Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Aug 15, 2017; 8(8): 390-396
Published online Aug 15, 2017. doi: 10.4239/wjd.v8.i8.390
Prevalence of obesity and diabetes in patients with schizophrenia
Aniyizhai Annamalai, Urska Kosir, Cenk Tek
Aniyizhai Annamalai, Urska Kosir, Cenk Tek, Department of Psychiatry, Yale School of Medicine, New Haven, CT 06519, United States
Author contributions: Annamalai A contributed data and wrote the manuscript; Kosir U analyzed data; Tek C designed and performed the research, analyzed data and contributed to and reviewed the entire manuscript.
Supported by National Institute of Diabetes and Digestive and Kidney Diseases, No. R01DK093924.
Institutional review board statement: The study was reviewed and approved by the Yale Human Investigations Committee.
Informed consent statement: Consent was not obtained as the study did not involve any clinical intervention. All presented data are de-identified.
Conflict-of-interest statement: None of the authors have any conflict of interest to report.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Aniyizhai Annamalai, MD, Assistant Professor, Department of Psychiatry, Yale School of Medicine, 333 Cedar St, New Haven, CT 06519, United states.
Telephone: +1-203-9747497 Fax: +1-203-9747322
Received: October 29, 2016
Peer-review started: November 3, 2016
First decision: February 15, 2017
Revised: March 12, 2017
Accepted: April 18, 2017
Article in press: April 19, 2017
Published online: August 15, 2017

To compare the prevalence of diabetes in patients with schizophrenia treated at a community mental health center with controls in the same metropolitan area and to examine the effect of antipsychotic exposure on diabetes prevalence in schizophrenia patients.


The study was a comprehensive chart review of psychiatric notes of patients with schizophrenia and schizoaffective disorder treated at a psychosis program in a community mental health center. Data collected included psychiatric diagnoses, diabetes mellitus diagnosis, medications, allergies, primary care status, height, weight, body mass index (BMI), substance use and mental status exam. Local population data was downloaded from the Centers for Disease Control Behavioral Risk Factor Surveillance System. Statistical methods used were χ2 test, Student’s t test, general linear model procedure and binary logistic regression analysis.


The study sample included 326 patients with schizophrenia and 1899 subjects in the population control group. Demographic data showed control group was on average 7.6 years older (P = 0.000), more Caucasians (78.7% vs 38.3%, P = 0.000), and lower percentage of males (40.7% vs 58.3%, P = 0.000). Patients with schizophrenia had a higher average BMI than the subjects in the population control (32.11, SD = 7.72 vs 27.62, SD = 5.93, P = 0.000). Patients with schizophrenia had a significantly higher percentage of obesity (58.5% vs 27%, P = 0.000) than the population group. The patients with schizophrenia also had a much higher rate of diabetes compared to population control (23.9% vs 12.2%, P = 0.000). After controlling for age sex, and race, having schizophrenia was still associated with increased risk for both obesity (OR = 3.25, P = 0.000) and diabetes (OR = 2.42, P = 0.000). The increased risk for diabetes remained even after controlling for obesity (OR = 1.82, P = 0.001). There was no difference in the distribution of antipsychotic dosage, second generation antipsychotic use or multiple antipsychotic use within different BMI categories or with diabetes status in the schizophrenia group.


This study demonstrates the high prevalence of obesity and diabetes in schizophrenia patients and indicates that antipsychotics may not be the only contributor to this risk.

Keywords: Schizophrenia, Antipsychotic, Diabetes, Body mass index, Obesity

Core tip: This study compares obesity and diabetes rates between schizophrenia patients treated in a community mental health center and a local population control. It demonstrates that prevalence of obesity and diabetes is significantly higher in patients with schizophrenia, which is consistent with previous research. In this cross-sectional study, second generation antipsychotic use and antipsychotic dosage were not correlated with obesity categories or diabetes status. This implies that antipsychotics alone may not be responsible for the increased diabetes risk in schizophrenia patients. Many factors may contribute to risk, including an inherent vulnerability to diabetes in schizophrenia patients that has been seen in earlier studies.