H/A: Monitoring of Food Intake (2009)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To determine whether reduced serum or plasma protein and micronutrient levels are common in children infected with the human immunodeficiency virus (HIV) and whether these levels are different in children with growth retardation compared to those with normal growth.
Inclusion Criteria:

Children with perinatally acquired HIV infection and their HIV-uninfected siblings who were followed up in the Intensive Primary Care Clinic at the Johns Hopkins Children's Center

Exclusion Criteria:
None listed.
Description of Study Protocol:


Children with perinatally acquired HIV infection and their HIV-uninfected siblings who were followed up in the Intensive Primary Care Clinic at the Johns Hopkins Children's Center.  


Case-control study. 

Blinding used

Assumed for laboratory measures.

Statistical Analysis

  • Differences in mean growth and laboratory analyses were assessed by analysis of variance with Duncan pairwise comparison
  • Chi-square analysis was used to identify differences in the frequency of micronutrient deficiencies between groups
  • Energy and nutrient intake from 24-hour weighed food intake was compared with 24-hour dietary recall by means of paired T-test.


Data Collection Summary:

Timing of Measurements

During a 24-hour stay in the Pediatric Clinical Research Unit, blood samples were taken, growth measurements obtained and dietary intake assessed.

Dependent Variables

Blood work conducted by the pathology department of the Johns Hopkins Hospital:

  • Serum total protein: Biuret method
  • Albumin: Doumas bromcresol green dye-binding reaction
  • Prealbumin: Methylometry
  • Plasma zinc and selenium: Atomic absorption spectroscopy
  • Serum vitamin A: High-performance liquid chromatography

Dietary intake assessed by 24-hour weighed food intake during the child's stay in the Pediatric Clinical Research Unit and also by 24-hour dietary recall of the previous day's dietary intake at home as provided by the parent and the child. Nutrient analysis was conducted using the Nutritionist IV software package (version 4.1, 1996). Nutrient levels were compared with the RDAs for each child according to his or her age. Caretakers were asked to report any micronutrient supplementation before the study.

  • Dietary energy
  • Dietary protein
  • Dietary zinc
  • Dietary selenium
  • Dietary vitamin A.

Independent Variables

 Three comparison groups:

  • HIV-infected with growth retardation defined as height or weight for age or weight for height Z-score of -1.5 or less based on National Center for Health Statistics growth standards (HIV+Gr)
  • HIV-infected with normal growth defined as height and weight for age and weight for height Z-score greater than -1.5 based on NCHS standards (HIV+)
  • HIV-uninfected with normal growth as defined above (HIV-).

Control Variables

  • CD4 cell number: The two groups of HIV-infected children were distributed similarly among the CDC classification system (1994 system)
  • Mean CD4 lymphocyte number was lower in the HIV+Gr group, but was not statistically significant.
Description of Actual Data Sample:
  • Initial N: 38 (21 boys; 17 girls)
  • Attrition (final N): None
  • Age
    • HIV+Gr: 7.2±2.2 years (mean ± standard deviation)
    • HIV+: 6.8±1.5 years
    • HIV-: 7.1±2.8 years
  • Ethnicity: Not given
  • Other relevant demographics
    • Disease information
      • All were afebrile and free of acute infection at the time of study
      • CD4 cell number
      • HIV+GR: 331±545
      • HIV+: 652±549.
  • Anthropometrics
    • Height-for-age Z-score
      • HIV+Gr: -1.6±1.2b
      • HIV+: -0.7±0.8
      • HIV-: 0.5±0.9c.
    • Weight-for-age Z-score
      • HIV+Gr: -1.5±0.6c
      • HIV+: -0.4±1.1
      • HIV-: 0.1±0.8d.
    • Weight-for-height Z-score
      • HIV+Gr: -0.5±1.1
      • HIV+: 0.1±0.8
      • HIV-: 0.3±0.8.
  • Location: Intensive Primary Care Clinic at the Johns Hopkins Children's Center, Baltimore, MD.

b Significantly lower than HIV+ and HIV- (P<0.05)
c Significantly greater than HIV+Gr and HIV+ (P<0.05)
d Definition of this superscript was not given.

