Glucose metabolism in patients with schizophrenia treated with olanzapine or quetiapine: a frequently sampled intravenous glucose tolerance test and minimal model analysis.

OBJECTIVE: Clozapine and olanzapine treatment has been associated with insulin resistance in non-obese schizophrenia patients. Much less is known regarding other agents such as quetiapine. The objective of this study was to compare matched olanzapine- and quetiapine-treated schizophrenia patients and normal controls on measures of glucose metabolism. METHOD: A cross-sectional comparison of quetiapine-treated and olanzapine-treated non-obese (body mass index < 30.0 kg/m2) schizophrenia subjects (DSM-IV) with matched normal controls using a frequently sampled intravenous glucose tolerance test and nutritional assessment was conducted from April 2002 to October 2004. Data from 24 subjects were included in the analysis (7 quetiapine, 8 olanzapine, 9 normal controls). RESULTS: There was a significant difference among groups for fasting baseline plasma glucose concentrations (p = .02), with olanzapine greater than normal controls (p = .01). The insulin sensitivity index (SI) differed significantly among groups (p = .039); olanzapine subjects exhibited significant insulin resistance compared to normal controls (p = .01), but there was no significant difference for quetiapine versus olanzapine (p = .1) or quetiapine versus normal controls (p = .40). SI inversely correlated with quetiapine dose (p = .0001) and waist circumference (p = .03) in quetiapine-treated subjects. Insulin resistance calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) also differed significantly among groups (p = .03). The olanzapine group had a higher HOMA-IR level than normal controls (p = .01). There was a significant difference in glucose effectiveness (SG) among the groups (p = .049). SG was lower in the olanzapine group than in the quetiapine group (p = .03) and in the olanzapine group compared to normal controls (p = .049). CONCLUSIONS: Our findings are consistent with our previous report that nonobese olanzapine-treated subjects showed insulin resistance, measured by both HOMA-IR and SI, and reduction in SG. Studies that include larger samples, unmedicated patients, and varying durations of antipsychotic exposure are necessary to confirm these results.

Glucose metabolism in patients with schizophrenia treated with atypical antipsychotic agents: a frequently sampled intravenous glucose tolerance test and minimal model analysis.

BACKGROUND: While the incidence of new-onset diabetes mellitus may be increasing in patients with schizophrenia treated with certain atypical antipsychotic agents, it remains unclear whether atypical agents are directly affecting glucose metabolism or simply increasing known risk factors for diabetes. OBJECTIVE: To study the 2 drugs most clearly implicated (clozapine and olanzapine) and risperidone using a frequently sampled intravenous glucose tolerance test. DESIGN: A cross-sectional design in stable, treated patients with schizophrenia evaluated using a frequently sampled intravenous glucose tolerance test and the Bergman minimal model analysis. SETTING: Subjects were recruited from an urban community mental health clinic and were studied at a general clinical research center. Patients Fifty subjects signed informed consent and 41 underwent the frequently sampled intravenous glucose tolerance test. Thirty-six nonobese subjects with schizophrenia or schizoaffective disorder, matched by body mass index and treated with either clozapine, olanzapine, or risperidone, were included in the analysis. MAIN OUTCOME MEASURES: Fasting plasma glucose and fasting serum insulin levels, insulin sensitivity index, homeostasis model assessment of insulin resistance, and glucose effectiveness. RESULTS: The mean +/- SD duration of treatment with the identified atypical antipsychotic agent was 68.3 +/- 28.9 months (clozapine), 29.5 +/- 17.5 months (olanzapine), and 40.9 +/- 33.7 (risperidone). Fasting serum insulin concentrations differed among groups (F(33) = 3.35; P = .047) (clozapine>olanzapine>risperidone) with significant differences between clozapine and risperidone (t(33) = 2.32; P = .03) and olanzapine and risperidone (t(33) = 2.15; P = .04). There was a significant difference in insulin sensitivity index among groups (F(33) = 10.66; P<.001) (clozapineolanzapine>risperidone) (clozapine vs risperidone, t(33) = 2.94; P = .006; olanzapine vs risperidone, t(33) = 2.42; P = .02). There was a significant difference among groups in glucose effectiveness (F(30) = 4.18; P = .02) (clozapine

A double-blind, placebo-controlled trial of sibutramine for olanzapine-associated weight gain.

OBJECTIVE: Weight gain is commonly observed with olanzapine treatment and can increase the risk for obesity, cardiovascular disease, hypertension, and diabetes mellitus. This study examined the effectiveness of sibutramine, an approved weight loss agent, in overweight and obese subjects taking olanzapine for schizophrenia or schizoaffective disorder. METHOD: Each subject had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder, had been taking a stable dose of olanzapine for at least 4 months, and had a body mass index of >/=30 kg/m(2) or >/=27 kg/m(2) plus at least one cardiovascular risk factor. In a 12-week double-blind, randomized, placebo-controlled study, 37 subjects received placebo or sibutramine (up to 15 mg/day). For the first 8 weeks all subjects participated in weekly group sessions focused on nutrition and behavioral modification. RESULTS: The sibutramine and placebo groups had no significant baseline differences on age, gender, education, ethnicity, diagnosis, weight, body mass index, and blood pressure. At week 12 the sibutramine group had significantly greater losses than the placebo group in weight (mean=8.3 lb, SD=2.4, versus mean=1.8 lb, SD=1.6), waist circumference, body mass index, and hemoglobin A(1c). There were no significant differences on most side effects, although the sibutramine group exhibited a mean increase in systolic blood pressure of 2.1 mm Hg (SD=8.5), and anticholinergic side effects and sleep disturbances were at least twice as common in the sibutramine group. CONCLUSIONS: Sibutramine was an effective and well-tolerated adjunct to behavior modification for weight loss in patients with schizophrenia and schizoaffective disorder being treated with olanzapine.

