HIV-associated Hypercholesterolemia Clinical Trial
Official title:
Double-blind, Placebo-controlled, Randomized 48 Weeks of Duration Study. The Effect of the Administration of Docosahexaenoic Acid on Lipid and Carbohydrate Metabolism Alterations and Body Fat Distribution in Patients With HIV Infection Under High Activity Antiretroviral Treatment
Highly active antiretroviral therapy (HAART) is able to cause lipid metabolism and glucose
homeostasis alterations, which are associated to the redistribution of body fat. Alterations
in lipid and carbohydrate metabolism contribute to the development of a highly atherogenic
profile, which together with altered fibrinolysis markers and increased presence of
proinflammatory cytokines in blood (especially tumor necrosis factor alpha) that comes
associated to the success of HAART can cause the development of accelerated atherosclerosis.
Docosahexaenoic acid (DHA) is a polyunsaturated fatty acid that has demonstrated its ability
to reduce triglyceride levels; modify cholesterol fractions and increase the size of LDL
particles thereby configuring less atherogenic plasma profile. Additionally, administration
of DHA has shown antiinflammatory and hypotensive activity, which contributes to reduce the
risk of cardiovascular complications in these patients. At a molecular level, DHA acts as a
stimulator of the nuclear receptor PPAR-gamma, which has been described to induce an
increase in adipocyte differentiation. Furthermore, the anti-inflammatory effects induced by
DHA, can decrease the elevated levels of TNF-alpha, which has been implicated in the
pathogenesis of body fat redistribution in HIV infected patients undergoing HAART.
Therefore, the hypothesis of this project is that DHA will be able to produce
lipid-lowering, anti-inflammatory, hypotensive and profibrinolytic effects, which all
together should improve atherogenic profile of patients with HIV-1 infection receiving
HAART. In addition, their proprieties as PPAR agonist can improve the redistribution of body
fat present in many of these patients. The study of the activity of DHA on dendritic cells
and monocytes should indicate the absence of immunosuppressive effect of DHA in the context
of HIV-1 infection.
In summary, DHA is a natural product, from the omega 3 polyunsaturated fatty acids, the
therapeutic properties of which have been described in recent years and has shown
cardio-vascular and metabolic beneficial effects, without recognized side effects. The
highly purified DHA administration at high doses could be able to reverse, at least
partially, lipid abnormalities associated with HAART and to exert a beneficial effect on fat
redistribution in HIV-infected patients treated with HAART. To ensure non deleterious
immunological treat in these sensitive poly-medicated patients, substantial changes in the
functionality of dendritic cells and monocytic will be studied.
Hypothesis: DHA treatment would be able to revert, at least partially, the lipid
disturbances associated with HAART and to improve or at least not to worse fat
redistribution associated with HAART, without inducing further derangements to dendritic
cells and monocyte functional ability.
Variables: effects of DHA treatment on total cholesterol and its fractions, triglycerides,
insulin, fibrinolysis markers, tumor necrosis factor alpha (TNF-α), and fat distribution
assessed by anthropometric measurements, bioimpedance, sonography, DEXA and abdominal CT.
Effects of DHA administration on phenotype and functional capabilities of dendritic and
mononuclear cells. Objective: To determine if treatment with high doses of highly purified
docosahexanoic acid (DHA) is able to revert, totally or partly, the lipid disturbances and
the fat redistribution associated with highly active antiretroviral therapy (HAART), and the
effects on phenotype and function of dendritic cells and monocytes Data analysis: Baseline
data will be analyzed for a good balance. Fisher´s exact test will be used to assess
differences between categorical variables, Student's t test for continuous variables, and
Mann-Whitney test for ordinal variables. The main efficacy variable will be differences
between baseline and final values using MANCOVA model taking baseline value as covariable.
Efficacy will be assessed by contrasting adjusted means at the end of the study between both
groups of treatment. Intention to treat analysis will be used.
