H/A: Hyperlipidemia (2009)

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

To assess the frequency of lipid abnormalities and treatment outcomes for hyperlipidemia in HIV-positive patients receiving antiretroviral therapy as outpatients at a Veterans Affairs HIV clinic.

Inclusion Criteria:

All patients in a HIV clinic at a Veterans Affairs Medical Center receiving antiretroviral therapy and monitored for at least three months as of February 2000 were reviewed.

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

All patients in a HIV clinic at a Veterans Affairs Medical Center receiving antiretroviral therapy and monitored for at least three months as of February 2000 were reviewed.

Design

Retrospective cohort.

Intervention

Antiretroviral therapy classified as including or not including protease inhibitors.

Statistical Analysis

Student's T-test was used to compare mean cholesterol, triglycerides, HDL and LDL values according to protease inhibitor status. Chi-square analysis was used to evaluate differences in patient demographics and for LDL goals according to protease inhibitor status.

Data Collection Summary:

Timing of Measurements

Lipid values were compared with goals per national guidelines and risk factors.

Dependent Variables

  • Fasting cholesterol, triglyceride, HDL and LDL cholesterol
  • CD4+ cell count and viral load.

Independent Variables

Antiretroviral therapy classified as including protease inhibitors or not including protease inhibitors.

Control Variables

Age.

Description of Actual Data Sample:
  • Initial N: 101 male patients
  • Attrition (final N): 101 males providing 210 lipid profiles
  • Age: Median age, 51 years
  • Other relevant demographics: 14 were diabetic, 31 were hypertensive and six had documents coronary disease
  • Location: Florida.

 

Summary of Results:

 

 

Taking Protease Inhibitors (N=50)

Not Taking Protease Inhibitors (N=51)

P-value

Average age (years) 49.4±8.6 50.5±10.0 P<0.05

CD4+ count (cells per mm3)

399±223

337±220

NS

Viral load (copies per ml) 24,348±66,204 29,044±66,502 NS
Undetectable viral load (N) 15 16 NS
Diabetes (N) 6 NS
CAD (N) 3 3 NS
HTN (N) 18 13 NS
Smoking (N) 15 28 P<0.05
Renal disease (N) 5 1 NS
Cholesterol (mg per dL) 206±47 185±48 P<0.05
Triglycerides (mg per dL) 295±311 193±213 P<0.05
LDL cholesterol (mg per dL) 121±41 110±45 P<0.05

HDL cholesterol (mg per dL)

43±17

44±13

NS

Other Findings

Mean cholesterol, triglycerides and LDL values were significantly higher in those taking protease inhibitors (N=50) compared with those who were not (N=51, P<0.05).

HDL values were not different between groups.

Significantly more subjects taking protease inhibitors had lipid concentrations above recommended goals compared with those not taking them (17 vs. 7, P=0.04).

Six patients achieved lipid goals after following a low-fat diet, four were taking protease inhibitors.

15 were being treated with medications, 11 of them were taking protease inhibitors.

10 patients (67%) reached lipid goals, two had not reached goals (13%) and three (20%) were undergoing medication titration. 

Author Conclusion:

Treatment of hyperlipidemia is becoming more common in HIV-positive patients due to aging as they live longer, as well as the need for protease inhibitor therapy. Dietary and pharmacotherapy interventions are important to achieve lipid goals similar to those of other populations. There are no data suggesting that the HIV-infected population would be at a lower risk from lipid abnormalities than HIV-negative individuals. Our patient population showed a similar prevalence of lipid abnormalities as previously reported. As expected, significantly more protease inhibitor-taking patients had lipid values above target goals. However, most patients achieved treatment goals while receiving antilipid agents, in contrast to previous reports. Using a multidisciplinary team for close monitoring and counseling for HIV-positive patients who need to start lipid-lowering therapy is paramount.

Funding Source:
Reviewer Comments:

Authors note limitations of the small number of men receiving therapy for hyperlipidemia and the small number of patients receiving ritonavir therapy. Three-month monitoring period.

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? ???
  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? ???
  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? ???
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? 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? 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)? 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