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Clozapine Induced Weight Gain

Conditions
Weight Gain
Pharmacogenetics
Antipsychotic Agents
Registration Number
NCT03996356
Lead Sponsor
Cwm Taf University Health Board (NHS)
Brief Summary

Clozapine is prescribed to patients with psychosis in whom other treatments have not worked. Research has shown, however, that clozapine may be associated with weight gain and abnormal blood sugar levels in some patients. There is strong evidence to suggest that genetic variation between individuals plays an important role in the development of these side effects in response to the medication. Our research aims to evaluate the effects of two genes and the blood level of clozapine on side-effects such as weight changes and blood sugar levels in patients receiving clozapine treatment. From out-patient clinics in Cwm Taf UHB, the investigators aim to recruit 160 patients who are taking clozapine; collect information/ measurements from recruits relating to size/ weight/ BMI, risk of diabetes and blood samples to measure markers of blood sugar, fat/lipids, clozapine and its breakdown products, blood cells and variants of two specific genes. From this information the investigators will be particularly interested to understand if there is any association between the variation in these two genes with weight gain or changes in blood sugar, in patients taking clozapine.

Detailed Description

Not available

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
160
Inclusion Criteria
  • Age 18 years or over
  • Taking/compliant with clozapine antipsychotic medications.
  • Patients meeting the ICD-10 criteria for a diagnosis of schizophrenia, schizoaffective or borderline personality disorders.
Exclusion Criteria
  • History of current alcohol/illicit substance dependency.
  • Unable/ unsuitable to complete the study protocol e.g. acutely ill, suicidal or aggressive patients.
  • Unable to consent to the study.

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Body-mass index (BMI)12 months

BMI will be calculated by weight (kg)/ height\^2 (m\^2).

Serotonin 5-HT 2C receptor gene single nucleotide polymorphisms (SNPs) (rs3813929)12 months

SNPs will be determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine (c.-759C or c.-759T) .

Leptin gene promoter region single nucleotide polymorphisms (SNPs) (rs7799039)12 months

SNPs will be determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine (c.-2548G or c.-2548A) .

Secondary Outcome Measures
NameTimeMethod
Blood haemoglobin A1c concentration6 months

Haemoglobin A1c concentrations will be determined by ion-exchange HPLC (G8, Tosoh, Amsterdam, Netherlands)

Clozapine:nor clozapine ratio12 months

Clozapine:nor clozapine ratio is calculated by clozapine (ug/L)/ nor clozapine (ug/L) both measured by high-performance liquid chromatography with diode-array detection.

Clozapine side effects assessment by Clinical Global Impression (CGI) scale12 months

Clinical Global Impression (CGI) scale is a validated tool to assess clozapine side effects (Ref: Guy W, editor. ECDEU Assessment Manual for Psychopharmacology. 1976. Rockville,MD, U.S. Department of Health, Education, and Welfare)

Waist:hip ratio12 months

Waist:hip ratio will be calculated by waist circumference (cm)/hips circumference (cm)

Lipid profile12 months

Serum lipid profiles will include total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride. These will be measured by enzymatic colorimetric methods on cobas-Roche analysers (Roche, Burges Hill, UK) except LDL cholesterol, which will be calculated using the Friedewald equation (\[LDL cholesterol\] = \[Total cholesterol\] - (\[Triglyceride\] / 2.2) - \[HDL cholesterol\]

Trial Locations

Locations (1)

Cwm Taf University Health Board

🇬🇧

Merthyr Tydfil, Wales, United Kingdom

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