The methodology to perform in the centers where the clinical trail will be conducted are the
following: After obtaining informed consent, the patient's baseline will be examined with
the collection of demographic data, HIV infection status, pharmacological data,
anthropometric parameters, and it will proceed to conduct a complementary examination
designed to identify and define body fat composition, body fat distribution and to perform a
basal analysis including the parameters previously mentioned. It also will be evaluated the
hygienic-dietetic habits of the patient with special attention to alcohol intake, physical
activity and concomitant medication. This procedure will be carried out by making
retrospective diaries from the last 7 days. The patient's daily caloric intake will be
quantified by the Nutrilogic ® software (Bio Logic, Barcelona, España). Physical activity
will be quantified by the Minnesota scale (Elosua R, Marrugat J, Molina L, Pons S, The
MARATHOM Investigators. Validation of the Minnesota leisure time physical activity
questionnaire in Spanish men. Am J Epidemiol 1994, 139: 1197-1209).
Body fat composition and body fat distribution: will be done with the following additional
tests:
Densitometry or DEXA: Will be determined with the patient in supine position with legs
straight and feet together, on a standardized examination table from a densitometry device
(Lunar Prodigy, Madison, WI, USA). In the initial study enerarán more faces of the different
regions that will be copied and transferred to the images of subsequent studies to reduce
the variability of successive determinations. There will be performed a body fat
measurement, body composition and assessment of bone mineral density by dual absorptiometry
technique. There will be performed a total body "scan" (body composition) or focused on
lumbar spine (trabecular bone) and proximal third of the femur (cortical bone) for the
evaluation in the last two cases of bone mineral density and a possible osteopenia or
osteoporosis.
Abdominal CT: Will be obtained by performing a spinal digital radiography, latero-lateral
view, locating L4 and getting a tomographic section passing through the center of the
vertebral body. Subsequently, there will be a digital calculation of intra-abdominal fat and
subcutaneous fat, manually selecting the area of interest. The areas measured will be done
in cm2.
Lab analysis: blood samples for biochemical determinations will be obtained in Vacutainer
tubes of 10 ml without additives. Blood will be clotted at room temperature for 30 minutes
and centrifuged at 2500 rpm for 15 minutes. After separating the serum from the clot (about
4-5 ml), will be divided into 1 aliquot of 1.5 ml (for the study of lipids) and 5-7 aliquots
of 0.5 ml aliquots which will be frozen at -20 °C until the biochemical analysis are carried
out.
Plasma lipids, glucose, glycosylated hemoglobin, insulin and C-peptide: measurements of
total cholesterol and triglycerides will be performed using automated trading methods
(enzyme colorimetry, Roche Diagnostics) adapted to the automated autoanalyzer Hitachi 911.
The determination of apolipoproteins AI, B and C-III, lipoprotein (a) will be held mediate
commercial methods (immunoturbidimetric assay, Roche Diagnostics and Wako Chemicals) adapted
to the automated autoanalyzer Hitachi 911. The determination of cholesterol lipoprotein
fractions (Lipid, ELIP) (VLDL, LDL, HDL) will be performed by the following methods: VLDL
separated by ultracentrifugation of flotation, cholesterol HDL determined by a direct method
(Roche Diagnostics) and cholesterol LDL determined by difference in total cholesterol and
VLDL and HDL cholesterol fractions. Glucose: by a commercial method (enzyme colorimetry,
Roche Diagnostics) adapted to the automated autoanalyzer Hitachi 747. Serum insulin
concentration will be determined by non-competitive chemiluminescent enzyme immunoassay
(Immulite 2000TM, Diagnostic Products Corp., Los Angeles, CA, USA). The serum concentration
of C-peptide is determined by non-competitive chemiluminescent enzyme immunoassay (Immulite
2000TM, Diagnostic Products Corp., Los Angeles, CA, USA).
Determining the size of LDL particles: The size of LDL particles will be determined from
total plasma using acrylamide gradient gel electrophoresis under nondenaturing conditions.
Will be used a standard of four known LDL diameter bands, previously determined by electron
microscopy.
Determination of fatty acids in plasma: Treatment compliance will be corroborated by
determining the fatty acid composition of plasma lipids by gas chromatography. Plasma total
lipids will be extracted by the method of Bligh and Dyer with chloroform: methanol (2:1, V:
V). Methyl esters of fatty acids will be obtained by transesterification with boron
trifluoride in methanol at 80 °C for 60 min. which allows a high recovery of all the lipidic
compounds including PUFAs. Aliquot containing the methyl esters of fatty acids will be
analyzed with a gas chromatography device (Hewlett-Packard model 5890) on a 30 m. RTX-2330
column (Restek, Bellefonte, PA) with an internal diameter of 0.25 mm equipped with a flame
ionization detector. The carrier gas will be helium at a pressure of 105 kPa. To the total
separation of the different compounds it has provided with two temperature settings: 140
°C-200 °C to 3 °C/min or in two stages of 140°C-180°C to 4°C/min and 180°C-210°C at 2°C/min.
