Jenny-Kay Sharpe

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. Method: 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 signifcantly 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.

Atypical antipsychotic weight gain: a major clinical challenge.

OBJECTIVE The major aim of this paper is to review findings from weight management intervention studies to consider clozapine and/or olanzapine induced weight gain. A parallel aim is to summarize the challenges facing future research and provide an overview of best practice in the management of weight in mental health patients. METHOD A systematic literature search was conducted using Medline, Cinahl and PsychINFO data bases and reference lists from relevant published articles. Five studies which reported weight control practices in patients taking atypical antipsychotic medications were located and reviewed. RESULTS The studies reviewed provide some important descriptive clinical insights; however, common shortcomings include small subject numbers and methodological drawbacks such as lack of a control group. CONCLUSIONS There is some evidence that weight gain associated with atypical antipsychotic medication can be ameliorated by lifestyle changes such as improved nutritional practices and increased physical activity. Lifestyle interventions for individuals with psychotic disorders may need to be adapted to be most effective; for example, using strategies to counter increased appetite and to enhance physical activity. Clinicians need to be vigilant and persistent in monitoring and intervening if weight gain occurs. A standardized screening tool and clinical pathway would help clinicians to target appropriate interventions for each person prescribed atypical antipsychotic medication.

Anthropometry and adiposity in a group of people with chronic mental illness.

Objective: The prevalence of excess body weight has been reported as two to four times greater in the chronic mentally ill than in the general population. However, there has been a paucity of body composition research with this population. The purpose of this study was to compare with population data the prevalence and distribution of body fat in a group of chronic mentally ill individuals. Method: An anthropometric profile consisting of height, weight, waist and hip girths was completed on 29 males and 23 females. Results: Consistent with other groups with excess adiposity, measures of skinfold thickness were generally unreliable. The biceps was the only site where a reliable skinfold measure was possible in all subjects. More than half of the males and three-quarters of the females had a waist circumference in excess of 100 cm. Conclusions: There were significantly higher levels of relative body weight and excess abdominal adiposity in the study group compared with the wider population. A brief anthropometric protocol of waist and hip girths and biceps skinfold in addition to height and weight, rather than the use of weight alone as an indicator of adiposity, is recommended.

Low-fat oxidation may be a factor in obesity among men with schizophrenia.

Objective:  Obesity associated with atypical antipsychotic medications is an important clinical issue for people with schizophrenia. The purpose of this project was to determine whether there were any differences in resting energy expenditure (REE) and respiratory quotient (RQ) between men with schizophrenia and controls.

Accelerometry is a valid measure of physical inactivity but not of energy expended on physical activity in people with schizophrenia

The relationship between physical inactivity and weight gain, obesity and related co-morbid conditions such as cardiovascular disease and diabetes is well established (Lees and Booth, 2005). People with schizophrenia have high rates of physical inactivity, obesity, cardiovascular disease and diabetes (Casey, 2005). It appears that aspects of the illness, the medications used to treat it and specific lifestyle behaviours of people with schizophrenia, contribute to this high prevalence. Recent research in the area by Faulkner et al. (2005) revealed that a physical activity questionnaire was not sufficiently precise to unravel the inter-relationships between physical activity, mental illness, lifestyle and medication side effects and obesity, weight gain, diabetes and cardiovascular disease in this clinical group. Volume 85, Issues 1-3, July 2006, Pages 300-301

Bioelectric impedance is a better indicator of obesity in men with schizophrenia than body mass index.

Body mass index (BMI) is commonly used as an indicator of obesity, although in both clinical and research settings the use of bioelectric impedance analysis (BIA) is commonplace. The purpose of this study was to examine the relationship between BMI, BIA and percentage body fat to determine whether either is a superior indicator of obesity in men with schizophrenia. The reference method of deuterium dilution was used to measure total body water and, subsequently, percentage body fat in 31 men with schizophrenia. Comparisons with the classification of body fat using BMI and BIA were made. The correlation between percentage body fat and BMI was 0.64 whereas the correlation between percentage body fat and BIA was 0.90. The sensitivity and specificity in distinguishing between obese and overweight participants was 0.55 and 0.80 for BMI and 0.86 and 0.75 for BIA. BIA proved to be a better indicator of obesity than BMI. BMI misclassified a large proportion of men with schizophrenia as overweight when they had excess adiposity of sufficient magnitude to be considered as obese. Because of the widespread use of BMI as an indicator of obesity among people with schizophrenia, the level of obesity among men with schizophrenia may be in excess of that previously indicated.