Dysglycemia in a Community Sample of People Treated for Schizophrenia: the Diabetes in Schizophrenia in Central-South Ontario (DiSCO) Study

Objective: Despite increasing recognition of schizophrenia as a risk factor for diabetes, the prevalence and correlates of dysglycemia in people with schizophrenia have not been adequately studied. Discerning the modifiable risk factors is crucial for developing diabetes prevention strategies in schizophrenia.

Methods: Socio-demographic, clinical and recent laboratory data were compiled from the case records and supplemental sources of 1123 people treated for schizophrenia who were living across five different communities in the region.

Results: Screening rates for fasting plasma glucose (FPG) varied between 63-100% across the five communities, while other metabolic indices were monitored less frequently. 39 subjects (3.5%) in the sample had an existing diagnosis of type 2 diabetes. Among the others, 845 (78%) had FPG measured in the preceding 6 months, with the following results: FPG < or = 5.6 mmol/l in 474 (56%), 5.6-6.9 mmol/l in 268 (31%), and > or = 7 mmol/l in 103 (12.2%) subjects. Dysglycemia (FPG > or = 5.6 mmol/l) was significantly associated with older age (odds ratio [OR] 1.031), longer duration of schizophrenia (OR 1.062), self reported family history of diabetes (OR 8.87), body mass index (OR 1.081), excess weight (OR 1.014) and independent living status (OR 1.779), while European ethnicity (OR 0.706) and regular physical activity (OR 0.958) lowered the risk. No statistically significant correlations were noted with gender, level of education or functioning, or the type of antipsychotic drug prescribed.

Conclusions: There was a two-fold increase in the prevalence of dysglycemia, while there was a substantial under-recognition of and intervention for, diabetes and pre-diabetes in this sample of people treated for schizophrenia.