An interventional study of Vitamin A in Olfactory Disorder, sponsored by St. Paul's Hospital, Canada. Status unknown at 2 sites in Canada. Open to participants aged 19 Years to 90 Years. Per ClinicalTrials.gov, last updated 2019-09-19.
Sponsored by St. Paul's Hospital, Canada · Not applicable, Interventional, and Treatment
About One to 2 percent of the North American population below the age of 65 years experience olfactory loss to a significant degree. It can result from advanced age, Post-infestious/inflammatory disorders, Obstructive disorders (e.g. nasal polyposis, tumors), posttraumatic (head trauma) and neurodegenerative disorders. Only a few studies have shown benefits of specific therapy for olfactory loss.
Vitamin has shown promise from both animal and human studies. However, none has studied the benefits of topical application of vitamin A. This study will be the first to examine this effect.
Purpose
To determine if there is an improvement in olfactory function following the use of intranasal Vitamin A in patients with post-inflammatory and/or post-traumatic olfactory loss.
Hypothesis
There a significant improvement in olfactory function in patients with olfactory loss using intranasal vitamin A when compared with patients with olfactory loss not using intranasal vitamin A
Null Hypothesis There is no significant improvement in olfactory function in patients with olfactory loss using intranasal vitamin A when compared with patients with olfactory loss not using intranasal vitamin A
Justification
To treat post inflammatory and post-traumatic olfactory loss, a few controlled studies have shown a positive effect of a specific therapy for olfactory loss, such as olfactory training (using repeated intensive stimulation of the olfactory system and the use of prednisone. Other drugs studied like Vitamin B and Zinc, have either been insufficiently studied or showed no significant effect on olfactory loss.
The use of Retinoic acid (Vitamin A), a fat-soluble vitamin, in the treatment of olfactory loss has been previously studied in both animal and human models and showed promise. However, no study has examined the use of topical administration of vitamin A. This study will be the first to examine this effect.
Objectives
Primary Objective To determine if there is an improvement in olfactory function following the use of intranasal Vitamin A in patients with post-inflammatory and/or post-traumatic olfactory loss.
Secondary Objectives To determine if patient quality of life is improved/affected by the use of intranasal vitamin A.
Research Method This is a Single blind Randomized Control Trial.
Procedure
The study population will be consecutive patients diagnosed with loss of olfactory function. It will be a single blind randomized control trial. Allocation concealment will be ensured by the use of sequentially numbered, opaque, sealed envelopes. An assessor blinded to which patient is using vitamin A will assess the primary outcome.
Consent will be obtained for this study following diagnosis of the patient. After diagnosis, the patient will be sent a consent form and will be recruited on the next clinic visit.
Screening: After diagnosis, there will be a screening period; inclusion/exclusion criteria for the study participation will be checked. Subjects who satisfy these criteria will be invited to participate in the study. The consent forms will be sent to them via email and their consent will be recorded.
Blinding: The study will be single-blinded study. The patients will be randomized into 3 arms/groups. An assessor blinded to which patient is using vitamin A will assess the primary outcome.
Study Arms/Groups: The patients will be randomized into 3 groups using the sealed envelope method. Each patient will be his or her own control. There will be two possible scenarios resulting from randomization:
Patients will also continue to receive all other standard of care medication and procedures as necessary.
Sample size calculations According to the study conducted by Hummel et al, a the mean olfactory test (TDI) score was 19 with a standard deviation of 6.4. In order to have an 80% chance of detecting a clinically significant 6 point improvement in olfactory test (TDI) scores at a significant level of 5%, 108 patients will be required. This will be 36 patients per group. There is an approximately 10% drop out rate in studies conducted at the St Paul's sinus centre. Accounting for this drop out rate, a total of 120 participants (40 participants per group) will be required to conduct the study.
Statistical Comparisons Descriptive analysis will be used to describe demographic and some clinical outcomes. Mean, median and standard deviations will be used to describe these outcomes. The primary objective of this study is to compare olfactory function before and after the respective interventions among participants in the three groups. The dichotomous and continuous outcomes will be analyzed using Pearson Chi-squared test and analysis of variance (ANOVA). Analysis of variance will also be used to compare the olfactory test scores between the 3 groups and paired t-test for evaluating for statistical within the groups. Probability values less than 5% (α=0.05) will be considered significant. Sub-analysis by etiology of olfactory loss will also be done using the same methods.
St. Paul's Hospital, Canada is the lead sponsor of 31 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients 19 years and above diagnosed with loss of olfactory function, (with or without history of sinonasal surgery) currently receiving sinonasal-related care at the St Paul's Sinus Centre.
Exclusion Criteria:
Group A: This study group will receive intranasal vitamin A at 10,000 I.U. per day and olfactory retraining using scented oils in addition to their standard of care.
Dietary Supplement: Vitamin A
Group B: This study group will receive Vitamin A in addition to their standard of care. They will not receive olfactory retraining.
Dietary Supplement: Vitamin A
Group C: This study group will receive only standard of care .
The use of Vitamin A , in the treatment of olfactory loss has been previously studied in both animals and humans. These studies have shown promising results in the treatment of olfactory loss.
Also known as: Essential oils
Olfactory Tests.
These tests will be performed by same blinded assessor using the "Sniffin sticks" kit described above. The test is divided into three subtests including tests for olfactory thresholds (using phenyl ethyl alcohol), odor discrimination, and odor identification (TDI). The sum of the three scores reliably indicates the degree of olfactory function.
Time frame: For each subject this test will take 30 minutes
Sinonasal Outcomes Test - 22 (SNOT-22)
The SNOT-22 is a sinus-specific questionnaire that evaluates subjective symptoms for patients suffering from chronic rhinosinusitis. SNOT-22 is scored out of 110 (22 questions, up to 5-points each) has demonstrated internal consistency, reliability, discriminate and concurrent validity and responsiveness to change. Responses will be summated and considered as a continuous, numerical variable. Mean, median, standard deviation and inter-quartile range will be reported.
Time frame: For each subject this test will take between 5-10 minutes.
Sinus Mucosal Inflammation - Philpott-Javer (PJ) and Modified Lund-Kennedy (MLK) Endoscopic Staging System (ESS)
Sinonasal mucosal inflammation is an objective measure assessed endoscopically and graded on both the PJ and MLK ESS for CRS. This is a standard of care procedure at all clinic visits. Similar to the MLK ESS, the PJ ESS scores the sinus cavities as a collective based on endoscopic findings and the presence or absence of allergic mucin. Images and/or videos of all sinuses are captured at each visit and archived on the hospital network as a standard of care.
Time frame: For each subject this test will take about 5 minutes.
Questionnaire of Olfactory Disorders
The consists of 25 statements that were divided into three general domains: 17 negative statements (QOD-NS), two positive statements (QOD-PS), and six socially desired statements (QOD-SD). Negative statements give information about the degree patients suffer from olfactory impairment, whereas positive statements indicate how well patients cope with their olfactory deficit. Socially desired statements indicate the extent to which an individual's answers were credible, or whether the person was trying to create a certain impression by providing socially desirable responses. In addition there are also problem questions and questions regarding sense of smell on a visual analogue scale.
Time frame: For each subject this test will take about 10 minutes.
Plan to share: Undecided
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St. Paul's Hospital, Canada