediatric Gastroenterology and Nutrition guidelines. Patients had presented with weight loss, diarrhea, dyspepsia, or biochemical abnormalities and in some of them a gluten-free diet relieved GI symptoms, normalized laboratory abnormalities, and demonstrated improvement of villous atrophy on histological examination of small bowel biopsies.

Exclusion Criteria:

Not specifically mentioned.

Description of Study Protocol:

Recruitment

Consecutive adolescents examined from September 1996 to December 1997.

Design

Cross-sectional study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Gluten-free diet for longer than 1 year.

Statistical Analysis

The results of changes in fat, fat-free and bone masses and anthropometric parameters were expressed as mean +/- standard deviation. Statistical analyses were performed with Student's t test and ANOVA, with p values <0.01 accepted as significant. The performance of fat mass BIA and fat-free mass BIA as predictors of fat mass and fat-free mass were evaluated using fat mass DEXA and fat-free mass DEXA as reference values, by the correlation test, and by the Bland and Altman's test.

Data Collection Summary:

Timing of Measurements

Each subject had nutritional parameters assessed after an overnight fast and had DEXA and BIA assessed the same morning.

Dependent Variables

Fat mass, fat-free mass and bone mass assessed by DEXA
Fat mass and fat-free mass assessed by BIA
Body height and weight measured with electronic beam scale and stadiometer, BMI calculated
Skinfold measurements was performed with a Holtain caliper with the sum of 4 skinfolds calculated for each

Independent Variables

Gluten-free diet. At time of entry to study, mean duration of diet was 12 +/- 3 months. 3 days of food records kept by all patients were analyzed for daily intake of protein, fat, carbohydrate, vitamins and minerals. Compliance with gluten-free diet evaluated by dietary assessment, clinical evaluation, and antiendomysial- and antigliadin-type IgA antibodies. Histological evaluation was also performed in 16 patients.

Control Variables

Description of Actual Data Sample:

Initial N: 43 adolescents with celiac disease (31 females, 12 males), 30 healthy age- and gender-matched control subjects

Attrition (final N): See above

Age: Mean age of patients: 12 +/- 2.4 years, range 10 - 18 years

Ethnicity: Not mentioned.

Other relevant demographics: Patients were divided into 2 groups: fully compliant with gluten-free diet (n=28) and patients with partial compliance (n=15).

Anthropometrics Controls were age- and sex-matched.

Location: Rome, Italy

Summary of Results:

Other Findings

All patients had a significantly lower body weight, height, fat-free mass, bone mineral density (p < 0.001) and BMI (p < 0.01) compared with controls.

The values of bone mineral content at the lumbar spine and total skeleton were significantly lower in celiac patients than in age-matched controls (p < 0.001), even corrected for lower body height.

18 (42%) patients with longer symptomatic periods (lasting from 14 months to 7 years, 6 months) before diagnosis presented the most significant reduction in bone mass (-23% compared with normal controls, p < 0.001).

In contrast, parameters predicting fat compartment (sum of skinfolds and fat mass) did not differ from those of controls.

No significant difference was found between patients strictly adherent to a gluten-free diet and patients partially compliant.

Compared with DEXA, BIA showed a high accuracy to estimate fat-free mass (R2 = 0.97) and limited accuracy for fat mass (R2 = 0.75). BIA was more reliable for estimating hydration of soft tissue underlying the fat-free mass changes.

Author Conclusion:

In adolescents with celiac disease, after a mean of 1 year of gluten-free diet all the parameters assessing body compartments, except fat mass, were affected, compared with healthy controls. Moreover, our data show that the gluten-free diet is not able to reverse the decrease in fat-free mass. Bioelectrical impedance holds promise for routine assessment of body composition changes in celiac adolescents on a gluten-free diet.

Funding Source:

University/Hospital:

University of Rome, Catholic University of Rome

Reviewer Comments:

Compliance to gluten-free diet carefully monitored.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	???
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	Yes
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	Yes
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	Yes
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	N/A
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	N/A
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes