There is one clinical trial.
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.
BMI will be calculated by weight (kg)/ height^2 (m^2).. Leptin gene promoter region single nucleotide polymorphisms (SNPs) (rs7799039).
Description: BMI will be calculated by weight (kg)/ height^2 (m^2).Measure: Body-mass index (BMI) Time: 12 months
Description: SNPs will be determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine (c.-2548G or c.-2548A) .Measure: Leptin gene promoter region single nucleotide polymorphisms (SNPs) (rs7799039) Time: 12 months
Description: SNPs will be determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine (c.-759C or c.-759T) .Measure: Serotonin 5-HT 2C receptor gene single nucleotide polymorphisms (SNPs) (rs3813929) Time: 12 months
Description: Haemoglobin A1c concentrations will be determined by ion-exchange HPLC (G8, Tosoh, Amsterdam, Netherlands)Measure: Blood haemoglobin A1c concentration Time: 6 months
Description: Waist:hip ratio will be calculated by waist circumference (cm)/hips circumference (cm)Measure: Waist:hip ratio Time: 12 months
Description: 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]Measure: Lipid profile Time: 12 months
Description: 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)Measure: Clozapine side effects assessment by Clinical Global Impression (CGI) scale Time: 12 months
Description: 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.Measure: Clozapine:nor clozapine ratio Time: 12 months