Physical risks in Japanese patients with schizophrenia: Current status in Japan

Abstract

Different reviews and studies have shown that patients with schizophrenia have an excess mortality, being 2 or 3 times as high as that in the general population. This mortality gap, which translates to about 15 year shortened life expectancy, has widened in recent decades. A higher prevalence of MetS is considered as one of the reason for this mortality gap. Patients with schizophrenia have a higher risk of metabolic syndrome (MetS). MetS prevalence varies with ethnicity. Although environmental factors, such as lack of physical activity and unbalanced diet, can lead to MetS, these may differ between outpatients and inpatients with schizophrenia. Moreover, several studies have reported that being underweight is a recognised health risk, and some studies have reported increased mortality with weight loss. Therefore, Japanese inpatients with schizophrenia may have higher mortality risk due to underweight compared with the general population. The Japanese mental health care system differs from that in other countries. Therefore, we conducted a nationwide survey to clarify the prevalence of MetS and underweight and under-nutrition in Japanese outpatients and inpatients with schizophrenia.

　We investigated the risk of MetS and underweight by questionnaire, and there were 7655 outpatients and 15461 inpatients with schizophrenia. The result revealed that MetS prevalence in Japanese outpatients was approximately 3-fold higher than in inpatients. On the other hand, the prevalence of underweight and under-nutrition in Japanese inpatients with schizophrenia was higher than in outpatients and the general population. The results also suggest that the difference in physical health between outpatients and inpatients with schizophrenia may be related to the mental health system in Japan. We should pay more attention to the risk of physical disease in Japanese patients with schizophrenia, considering the difference in health characteristics between outpatients and inpatients in clinical practice.