Study setting and interventions
PAD
The patients included in the study were randomly divided into two groups using a computer-generated random number table. The patients and the physician were both completely blinded, and the assignment and the randomization were performed by a third person.The intervention treatment group received one bottle containing 180 pills of alpha-lipoic acid 300 mg/pill and the comparison treatment group received one identical bottle including 180 pills of placebo (starch) 300 mg/pill. The patients should take 01 pill twice a day, for 12-weeks, followed by Hummel et al. previous study.Furthermore, both groups received an olfactory training kit with four odorants (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon and eugenol: cloves), in plastic pots labelled with the odor name (made by Clínica Olfact- Londrina/PR-Brazil). Inside, there was a cotton pad soaked with 1 mL of each scent. Patients were advised to sniff the odors twice a day for approximately 10 s each. To help therapeutic adherence, patients received a diary to take notes daily. Moreover, patients received a phone call by every 4-weeks into the treatment period to ask about the patients’ subjective olfactory function by Visual Analogic Scale, to maintain compliance to the study and to collect data about side effects.