Effects of Lipoic Acid on Oxidative, Inflammatory and Functional Markers in Asthmatic Patients

Not Applicable

Completed

Conditions: Asthma
Allergic Rhinitis

Interventions: Dietary Supplement: Placebo
Dietary Supplement: Lipoic acid

Registration Number: NCT01221350

Lead Sponsor: Centro Universitario de Ciencias de la Salud, Mexico

Brief Summary: The aim of the study is to use the antioxidant and antiinflammatory effects of lipoic acid to improve the quality of life of patients with asthma.

The investigators will administrate 600 mg lipoic acid orally on a daily basis during two months concurrent with the patient anti-asthmatic therapy and evaluate the effects on resulting pulmonary function, inflammatory and oxidative stress biomarkers and health-related quality of life previous to the initial of the treatment and at 60 days of the supplementary therapy.

Detailed Description: Asthma is an inflammatory disease of high prevalence around the world. During development of asthma the presence of oxidative stress has been related to susceptibility and severity of the disease, thus making the use of antioxidant adjuvant therapy with lipoic acid (LA) an interesting treatment option. The objective of the study is to evaluate the efficacy of LA as an adjuvant treatment on functional, antioxidant, inflammatory, quality and control parameters of asthma in human subjects. The trial design is a randomized, double blind, placebo controlled parallel study.

Adult patients (\>18 years) with history of mild intermittent to moderate asthma according to the Global Initiative for Asthma (GINA) guidelines were enrolled. It was required a positive skin prick test (\>3 mm) for at least two regional allergens. Patients were randomly assigned to receive lipoic acid or placebo for 60 days. Participants had an intermediate visit to the attending physician one month after initial of treatment to monitor adverse events and to undergo laboratory tests.

1. Introduction. Asthma is an inflammatory disease of high prevalence around the world. During development of asthma the presence of oxidative stress has been related to susceptibility and severity of the disease, thus making the use of antioxidant adjuvant therapy with lipoic acid (LA) an interesting treatment option.

2. Study design. A randomized, double blind, placebo controlled parallel study

3. Methods. Participants and interventions: 55 patients with mild to moderate asthma from Hospital Civil "Juan I. Menchaca" in Guadalajara, Jalisco, México were included and randomized in block of 10 to receive; LA (600 mg/day) or placebo for eight weeks from January to October of 2011.

4. Objective. To evaluate the efficacy of LA as an adjuvant treatment on functional, antioxidant, inflammatory, quality and control parameters of asthma in human subjects. Primary outcome: change on Forced expiratory volume in 1 second (FEV1), secondary outcomes were levels of Oxygen radical absorbance capacity (ORAC), glutathione (GSH), glutathione disulfide (GSSG), protein carbonyls, differential count of sputum cells, interleukin-4 (IL-4) and scores of quality of life and control of asthma questionnaires.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 55

Inclusion Criteria

Outpatients (≥18 and ≤ 75 years of age) female or male
Willingness to participate and comply with procedures by signing a written informed consent
Moderate/severe persistent allergic rhinitis according to Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines with a history of intermittent, mild persistent or moderate persistent asthma according to GINA guidelines
Confirmed allergy to at least one of the following allergen preparations: house dust mite f; house dust mite p; cockroach; bush mix; tree mix; grass mix; weed mix, cat; or dog.
All prior medication washout times had been observed
Female volunteers of childbearing potential had to agree to use a medically accepted method of contraception
Negative urine pregnancy test
Without a concomitant chronic medical condition (e.g., significant cardiovascular disease, diabetes requiring medication, chronic kidney disease, chronic thyroid disease, or coagulation defects)
Willingness to adhere to the dosing and visit schedules

Exclusion Criteria

Pregnant or breastfeeding
Female who was or intended to become pregnant during the study or within 12 weeks after study completion
Taking medications prohibited during the study or had not complied with the requirements for the designated washout periods for any of the prohibited medications
Anatomical abnormalities of the nose (turbinate hypertrophy, septal deviation, polyps)
Acute or chronic sinusitis currently being treated with antibiotics and/or topical or oral decongestants
Upper respiratory tract or sinus infection that required antibiotic therapy and had not had at least a 14-day wash-out period prior to the run-in period
Patients undergoing a progressive course of immunotherapy. Subjects on a regular maintenance schedule prior to the screening visit are eligible for study inclusion; however, subject could not receive hyposensitization treatment within 24 hours prior to any study visit
Concomitant medical problem
In a situation or condition that could interfere with participation in the study
Allergic or sensitivity to the study drug or its excipients
History of inadequate adherence to treatment

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Placebo (two placebo capsules) orally once daily in the morning during 60 days
Lipoic acid	Lipoic acid	Lipoic acid 600 mg oral dose (two 300 mg capsules) once daily in the morning during 60 days

Primary Outcome Measures

Name	Time	Method
Spirometric FEV1 Values at Baseline	Baseline	Measurement of spirometric predicted parameters at baseline: Forced expiratory volume in 1 second (FEV1), volume that has been exhaled at the end of the first second of forced expiration.
Spirometric FVC Values at Baseline	Baseline	Measurement of spirometric predicted parameters at baseline. Forced vital capacity (FVC) is the volume of air that can forcibly be blown out after full inspiration, measured in liters.
Spirometric FVC Values at Endpoint	60 days	Measurement of spirometric predicted parameters at the baseline and after 60 days of treatment: Forced vital capacity (FVC) is the volume of air that can forcibly be blown out after full inspiration, measured in liters.
Spirometric FEF Values at Endpoint	60 days	Measurement of spirometric FEF after 60 days of treatment: Forced expiratory flow (FEF) is the flow (or speed) of air coming out of the lung during the middle portion of a forced expiration.
Spirometric FEV1 Values at Endpoint	60 days	Measurement of spirometric predicted parameters after 60 days of treatment. Forced expiratory volume in 1 second (FEV1), volume that has been exhaled at the end of the first second of forced expiration.
Spirometric FEF Values at Baseline	Baseline	Measurement of spirometric parameters at baseline: Forced expiratory flow (FEF) is the flow (or speed) of air coming out of the lung during the middle portion of a forced expiration.

