EAL

H/A: Monitoring of Food Intake (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the relationships between drug abuse, weight, BMI, body composition and dietary intake in persons infected with HIV.

Inclusion Criteria:

Persons 18 years of age and older who were HIV positive and consented to participate were considered eligible.

Exclusion Criteria:

People who met any one of the following criteria were excluded:

Pregnant at recruitment
Diagnosed with diabetes mellitus, thyroid disease or malignancies other than HIV-associated malignancies
Inadequate fluency in English
Refusal to sign a consent form for release of medical records.

Description of Study Protocol:

Recruitment

Data were taken from the baseline visits of the first 588 participants to enroll in the Nutrition for Healthy Living Study, a longitudinal study of the role of nutrition in HIV disease. Recruitment of participants was done through advertisements on radio, in local newspapers, health clinics and physician networks.

Design

Cross-sectional analysis of baseline data from a cohort study.

Statistical Analysis

Cross-sectional analyses of the data were done using linear regression models
Analyses of between-group differences used reference-cell coding, with the nonuser group as the reference category
Trends in weight, BMI, fat mass and fat-free mass across the drug use categories were tested by assigning each subject a score
Between-group differences in micronutrient intakes were tested using the natural log transformation of the micronutrient values and robust variance estimators
All models were checked for violations of assumptions by examination of residuals
Influential observations were checked by Cook's distance but none was found.

Data Collection Summary:

Timing of Measurements

Data were taken from the baseline visits of the first 588 participants.

Dependent Variables

Height, weight, BMI
Body composition measured by bioelectrical impedance analysis
Dietary data collected by three-day food records or 24-hour recalls.

Independent Variables

HIV infection
Drug abuse: Non-users, non-IV drug users, past IV drug users, current IV drug users
Marijuana-only users were classified with non-users because marijuana is frequently used as an appetite stimulant.

Control Variables

Age
HIV disease stage using CD4 cell counts
Current use of antiretroviral therapy, protease inhibitors and anabolic steroids.

Description of Actual Data Sample:

Initial N: 588 recruited to the study
Attrition (final N): Drug abuse classified for 502 participants. 442 subjects had complete data on weight and body composition. 39 current IV drug users, 103 past IV drug users, 239 users of non-IV drugs, and 61 non-users.
Age: See Results.
Location: Massachusetts.

Summary of Results:

Weight, Body Composition and Macronutrient Intake in Relation to Drug Use in HIV-Positive Men

Variables	Never Used Drugs (N=35)	Non-IV Drug User (N=197)	Past IV Drug User (N=52)	Current IV Drug User (N=28)	P-value Test for Trend
Age (years)	44.3±11.2	39.8±7.4	42.7±6.9	42.7±4.4	---
Weight (kg)	75.7±13.5	76.4±12.6	76.8±12.6	78.0±10.6	0.5
BMI	24.3±3.9	24.6±3.5	25.3±3.4	25.1±3.1	0.3
Fat free mass (kg)	57.6±8.9	58.8±8.2	57.2±6.8	59.7±6.9	0.6
Fat mass (kg)	18.2±6.9	17.6±6.9	19.6±8.0	18.2±6.5	0.6
Percentage Body fat	23.5±6.5	22.3±6.1	24.8±6.6	23.1±6.1	0.5
Energy per kg (kcal per kg)	36.4±8.9	40.2±12.7, P<0.05	36.1±13.1	46.2±16.7, P<0.01	---
Percentage kcal from alcohol	0.02 (0, 1.4)	0.04 (0, 1.8)	0.03 (0, 0.09)	0.01 (0, 0.06)	---
Protein per kg (g per kg)	1.4±0.42	1.5±0.52	1.4±0.68	1.5±0.66	---
Carbohydrate (g)	343±105	372±116	312±97, P<0.05	447±160, P<0.01	---
Total fat (g)	105±34	111±41	113±42, P<0.05	142±61, P<0.01	---

Weight, Body Composition and Macronutrient Intake in Relation to Drug Use in HIV-Positive Women

Variables	Never Used Drugs (N=26)	Non-IV Drug User (N=42)	Past IV Drug User (N=51)	Current IV Drug User (N=11)	P-value Test for Trend
Age (years)	38.4±10.1	37.6±7.3	38.7±6.0	38.4±7.2	---
Weight (kg)	71.4±19.0	69.2±20.6	66.7±13.5	57.7±8.6	0.04
BMI	27.5±7.5	26.3±7.1	25.7±5.2	21.9±3.0	0.04
Fat free mass (kg)	45.5±10.2	44.4±9.6	43.4±7.0	41.7±5.8	0.20
Fat mass (kg)	26.0±10.2	24.8±11.8	23.4±7.9	16.2±5.1	0.01
Percentage Body fat	35.6±6.6	34.7±7.0	34.5±6.0	29.4±5.1	0.03
Energy per kg (kcal per kg)	27.7±11.8	35.0±17.0, P<0.05	34.6±15.9, P<0.05	42.4±16.3, P<0.01	---
Percentage kcal from alcohol	0 (0, 0.01)	0.02 (0, 0.04)	0 (0, 0.07)	0 (0, 0.8)	---
Protein per kg (g per kg)	1.1±0.45	1.2±0.48	1.2±0.56	1.6±0.60, P<0.05	---
Carbohydrate (g)	242±92	284±117	271±119	312±125	---
Total fat (g)	69.7±33.8	93.3±51.0, P<0.05	90.7±38.0, P<0.05	92.9±46.3	---

Other Findings

In men, there were no differences in weight, BMI or body composition among the drug-use groups.

In the women, there was a trend to lower weight and BMI across the drug-use categories: IV-drug-using women had lower average weight (-13.7kg, P=0.006), BMI (-5.6 units, P=0.003), and less fat mass than non-users (-9.8kg, P=0.0001).

In women, drug users had higher weight-adjusted energy intakes than non-users, whereas in the men both drug-using groups, non-IV drug users and IV drug users, had higher energy intakes than non-users.

Author Conclusion:

In summary, these data provide evidence that in women with HIV infection, those who use intravenous drugs have lower weight and fat mass than women who do not use drugs, despite reported adequacy in energy and micronutrient intakes. Thus, HIV-positive women who use intravenous drugs may be at higher risk of developing the AIDS-wasting syndrome. More studies of the contribution of drug abuse to weight loss and the progression of HIV disease are needed. Better methods to measure usual nutrient intake in drug users need to be designed. Studies done in populations that use drugs will require additional resources.

Funding Source:

Government:

NIH (M01-RR00054), NIDDK (DK4 5734-03)

Reviewer Comments:

Marijuana-only users were classified with non-users.

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?		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?	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.)	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?	Yes
	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.)	N/A
	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?		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?	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)?	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