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HIV/AIDS

H/A: Monitoring of Food Intake (2009)

Citation:

Forrester JE, Tucker KL, Gorbach SL. Dietary intake and body mass index in HIV-positive and HIV-negative drug abusers of Hispanic ethnicity. Public Health Nutrition. 2004; 7(7): 863-870.

PubMed ID: 15482611
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

The purpose of the study was to examine the dietary intake and body mass index (BMI) of Hispanic drug abusers with human immunodeficiency virus (HIV) and determine the following:

  • Compare diet of HIV-positive drug abusers with those of HIV-negative drug abusers
  • Assess the relationship between diet and specific type of drugs used as well as the frequency of drug abuse.

 

Inclusion Criteria:

Participants were self-identified Hispanics, older than 18 years of age, who spoke Spanish fluently.

Exclusion Criteria:
  • Pregnant at recruitment
  • History of hormone treatments for sex change
  • Non–HIV-related malignancies
  • Refused to sign consent form.

 

Description of Study Protocol:

Recruitment

Participants were recruited via:

  • Outreach in streets
  • Homeless shelters
  • Health clinics
  • Physician offices.

Design

The study used a cross-sectional design as it used baseline data collected from a cohort study. Although participants were assessed on two different occasions, the measures and observations at each visit were different.

Participants were classified according to their HIV status (positive or negative) and drug use (drug abuser or not a drug abuser). Participants' data was also analyzed separately by sex.

Statistical Analysis

Medians were used to compare micronutrient intake among groups. Least-squares means using the generalized linear model were calculated for continuous variables with normal distribution to examine significant differences among groups.  Non-normally distributed variables were log-transformed to fit parametric statistics. Chi-square and Fisher exact tests were used for categorical variables.

Data Collection Summary:

Timing of Measurements

Measurements were taken once at two different visits, 10 days apart. The exception was the variable for dietary intake that was measured twice for participants who were unable to complete three-day food records on their own. The authors do not indicate the number of participants who were unable to complete the three-day food records.

Variables

  • BMI (calculated as weight [kg]/height [m2])
  • Dietary intake, mean dietary intake of four days for participants who completed three-day food records and one 24-hour recall at the first visit. For an unknown number of participants, dietary intake data is the mean intake of two days corresponding to a 24-hour recall conducted at the first visit and a second 24-hour recall conducted at the second visit if their food records were incomplete.
  • Depression, measured using the Burnam Depression Screen
  • Homelessness, determined if participant lived at a shelter or on the streets. Value represents percentage of participants.
  • Alcohol and drug abuse, measured using standardized questionnaires
  • HIV status, measured by self-report and confirmed with enzyme-linked immunosorbernt assay
  • CD4 count
  • Use of highly active anti-retroviral therapy (HAART), percentage of participants
  • Medical insurance, percentage of participants.

Control Variables

The authors indicate several analyses were adjusted for homelessness and the source of the dietary intake data (24-hour recall or food diary). Also, reports of energy intake were adjusted to exclude calories from alcohol.

Description of Actual Data Sample:

Initial N

284 subjects (212 male, 72 female).

Attrition (final N)

284.

Age

Mean age among participants was reported separately for each group compared and by sex. Mean age:

  • Men
    • HIV-positive drug abusers, 41.0 years
    • HIV-positive non-drug abusers, 40.2 years
    • HIV-negative drug abusers, 36.7 years.
  • Women
    • HIV-positive drug abusers, 36.1 years
    • HIV-positive non-drug abusers, 38.1 years
    • HIV-negative drug abusers, 33.0 years.

Ethnicity:

Sample was self-identified Hispanic.

Other relevant demographics

Place of birth among participants was reported as follows:

  • 72% born in Puerto Rico
  • 16% born in mainland United States
  • 12% were born in other parts of Latina America or the Caribbean.

Anthropometrics

BMI was reported separately for each comparison group.

  • Men
    • HIV-positive drug abusers, 25.2
    • HIV-positive non-drug abusers, 27
    • HIV-negative drug abusers, 25.8.
  • Women
    • HIV-positive drug abusers, 27.1
    • HIV-positive non-drug abusers, 29.7
    • HIV-negative drug abusers, 30.8.

