EAL

CD: Nutritional Adequacy (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To review BMI in celiac patients diagnosed over a 10-year period in order to obtain an updated prevalence of overweight in celiac disease, to assess associated clinical characteristics, and to determine the impact of gluten exclusion on BMI.

Inclusion Criteria:

Database of 371 celiac patients newly diagnosed over a 10 year period (November 1995 - October 2005) and seen by a single gastroenterologist
Only patients with a Marsh III lesion were included

Exclusion Criteria:

Younger patients under age 20

Description of Study Protocol:

Recruitment

Database of 371 celiac patients diagnosed over a 10 year period (November 1995 - October 2005) and seen by a single gastroenterologist.

Design

Cohort Study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Gluten-free diet for 2 years.

Statistical Analysis

Discrete variables analyzed using chi-square test for trend and continuous variables by Mann Whitney U test for 2 categories, Kruskal-Wallis one-way analysis for 3, and the Wilcoxon signed-ranks test for paired variables.

Data Collection Summary:

Timing of Measurements

BMI measurements, and other clinical and pathological characteristics were reviewed - compared at diagnosis and after 2 years of treatment.

Dependent Variables

Weight, height, BMI
Grade of villous atrophy
Hemoglobin concentration and corrected serum calcium levels
Bone mineral density through DEXA

Independent Variables

Gluten-free diet for 2 years
Serological testing for compliance

Control Variables

Age
Gender
Clinical presentation

Description of Actual Data Sample:

Initial N: 371 celiac patients, 257 were female

Attrition (final N): 371

Age: mean age BMI < 20: 51 years, mean age BMI 20 - 24.9: 48 years, mean age BMI > 25: 46 years

Ethnicity: not mentioned

Other relevant demographics:

Anthropometrics:

Location: United Kingdom

Summary of Results:

Effect of 2 years of Gluten Exclusion on BMI Category in 188 Patients

Initial BMI category	Patients Increasing Weight (%)	BMI After 2 Years: <20	BMI After 2 Years: 20 - 24.9	BMI After 2 Years: >25
< 20 (n=27)	25 (93%)	7 (26%)	18 (67%)	2 (7%)
20 - 24.9 (n=94)	72 (77%)	1 (1%)	64 (68%)	29 (31%)
>25 (n=67)	55 (82%)		3 (4%)	64 (96%)

Other Findings

Mean BMI was 24.6 (range 16.3 - 43.5).

17 patients (5%) were underweight (BMI < 18.5), 211 were normal (57%), and 143 (39%) were overweight (BMI >25), including 48 (13% of all patients) in the obese range (BMI > 30).

There was a significant association between low BMI and female gender, history of diarrhea, reduced hemoglobin concentration, reduced bone mineral density, osteoporosis, and higher grades of villous atrophy (subtotal/total).

Of 188 patients compliant with a gluten-free diet, 81% had gained weight after 2 years, including 82% of initially overweight patients.

Author Conclusion:

In conclusion, few celiac patients meet the underweight stereotype and almost half are overweight. Failure to recognize this undoubtedly contributes to failed and delayed diagnosis, particularly as other classic symptoms like diarrhea are less common in heavier patients. A high proportion of overweight patients will gain further weight with gluten exclusion. This represents a potential cause of morbidity that may counteract any benefits of diagnosis, particularly in patients identified by screening. Dietetic advisors need to recognize this and modify advice depending on BMI at diagnosis.

Funding Source:

University/Hospital:

Altnagelvin Hospital (Ireland/UK)

Reviewer Comments:

Authors note that records did not allow retrospective analysis of dietary advice given regarding calorie restriction or caloric intake of patients before and after gluten exclusion. Authors did not address intentional or unintentional weight loss/gain over 10 years. Measurements of outcome variables not well described.

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?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
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
	3.2.	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
	3.4.	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
	3.6.	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?	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
	5.1.	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
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	Yes
	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?		???
	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
	6.3.	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?	???
	6.6.	Were extra or unplanned treatments described?	???
	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
7.	Were outcomes clearly defined and the measurements valid and reliable?		???
	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?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	???
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	???
	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?		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
	8.3.	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)?	N/A
	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?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
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