The metabolic syndrome in untreated schizophrenia patients: prevalence and putative mechanisms.

The Metabolic Syndrome (MetS) is a constellation of commonly coexisting clinical markers. It is well established that MetS is more prevalent in schizophrenic (SCZ) patients medicated with atypical antipsychotics, however, questions still exist over whether schizophrenia itself can contribute directly to metabolic dysfunction. We evaluated the antipsychotic-independent link between MetS and schizophrenia, by conducting a systematic literature search. Twelve papers were identified, from which 893 patients were evaluated. The mean prevalence of MetS was 10.8%, suggesting its incidence is not increased. However, some aspects of MetS may be increased, such as diabetes. Hypothalamic-pituitary axis dysfunction, sympathetic nervous system dysfunction, proinflammatory states and several genetic mutations have been implicated in the observed metabolic dysregulation in schizophrenic patients, however much controversy exists in this area. The huge cardiovascular burden makes it crucial to establish the causes and optimal management of MetS in schizophrenia.