EAL

H/A: Monitoring of Food Intake (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate the role of dietary macronutrients, exercise and smoking in contributing to dylipidemia in HIV-infected individuals with lipodystrophy taking protease inhibitors.

Inclusion Criteria:

HIV-infected patients
Taking protease inhibitors for six months or more
Presence of fat redistribution confirmed by a physician during a physical exam.

Exclusion Criteria:

Current substance abusers
Had a major opportunistic infection within the previous six weeks.

Description of Study Protocol:

Recruitment

Subjects recruited from Parkland Health and Hospital Systems and the Aston Center HIV clinics at the University of Texas Southwestern Medical Center, Dallas, Texas. Subjects also recruited through newspaper and radio advertisements, from community resource centers, and fund-raisers for HIV-infected patients and from private medical practices.

Design

Cross-sectional study.

Statistical Analysis

Relationships between lifestyle factors and metabolic variables were analyzed in male patients by Spearman's correlation test and the significant relationships were further analyzed by adjusting for age, protease inhibitor duration and waist circumference by Spearman's partial correlation test. Any differences by sex were analyzed by the Wilcoxon rank sum test for continuous variables. Male and female subjects were not pooled due to gender differences in lipid profiles.

Data Collection Summary:

Timing of Measurements

Data collected on smoking, exercise, diet and fasting levels of serum lipids and lipoproteins. Information on sociodemographics, HIV diagnosis date, nadir and recent CD4 count and viral load, medication and medical history were collected via questionnaire.

Dependent Variables

Fasting levels of serum lipids and lipoproteins
Height, weight.

Independent Variables

Diet measured through three-day food records
Exercise assessed through typical number of hours spent exercising
Smoking was categorized as smoker, non-smoker, ex-smoker.

Control Variables

Age
HIV viral load
Blood lymphocyte CD4 count
Protease inhibitor duration
Waist and hip circumference
Medical conditions and sociodemographics.

Description of Actual Data Sample:

Initial N: 51 subjects (45 males, six females)
Attrition (final N): 51 subjects
Age: Males, 47.1±8.4 years; females, 42.5±5.9 years
Ethnicity: 50 Caucasian, one African-American
Anthropometrics: There were no significant differences by sex in concentrations of total cholesterol, non-HDL cholesterol, HIV infection and antiretroviral therapy variables, or age
Location: Texas.

Summary of Results:

	Total Cholesterol	HDL-Cholesterol	Triglycerides	Non-HDL Cholesterol
Total protein (% energy)	0.40, P<0.01	-0.21	0.43, P<0.01	0.54, P<0.001
Animal protein (% energy)	0.35, P<0.01	-0.22	0.46, P<0.01	0.49, P<0.001
Plant protein (% energy)	-0.17	0.04	-0.29, P<0.05	-0.25
Trans fat (% energy)	0.16	-0.14	0.37, P<0.01	0.17
Alcohol (% energy)	-0.03	0.26	-0.34, P<0.05	-0.03
Soluble fiber (g)	-0.31, P<0.05	0.11	-0.26	-0.42, P<0.01

Other Findings

In men, mean serum concentrations of total cholesterol, HDL cholesterol, triglycerides and non-HDL cholesterol were 212±70, 35±7.3, 325±230 and 169±44mg per dL, respectively.

67% of men exercised regularly and 31.1% smoked.

The reported diet was high in cholesterol (390±212mg) and percentage of energy from saturated (12.2%±3.3%) and trans (2.4%±1.2%) fats, and low in soluble fiber (6.9±2.3g) compared with recent dietary guidelines.

Following adjustments for the confounding variables, percentage energy intake from total protein and animal protein was positively related to total cholesterol (R=0.44, P<0.01 and R=0.37, P<0.05, respectively), triglycerides (R=0.40, P<0.01 and R=0.46, P<0.01, respectively) and non-HDL cholesterol (R=0.56, P<0.001 and R=0.49, P<0.01, respectively), that from trans fat was positively related to triglycerides (R=0.34, P<0.05) and soluble fiber was negatively related to non-HDL cholesterol (R=-0.41, P<0.001).

Moderate to heavy aerobic exercise tended to be associated with higher HDL cholesterol (R=0.30, P=0.07) whereas smoking was not associated with any of the metabolic variables.

Author Conclusion:

In conclusion, the HIV-infected subjects with lipodystrophy on protease inhibitors were far short of the Institute of Medicine guidelines for exercise and 17% to 33% of them smoked. They consumed too much energy from saturated and trans fats and not enough from unsaturated fat, had a high cholesterol intake and did not eat enough soluble fiber compared to the National Cholesterol Education Program dietary guidelines. Percentage energy from total protein and animal protein was positively related to levels of total cholesterol, triglycerides and non-HDL cholesterol, and percentage energy from trans fat was positively related to triglyceride level, whereas soluble fiber intake was negatively related to non-HDL cholesterol level. Moderate-heavy exercise tended to be associated with dyslipidemia. Whether diet, exercise and smoking cessation intervention will improve levels of lipids and lipoproteins in HIV-infected subjects with lipodystrophy on protease inhibitors needs to be evaluated by randomized controlled clinical trials.

Funding Source:

Reviewer Comments:

All data based on self-report. Questionnaires not shown to be valid or reliable. Authors note that lack of statistical significance may be due to small sample size. Power calculations not done.

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