Summary of Results:

 Table Two: Plasma and Micronutrient Levels in Serum and Plasma





Normal Range

Serum Total Protein (g/L)





Albumin (g/L)





Prealbumin (g/L)




0.13±0.27 (-?)
Plasma zinc (umol/L) 13.0±2.8 12.7±1.7 13.0±1.7 8.4-23.0
Plasma Selenium (umol/L) 1.37±0.16 1.35±0.11 1.43±0.16 1.14-2.15
Serum Vitamin A (umol/L) 1.78±0.42z 1.47±0.35 1.40±0.35 1.05-3.32

y Significantly different from HIV- (P<0.05)
z Significantly different from HIV+ and HIV- (P<0.05).

Dietary Energy Intake Assessed by 24-Hour Weighed Diet (WD) and 24-Hour Dietary Recall (DR): Percentage RDA for Age

  24-Hour Weighed Diet 24-Hour Dietary Recall
HIV+Gr (N=9) 103±25  116±23x
HIV+ (N=18) 94±23
HIV- (N=10)

x Mean is significantly different from the mean for HIV+ group (P<0.05).

Dietary Protein Intake Assessed by 24-Hour Weighed Diet (WD) and 24-Hour Dietary Recall (DR): Percentage RDA for Age

  24-Hour Weighed Diet 24-Hour Dietary Recall
HIV+Gr (N=9) 212±63 322±106y,z
HIV+ (N=18) 224±71 232±80
HIV- (N=10) 188±41 220±99

y Mean is significantly different from the mean for HIV+ and HIV- groups (P<0.05)
z Dietary recall is significantly different from kilocalorie count (P<0.02).

Other Findings

  • Mean energy intake approximated the RDA for energy
  • Mean protein intake exceeded the RDA for protein
  • Only mean zinc intake was less than two-thirds of the RDA
  • There were no significant differences between groups in the frequency for any nutrient studied.
Author Conclusion:
  • Abnormal serum or plasma protein or micronutrient levels were uncommon in this cohort of HIV-infected children, even in children with growth retardation
  • These findings suggest that routine monitoring of the level of proteins and micronutrients studied is unnecessary in the absence of specific clinical indicators of deficiency.
Funding Source:
Government: NIH
Reviewer Comments:

This reviewer has concerns regarding the authors' second conclusion statement regarding routine monitoring. The children were afebrile and free of acute infection at the time of study. It is well known that fever and infection alters metabolism and can also negatively influence micronutrient status. These changes, due to the presence of infection, may occur before clinical signs of a nutrient deficiency occur. So, based upon the reviewers experience, it seems that monitoring would be warranted in the case of a child who is undergoing an opportunistic infection.

It was not clear to the reviewer why the subjects were admitted to the Pediatric Clinical Research Unit and the length of admit was not mentioned. It was unclear whether the children were admitted for study purposes or if the child was admitted and then enrolled in the study.

  • Body composition analyses is mentioned in the methods section, but then is not mentioned in the results or discussion
  • The basis of free of acute infection is not given. Measurement of markers of inflammation may have been beneficial in addition to clinical symptoms of infection.
  • There is no indication as to whether the investigators used fasting or non-fasting blood draws. Non-fasting blood collections will impact plasma zinc values.
  • Limitations: The nutrient requirements of HIV-infected children may well be different from those of uninfected children, however and the nutrient intake demonstrated in our study may be insufficient for optimal growth and nutritional status. This is really the only limitation that is mentioned.
  • Sources of funding were not disclosed.
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? ???
  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? No
  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.) ???
  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? ???
  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.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  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? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  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? 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? N/A
  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)? No
  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? ???