Niacin Skin Flush Response in Patients With Schizophrenia

Study Overview
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Brief Summary
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Patients with schizophrenia have abnormal skin flush response to niacin, but the niacin skin test accuracy is not well studied in these patients. The study evaluated the niacin skin test accuracy in adult hospitalized schizophrenia patients and their first degree relatives, bipolar disorder patients, and healthy controls.

Official Title
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Niacin Skin Flush Response in Patients With Schizophrenia, Their First Degree Relatives, Bipolar Disorder Patients, and Healthy Controls

Conditions
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Schizophrenia

Intervention / Treatment
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* Biological: Niacin skin test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of schizophrenia patients and bipolar disorder patients diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders version IV criteria Normal healthy subjects without a psychiatric history First degree relatives of schizophrenic patients Exclusion Criteria: Dermatological lesions, asthma or allergic disease, diabetes, chronic hypertension, vasculitis, substance use disorders (except cigarette smoking), or pregnancy Taking any oral medication that could affect the metabolism of prostaglandins such as nonsteroidal anti-inflammatory drugs or corticosteroids

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Schizophrenia<br>Skin niacin test was performed by two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate. The two solutions were applied for one minute to the inside of the different forearms of each individual. | Biological: Niacin skin test<br>* Two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate were applied for one minute to the inside of the different forearms of each individual.<br>* Other names: Methyl nicotinate;|
| Active Comparator: Bipolar disorder<br>Skin niacin test was performed by two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate. The two solutions were applied for one minute to the inside of the different forearms of each individual. | Biological: Niacin skin test<br>* Two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate were applied for one minute to the inside of the different forearms of each individual.<br>* Other names: Methyl nicotinate;|
| Active Comparator: First degree relatives<br>Skin niacin test was performed by two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate. The two solutions were applied for one minute to the inside of the different forearms of each individual. | Biological: Niacin skin test<br>* Two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate were applied for one minute to the inside of the different forearms of each individual.<br>* Other names: Methyl nicotinate;|
| Active Comparator: Health controls<br>Skin niacin test was performed by two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate. The two solutions were applied for one minute to the inside of the different forearms of each individual. | Biological: Niacin skin test<br>* Two concentrations including 0.5 ml solutions of 0.01 M and 0.1 M diluted methyl nicotinate were applied for one minute to the inside of the different forearms of each individual.<br>* Other names: Methyl nicotinate;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skin flush response | Skin response was assessed by a single physician every 5 minutes for 20 minutes after removal of the substance. The outcome assessor was not blinded to the applied solution dosages. The strength of the flushing reaction was classified as 0 = no redness, 1 = faint redness, 2 = distinct redness, and 3 = extreme or maximum redness. | Every 5 minutes for 20 minutes |