Meta-analysis of comorbid diabetes and family history of diabetes in non-affective psychosis

Objective: Schizophrenia and other non-affective psychoses (NAP) are associated with an increased prevalence of both type 2 diabetes (DM2) as well as a family history of DM2. We performed a systematic review and meta-analysis of the association between comorbid DM2 and a family history of DM2 in patients with NAP. Method: We searched major electronic databases from inception until August 2018 for studies of comorbid DM2 in patients with non-affective psychosis and family history of DM2 status. Random effects meta-analysis calculating odds ratios (ORs) and 95% confidence intervals (CI) and meta-regression analyses were performed. Results: Ten studies met the inclusion criteria. Across these studies, there were 804 patients with non-affective psychosis and comorbid DM2, and 2976 patients with non-affective psychosis without this comorbidity. A family history of DM2 was associated with an over four-fold increased odds of comorbid DM2 in patients with NAP (OR = 4.3, 95% CI 2.9-6.4, p<0.001). In; meta-regression analyses older age, but not sex, BMI, geographic region, study quality, or year; of publication moderated the association between comorbid DM2 and family history of DM2. Conclusion: We found that a family history of DM2 was associated with an over four-fold increased odds of comorbid DM2 in patients with NAP. This association may be due to shared environmental or genetic risk factors, or gene-environment interactions. Given the increased risk of incident diabetes with antipsychotic treatment, screening for a family history of DM2 is germane to the clinical care of patients with NAP.