Diabetes treatment in people with type 2 diabetes and schizophrenia: Retrospective primary care database analyses

Aim of this study were to compare outcomes (HbA1c, BMI) and antidiabetic treatment of type 2 diabetes patients with and without schizophrenia under real-life conditions in primary care practices in Germany.

1321 type 2 diabetes patients with and 1321 matched controls (age, sex, diabetes duration, diabetologist care, practice) without schizophrenia in 1072 general practices throughout Germany were retrospectively analyzed (Disease Analyser: 01/2009-12/2013). Antidiabetic treatment, HbA1c and BMI were compared using paired t-tests, McNemar tests and conditional logistic regression adjusting for macro- and microvascular comorbidity (ICD-10).

Mean age (±SD) of patients and controls was 67.4±13.2 years (males: 38.9%). Diabetes duration was 5.7±4.3 years, 6% were in diabetologist care. Private health insurance was less often found among patients with schizophrenia than controls (2.2% vs 6.3%; p<0.0001). There was no difference in the mean HbA1c values (cases: 7.1±1.4%; controls: 7.2±1.5%) (54.1 vs. 55.2 mmol/mol) (p=0.8797) and in the average BMI (32.4±6.6 vs. 31.0±5.0 kg/m(2); p=0.2072) between the two groups. Novel cost-intensive antidiabetic agents (DPP-4- or SGLT2-inhibitors, GLP-1 receptor agonists) were less often prescribed in cases (15.3 vs. 18.3%; p=0.0423). However, in multivariable logistic regression, schizophrenia (odds ratio, 95%CI: 1.101; 0.923-1.317) was not associated with prescription use of novel antidiabetic agents (reference: other antidiabetic agents) after adjusting for private health insurance (OR: 2.139; 1.441-3.177) and comorbidity.

There is no evidence that type 2 diabetes patients with schizophrenia have worse diabetes control than those without a severe mental illness in general practices.