EAL

CD: Nutritional Adequacy (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To assess the nutritional changes associated with the long-term treatment of celiac disease and analyze whether these changes were related to the degree of compliance with a gluten-free diet.

Inclusion Criteria:

Newly diagnosed celiac disease, diagnosis based on clinical features, presence of severe mucosal atrophy on small bowel biopsy, and on positive-related serology

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

47 unselected, consecutive patients with newly diagnosed celiac disease enrolled between September 1991 and October 1993. At the end of 1995, 25 of the patients were reevaluated.

Design

Longitudinal Study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Gluten free diet for a mean period of 37 months (range 25 - 49 months).

Statistical Analysis

Results of changes in fat, lean tissue, and bone mass are expressed as absolute values, Z scorfes and percentage of variation from the mean normal value. Comparisons between baseline and final measurements was performed by paired t tests. Statistical significance of differences between data from patients who strictly avoided gluten and those with partial restriction was calculated by Mann-Whitney rank sum test. Correlation between parameters assessed by Spearman's correlation test.

Data Collection Summary:

Timing of Measurements

Nutritional parameters and body composition studied after gluten free diet.

Dependent Variables

Anthropometry: height, weight, triceps skinfold thicknesses
Body composition parameters (fat, lean tissue, bone mass) measured by DEXA

Independent Variables

Gluten free diet for a mean period of 37 months (range 25 - 49 months)
Dietary instructions were reinforced in every interview and assessments of dietary compliance
Detailed dietary assessment based on 7-day weighed food records

Control Variables

Description of Actual Data Sample:

Initial N: 47 patients with newly diagnosed celiac disease.

Attrition (final N): 25 were reevaluated several years later, 24 female, 1 male. 16 had refused reevaluation, 4 had moved, 1 had died, 1 required steroids.

Age: median age 41 years, range 19 - 72 years

Ethnicity: not mentioned

Other relevant demographics:

Anthropometrics: Baseline clinical characteristics of the 22 patients not reevaluated were similar to those of patients included in the study.

Location: Argentina

Summary of Results:

	Strict GFD	Partial GFD
Median follow-up time (months)	36 (21 - 48)	36 (25 - 49)
Final weight (kg)	56.1 +/- 2.8	55.2 +/- 4.4
% change of baseline weight	20	12
BMI	22.0 +/- 0.8	22.5 +/- 1.4
Fat mass (kg)	18.5 +/- 2.1	17.8 +/- 3.0
Lean tissue mass (kg)	34.8 +/- 1.2	36.4 +/- 1.4
Bone mass (kg)	2.00 +/- 0.14	1.99 +/- 0.17
Triceps skinfold (cm)	16.0 +/- 1.8	15.4 +/- 2.1
Mid-arm muscle circumference (cm)	20.6 +/- 0.3	21.7 +/- 0.7
Muscle mass (kg)	17.0 +/- 0.9	18.2 +/- 1.0
Calorie intake (kcals/day)	1997 +/- 88	2415 +/- 88, p < 0.05
Number of interviews/year	2.6	2.0
Patients with hemoglobin <12 g/dl	1/13	1/9
Patients with serum albumin <3.5 g/dl	1/12	3/9
Patients with elevated titers of AGA-IgA	0/13	1/9
Patients with elevated titers of AGA-IgG	0/13	3/9
Patients with elevated titers of EmA	0/11	2/9

Other Findings

At diagnosis, fat (-49%), lean tissue (-12%), and bone (-24%) compartments were reduced, compared with that of sex- and age-matched controls.

After treatment, we noted a significant increase in body weight (p < 0.0001), fat mass (p < 0.0005), bone mass (p < 0.002) and BMI (p < 0.005).

In contrast, we did not observe a significant increase in lean-tissue mass or muscle mass.

Patients who adhered strictly to a gluten-free diet experienced a greater, though nonsignificant improvement in fat mass, body weight and BMI than patients whose compliance had been partial.

Mean caloric intake at the end of the study was significantly lower among those patients who had adhered strictly to a gluten-free diet, compared with those who had complied only partially with the diet (p < 0.05).

Author Conclusion:

In conclusion, this study shows that treatment with a gluten-free diet produces a significant improvement in anthropometric parameters and modifies body composition of celiac disease patients. This nutritional effect was more pronounced in patients who followed strict gluten restriction and related for the most part to changes in the fat and bone compartments.

Funding Source:

Government:

National Council of Research (CONICET)

Not-for-profit

Foundation associated with industry:

Reviewer Comments:

Only 25/47 patients seen after several years. No power calculations done.

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
	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
	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
	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
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
	1.	Was the research question clearly stated?	Yes
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.1.	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
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
	1.3.	Were the target population and setting specified?	Yes
	2.	Was the selection of study subjects/patients free from bias?	???
2.	Was the selection of study subjects/patients free from bias?		???
	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?	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?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	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?	???
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
	3.	Were study groups comparable?	N/A
3.	Were study groups comparable?		N/A
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	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?	N/A
	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?	N/A
	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.)	N/A
	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.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
	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.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	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
	4.2.	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
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
	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?	Yes
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	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.)	Yes
	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.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	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
	5.4.	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
	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.	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
	6.1.	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?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	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
	6.4.	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
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments 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?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
	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.	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
	7.1.	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
	7.2.	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
	7.3.	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
	7.4.	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
	7.5.	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
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	N/A
	7.7.	Were the measurements conducted consistently across groups?	N/A
	8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?	???
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		???
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	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
	8.3.	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
	8.4.	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)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	8.6.	Was clinical significance as well as statistical significance reported?	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?	No
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	No
	9.	Are conclusions supported by results with biases and limitations taken into consideration?	???
9.	Are conclusions supported by results with biases and limitations taken into consideration?		???
	9.1.	Is there a discussion of findings?	Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
	9.2.	Are biases and study limitations identified and discussed?	No
	10.	Is bias due to study's funding or sponsorship unlikely?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes