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

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.

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.

Eligibility Criteria:
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