Energy expenditure and physical activity in clozapine use: implications for weight management.
OBJECTIVE
The management of atypical antipsychotic-induced weight gain is a significant challenge for people with mental illness. Fundamental research into energy metabolism in people taking atypical antipsychotic medication has been neglected. The current study of men with schizophrenia taking clozapine aimed to measure total energy expenditure (TEE) and energy expended on physical activity--activity energy expenditure (AEE) and to consider the clinical implications of the findings.


METHODS
The well-established reference method of doubly labelled water (DLW) was used to measure TEE and AEE in men with schizophrenia who had been taking clozapine for more than 6 months. Resting energy expenditure was determined using indirect calorimetry.


RESULTS
The TEE was 2511+/-606 kcal day-1 which was significantly different to World Health Organization recommendations (more than 20% lower). The Physical activity level (PAL) was 1.39+/-0.27 confirming the sedentary nature of people with schizophrenia who take clozapine.


CONCLUSIONS
The findings support the need for weight management strategies for people with schizophrenia who take clozapine to focus on the enhancement of energy expenditure by increasing physical activity and reducing inactivity or sedentary behaviours, rather than relying primarily on strategies to reduce energy intake.
Sharpe
Jenny-Kay
JK
General Health Services, The Park-Centre for Mental Health Research, Treatment, Research and Education, Richlands, Queensland, Australia. j.sharpe@qut.edu.au
Stedman
Terry J
TJ
Byrne
Nuala M
NM
Wishart
Connie
C
Hills
Andrew P
AP
D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002153:Calorimetry, Indirect; D003024:Clozapine / Q000494:pharmacology* / Q000627:therapeutic use; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D012559:Schizophrenia / Q000188:drug therapy; D015430:Weight Gain / Q000187:drug effects*
D014150:Antipsychotic Agents; D003024:Clozapine