Visceral adipose tissue in patients with severe mental illness

Severe mental illnesses (SMIs), i.e. major depression, schizophrenia and bipolar disorder, are associated with an elevated risk for the development of type-2 diabetes mellitus and cardiovascular disorders. Several factors have been associated with increased cardiometabolic morbidity and mortality in SMI, including lifestyle factors (smoking, inactivity, unhealthy diet), endocrine and immunologic alterations; however, the underlying mechanisms remain to be fully uncovered. It is now well accepted that visceral adipose tissue (VAT) promotes the development of cardiometabolic disorders, at least in part by inflammatory and metabolic functions. This paper reviews studies concerning VAT, with special focus on intra-abdominal and pericardial adipose tissue, in SMI. In patients with SMI, several studies have been performed concerning VAT. Most of these studies reported alterations of VAT particularly in patients with major depression and schizophrenia, independent of body weight and body mass index. Some of the studies also reported an increased cardiometabolic risk. Patients with SMI are at increased risk of developing cardiometabolic disorders, and display increased amounts of VAT. As studies so far were mainly performed on patients before the onset of cardiometabolic disorders, VAT may serve as a biomarker for patients with SMI to assess cardiometabolic risks beyond established risk scores. Further, interventions aiming at reducing VAT in SMI are highly recommended in long-term multimodal treatment plans.