High Prevalence of Obesity, Hypertension, Hyperlipidemia, and Diabetes Mellitus in Japanese Outpatients with Schizophrenia: A Nationwide Survey

BACKGROUND Patients with schizophrenia have significantly shorter life expectancy than the general population, and a problem they commonly face is an unhealthy lifestyle, which can lead to obesity and metabolic syndrome. There is a very clear need to determine the prevalence of obesity, hypertension, hyperlipidemia, and diabetes mellitus which are components of metabolic syndrome in patients with schizophrenia, but there has been a paucity of large-scale studies examining this situation in Japan. The aim of our study was to address this need. SETTING & PARTICIPANTS We conducted a large-scale investigation of the prevalence of obesity, hypertension, hyperlipidemia, and diabetes mellitus using a questionnaire in 520 outpatient facilities and 247 inpatient facilities of the Japan Psychiatric Hospitals Association between January 2012 and July 2013. There were 7,655 outpatients and 15,461 inpatients with schizophrenia. RESULTS The outpatients had significantly higher prevalence of obesity, hypertension, hypertriglyceridemia, hyper-LDL cholesterolemia, and diabetes mellitus than the inpatients. The prevalence of hypo-HDL cholesterolemia was higher in inpatients than outpatients. Age-specific analysis showed the prevalence of obesity, hypertension, hypertriglyceridemia, hyper-LDL cholesterolemia, and diabetes mellitus among outpatients to be 2- to 3-fold higher than among inpatients. In individuals aged ≥60 years, the prevalence of obesity and DM among outpatients was about 3-fold higher than among inpatients. CONCLUSION Japanese outpatients with schizophrenia were more likely to have physical risk such as obesity, hypertension, hyperlipidemia, and diabetes mellitus than inpatients. The physical risk to patients with schizophrenia may be affected by environmental parameters, such as type of care. The physical risk to Japanese patients with schizophrenia demands greater attention.