Ignite Creation Date:
2024-05-05 @ 5:03 PM
Last Modification Date:
2024-10-26 @ 9:27 AM
Study NCT ID:
NCT00376233
Status:
COMPLETED
Last Update Posted:
2006-10-12
First Post:
2006-09-13
Brief Title:
Niacin Flushing as Marker of Cannabis Effects on Arachidonic Acid Pathways in Schizophrenia
Sponsor:
University of Jena
Organization:
University of Jena
Study Overview
Official Title:
First Detailed Study on Effects of Long Term Regular Cannabis Use on Arachidonic Acid-Prostaglandine Pathways in Schizophrenia
Status:
COMPLETED
Status Verified Date:
2006-09
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Increasing evidence suggests modulating effects of cannabinoids on time of onset severity and outcome of schizophrenia Efforts to discover the underlying pathomechanism have led to the assumption of gene x environment interactions including premorbid genetical vulnerability and worsening effects of continuing cannabis use For a main characteristic of psychoactive delta-9-tetrahydrocannabinol is its affinity to biological membranes which are known to be disturbed in schizophrenia patients and genetic high-risk populations
Here we assess an hypothesised association between premorbid lipid disturbance and metabolic effects of external cannabinoids in schizophrenia
Intensity of niacin methylnicotinate skin flushing indicating disturbed prostaglandin-mediated processes is used as peripheral marker of lipid-arachidonic acid pathways and investigated in cannabis consuming and non-consuming schizophrenia patients and in healthy controls Methylnicotinate is applied in three concentrations onto the forearm skin Flush response is assessed in three minute intervals over 15 min using optical reflection spectroscopy
Here we assess an hypothesised association between premorbid lipid disturbance and metabolic effects of external cannabinoids in schizophrenia
Intensity of niacin methylnicotinate skin flushing indicating disturbed prostaglandin-mediated processes is used as peripheral marker of lipid-arachidonic acid pathways and investigated in cannabis consuming and non-consuming schizophrenia patients and in healthy controls Methylnicotinate is applied in three concentrations onto the forearm skin Flush response is assessed in three minute intervals over 15 min using optical reflection spectroscopy
Detailed Description:
Subjects Niacin skin tests are performed on acutely ill consecutively admitted schizophrenia patients suffering not more than two psychotic episodes All meet DSM-IV criteria for paranoide schizophrenia Diagnosis is made by two independent experienced psychiatrists and further supported by structured clinical interview SCID IV Wittchen et al 1997 Majority of patients is treated mostly with atypical neuroleptic drugs The patient population is subdivided in one group having used cannabis on a regular basis 05 gd at least 3 month prior to admission and another group having never used cannabis apart from unique trials Cannabis consuming patients do not use any other drug or alcohol on a regular basis Psychiatric symptoms are assessed using Brief Psychiatric Rating Scale BPRS Overall and Gorham 1962 Scale of Assessment of Positive Symptoms SAPS Andreasen 1984 Scale of Assessment of Negative Symptoms SANS Andreasen 1983 and Symptom Check List 1990 Revised SCL 90-R Kaplan et al 1998
Patients are compared to healthy volunteers recruited by newspaper advertisement including again one group of cannabis users duration and dose of cannabis use as in patients and one group without any cannabis experience Controls are interviewed in-depth to rule out a current psychiatric diagnosis or psychiatric personal or family history As in patients SCL 90-R is also applied in controls
All cannabis-using participants are tested positive for cannabinoids in urine at the time of niacin testing Subjects with any current or history of skin disorders eczema atopical dermatitis psoriasis or recent treatment with steroids or non-steroidal antiinflammatory drugs eg acetylsalicylic acid are excluded from the study before niacin testing The study is approved by the Ethics Committee of Friedrich-Schiller-University Jena All participants give written informed consent to participate in the study
Niacin skin test protocol Methylnicotinate C7H7NO2 99 Sigma-ALDRICH Chemie GmbH Germany is applied simultaneously in three dilutions 0001 M 001 M 01 M of 50 µl each to the skin at the inner side of the forearm using chambered plaster for epicutaneous testing After 90 sec the plaster is removed Skin flushing is quantified before and up to 15 minutes after methylnicotinate exposure in 3-min intervals starting 90 sec after removal of the methylnicotinate patches Methylnicotinate solutions are freshly prepared for each test to prevent any influence of sunlight