The temperature of the injector and detector is 260 °C. The linear response of the detector
will be tested periodically with standard mixtures. Typically, two internal standards with
different molecular weight (13:0 and 23:0 or 27:0) will be used. Peaks will be integrated
with an integrator D-2500 (Hitachi Ltd., Tokyo) and identified by comparison of retention
times with standards. When necessary, the identification may be confirmed by mass
spectrometry (Hewlett-Packard detector model 5970B) at an ionization potential of 70 eV.
Study of markers of inflammation: blood will be withdrawn in 5 ml EDTA tube. After
extraction, the tube will be centrifuged, and plasma collected in eppendorf tubes and frozen
at -70°C until cytokines determination. The content of TNF-alpha, IL-1 beta and IL-6 in the
plasma samples will be measured by ELISA. Each sample will be analyzed in duplicate using
ELISA kits "R & D Systems" following the specifications that commercial supplier.
Intervention: Patients will be randomized to one of two treatment groups (placebo and DHA),
using a centralized randomization list. The study will be conducted according to the
double-blind trial methodology, in which neither the patient nor the physician are unaware
of the active substance administered to the patients. The randomization procedure will be
performed assigning either strategy according to a randomization scheme generated by the
module PROC PLAN SAS (version 8.2) in multiple of 2 blocks and following a pattern 1:1
stratified by center. A list of random assignment will generated according to the above
mentioned, and as from the same will be issued a sealed opaque envelope, identified by a
sequential number and the name of the center. The envelopes shall be deposited in the center
of central data management and analysis, which will act as coordinator of the centralized
randomization assignment by telephone contact.
Patients will be evaluated for inclusion in the study, and their personal data collected in
a specific collection data notebook. After the informed consent procedure and if the patient
consents to be included in the study, the centralized randomization assignment center will
be contacted. When patient data are registered, the envelope will be opened and the strategy
assigned to the patient reported to the investigator. The procedure shall be transcribed
into a document contained in the envelope, signing and dating this register the person
responsible at the central randomization center.
Capsules with identical external appearance containing oleic acid (placebo) and
docosahexaenoic acid at doses of 500 mg per capsule will be previously prepared. The
capsules are coated with a protective cover which makes it taste imperceptible to the
patient. The dosage of DHA will be of 4 g daily. At the same intervals, patients in the
placebo group will take 4 g daily of oleic acid.
Data collection: The data of patients will be collected by a physician devoted entirely to
guide patients, coordinating tests to perform, and recording information into a database.
Data will be collected in a previously designed specific collection data notebook.
o Sample size assessment to specify the number of participants or participant years
necessary to demonstrate an effect.
Estimating sample size and data analysis:
It is expected to be able to show a difference in favor of the active treatment in the main
variable, namely, reduction in triglycerides values at the end of the follow-up period (48
weeks) of at least 20% in magnitude, in the comparison of the means adjusted by a covariance
analysis. According to the estimated standard deviation of 86 from our own data, consistent
with literature data (AIDS 1999, 13:1424-1425), and the magnitude of the minimum effect
pre-defined as relevant (20% reduction), it would be enough to some 29 evaluable patients
per group. It is intended to recruit more patients as forecast of possible expected losses
of about 10%, or in other words, 33 subjects per group.
Re-estimation of the sample size:
Since variability is estimated from data from other situations (pre-treatment baseline
data), and there is no concrete data on the experimental situation (variability after DHA
treatment), it is predefined in this protocol to perform a re-estimation of the sample size
when will be obtained a follow up of the 50% after 4 weeks of treatment of the triglycerides
values. To this objective data from the main variable, triglyceride levels at baseline and
after 4 weeks post-treatment, along with the random assignment but masking the codes will be
provided to a second independent statistical group (Catalan Institute of Oncology,
Department of Epidemiology and Cancer Registration. Statistician: Dr. Victor Moreno) respect
to central statistical analysis of this study (Laboratory of Biostatistics and Epidemiology
(LBE), Section Clinical Trials, Autonomous University of Barcelona. Statistician: Dr. Ferran
Torres). This new group will perform the analysis, and will only reveal variability data to
recalculate the sample size. If the sample size were less than expected, it will be
maintained according to the initial design. Under no circumstances significance tests will
be performed or the study will be prematurely stopped secondarily to re-estimate
variability. According to this method, you do not need any adjustment of multiplicity.
