H/A: Dietary Intake (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To evaluate the effects of an oral nutritional supplement enriched with two potentially immunostimulant compounds (arginine and omega-3 fatty acids) on the changes in food intake, body composition, immune parameters and viraemia in HIV-infected outpatients.
Inclusion Criteria:
HIV infected outpatients with CD4 lymphocyte counts above 100 x 106 per L.
Exclusion Criteria:
  • Patients with changes in antiviral treatment during the preceding eights weeks
  • Those with asymptomatic neuropathy or myopathy, neoplasia, endocrine disorders (pituitary dysfunction, diabetes mellitus, treated hyper/hypothyroid activity), renal failure, liver cirrhosis, gastrointestinal resection
  • Those treated for psychiatric disorders or active intravenous drug consumption.
Description of Study Protocol:
  • Recruitment: Methods not specified; were subjects from the Swiss HIV Cohort Study in 1995-1996.
  • Design: Randomized controlled study
  • Blinding used: Double blind.
  • Intervention: All patients received a daily oral nutritional supplement (606kcal supplemented with vitamins, trace elements and minerals).  In addition, half of the patients were randomized to receive 7.4g arginine and 1.7g omega-3 fatty acids for six months.
  • Statistical Analysis: All patients were included on an intention to treat basis. Statistical methods for univariate group comparisons included chi-square tests for proportions and T-tests for the continuous variables.
Data Collection Summary:

Timing of Measurements

Measurements made monthly during clinical examinations.

Dependent Variables

  • Disease progression measured by AIDS-defining events
  • CD4 and CD8 lymphocyte counts
  • Viraemia
  • Tumor necrosis factor soluble receptors
  • Nutritional status determined by anthropometric, bioelectrical impedance and dietetic assessment
  • Body weight, height, BMI
  • Quality of life assessed using French language validated Medical Outcome Studt 36-item short form health survey

Independent Variables

  • All patients received a daily oral nutritional supplement (606kcal supplemented with vitamins, trace elements and minerals). In addition, half of the patients were randomized to receive 7.4g arginine and 1.7g omega-3 fatty acids for six months.

  • Overall food intake was monitored each month by standard three-day calorie count food intake questionnaire.

Description of Actual Data Sample:
  • Initial N: 64 HIV-infected outpatients
  • Attrition (final N): 55 completed the protocol, 28 in standard supplementation (21 men, seven women), 27 in arginine omega-3 supplementation (23 men, four women)
  • Age
    • Mean age standard supplementation: 32.6±1.8 years
    • Mean age arginine omega-3 supplementation: 36.7±1.6 years.
  • Ethnicity: Not mentioned
  • Anthropometrics: There were no statistically significant differences between groups
  • Location: Switzerland.
Summary of Results:

Other Findings

Compliance and tolerance of the oral nutritional supplement was excellent.

In both groups of patients the following were found: 

  • Total energy intake was transiently increased and then returned to baseline level
  • Nitrogen-energy intake ratio was increased throughout the study
  • Gain of body weight and fat mass were approximately two kg and one kg, respectively, over six months and were similar in both groups.

In addition, CD4 and CD8 lymphocyte counts, viraemia, tumor necrosis factor soluble receptors remained statistically unchanged and were similar in both groups.

No significant changes in quality of life were observed during the study period.

Author Conclusion:
  • In conclusion, oral nutritional supplements balanced for protein and energy supplying 606kcal daily for a six-month period were well tolerated and resulted in a body weight gain in HIV-infected patients
  • Supplement enriched with nutrients potentially active in stimulating immune function, such as arginine and omega-3 fatty acids, produced statistically similar results
  • No improvement in immune status, as reflected by CD4 lymphocyte counts, sTNF-R and viraemia, was observed
  • Quantities of arginine and omega-3 fatty acids other than those used in this study may be found to have beneficial effects on immune function
  • Oral nutritional supplementation and diet counseling are likely to continue to be indicated in HIV-infected patients as supportive measures to anti-retroviral treatments.
Funding Source:
Industry:
Sandoze Nutrition (Sweden)
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:
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? 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? 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? ???
  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? 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
  5.4. 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? 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? 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)? Yes
  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