Asthma
Conditions
Keywords
Asthma, Borage, Echium, Botanical
Brief summary
This study plans to look at whether borage and echium seed oils (natural oils from two plants) help decrease asthma symptoms and affect cells involved in inflammation. The investigators also want to look at how these plant oils decrease the generation of inflammatory cells in people with asthma.
Detailed description
To evaluate the mechanisms by which borage seed oil and echium seed oil block mediator generation in asthma, we performed a cross-over trial design to reduce the numbers of patients needed for the study. Each treatment period was six weeks with a six-week washout period. For simplicity all power calculations are made assuming a single factor or predictor variable and a single result or outcome variable. We focused on changes in mediator generation by effector cells. Calculations below suggest that we have resolution to pick up clinically meaningful effects of potentially important explanatory variables with acceptable or high power. 1\. Study Design The goals were to examine the mechanisms that underlie the effects of borage seed oil and echium seed oil on proinflammatory mediator production by effector leukocytes. In the treatment arm, subjects consumed 4.0 g/day borage seed oil and 7.0 g/day echium seed oil (containing totals of \ 1.6 g/day of GLA and \ 0.9 g/day of SDA). The oils were packaged in capsules each of which contained 1 gram of oil. Therefore subjects will ingest 10 capsules a day (3 in the morning, 3 in the afternoon, and 4 in the evening) with meals. In the placebo arm, subjects took matching capsules containing corn oil; three 1 gram capsules in the morning and afternoon, and four in the evening, with meals. The study began with a screening visit. All subjects had physician-diagnosed asthma. All performed a baseline set of lung function measurements. They entered a 2-week run-in period during which they kept a diary of peak flows, asthma symptoms, and beta agonist use. Subjects were instructed in peak flow technique and asked to perform three maneuvers each time. The maneuver was considered technically sufficient if the variation in the values obtained on the three attempts are with 10% of each other, and the highest value was recorded in a diary. Subjects whose diaries were \> 80% complete entered the study and were randomly assigned to active treatment or placebo. Spirometry was repeated. Blood was taken for fatty acid composition of plasma and leukocytes, LT generation, and DNA for genotyping at the LTC4S locus. Subjects were provided with peak flow diaries, instructed in the appropriate performance or peak flow maneuvers, and asked to record morning and evening peak flow each day (reflecting the best of three efforts each time). After three weeks of treatment, diary cards will be collected and spirometry repeated. After six weeks of treatment, blood was drawn for safety monitoring, for measurements of fatty acids in plasma and leukocytes, and for the functional analyses. Spirometry was repeated. Subjects then entered a six-week washout period. Two weeks before the end of this period they again started to keep diary cards. At the conclusion of the 6-week washout period they entered the cross-over treatment phase (six weeks) which followed the same protocol as the first treatment period with assessment of fatty acid analyses, cellular function studies, safety monitoring, and spirometry. Pregnancy testing was performed before and after each treatment period. Dairy cards (with peak flow monitoring results) will be collected at each visit (3 week intervals during the placebo and active treatment arms of the study). 3\. Statistical Analyses a. Power Calculations - For simplicity all power calculations are made assuming a single factor or predictor variable and a single result or outcome variable. While a number of correlated outcomes will be investigated, we will focus on changes in mediator generation and levels of enzyme expression. Calculations below suggest that we have resolution to pick up clinically meaningful effects of potentially important explanatory variables with acceptable or high power. i. Biochemical Endpoints - Power is based on paired t-tests comparing continuous measures of response between treatment and placebo. We assume 40 subjects will be available after allowing for a drop out rate of 20% from our original sample of 50 subjects. For the endpoint of leukotriene production by leukocytes, the power calculations suggested that we will have 80% power to detect a true within-subject difference of 0.8 of the within-subject SD between treatment and placebo with an α value of 0/05. On the basis of our previous studies, we assume a within-subject coefficient of variation (CV) of 13% for LTC4 generation. This will translate to an approximate detectable difference from 10.5% in these parameters.Using a paired two-sided t-test and prior mean(standard deviation) estimates for the placebo of .001464 ( .002268) and for the borage oil of .000289( .000709) , we would need 40subjects for 80-90% power at a 0.05 level of significance to detect a change in LTC4S transcript, protein, and enzymatic activity of 50% between placebo and borage arms. b. Analysis Plan - Initially, we will present descriptive statistics (mean, standard deviation, range) for all endpoints to treatment and placebo groups. We will also present graphical plots of all measures across the study and for each group within each period. For the 2x2 crossover study, we will compare the treatment and control on each endpoint separately by employing a generalized mixed model approach with the predictors: group(sequence), patient nested within group as a random effect, period(dichotomous), treatment(dichotomous), and seasonality(dichotomous), with unstructured covariance. We will utilize mixed model diagnostics such as residual plots to assess goodness of fit.
