Severe Mental Illness and Type 2 Diabetes Outcomes and Complications: A Nationwide Cohort Study.

OBJECTIVE: To compare cardiovascular and mortality outcomes in people with severe mental illness (SMI) versus no mental illness in a national cohort study of people with type 2 diabetes. RESEARCH DESIGN AND METHODS: We included adults diagnosed with type 2 diabetes between 2004 and 2018 from the national Scottish diabetes register, ascertaining history of mental illness from linked psychiatric and general hospital admission records. We identified major cardiovascular disease (CVD) events, all-cause mortality, and CVD-specific mortality through record linkage. Using Cox regression, we estimated hazard ratios (HRs) for associations between SMI and outcomes, adjusting for baseline sociodemographic and clinical characteristics, including history of CVD, comorbidity, hypertension, high cholesterol, HbA1c, BMI, alcohol use disorder, and smoking. RESULTS: Among 259,875 people with type 2 diabetes, 1.0%, 0.5%, and 3.0% had schizophrenia, bipolar disorder, and major depression, respectively. After adjusting for sociodemographic characteristics, the risk of major CVD events was higher in people with schizophrenia (HR 1.22, 95% CI 1.06-1.41), bipolar disorder (HR 1.58, 95% CI 1.33-1.87), and major depression (HR 1.59, 95% CI 1.49-1.70) compared with people without a history of mental illness. SMI was also associated with an approximately twofold increased risk of CVD-specific and all-cause mortality. All associations attenuated following further adjustment for clinical characteristics. CONCLUSIONS: Among people with diabetes, people with a history of SMI have poorer cardiovascular and mortality outcomes compared with those without mental illness. While the underlying mechanisms are further investigated, effective prevention and management of cardiovascular risk factors is needed in this high-risk group.

Severe mental illness and quality of care for type 2 diabetes: A retrospective population-based cohort study.

AIMS: To compare quality of care for type 2 diabetes in people with severe mental illness (SMI) versus no mental illness. METHODS: We used routinely collected linked data to create a retrospective cohort study. We included 158,901 people diagnosed with type 2 diabetes in Scotland during 2009-2018 of whom 1701 (1%), 768 (0.5%) and 5211 (3%) had a prior hospital admission record for schizophrenia, bipolar disorder, and major depression, respectively. We compared recording of HbA1c, cholesterol, creatinine, blood pressure, urinary albumin, foot examination, retinopathy screening, body mass index and smoking during the first year after diabetes diagnosis using logistic regression and recording of HbA1c and retinopathy screening over longer follow-up using generalised linear mixed effects model, adjusting for confounding factors. RESULTS: Receipt of care during the first year was generally similar, or better, for people with each SMI than for people without any mental illness. During mean follow up of 4.8 (SD 2.5) years, depression and bipolar disorder were associated with lower odds of receiving retinopathy screening. CONCLUSIONS: Receipt of diabetes care was similar or better among people with SMI versus without SMI. However, mechanisms to support improved retinopathy screening for people with SMI are needed.