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H/A: Hyperlipidemia (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To assess the efficacy of a low-fat diet on reduction of cholesterol and triglyceride levels in HIV patients under HAART with dyslipemia.

Inclusion Criteria:
  • None expressly reported, but based on purpose, can infer HIV patients under highly active antiretroviral therapy (HAART) with dyslipemia
  • Not on drugs for dyslipemia
  • Antiretroviral drugs remaining unchanged for period of the study.
Exclusion Criteria:
  • Receiving dyslipemia drugs
  • Antiretroviral regimens changes.
Description of Study Protocol:

Recruitment

Procedure for recruiting was not reported. 

Design

Nonrandomized trial. 

Intervention

  • Participants with hypercholesterolemia (cholesterol greater than 200mg per dL) or hypertriglyceridemia (triglycerides more than 200mg per dL) were prescribed a lipid-lowering diet
  • Followed for three or six months
  • Fasting lipid levels, lipid variations (percentages), weight and serum albumin levels were recorded longitudinally.

Statistical Analysis

  • Mean values for diet adherence were calculated
  • Student's T-test and Mann Whitney U-tests were used
  • Multivariate analysis.
Data Collection Summary:

Timing of Measurements

  • Three months for 161 patients
  • Six months for 70 patients.

Dependent Variables

  • Diet adherence; no description on measurement was provided
  • Physical activity; no description on measurement was provided 
  • Weight loss measured in kg
  • Lipid levels measured in mg per dL from baseline to three or six months of duration.

Independent Variables

 Lipid-lowering diet, no indication on the details of the diet.

Description of Actual Data Sample:

Initial N

231 patients (81% were males).

Attrition (Final N)

  • N=161 followed for three months
  • N=70 followed for six months

Age

Mean age was 40±8 years.

Other Relevant Demographics

  • CD4 lymphocyte count
  • Viral loads
  • Antiretroviral regimens
  • Cholesterol and triglyceride levels.

Location

Spain.

 

Summary of Results:
  • Mean age reported was 40±8 years
  • Mean CD4 lymphocyte count was 535±274 cells
  • 66% of patients has undetectable viral loads
  • Lipodystrophy body changes were present in 66% of participants
  • 40% had hypercholesterolemia only
  • 7% had hypertriglyceridemia only
  • 53% had both hypertriglyceridemia and hypercholesterolemia
  • Mean cholesterol and triglyceride values were 257±38mg per dL and 320±108mg per dL respectively 
  • 58 (36%) and 32 (45%) reported good compliance with the prescribed diet at three and six months respectively
  • Mean values for lipid levels significantly (P<0.05) decreased from baseline for patients who were compliant with the diet. Cholesterol decreased 11% at three months (baseline values were 282mg per dL, at three months they were 235mg per dL) and 10% at six months (253mg per dL at six months); triglyceride levels decreased 12% at three months and 23% at six months (P<0.05) (baseline was 345mg per dL and 280mg per dL at three months and 240mg per dL at six months).
  • Patients who were non-compliant showed 1% and 2% decreased in cholesterol at three and six months, respectively (baseline was 253mg per dL and 251mg and 246mg per dL at three and six months) and 1% and 9% decrease in triglyceride at three and six months (baseline was 325mg per dL and 303mg per dL and 295 at three and six months).
  • Multiple regression showed good compliance was associated with a statistically significant weight loss of 2.2kg and 2kg at three months and six months, respectively
  • No significant changes in weight were found for noncompliant participants
  • Serum albumin values remained stable regardless of diet compliance
  • Statistical significance was found for patients using protease inhibitors (PI) and were compliant with diet: Patients on PI had significant reductions in cholesterol and TG of 13% and 15% (P<0.05) from baseline at three months and 22% and 49% at six months (P<0.05)
  • Patients under PI-sparing regimens had 8% and 7% reductions at three months for cholesterol and TG, respectively, from baseline (P>0.05) and 3% and 8% at six months (P>0.05)
  • Physical activity was significantly associated with TG level variation
  • Good adherence to dietary advice was significantly associated with cholesterol level variation at three months
  • At six months the variables significantly associated with decrease in lipids were good diet compliance with TG level variation and good diet compliance along with PI-based treatment with cholesterol level variation.

 

Author Conclusion:
  • Dietary intervention seems to be moderately effective for reducing lipid levels in HIV-infected patients with HAART-related dyslipemia
  • In individuals with mild or moderate dyslipemia, a low-fat prescription could be sufficient to treat their metabolic abnormality, especially if no cardiovascular risk factors are present
  • A good diet compliance may result in significant reduction in TG levels without compromising nutritional status; this benefit is less apparent on cholesterol levels
  • Reduction in cholesterol levels are more apparent in subjects under PI-based combinations.
Funding Source:
Other: None disclosed
Reviewer Comments:

Concerns include:

  • No description of the composition of the diet, or whether the diet was one commonly used such as a Step I diet
  • Weight was mentioned; however, there was no indication as to how the data for weight and serum albumin were collected. Was the weight self-reported? No indication. Similar comment for physical activity.
  • Good compliance was reported, but I would have liked to see the definition used for "good compliance" and how it was measured. This seemed to play a big role in the findings reported.
  • In the methods initial N seemed to be 230, but then it was further divided with 161 participants by month three and only 70 by month six. This was confusing, especially because attrition was not described in the article.
  • Relevant topic, but too much was not reported.
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? N/A
  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? No
  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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.4. Were reasons for withdrawals similar across groups? ???
  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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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? No
  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? No
  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? No
  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? No
  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)? No
  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? No
  9.1. Is there a discussion of findings? No
  9.2. Are biases and study limitations identified and discussed? No
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