o Plan for missing data to address situations where variables are reported as missing,
unavailable, "non-reported," uninterpretable, or considered missing because of data
inconsistency or out-of-range results Treatment of missing values
The main analysis by intention to treat will require using all subjects without relevant
deviations from the selection criteria, whom they have taken at least one dose of the
studied medication and who have evaluation of the main variable prospectively, at least at
three months of the follow up. Under this assumption, it is expected that in a 1-year study
follow up find subjects with measurements not made. Therefore it is set out the imputation
of missing values of the main variable as follows:
- If the lack of data is due to problems of efficiency, or the cause is unknown, shall be
attributed the 95% percentile value for the study group.
- In case of missing data for other reasons, will be implemented the LOCF (Last
Observation Carried Forward) method provided the availability of a value of at least
three months after its baseline measurement.
The detailed procedure will be included in the statistical report and it is planed evaluate
the consistency of the method before closing the database at a meeting at which anonymous
listings will be facilitated for its evaluation 'Blind Review' where the procedure may be
re-evaluated (CPMP/EWP/1776/99: Points to Consider on Missing Data).
Difficulties and limitations of the study:
The number of patients and the peculiar management that they will have, due to the
additional tests performed, make the study inevitably complex. However, there will be a
physician who permanently coordinates all patients and all tests performed. In addition, the
research team is wide with concrete and synergistic functions for each researcher. Finally,
researchers constitute a consolidated group and are experienced in previous studies with
similar requirements.
o Statistical analysis plan describing the analytical principles and statistical techniques
to be employed in order to address the primary and secondary objectives, as specified in the
study protocol or plan.
Statistical analysis Descriptive analysis
The following descriptive indexes will be detailed in the statistical report according with
the nature of the variables:
- In continuous variables: Mean, CI 95%, SD, minimum, P25, median, P75, max, N and
missing. Per group and globally.
- In categorical variables: % total with respect to the column, N in each category. Per
group and globally.
- In ordinal variables: They will be described with two tables: one with descriptive
parameters of the continuous variables and the other with categorical variables.
In open fields or when are interested to list all cases for one or more variables, will be
described by lists.
Inferential analysis The statistical treatment of the primary and secondary efficacy
variables will be specifically described in a section below. For all other variables, the
appropriate hypothesis test will be applied according to its nature: Fisher exact test for
categorical variables, the Student t test for continuous variables, Mann-Whitney U test for
ordinal variables.
Basal homogeneity between groups An analysis of the baseline comparability of treatment
groups will be established regarding demographic variables, risk factors and clinical
characteristics at the time of inclusion.
Main efficacy analysis The main variable of efficacy will be evaluated by comparing the
difference between baseline and end values of the different treatments using ANCOVA model
with the baseline value of the test as covariate. Adjusted means were calculated and
confidence intervals at 95% (95%) by the ANCOVA model. As the main decision criterion of
efficacy the contrast between the adjusted means at the endpoint of the study between the
two treatment groups will be performed. Additionally and as an exploratory intent, shall be
evaluated the compared effect at the different times of observation. No multiplicity
adjustments will be made due to the exploratory nature of this second analysis.
In case of relevant deviations in the cases pursuant of the parametric tests, it will be
applied a nonparametric approach using transformations to ranges of the corresponding
variables. The main analysis of the efficacy will be done with the population intended to
treat. However, as evidence of sensitivity and robustness of the results, the analysis under
the protocol approach will be provided.
Tolerability and acceptability tests All patients who have been randomized and treated will
be included in the safety analysis. The frequency of appearance of adverse events in the two
groups will be compared using the Fisher's exact test.
Level of significance In all proposed statistical tests the level of significance required
shall be the conventional (p < 0.05 bilateral). No provisions have been made to perform any
multiplicity adjust except in the intermediate analysis.
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Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment