Obesity and Associated Complications in Patients With Severe Mental Illnesses: A Cross-Sectional Survey

Margaret T. Susce, R.N., M.L.T.; Noemi Villanueva, Pharm.D.; Francisco J. Diaz, Ph.D.; and Jose de Leon, M.D.

Background: This naturalistic cross-sectional survey of patients with severe mental illnesses explores the association between important variables and obesity, extreme obesity, diabetes mellitus type 2, hypertension, and hyperlipidemia in the clinical environment.

Method: Weight and height were obtained from 560 patients with severe mental illnesses (including DSM-IV schizophrenia, schizoaffective disorder, bipolar disorder, and major depressive disorder) at central Kentucky inpatient and outpatient facilities to estimate their body mass index (BMI). Chart diagnoses of diabetes mellitus, hypertension, and hyperlipidemia were obtained.

Results: When comparing the patients with severe mental illnesses with Kentucky adults from the general population, the odds ratio (OR) of obesity (BMI >= 30 kg/m²) was 2.6 (95% confidence interval [CI] = 2.2 to 3.0), and the OR of diabetes mellitus was 2.9 (95% CI = 2.3 to 3.6). Female gender, African American race, early start of psychiatric medication, and long psychiatric medication duration were significantly associated with obesity. Current alcohol and nicotine use exhibited significant ORs of obesity lower than 1, particularly in males. Obesity was closely associated with hypertension, type 2 diabetes mellitus, and hyperlipidemia. These complications were closely associated with each other and may indicate a further progression of obesity after aging.

Conclusions: These results suggest a complex pattern of variables that may influence the development of obesity and its complications in patients with severe mental illnesses, but they need replication. The major factors associated with obesity appear to be a long-term illness or treatment duration and substance use. The former may be more important in females, while the latter may be more important in males. Clinical diagnoses (schizophrenic or mood disorders) or current treatment did not appear to be fundamental factors.

(J Clin Psychiatry 2005;66:167-173)

Received April 8, 2004; accepted July 15, 2004. From the University of Kentucky Mental Health Research Center at Eastern State Hospital, Lexington, Ky. (Ms. Susce and Drs. Villanueva and de Leon), and the Department of Statistics, Universidad Nacional, Medellin, Colombia (Dr. Diaz).

These analyses were conducted without external funding support. The subject recruitment for this sample was conducted for a pharmacogenetic risperidone study that was supported by several sources: a research-initiated grant from the Eli Lilly Research Foundation (to Dr. de Leon; 24% of direct costs), a National Alliance for Research on Schizophrenia and Depression (NARSAD) Independent Award (to Dr. de Leon; 11% of direct costs), and internal funding (37% of direct costs). Roche Molecular Systems, Inc. provided free genotyping and laboratory supplies (equivalent to 28% of direct costs).

In the past 2 years, Dr. de Leon has been on the advisory board of Bristol-Myers Squibb and AstraZeneca, has received a research-initiated grant from Roche Molecular Systems, Inc., and has lectured once supported by Eli Lilly.

Corresponding author and reprints: Jose de Leon, M.D., University of Kentucky Mental Health Research Center at Eastern State Hospital, 627 West Fourth St., Lexington, KY 40508 (e-mail: jdeleon@uky.edu).