EAL

H/A: Hyperlipidemia (2009)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To address the potential role of diet in changes in cholesterol and triglycerides in the initiation of protease inhibitor therapy, changes in serum concentrations of lipids and cholesterol before and after the initiation of protease-inhibitor based highly active antiretroviral therapy in a group of HIV-infected men and women.

Inclusion Criteria:

Nutrition for Healthy Living cohort of 425 HIV-infected adults. Patients enrolled with data collection between February 1995 and December 1999 were included in the analysis.
For this analysis, individuals were selected from the cohort that had not been taking protease inhibitor therapy at the time of enrollment but began protease inhibitor therapy while they were in the cohort, and for whom blood at pre-protease inhibitor visit and a post-protease inhibitor visit was available for analysis
Individuals were also selected if they had a three-day food record at each of the identified visits.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Nutrition for Healthy Living cohort of 425 HIV-infected adults. Patients enrolled with data collection between February 1995 and December 1999 were included in the analysis.

Design

Longitudinal cohort study.

Intervention

Protease-inhibitor therapy and diet were evaluated.

Statistical Analysis

Descriptive statistics were used to determine the characteristics of the cohort. Specific nutrients were compared pre- and post-protease inhibitor therapy using paired T-tests for continuous, normally distributed variables and Wilcoxon rank sum tests for non-normal variables. Categorical variables were compared using the chi-square test. Pearson's correlation coefficients were used to assess the relationship between dietary intake and serum lipids.

Data Collection Summary:

Timing of Measurements

Lipid profiles were evaluated pre- and post-protease inhibitor therapy, at baseline and at every six-month visit.

Dependent Variables

Blood chemistries including lipid profiles
Weight, height, BMI
Body composition through bioelectric impedance and skinfold measurements.

Independent Variables

Protease-inhibitor therapy and diet were evaluated through three-day dietary intake.

Control Variables

Clinical and demographic data were collected by an interviewer administered questionnaire at baseline and at each six-month visit: Medical history, medications, resting energy expenditure, health-related quality of life assessment.

Description of Actual Data Sample:

Initial N: 49 HIV-infected patients, 42 men, seven women
Attrition (final N): 49 subjects
Age: Mean age, 40.6 years
Ethnicity: 33% Non-white
Location: United States.

Summary of Results:

	Pre-protease Inhibitor	Post-protease Inhibitor	P-value
CD4 (cells per mm³)	242±205	384±323	P< 0.001
HIV RNA (copies per ml)	97,115±1,567	60,800±26,985	NS
Log RNA	4.2±10	3.2±1.2	P<0.001
Calories	2,654±732	2,656±608	NS
Weight (kg)	75.5±14.6	76.9±16.2	NS
BMI	24.7±3.6	25.2±4.4	NS
Body fat (kg)	17.1±9.1	17.4±10.8	NS
Triceps skinfold (mm)	9.1±6.9	9.45± 6.4	NS
Smoking (yes)	18/48 (37%)	16/49 (33%)	NS
Men: Total cholesterol (mg per dL)	167.6±42.4	190.4±47.9	P<0.0001
Men: Triglycerides (mg per dL)	154.5±109.4	266.1±363.6	P<0.03
Men: LDL cholesterol (mg per dL)	97.8±31	107.1±34.7	P<0.05
Men: HDL cholesterol (mg per dL)	35.2±10.0	35.6±11.4	NS
Men: Lp(a) (mg per dL)	12.2±12.5	14.0±12.7	NS
Women: Total cholesterol (mg per dL)	146.3±33.7	177.7±44.7	P=0.002
Women: Triglycerides (mg per dL)	174.0±125.8	183.3±103.1	NS
Women: LDL cholesterol (mg per dL)	83.1±34.5	103.9±37.5	P=0.002
Women: HDL cholesterol (mg per dL)	38.1±12.9	39.7±16.8	NS
Women: Lp(a) (mg per dL)	14.7±14.4	16.3±16.8	NS
Women: HDL:LDL ratio	0.40±0.14	0.36±0.15	P=0.006

Other Findings

Mean duration of protease inhibitor therapy was 5.7 months.

Author Conclusion:

Protease inhibitor therapy significantly alters lipid profiles in HIV-infected patients. Dietary intake did not contribute to changes in lipid profile. More longitudinal studies are needed to demonstrate whether these alterations contribute to additional cardiovascular risk.

Funding Source:

Reviewer Comments:

Authors note that the CD4 count and viral load response seen in the patients suggest high compliance with their medication regimens.

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?		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?	Yes
	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?	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?	Yes
	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?	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?	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?	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