Interventions
DRUGBorage and Echium Seed Oils
4.0 g/day borage seed oil and 7.0 g/day echium seed oil. Pills will be taken three times per day for six weeks.
DIETARY_SUPPLEMENTCorn oil pills
Corn oils pills will be taken three times per day for six weeks.
Sponsors
Wake Forest University
Brigham and Women's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
1. Male or female 18 years to 65 years of age 2. Stable physician diagnosed asthma with FEV1 of greater than 50% of predicted but less than 90% of predicted or less than 90% of known best and an asthma control questionnaire(ACQ) \< 1.5.
Exclusion criteria
1. Pregnant or nursing 2. Smoking history of \> 10 pack years or active smoking within the past year. 3. Due to possible effects on LT biosynthesis, use of the following asthma treatments within the preceding month will be
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cellular Changes That Occur With Borage and Echium Seed Oil Supplementation | Assessed at 2, 8, 14, and 20 weeks | Primary outcome measures will be changes in the generation of LTC4 production by granulocytes. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). |
| Change in LTB4 Production | At 2, 8, 14, and 20 weeks | Primary outcome measures will be changes in the generation of LTB4 production by granulocytes. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). A negative number implies that the level of LTB4 produced by granulocytes at the end of the arm was less than the amount produced at the start of the arm, while a positive number means that more was generated at the end than at the beginning. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Plasma Level of Gamma Linolenic Acid (GLA) | Measurements obtained at 2, 8, 14, and 20 weeks | Changes in plasma level of gamma linolenic acid (GLA), a major constituent of Borage oil, as a measure of compliance. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). |
| Number of Subjects Bearing a Polymorphic Variant of LTC4 Synthase | two weeks | All individuals will be genotyped at the LTC4S locus. |
| Asthma Control | Assessed at 2, 8, 14, and 20 weeks | Changes in asthma control will be assessed via the Asthma Control Questionnaire (ACQ) at each visit. The ACQ is a 6-point questionnaire that reflects the degree of asthma activity. Each point is assigned a scale of 0-5, with 5 being the worst. Thus, the range is from 0 (no asthma symptoms) to 30 (severe asthma symptoms). For each arm, we generate two values (week 2 vs. week 8 and week 14 vs.week 20). These values are then averaged for each arm to obtain the final single value. A negative number implies improved symptoms. |
| Measure of DHA in Cell Pellets | Assessed at 2, 8, 14, and 20 weeks | Secondary outcome measures include changes in concentrations of omega 3 fatty acids in cell pellets, indicating incorporation of botanical oil metabolites in cell membrane lipids.. This was calculated by the difference between the amount present at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). |
| Change in Activity of LTC4 Synthase | Days 0, 42, 84, and 126 | Differences in LTC4S activity while receiving borage/echium oils versus corn oil stratified by LTC4S genotype. We analyzed the genotype for 32 subjects for the borage arm and 30 subjects for the placebo arm. |
| Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil. | 0, 42, 84, and 126 days | FEV1 was measured in all subjects at the beginning and end of both study arms. Subjects were genotyped at LTC4S locus and those bearing at least one A to C polymorphism were compared with those bearing two A alleles. |
| Measure of EPA in Cell Pellets | Assessed at 2, 8, 14, and 20 weeks | Secondary outcome measures include changes in concentrations of omega 3 fatty acids in cell pellets, indicating incorporation of botanical oil metabolites in cell membrane lipids.. This was calculated by the difference between the amount present at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). |