Reflection spectroscopy Optical reflection spectroscopy ORS is applied as described in more detail by Smesny et al 2001 Skin content of oxygenated blood is assessed with a handheld optical reflection spectrometer spectral range 400 nm to 700 nm area of measurement diameter 5 mm using the oxyhemoglobin HbO2 absorption double peak at 542 nm and 577 nm Each measurement is repeated three times within 10 sec and then averaged
Spectroscopic data are processed automatically creating difference spectra by subtraction of pre-stimulation reflection intensities also measured three times from test intensities Two Gaussian curves are fitted to the HbO2-absorption double peak The area under the resulting sum curve is taken as measure of current skin flushing measured in arbitrary units au
Data analysis We plan to conduct a repeated measure analysis of variance ANOVA with TIME 3 6 9 12 15 min and methylnicotinate CONCENTRATION 0001 M 001 M 01 M as within-subject factors and GROUP patients controls and CANNABIS cannabis user cannabis non-user as between subjects factors GENDER and AGE are treated as co-variates For post-hoc comparison of single values Mann-Whitney-U-Tests are calculated Psychopathological ratings of the SCL 90-R are compared between groups using an univariate ANOVA with the same between group factors GROUP CANNABIS and co-variates AGE GENDER as above Furthermore effects of cannabis use on SAPS SANS and BPRS are investigated within the patient group In order to explore a possible association between age or psychopathological ratings and skin flushing Spearman correlation coefficients will be calculated Due to the high number of calculated coefficients the significance level will be set on p 001
Patients are compared to healthy volunteers recruited by newspaper advertisement including again one group of cannabis users duration and dose of cannabis use as in patients and one group without any cannabis experience Controls are interviewed in-depth to rule out a current psychiatric diagnosis or psychiatric personal or family history As in patients SCL 90-R is also applied in controls
All cannabis-using participants are tested positive for cannabinoids in urine at the time of niacin testing Subjects with any current or history of skin disorders eczema atopical dermatitis psoriasis or recent treatment with steroids or non-steroidal antiinflammatory drugs eg acetylsalicylic acid are excluded from the study before niacin testing The study is approved by the Ethics Committee of Friedrich-Schiller-University Jena All participants give written informed consent to participate in the study
Niacin skin test protocol Methylnicotinate C7H7NO2 99 Sigma-ALDRICH Chemie GmbH Germany is applied simultaneously in three dilutions 0001 M 001 M 01 M of 50 µl each to the skin at the inner side of the forearm using chambered plaster for epicutaneous testing After 90 sec the plaster is removed Skin flushing is quantified before and up to 15 minutes after methylnicotinate exposure in 3-min intervals starting 90 sec after removal of the methylnicotinate patches Methylnicotinate solutions are freshly prepared for each test to prevent any influence of sunlight
Reflection spectroscopy Optical reflection spectroscopy ORS is applied as described in more detail by Smesny et al 2001 Skin content of oxygenated blood is assessed with a handheld optical reflection spectrometer spectral range 400 nm to 700 nm area of measurement diameter 5 mm using the oxyhemoglobin HbO2 absorption double peak at 542 nm and 577 nm Each measurement is repeated three times within 10 sec and then averaged
Spectroscopic data are processed automatically creating difference spectra by subtraction of pre-stimulation reflection intensities also measured three times from test intensities Two Gaussian curves are fitted to the HbO2-absorption double peak The area under the resulting sum curve is taken as measure of current skin flushing measured in arbitrary units au
Data analysis We plan to conduct a repeated measure analysis of variance ANOVA with TIME 3 6 9 12 15 min and methylnicotinate CONCENTRATION 0001 M 001 M 01 M as within-subject factors and GROUP patients controls and CANNABIS cannabis user cannabis non-user as between subjects factors GENDER and AGE are treated as co-variates For post-hoc comparison of single values Mann-Whitney-U-Tests are calculated Psychopathological ratings of the SCL 90-R are compared between groups using an univariate ANOVA with the same between group factors GROUP CANNABIS and co-variates AGE GENDER as above Furthermore effects of cannabis use on SAPS SANS and BPRS are investigated within the patient group In order to explore a possible association between age or psychopathological ratings and skin flushing Spearman correlation coefficients will be calculated Due to the high number of calculated coefficients the significance level will be set on p 001
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None