EAL

H/A: Dietary Intake (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine dietary intake in HIV-infected men with lipodystrophy.

Inclusion Criteria:

Documented HIV-1 infection and lipodystrophy
Age older than 17 years
Limb fat less than 20% of limb tissue or limb fat percentage at least 10% less than truncal fat percentage by dual-energy X-ray absorptiometry (DEXA).

Exclusion Criteria:

HIV wasting syndrome
Any serious medical condition such as active AIDS, pancreatitis or hepatitis within the previous six months
Receiving insulin, oral diabetic agents, anabolic steroids (except testosterone replacement), glucocorticosteroids at more than replacement dose, growth hormone, agents stimulating appetite or weight gain, immune modulators, hydroxyurea or cimetidine
Fasting glucose more than 7.0mmol per L and fasting triglycerides more than 15.0mmol per L.

Description of Study Protocol:

Recruitment: Participants were enrolled in a 48-week study of the effects of rosiglitazone. Participants had been recruited at 17 HIV primary care or hospital outpatient sites in Australia
Design: Cross-sectional analysis of baseline study data
Blinding used: Not applicable
Intervention: Not applicable.

Statistical Analysis

After exclusion of energy under-reporters, the relationships between dietary intake and metabolic parameters, body composition and visceral adiposity were examined using simple regressions and Spearman correlations for non-parametric measures
Comparisons were made by T-tests and all data were presented as means ± standard deviation.

Data Collection Summary:

Timing of Measurements

Dietary intakes were determined at study entry and examined with body composition, visceral fat and analysis of blood samples.

Dependent Variables

Body composition measured with DEXA
Visceral obesity measured by computed tomography
Blood samples analyzed for fasting glucose, insulin, lipids, adiponectin, leptin and insulin resistance (IR) [by homeostasis model assessment (HOMA)].

Independent Variables

Dietary intake measured through food frequency questionnaires
Participants were divided into adequate energy reporters and under-reporters.

Description of Actual Data Sample:

Initial N: 108 subjects were included in the analysis
Attrition (final N): 86 were adequate energy reporters, 22 were under-reporters
Age: Mean, 45 years
Ethnicity: Not reported
Other relevant demographics: HIV data reported elsewhere
Location: Australia.

Summary of Results:

Key Findings

There were no relationships between diet composition and BMI, percentage body fat and adiposity (P>0.3)
Only modest relationships were found between BMI and fat sub-types: Polyunsaturated fats (R=0.14, P=0.007), monounsaturated fat (R=0.06, P=0.001), saturated fat (R=0.02, P<0.0001)
Only saturated fat related to percentage total body fat (P<0.0001)
No nutrient related to visceral adiposity
Dietary fat intake was not related to total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, fasting insulin, glucose, leptin, adiponectin or HOMA-IR scores (P>0.4)
Fat sub-type did not relate to fasting insulin, insulin resistance, total cholesterol, HDL, triglycerides, glucose or adiponectin.

Author Conclusion:

In summary, there are only very weak relationships between saturated fat intake and adiposity and in HIV-infected subjects and no relationships between nutrient intake and visceral adiposity, glucose metabolism, insulin resistance or adipokines. Only interventional, prospective studies will determine whether any nutrition strategy can assist in reducing the cardiometabolic complications associated with HIV lipodystrophy.

Funding Source:

Other:

Not reported

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)	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?		N/A
	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?	N/A
	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.)	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?		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?		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.)	Yes
	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?	N/A
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)?	N/A
	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?	???
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes