H/A: Micronutrient Supplementation (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

The purpose of this study was to examine the relationship between micronutrient intakes and human immunodeficiency virus (HIV) infection in youths who were at increased nutritional risk because of the demands of growth and disease as well as poor dietary habits.

Inclusion Criteria:
  • Adolescents between the ages of 12 to 18 years who had acquired HIV through sexual activity or intravenous drug use
  • HIV-uninfected adolescents and young adults.
Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Subjects were recruited as part of the Excellence in Adolescent Care and Health study, a prospective, observational, cohort study on the progression of HIV infection in adolescents in 15 clinical US sites. In addition, non-HIV infected controls were recruited from the same clinic sites. 

Design

Case-Control Study

The Block Food Frequency Questionnaire was administered at one study visit between January and October 2000. Analysis of micronutrients were compared between the HIV-positive and HIV-negative individuals as well as to the Estimated Average Requirements (EAR) of the Dietary Reference Intakes (DRI). 

Blinding used (if applicable) 

Intervention (if applicable) 

Statistical Analysis

  • Continuous variables were reported as mean ± standard error of mean (SEM) and percentiles, significant differences by presence of HIV infection were determined by two-sample Student's T-tests
  • Differences by CD4 T-cell stratification were determined by using analysis of variance (ANOVA) with post-hoc tests using Bonferroni multiple comparisons
  • For categorical analyses, differences were determined by Chi-Square test of goodness-of-fit
  • Generalized linear regression determined predictors of vitamins A, C and E, iron and zinc intakes.
Data Collection Summary:

Timing of Measurements

The BFFQ was administered in an interview format by trained clinical staff and completed within 1.4±0.4 days of the clinic visit

Dependent Variables

  • Intakes of vitamins A, C, E, iron and zinc (measured by BFFQ)
  • HIV serum antibody and CD4 cell T-cell counts (serum measures)
  • Measure of psychological health (Revised Children's Manifest Anxiety Scale).

Independent Variables

HIV-positive vs. HIV-negative

Control Variables

Patients were stratified by CD4 T-cell counts

Description of Actual Data Sample:

Initial N

391 (264 HIV-positive, 127 HIV-negative)

Attrition (final N)

Same. 3/4 of participants were female

Age

HIV-infected: 20.0±0.1 years vs. 19.4±0.1 years (P<0.001)

Ethnicity

96% were Black, non-Hispanic or Hispanic

Other relevant demographics

HIV-infected were more likely to live on their own (33.3% vs. 17.3%, respectively, P<0.001, and less likely to have completed or be enrolled in high school or a general equivalency diploma program (57.2% vs. 78%, respectively; P<0.01) than HIV-uninfected participants.

Anthropometrics

CD4 counts in HIV-positive group:

  • Greater than or equal to 500 48.9%
  • Greater than 200, less than 500 38.6%
  • Less than 200 12.5%.

46.2% were not on anti-retroviral therapy. Of those taking anti-retroviral therapy, 34.5% were on a monotherapy or combination therapy without a protease inhibitor; 19.3% were on combination therapy which included a protease inhibitor.

Location

15 clinical sites in the United States

 

Summary of Results:

 

Micronutrient Intake HIV-positive males
Mean ±SEM
HIV-negative males
Mean SEM
P-Value
Energy, kcal 4,507±304 3,732±333  0.090
Vitamin A, RAE 1,241.0±101.2 994.4±139.3  0.173
Vitamin C, mg 285.1±22.1  275.2±31.5 0.798
Vitamin E, mg 16.0±1.1 15.1±1.0 0.013
Iron, mg 31.1±2.5  26.0±3.1 0.201 
Zinc, mg 21.9±1.9 17.6±1.3 0.069 

 

Micronutrient Intake HIV-positive females
Mean ± SEM
HIV-negative females
Mean SEM
P-Value
Energy, kcal 3,691±137 3,445±191  0.298 
Vitamin A, RAE 1,025.0±55.3 944.0±72.2  0.374 
Vitamin C, mg 246.5±11.4 255.0±16.8 0.678 
Vitamin E, mg 12.8±0.5 12.4±0.8  0.692 
Iron, mg 23.9±1.1 23.4±1.8  0.828 
Zinc, mg 16.8±0.8 14.9±0.9  0.107 

Other Findings

  • 36% of participants reported using a vitamin or mineral supplement. 119 reported taking a multivitamin or mineral supplement, 39 reported taking iron supplements and 32 reported taking vitamin C 
  • The proportion of those who reported "fair or poor" health status increased with decreasing CD4 T-cell strata among HIV-positive individuals (30.2%, 33.3%. 60.6% respectively, P<0.01)
  • HIV-positive with CD4 T-cells greater than 500 cells/mcg/L was associated with lower intake of iron and tended to be associated with lower vitamin C and E (P<0.10) 
  • Increased energy intake was associated with higher intakes of all micronutrients
  • Positive associations between food group servings and micronutrient intakes varied: Dairy and vegetable intakes were associated with Vitamin A, fruit with vitamin C, meat and vegetables with iron, dairy and meat servings with zinc
  • The percentage of energy from fat was positively associated with vitamin E intake
  • Vitamin and mineral supplement use was associated with higher intakes from food for vitamins A and E and iron.

 

 

Author Conclusion:

Practitioners should recognize the following:

Young patients with HIV are at highest risk of being deficient in vitamins A, E and zinc. HIV-infected youths may have increased micronutrient needs related to impaired immune function and metabolic complications of the disease. Dietitians and health care professionals should focus on setting individualized behavioral goals with HIV-infected youths, emphasizing foods rich in micronutrients early in the infection. Additional research is needed to determine the micronutrient needs for HIV-infected youths that will meet their nutritional needs for growth as well as help slow the disease progression of HIV.

Funding Source:
Government: National Institutes of Health, National Institute of Child Health and Human Development; National Institutes on Drug Abuse, Allergy and Infectious Diseases and Mental Health
Reviewer Comments:

Large sample size, multicenter study. Used Block Food Frequency Questionnaire which is not the best indicator of dietary intake (discussed by authors in discussion). 

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.) 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.) Yes
  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? ???
  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.) No
  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? No
  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? ???
  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? ???
  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? 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? ???
  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? ???
  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? ???
  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? N/A
  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)? Yes
  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