| Lung Function | Assessed at 2, 8, 14, and 20 weeks | Changes in lung function (forced expiratory volume in 1 second) will be assessed via spirometry at each visit. This was calculated by the difference between the FEV1 at weeks 2 and 8 versus weeks 14 and 20. The differences were compared as a delta-delta. A negative number for this parameter means that the FEV1 was lower at the end of the arm than at the beginning, while a positive number means that the FEV1 was higher at the end. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| All Study Participants Participants were randomized to receive either borage and echium oils first, and corn oil second, or vice versa | 62 |
| Total | 62 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| First Intervention (Six Weeks) | Lost to Follow-up | 7 | 4 |
| First Intervention (Six Weeks) | Withdrawal by Subject | 3 | 0 |
| Washout (Six Weeks) | Lost to Follow-up | 2 | 2 |
Baseline characteristics
| Characteristic | All Study Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 62 Participants |
| Region of Enrollment United States | 62 participants |
| Sex: Female, Male Female | 43 Participants |
| Sex: Female, Male Male | 19 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 42 | 0 / 38 |
| other Total, other adverse events | 14 / 42 | 6 / 38 |
| serious Total, serious adverse events | 0 / 42 | 0 / 38 |
Outcome results
Primary
Cellular Changes That Occur With Borage and Echium Seed Oil Supplementation
Primary outcome measures will be changes in the generation of LTC4 production by granulocytes. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta).
Time frame: Assessed at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Cellular Changes That Occur With Borage and Echium Seed Oil Supplementation | 5.06 ng | Standard Deviation 15.7 |
| Corn Oil Pills | Cellular Changes That Occur With Borage and Echium Seed Oil Supplementation | 2.56 ng | Standard Deviation 15 |
Primary
Change in LTB4 Production
Primary outcome measures will be changes in the generation of LTB4 production by granulocytes. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta). A negative number implies that the level of LTB4 produced by granulocytes at the end of the arm was less than the amount produced at the start of the arm, while a positive number means that more was generated at the end than at the beginning.
Time frame: At 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Change in LTB4 Production | -.99 ng | Standard Deviation 8.73 |
| Corn Oil Pills | Change in LTB4 Production | 0.12 ng | Standard Deviation 6.21 |
Secondary
Asthma Control
Changes in asthma control will be assessed via the Asthma Control Questionnaire (ACQ) at each visit. The ACQ is a 6-point questionnaire that reflects the degree of asthma activity. Each point is assigned a scale of 0-5, with 5 being the worst. Thus, the range is from 0 (no asthma symptoms) to 30 (severe asthma symptoms). For each arm, we generate two values (week 2 vs. week 8 and week 14 vs.week 20). These values are then averaged for each arm to obtain the final single value. A negative number implies improved symptoms.
Time frame: Assessed at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Asthma Control | -.18 Change in ACQ points | Standard Deviation 0.64 |
| Corn Oil Pills | Asthma Control | -.12 Change in ACQ points | Standard Deviation 0.5 |
Secondary
Change in Activity of LTC4 Synthase
Differences in LTC4S activity while receiving borage/echium oils versus corn oil stratified by LTC4S genotype. We analyzed the genotype for 32 subjects for the borage arm and 30 subjects for the placebo arm.
Time frame: Days 0, 42, 84, and 126
Population: Since this is a crossover study, 30 of 32 who completed the borage arm also completed the corn oil arm. The data presented reflect the effects of borage/echium versus corn oil for individuals with two wild type alleles (AA) versus those with one variant allele (CC or AC).
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Borage and Echium Seed Oils | Change in Activity of LTC4 Synthase | Genotype AA | .95 ng/million cells | Standard Deviation 11.3 |
| Borage and Echium Seed Oils | Change in Activity of LTC4 Synthase | Genotype AC or CC | 18.0 ng/million cells | Standard Deviation 18.5 |
| Corn Oil Pills | Change in Activity of LTC4 Synthase | Genotype AA | -.10 ng/million cells | Standard Deviation 7.83 |
| Corn Oil Pills | Change in Activity of LTC4 Synthase | Genotype AC or CC | 11.7 ng/million cells | Standard Deviation 25.9 |
Secondary
Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil.