Secondary Outcome Measures

Name	Time	Method
Induced Sputum Carbonylated Proteins at Baseline	Baseline	Proteins can become modified by a large number of reactions involving reactive oxygen species. Among these, carbonylation is an irreversible and unrepairable oxidative reaction. The main protein modifications originated from oxidative stress comprise direct oxidation of aminoacids with a thiol group, such as cysteine, oxidative glycation, and carbonylation. Oxidative protein carbonylation induce protein degradation in a nonspecific manner. Chemically, oxidative carbonylation preferentially occurs at proline, threonine, lysine, and arginine, presumably through a metal-catalyzed activation of hydrogen peroxide to a reactive intermediate. Carbonylation usually refers to a process that forms reactive ketones or aldehydes that can be reacted by 2,4-dinitrophenylhydrazine (DNPH) to form hydrazones. Direct oxidation of side chains of lysine, arginine, proline, and threonine residues, among other aminoacids, produces DNPH detectable protein products
Induced Sputum of Glutathione (GSH)/Glutathione Disulfide (GSSG) Ratio at Baseline	Baseline	Induced sputum of GSH and GSSG levels at baseline. The ratio GSH/GSSG is considered an index of antioxidant status and reductive -SH groups. GSH and GSSG were measured by a microplate fluorescent assay.
Induced Sputum Eosinophils at Baseline	Baseline	Eosinophils, a prominent feature of asthma, are found in increased numbers in the circulation and sputum, usually in relation to the severity of asthma.
Induced Sputum of Glutathione (GSH)/Glutathione Disulfide (GSSG) Ratio at Endpoint	60 days	Change in the induced sputum of antioxidant parameters GSH and GSSG levels after 60 days of treatment. The ratio GSH/GSSG is considered an index of antioxidant status and reductive -SH groups. GSH and GSSG were measured by a microplate fluorescent assay.
Induced Sputum Eosinophils at Endpoint	60 days	Eosinophils, a prominent feature of asthma, are found in increased numbers in the circulation and sputum, usually in relation to the severity of asthma.
Induced Sputum Carbonylated Proteins at Endpoint	60 days	Proteins can become modified by a large number of reactions involving reactive oxygen species. Among these, carbonylation is an irreversible and unrepairable oxidative reaction. The main protein modifications originated from oxidative stress comprise direct oxidation of aminoacids with a thiol group, such as cysteine, oxidative glycation, and carbonylation. Oxidative protein carbonylation induce protein degradation in a nonspecific manner. Chemically, oxidative carbonylation preferentially occurs at proline, threonine, lysine, and arginine, presumably through a metal-catalyzed activation of hydrogen peroxide to a reactive intermediate. Carbonylation usually refers to a process that forms reactive ketones or aldehydes that can be reacted by 2,4-dinitrophenylhydrazine (DNPH) to form hydrazones. Direct oxidation of side chains of lysine, arginine, proline, and threonine residues, among other aminoacids, produces DNPH detectable protein products.
Inflammatory IL-4 Sputum Levels at Endpoint	60 days	Inflammatory IL-4 sputum levels after 60 days of treatment. Sputum induction is a semi-invasive technique used to detect and monitor airway inflammation. IL-4 is a Th2 cytokine that promote airway inflammation in asthma. IL-4 drives the production of IgE in B cells. IL-4 was measured by ELISA.
Measurement of Quality of Life With the ACT (Asthma Control Test) at Endpoint	60 days	Assessment of Quality of life scores with the ACT (Asthma Control Test). The ACT is a way to determine if the asthma symptoms are well controlled. The Asthma Control Test™ (ACT™) is a five question health survey used to measure asthma control in individuals 12 years of age and older. The survey measures the elements of asthma control as defined by the National Heart, Lung, and Blood Institute (NHLBI). ACT is an efficient, reliable, and valid method of measuring asthma control, with or without, lung functioning measures such as spirometry. Each item includes 5 response options corresponding to a 5-point Likert-type rating scale. In scoring the ACT survey, responses for each of the 5 items are summed to yield a score ranging from 5 (poor control of asthma) to 25 (complete control of asthma).
Measurement of Quality of Life With the AQLQ (Asthma Quality of Life Questionnaire) at Endpoint	60 days	The Asthma Quality of Life Questionnaire (AQLQ) was developed to measure the functional problems (physical, emotional, social and occupational) that are most troublesome to adults (17-70 years) with asthma. There are 32 questions in the AQLQ and they are in 4 domains (symptoms, activity limitation, emotional function and environmental stimuli). The activity domain contains 5 'patient-specific' questions. This allows patients to select 5 activities in which they are most limited and these activities will be assessed at each follow-up. Patients are asked to think about how they have been during the previous two weeks and to respond to each of the 32 questions on a 7-point scale (7 = not impaired at all - 1 = severely impaired). The overall AQLQ score is the mean of all 32 responses and the individual domain scores are the means of the items in those domains (http://www.qoltech.co.uk/aqlq.html).
Measurement of Quality of Life With the ACT (Asthma Control Test) at Baseline	Baseline	Assessment of Quality of life scores with the ACT (Asthma Control Test). The ACT is a way to determine if the asthma symptoms are well controlled. The Asthma Control Test™ (ACT™) is a five question health survey used to measure asthma control in individuals 12 years of age and older. The survey measures the elements of asthma control as defined by the National Heart, Lung, and Blood Institute (NHLBI). ACT is an efficient, reliable, and valid method of measuring asthma control, with or without, lung functioning measures such as spirometry. Each item includes 5 response options corresponding to a 5-point Likert-type rating scale. In scoring the ACT survey, responses for each of the 5 items are summed to yield a score ranging from 5 (poor control of asthma) to 25 (complete control of asthma).
Measurement of Quality of Life With the AQLQ (Asthma Quality of Life Questionnaire) at Baseline	Baseline	The Asthma Quality of Life Questionnaire (AQLQ) was developed to measure the functional problems (physical, emotional, social and occupational) that are most troublesome to adults (17-70 years) with asthma. There are 32 questions in the AQLQ and they are in 4 domains (symptoms, activity limitation, emotional function and environmental stimuli). The activity domain contains 5 'patient-specific' questions. This allows patients to select 5 activities in which they are most limited and these activities will be assessed at each follow-up. Patients are asked to think about how they have been during the previous two weeks and to respond to each of the 32 questions on a 7-point scale (7 = not impaired at all - 1 = severely impaired). The overall AQLQ score is the mean of all 32 responses and the individual domain scores are the means of the items in those domains (http://www.qoltech.co.uk/aqlq.html).
Inflammatory Interleukin-4 (IL-4) Sputum Levels at Baseline	Baseline	Inflammatory IL-4 sputum levels after 60 days of treatment. Sputum induction is a semi-invasive technique used to detect and monitor airway inflammation. IL-4 is a Th2 cytokine that promote airway inflammation in asthma. IL-4 drives the production of immunoglobulin E (IgE) in B cells. IL-4 was measured by ELISA.

Trial Locations

Locations (2): Departamento de Fisiología, CUCS, UdeG
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Guadalajara, Jalisco, Mexico
Hospital Civil de Guadalajara "Juan I. Menchaca"
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Guadalajara, Jalisco, Mexico