CD: Oats and Gluten Intolerance (2005)

Citation:

Hardman CM, Garioch JJ, Leonard JN, Thomas HJW, Walker MM, Lortan JE, Lister A, Fry L. Absence of toxicity of oats in patients with dermatitis herpetiformis. N Engl J Med 1997; 337: 1884-7. 

PubMed ID: 9407155
 
Study Design:
Non-Randomized Controlled Trial
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To study the effect of adding oats to a GFD in patients with dermatitis herpetiformis.

Inclusion Criteria:
  • All patients had biopsies done at the time of diagnosis and had histologic evidence of CD, with villous atrophy and elevated IEL counts.
  • Subjects had GI symptoms of bloating and frequent stools.
  • The diagnosis of dermatitis herpetiformis was confirmed through granular deposits of IgA in dermal papillae.
Exclusion Criteria:
  • None specifically mentioned.
Description of Study Protocol:

Recruitment

  • 10 adult patients with dermatitis herpetiformis asked to participate.

Design

  • Nonrandomized clinical trial.

Blinding used (if applicable)

  • No blinding used.

Intervention (if applicable)

  • Subjects advised to eat 50-70 g oats daily for 12 weeks.

Statistical Analysis

  • Results presented as mean±SD.
Data Collection Summary:

Timing of Measurements

  • Subjects assessed clinically by nutritionist and MD at weeks zero, six and 12 and two months after study. Duodenal biopsy, serum samples and skin specimens obtained at beginning of study and 12 weeks later.

Dependent Variables

  • Duodenal biopsies: Three specimens taken from second part of duodenum through endoscopy, morphometric measurements of ratio of villi height to crypt depth, height of surface enterocytes and IEL counts   
  • Serum samples assessed for presence of IgG and IgA AGA by ELISA, IgG ARA and IgG EMA detected by indirect immunofluorescence
  • Skin specimens: Three-mm skin specimens obtained by punch biopsy of subject forearm and assessed by direct immunofluorescence for IgA deposits in dermal papillae
  • Clinical visits: Examinations, assessment of compliance.

Independent Variables

  • Oats cereal to be included in porridge was provided to subjects and was determined to be free of gluten contamination by ELISA and polymerase chain reaction techniques. Daily intake targeted at 50-70 g.
  • Subjects weighed and kept daily records of oat intake.
Description of Actual Data Sample:

  • Initial N: 10 subjects, seven men and three women
  • Attrition (final N): 10 subjects
  • Age: Mean age, 58 years (44-71 years) 
  • Ethnicity: Not mentioned.
  • Other relevant demographics: In all subjects, their disease had been controlled by strict GFD without the need for dapsone to control the rash.
  • Location: St. Mary's Hospital, London.
Summary of Results:

Before Oats: Villous Height: Crypt Depth

Before Oats: Enterocyte Height Before Oats: IEL Count After Oats: Villlous Height: Crypt Depth After Oats: Enterocyte Height After Oats: IEL Count

1

3.33

32.9

9

3.06

29.6

12

2

3.00

34.0

20

3.59

32.0

18

3

3.75

29.8

12

3.72

32.9

10

4

3.66

29.1

13

3.83

30.4

10

5

3.53

30.4

15

3.77

33.0

11

6

3.35

32.1

13

3.83

33.0

13

7

3.28

34.0

10

3.86

32.9

19

8

4.00

31.6

14

3.76

30.4

13

9

4.12

29.3

17

4.15

30.4

17

10

3.84

30.4

15

3.51

32.9

19

Mean

3.59±0.11

31.36±0.58

13.8±1.03

3.71±0.09

31.75±0.44

14.2±1.2

Other Findings

  • Mean daily intake of oats was 62.5±10.8 g (47.9-77.5 g).
  • None of the patients had any adverse effects. Serologic tests for antigliadin, antireticulin and antiendomysial antibodies were negative before oats were introduced into the diet and after they were discontinued.
  • Dermal IgA showed no significant changes.
Author Conclusion:
  • In conclusion, we found that in patients with dermatitis herpetiformis, like those with CD alone, the addition of moderate amounts of oats to a GFD did not produce and deleterious effects to either the skin or intestine.
Funding Source:
Industry:
Mushroom Council
Commodity Group:
University/Hospital: Louisiana State University and Medical Center
Reviewer Comments:
  • Small sample size.
  • Length of study only 12 weeks long.
  • Since completion of study, nine continue to eat oats regularly.
  • Subjects were on strict GFD, not requiring dapsone for rash.
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? ???
  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? ???
  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? ???
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%.) N/A
  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? N/A
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
  8.2. 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? No
  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? No
  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