CD: Nutritional Adequacy (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To evaluate the nutritional status and body composition of adult celiac disease patients who followed a strict gluten-free diet and were in clinical, biochemical and histological remission; and compare the anthropometric data and dietary intakes of the celiac disease patients with those of controls.
Inclusion Criteria:
  • Asymptomatic
  • Maintained constant body weight during previous six months
  • Had negative results on medical examination
  • Not taking any drugs.

Additional Inclusion Criteria
  • Strict compliance with gluten-free diet (evaluated through medical interview)
  • Normal routine biochemical data (hemoglobin, serum ferritin and iron, liver function, serum calcium and potassium and albumin)
  • Normal immunoglobulin A antigliadin and antiendomysium antibody concentrations
  • Normal results on permeability test (lactulose-mannitol sugar test)
  • Normal duodenal biopsies obtained endoscopically during consumption of gluten-free diet.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:

Recruitment

  • Over a six-month period, 212 treated patients with histologically confirmed celiac disease were seen as outpatients for annual follow-up exams.
  • 71 met inclusion criteria.

Design

  • Cross-sectional study.
Intervention
  • Strict gluten-free diet.

Statistical Analysis

  • Weight, height, BMI and body composition of patients and controls were compared using Kruskal-Wallis test.
  • Daily dietary intakes were compared by using Kolmogorov-Smirnov test. 
Data Collection Summary:

Timing of Measurements

  • Height, weight, body mass index, fat and lean mass and bone mineral content were measured. A three-day dietary questionnaire was administered and total daily energy, fat, carbohydrate and protein intakes were calculated. 

Dependent Variables

  • Height measured with fixed stadiometer
  • Weight measured in bare feet with standard clinical balance
  • Fat mass, lean mass and bone mineral content calculated through dual-energy X-ray absorptiometry.

Independent Variables

  • Dietary intake measured through three-day food questionnaire.  Subjects trained by dietitian and reviewed through dietitian interview with subject.  Composition of commercially sold gluten-free food evaluated on basis of manufacturer information or packaging.
Description of Actual Data Sample:

 

Initial N

  • 71 patients (51 women, 20 men)
  • 142 healthy age- and sex-matched controls (two per patient).

Attrition (Final N)

  • 71 patients
  • 142 controls.

Age

  • Mean age: 27 years (17-58 years). 

Ethnicity

  • Not mentioned.

Other Relevant Demographics

  • 43 had started a gluten-free diet in childhood as a result of diagnosis of celiac disease or dermatitis herpetiformis with intestinal involvement (28 women and 15 men; mean age 5.2 years at diagnosis and 22 years at enrollment).
  • 28 patients had the disease diagnosed in adulthood (23 women and five men; mean age 28 years at diagnosis and 34 years at enrollment) and had been consuming a gluten-free diet for over two years. 

Anthropometrics

  • Two age- and sex-matched controls per patient. 

Location

  • Italy.
Summary of Results:

 

Male Patients (N=20) 

Male Controls (N=40)

P-value

Female Patients (N=51)

Female Controls (N=102)

P-value

Weight

69.2±11.1kg

73.3±8.5kg

0.03

55.5±8.0kg

58.7±8.6kg

0.04

Height

175±6.8cm

178±6.8cm

0.05

163±6.4cm

162±6.8cm

NS

BMI

21.9±2.9

23.5±2.9

0.05

20.9±2.7

22.4±4.3

0.03

Bone Mineral Density

1.1±0.07g/cm2

1.2±0.12g/cm2

NS

1.03±0.06g/cm2

1.1±0.09g/cm2

NS

Energy Intake

9,686±1,569kJ

11,297±1,318kJ

0.05

6,736±1,318kJ

7,740±1,715kJ

0.05

Other Findings

  • The weight, height and BMI of male celiac disease patients and the weight and BMI of female celiac disease patients were significantly lower than in control subjects (see table).
  • Fat mass and lean mass were both lower in the female patients than in female controls, 22.9±4.4, compared with 27.5±5.2% (P<0.05) and 38.8±4.2, compared with 40.5±3.2kg (P<0.03), but there was no significant difference in bone mineral density between groups.
  • However, when the bone mineral density values of the groups of patients whose disease was diagnosed either in childhood (1.1±0.06g/cm2) or adulthood (0.9±0.09g/cm2) were considered separately, the bone mineral density of the latter group was significantly lower than the control value of 1.1±0.09g/cm2 (P<0.01).
  • There was no significant difference in bone mineral density between the male patients and male controls, but fat mass and lean mass were both lower in patients than in controls: 13.9±6.4 compared with 16.8±4.6% (P<0.05) and 55.5±6.5 compared with 56.7±5.3kg (P<0.03).
  • Total energy intake was lower in patients than in control subjects (9,686±1,569 and 11,297±1,318kJ per day in males and 6,736±1,318 and 7,740±1,715kJ per day in females) and the diet was unbalanced, with a higher percentage of energy as fat (P<0.05) and a lower percentage of energy as carbohydrates (P<0.01).
Author Conclusion:
In conclusion, the results of our study showed that celiac disease patients consuming a strict gluten-free diet and in complete clinical, biochemical and histologic remission had lower BMI, fat mass and lean mass than did control subjects. Furthermore, when celiac disease was diagnosed in adulthood, celiac disease patients also had lower bone mineral density associated with a lower total daily energy intake. Early diagnosis and treatment, together with regular follow-up visits and dietary advice in terms of the choice and composition of foods, seem necessary to prevent malnutrition in these subjects who require lifelong dietetic treatment.
Funding Source:
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:
The author notes that observed differences in anthropometric measurements and body composition seem to be justified by lower daily energy intakes in celiac disease patients.
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? 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? N/A
  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? 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? 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? 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? N/A
  6.6. Were extra or unplanned treatments described? 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
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? 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? 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