Clozapine and hypertension: a chart review of 82 patients.

OBJECTIVE: Clozapine has been linked to significant weight gain and increase in serum lipids and appears to negatively impact glucose metabolism. In this retrospective chart review study, we examine changes in systolic and diastolic blood pressure and treatment for hypertension in clozapine-treated patients. METHOD: Data on demographics and systolic and diastolic blood pressure were examined for up to 5 years (September 1987 to September 1992) in 82 patients treated with clozapine. Rates of hypertension treatment in clozapine-treated patients were compared with patients receiving conventional antipsychotics (N = 56) and other atypical antipsychotic agents (N = 102). RESULTS: The mean age of the 82 patients at the time of clozapine initiation was 36.4 +/- 7.8 years, with 22 (27%) female, 75 (91%) white, 3 (4%) black, 3 (4%) Hispanic, and 1 (1%) Asian. The baseline weight was 175.5 +/- 34.0 lb (79.0 +/- 15.3 kg) and baseline body mass index was 26.9 +/- 5.0 kg/m(2). There was a significant increase in systolic blood pressure (p =.0004) and diastolic blood pressure (p =.0001). Overall, 22 patients (27%) received treatment for hypertension following clozapine initiation. Only 2 (4%) of 56 patients in the conventional antipsychotic group and 9 (9%) of 102 patients in the other atypical antipsychotic group (olanzapine, N = 6; risperidone, N = 3) received treatment for hypertension. CONCLUSION: Our findings suggest that long-term clozapine treatment is associated with increased rates of hypertension, which may have a significant impact on medical morbidity and mortality.

Dietary intake profile of patients with schizophrenia.

BACKGROUND: The increasing prevalence of overweight and obesity has become a priority public health issue in the United States. Forty to 62% of people with schizophrenia are obese or overweight (1, 2). High morbidity and mortality in schizophrenia may be attributed to an unhealthy lifestyle such as poor diet, lack of exercise, smoking, and substance abuse (3). Obesity is associated with greater risk of developing hypertension, type 2 diabetes, coronary heart disease, stroke, death, and reduced quality of life compared with that found in the general population (4, 5). We performed a cross-sectional study evaluating the dietary intake of patients with schizophrenia or schizoaffective disorder treated with atypical antipsychotic agents. METHODS: Dietary intake of 88 patients from an urban community mental health clinic was measured using a four-day dietary record. Nutritional variables included total energy intake, fat, protein, carbohydrate, cholesterol, fiber, sucrose, folate, calcium, sodium, zinc, alcohol and caffeine. Data were compared to the general population using data matched for age, gender, and ethnicity from the National Health and Nutrition Examination Survey (NHANES), 1999-2000. RESULTS: The Body Mass Index (BMI) of the schizophrenia group (M = 31.3, SD = 12.67) was significantly greater than the NHANES group (M = 28.3, SD = 6.62) (p = .001). The schizophrenia group consumed significantly fewer calories, carbohydrate, protein, total fat, saturated fat, monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), fiber, folate, sodium and alcohol and significantly more caffeine than the NHANES group. CONCLUSIONS: The findings may suggest that obesity in schizophrenia patients is not solely related to food consumption, but perhaps other effects including medication side effects and reduced physical activity. Education and interventions for the schizophrenia population should focus more on overall lifestyle factors such as physical activity and healthy food choices.

Modafinil-associated weight loss in a clozapine-treated schizoaffective disorder patient.

BACKGROUND: We report a case of weight loss associated with modafinil-initiation in a clozapine-treated man with schizoaffective disorder. METHODS: To report the impact of modafinil, a wake promoting agent that lacks the unwanted side affects brought on by many psychostimulants, on weight in a clozapine-treated patient. RESULTS: Modafinil was initiated, and over the course of 1 year, Mr. B. experienced a weight loss of 40 lbs (from 280 lbs to 240 lbs) and a reduction in body mass index (BMI) of 5.08 Kg/m2 (from 35.52 Kg/m2 to 30.44 Kg/m2). After 3 years on the combination of clozapine and modafinil, his weight stabilized at 230 lbs (BMI = 29.59 Kg/m2). A 30-lb weight gain over a 6-month period occurred following discontinuation of modafinil. Reinstitution of modafinil resulted in a 10-lb. weight loss over a 6-week period. CONCLUSIONS: Modafinil treatment resulted in a significant weight loss in this patient, possibly due to reducing clozapine-associated fatigue. Randomized placebo-controlled trials are necessary to evaluate the safety and efficacy of modafinilfor clozapine-associated weight gain.