FEV1 was measured in all subjects at the beginning and end of both study arms. Subjects were genotyped at LTC4S locus and those bearing at least one A to C polymorphism were compared with those bearing two A alleles.
Time frame: 0, 42, 84, and 126 days
Population: We analyzed all samples available including subjects who did not complete the entire protocol. Therefore the number of subjects analyzed differs from the total number of subjects per arm.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Borage and Echium Seed Oils | Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil. | Genotype AA | -.02 Liters | Standard Deviation 0.23 |
| Borage and Echium Seed Oils | Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil. | Genotype AC or CC | 0.08 Liters | Standard Deviation 0.25 |
| Corn Oil Pills | Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil. | Genotype AA | -.02 Liters | Standard Deviation 0.16 |
| Corn Oil Pills | Genotype-specific Differences in Change in Lung Function While Receiving Borage and Echium Oils Versus Corn Oil. | Genotype AC or CC | .18 Liters | Standard Deviation 0.22 |
Secondary
Lung Function
Changes in lung function (forced expiratory volume in 1 second) will be assessed via spirometry at each visit. This was calculated by the difference between the FEV1 at weeks 2 and 8 versus weeks 14 and 20. The differences were compared as a delta-delta. A negative number for this parameter means that the FEV1 was lower at the end of the arm than at the beginning, while a positive number means that the FEV1 was higher at the end.
Time frame: Assessed at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Lung Function | -.12 Percent change | Standard Deviation 6.7 |
| Corn Oil Pills | Lung Function | 0.22 Percent change | Standard Deviation 5.77 |
Secondary
Measure of DHA in Cell Pellets
Secondary outcome measures include changes in concentrations of omega 3 fatty acids in cell pellets, indicating incorporation of botanical oil metabolites in cell membrane lipids.. This was calculated by the difference between the amount present at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta).
Time frame: Assessed at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Measure of DHA in Cell Pellets | 1.18 ng | Standard Deviation 8.51 |
| Corn Oil Pills | Measure of DHA in Cell Pellets | -1.01 ng | Standard Deviation 11 |
Secondary
Measure of EPA in Cell Pellets
Secondary outcome measures include changes in concentrations of omega 3 fatty acids in cell pellets, indicating incorporation of botanical oil metabolites in cell membrane lipids.. This was calculated by the difference between the amount present at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta).
Time frame: Assessed at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Measure of EPA in Cell Pellets | .094 ng | Standard Deviation 2.01 |
| Corn Oil Pills | Measure of EPA in Cell Pellets | -0.02 ng | Standard Deviation 2.1 |
Secondary
Number of Subjects Bearing a Polymorphic Variant of LTC4 Synthase
All individuals will be genotyped at the LTC4S locus.
Time frame: two weeks
Population: We analyzed all samples available including those who did not complete both arms of the protocol. Therefore the number of subjects in the two arms are not identical.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Borage and Echium Seed Oils | Number of Subjects Bearing a Polymorphic Variant of LTC4 Synthase | 10 participants |
Secondary
Plasma Level of Gamma Linolenic Acid (GLA)
Changes in plasma level of gamma linolenic acid (GLA), a major constituent of Borage oil, as a measure of compliance. This was calculated by the difference between the amount produced at the start of each arm and at the end of each arm (i.e., two values were obtained in each arm and used to calculate the difference, and the differences were compared as a delta-delta).
Time frame: Measurements obtained at 2, 8, 14, and 20 weeks
Population: We analyzed all samples available, including from subjects who did not complete the entire protocol (i.e., 40 subjects crossed over and completed both arms, but 44 completed the corn oil and 44 completed the borage and echium arm, and the overlap was incomplete). Thus, the number of subjects differs from the total number of subjects per arm
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Borage and Echium Seed Oils | Plasma Level of Gamma Linolenic Acid (GLA) | 6.11 ng | Standard Deviation 10.2 |
| Corn Oil Pills | Plasma Level of Gamma Linolenic Acid (GLA) | -.25 ng | Standard Deviation 2.32 |