Location

Boston, MA.

Summary of Results:

 

 
HIV-positive
drug abusers
HIV-positive
non-drug abusers
HIV-negative
drug abusers
Men (n=71)
Women
(n=14)
Men (n=60)
Women (n=37)
Men (n=81)
Women (n=21)
BMI
25.2*
27.1*
27
29.7
25.8
30.8
Years with HIV
9.3
5
7.8
6.3
-
-
HAART use (%)
38
5
49
22
-
-
Homeless (%)
14
2
0
4
47
5
Completed three-day food record  (% with four days of intake)
40
4
32
26
32
5
Energy (kcal)
2671
2171
2536
1852
2734
2102
Protein (% energy)
15.1
13.2
15.9
15.4*
14.7*
13.2
Fiber (g)
19.6
13.9
18.9
15.9*
18.3
11.6
Carbohydrate (% energy)
54.2
56.6
52.2
54.1
54.9*
54.5
Simple carbohydrate (sugars) (g)
24
26.5
23
23.3*
26.1
28.1
Supplement use (%)
24
3
26
7
11
3
Zinc (% DRI)
131
127
119
110
111
88
Vitamin B6 (% DRI)
205*
187*
197
140*
168
107
Vitamin A (% DRI)
116
110
149
107
103*
79
Vitamin B12 (% DRI)
233
156
247
149
202*
124
Alpha tocopherol (% DRI)
72
49
97
42
63*
43

 * Denotes significant difference at P<0.05 among groups.

 
Other Findings
  • HIV-positive drug abusers had a BMI that was significantly lower than that of HIV-positive non-drug abusers
  • Reported energy, fat and fiber intakes did not differ between groups
  • All groups had median reported intakes of vitamin A, vitamin B6, vitamin B12, selenium and zinc that were in excess of the dietary reference intakes (DRI)
  • Intakes of alpha-tocopherol were less than the DRI, but did not differ from intakes of the general US population
  • However, increasing levels of drug abuse were associated with lower reported intakes of vitamin B6, vitamin B12, selenium and zinc
  • The most frequent drugs used were heroin and cocaine or a combination (speedball) (48%)
  • There were no differences in nutrient intake according to the type of drug used
  •  After adjusting statistical analysis, differences in nutrient intake among HIV-positive and HIV-negative groups were attributed to homelessness.
Author Conclusion:

Data suggests that whereas there are some differences in dietary intake that can be attributed to drug abuse, especially among heavy users, overall diet does not seem to explain the high prevalence of lower BMI found in this study. Further studies pursuing other explanations of lower BMI in HIV-positive and HIV-negative drug abusers are warranted.

Funding Source:
Government: National Institute of Health
University/Hospital: New England Medical Center
Reviewer Comments:

This was a well conducted study that provides a thorough analysis of the data and justification for adjustments to the statistical analysis. The results suggest that the poor dietary intake observed among HIV-negative drug abusers was attributed to homelessness and not drug abuse. However, the authors do not provide the data of the frequency of drug use to be able to evaluate the severity of their drug use, only that they were drug abusers. Although BMI was reported as significantly less among HIV-negative drug-abusing men, mean BMI among the total sample was more than 24.9 and thus on average the sample was classified as overweight.

Even though dietary intake data was collected via two different methods, which may jeopardize the integrity of the data, the authors accounted for the source of dietary intake data in their analysis. The authors did not take into account, however, the potential influence of HAART use among women and their dietary intake. Very few (n=5) HIV-positive drug abusers were taking HAART, whereas more than half of the women who were HIV-positive non-drug abusers were taking them. Considering the disrupting effect of HAART on dietary intake, this may also have a confounding effect on overall dietary intake.

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? N/A
  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? 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? No
  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? No
  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? 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.) No
  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? N/A
  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? No
  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? No
  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? 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? 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? N/A
  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)? Yes
  8.6. Was clinical significance as well as statistical significance reported? N/A
  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