H/A: Caloric Needs (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To determine the relationship between energy metabolism and growth abnormalities in HIV-infected children and to assess clinical or laboratory characteristics that may be contributing factors to their growth impairment.
Inclusion Criteria:
None specifically mentioned.
Exclusion Criteria:
None specifically mentioned.
Description of Study Protocol:

Recruitment

Pre-pubertal children attending the New York Hospital Program for Children with AIDS were recruited.

Design

Cohort study.

Statistical Analysis

  • Differences in Z-scores between the group of HIV-infected children with growth impairment and the group with normal growth parameters were assessed by Wilcoxon's rank sum analysis
  • Differences between means of continuous data were analyzed by Student's T-test
  • Comparison of measured values in HIV-infected subjects to expected age and gender matched normal values utilized the paired Student's T-test
  • Distribution of non-continuous data was compared by Fisher's exact test of probability.
Data Collection Summary:

Timing of Measurements

Measurements made at a time point of wellness.

Dependent Variables

  • Energy intake measured by inpatient calorie count and outpatient 24-hour food recalls
  • Resting energy expenditure measured by indirect calorimetry
  • Total energy expenditure measured by doubly-labeled water technique
  • Blood samples analyzed for markers of iron, protein and lipid metabolism markers as well as CD4 count, viral load, insulin-like growth factor-1, serum interleukin-6 and whole blood stimulated IL-6 levels.

Independent Variables

Normal or impaired growth pattern.

Description of Actual Data Sample:
  • Initial N: 23 HIV-infected children, 15 girls and eight boys
  • Attrition (final N): 23
  • Age: 1.3 to 13.2 years
  • Ethnicity: Not mentioned
  • Other relevant demographics: 12 were considered to have normal growth development
  • Location: New York.
Summary of Results:

 

Expected Normal Values for Age and Gender

All HIV+ Subjects (N=23)

HIV+ and Normal Growth (N=12)

HIV+ and Growth-Impaired (N=11)
Total EE (kcal/Day) 1,710.87±70.5 1,566.6±119 1,521±173 1,622±166
REE (kcal/Day)

923.4±53.5

937.4±50.4

990±59

880±83

Energy Intake (kcal/kg/Day)

84.7±3.1

75.7±4.7 (P<0.04)

72±5.8

80±7.8

Other Findings

  • Differences in energy expenditure were not found between normal and growth-impaired HIV-infected children
  • Energy intake but not energy expenditure was significantly reduced when HIV-infected children were compared to expected normal values for age and gender (P<0.04)
  • Advanced HIV clinical disease, severe immune suppression, increased viral burden, increased IL-6 activity, decreased total serum protein and decreased IGF-1 levels were more likely to be found in HIV-infected children with growth impairment compared to HIV-infected children with normal growth. 
Author Conclusion:
  • In summary, we have identified several clinical and laboratory determinants which were associated with growth impairment in HIV-infected children
  • Advanced HIV clinical disease, severe immune suppression, increased viral burden, increased IL-6 activity, decreased total serum protein and decreased IGF-1 levels were more likely to be found in HIV-infected children with growth impairment than in HIV-infected children with normal growth
  • Energy consumed by our cohort of HIV-infected children was found to be substandard when compared to expected normal energy intake.
Funding Source:
Reviewer Comments:
  • Inclusion and exclusion criteria were not described
  • Authors note that the study is limited by the size of the cohort and the fact that the children were studied at one time-point of wellness.
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) N/A
  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) N/A
 
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? No
  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? 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? Yes
  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? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? 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? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  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? No
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