Anthropometric parameters as indicators of metabolic derangements in schizophrenia patients stabilized on olanzapine in an Indian rural population

CONTEXT: For any given body mass, Asian Indians have higher central obesity than Europeans. A periodic measurement of body mass index (BMI) and waist hip ratio (WHR) is practically more feasible than other parameters of metabolic syndrome by repeated blood collection. However, few studies are available on the relative importance of BMI and WHR as markers of dyslipidemia and insulin resistance in schizophrenia patients stabilized on second generation antipsychotics in Indian population. AIM: We conducted the present study on such patients to examine whether BMI or WHR can better predict dyslipidemia and insulin resistance in these patients in a rural area. SETTINGS AND DESIGN: The study was a hospital based case control study under rural settings on 38 schizophrenia patients stabilized on olanzapine and 30 matched controls. MATERIALS AND METHODS: Fasting concentrations of blood glucose, lipid parameters and serum insulin were assessed. Data for Homeostatic model for assessment of insulin resistance (HOMA-IR), BMI, and WHR were obtained to assess the insulin resistance, overall body fat distribution and abdominal fat dispensation respectively. STATISTICAL ANALYSIS USED: ‘t’ test was performed to assay any difference in corresponding mean values between cases and controls. Dependence of HOMA-IR on key parameters was assessed by analysis of co-variance (ANCOVA) study. RESULTS: Cases exhibited significantly higher values for HOMA-IR, serum triglyceride and low density lipoprotein cholesterol (LDLc) with a significantly lower high density lipoprotein cholesterol (HDLc) level. ANCOVA study reflected that irrespective of age and sex, HOMA-IR was dependent on serum triglyceride level and WHR (F=8.3 and 5.7 respectively, P<0.05), but not on BMI (F<0.001, P=0.997). CONCLUSIONS: Central obesity could be more closely associated with the pathogenesis of prediabetic state in our case group. So, WHR is a better anthropometric parameter than BMI for an early assessment of insulin resistance and dyslipidemia in schizophrenia patients stabilized on olanzapine in our region.