EAL

H/A: Monitoring of Food Intake (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

Evaluation of the baseline nutrient intake of an HIV-positive population that includes significant representation from women and minorities, and to determine the relationship between the state of disease and nutritional intake.

Inclusion Criteria:

Nutrition for Life Study participants. No criteria given in this article; can refer to Woods et al, 2003, for inclusion and exclusion.

Exclusion Criteria:

No criteria listed.

Description of Study Protocol:

Recruitment

Participants in Nutrition for Life study.

Design

Baseline data from the prospective study, Nutrition for Life study.

Blinding Used

Blood samples were sent to a clinical lab for analysis.

Intervention

Subjects were stratified within three CD4 categories: CD4 lymphocyte cell counts 500 (x10⁶) or more, counts between 200 and 499 units (x10⁶), and less than 200 (x10⁶).

Statistical Analysis

Associations between dietary intake and other variables were determined using non-parametric statistics due to skewed distributions
Spearman correlation coefficients were used to assess associations between nutrient intake and CD4 counts
The difference between nutrient intake in this study's data and NHANES III, matching by gender and the age group closest to this sample group (30 to 39 years of age), was assessed by a one-sample Wilcoxon signed rank test, treating the NHANES data as a national standard
The significance of the differences in percent supplement usage between subgroups was determined by the C² test.

Data Collection Summary:

Timing of Measurements

Initial entry visit (questionnaires)
Second entry visit seven to 14 days later; blood draw and anthropometrics were assessed.

Dependent Variables

Kilocalories per day per kg body weight
Nutrient intakes (food and supplements)
Serum vitamin B₁₂, vitamin B₆, folate, iron.

Independent Variables

CD4 counts.

Description of Actual Data Sample:

Initial N: 516
Attrition (final N): 516
Age: 40±7.6
Ethnicity: 65% White; 24% African-American; 7% Hispanic; 5% Other.

Other Relevant Demographics

75% men, 25% women
Listed HIV transmission group (e.g., homosexual, IVDU, transfusion), education completed and annual income.

Anthropometrics

Split out by CD4 counts (CD4 less than 200, 200 to 499, more than or equal to 500mm³); listed in Table 2.

Location

Boston and Rhode Island.

Summary of Results:

Variables

CD4 < 200

CD4 200 to 499

CD4 > 500

Statistical Significance of Group Difference

BMI, men

BMI, women

Median (25th, 75th percentile)

23.0 (20.9, 24.8)

23.3 (20.9, 25.6)

24.5 (22.9, 26.4)

25.3 (22.7, 29.4)

25.1 (23.3, 28.4)

25.3 (23.3, 30.2)

P=0.001

P=0.014

Energy intake (kcal)

Men

Women

2,934 (2,348; 3,468)

1,878 (1,499; 2,584)

2,835 (2,322; 3,229)

2,136 (1,567; 2,633)

2,813 (2,470; 3,502)

2,081 (1,369; 2,621)

P=0.511

P=0.501

Kcal per kg

Men

Women

40.3 (33.7, 47.9)

30.0 (24.3, 46.0)

36.9 (29.53, 44.7)

31.0 (21.8, 40.0)

36.0 (29.5, 43.9)

29.4 (18.1, 37.1)

P=0.001

P=0.047

Protein (g per kg)

Men

Women

1.5 (1.1, 1.9)

1.1 (0.91, 1.5)

1.3 (1.1, 1.6)

1.0 (0.79, 1.5)

1.4 (1.1, 1.8)

1.0 (0.60, 1.5)

P=0.012

P=0.108

Other Findings

Figure 1 gives the association between kcals per day per kg body weight and CD4 count for males and females. In men, this association was not linear, and with CD4 cell counts less than 478, the daily kcal per kg of body weight was higher by two kcal per kg body weight per 100-point decline in CD4 cell counts. In women the association was linear over the full range of CD4 cell counts. Energy intake was higher by one kcal per day per kg body weight for every 100-point decrease in CD4 cell count.

Table 2 gives median BMI and weight by CD4 cell count category with the 25th and 75th percentiles. The largest CD4 subgroup was that with 200 to 499 cell counts. 35% of all men and 23% of all women were in the category of less than 200.

Energy intake (kcal per day) was comparable to intake data from NHANES III for the same age and gender groups. Table 3 also gives micronutrient intakes by CD4 cell count. Micronutrient levels were generally higher with decreasing CD4 cell counts, but were not significant. Intake of nutrients was above the general population median (NHANES III) for both men and women. In spite of the median increase in many micronutrients, a significant percentage of the population had dietary intakes below the DRIs and was most notable among women.

Table 4 gives the nutrient intake (food and supplements) in white and nonwhite subsets. Significant differences in macro- and micronutrient intakes were observed for men (white more than nonwhite male subjects). Whereas for women, only vitamin A intake was greater for white women than for nonwhite women.

48% of the study sample reported using vitamin/mineral supplements; 55% of men and 29% of women. Sixty-one percent of white vs. 40% of nonwhite men reported using supplements. There was no difference in supplement usage between white and non-white women.

Subjects whose primary route of HIV transmission was intravenous drug use reported lower supplement use than other participants.

Thirty-three percent of subjects with CD4 cell counts of more than 500 reported using supplements whereas 50% with CD4 cell counts of 200 to 499 used supplements. Fifty-four percent of subjects with CD4 cell counts less than 200 reported using supplements.

Intakes of vitamins B₁₂, B₆ and folate were correlated with serum values. As expected, dietary iron intake was not correlated with serum iron.

Author Conclusion:

Median values for micronutrient intake from food plus vitamin/mineral supplements were adequate in the overall population studied, but a large percent of women and minorities had inadequate nutrient intakes and would benefit from dietary assessment and counseling.

The authors stated that emphasis on nutritional intake improves as the disease progresses.

The study does address the question, "What is the evidence that dietary strategies manage symptoms for a healthy lifestyle (quality of life, physical function, nutritional status, dietary intake) in an HIV-infection individual?". It demonstrates that HIV-positive women and minorities are especially at risk of inadequate nutrient intake.

Funding Source:

Reviewer Comments:

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)	N/A
	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?	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?		N/A
	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?	N/A
	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.)	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?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	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?		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)?	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