Mortality patterns in Dutch diabetes outpatients

Diabetes mellitus is a major cause of death. Outpatients with diabetes have more complications than patients in general practice; mortality patterns have only been studied in the total diabetes population. This study aims to assess mortality, causes, and predictors in outpatients with diabetes.

A cohort study, included people with diabetes mellitus from the nationwide Dutch Paediatric and Adult Registry of Diabetes (DPARD) visiting diabetes outpatient clinics in 2016-2020. DPARD data were linked to Statistics Netherlands (CBS), comprising data on mortality, ethnicity and education. All-cause and cardiovascular mortality rates were estimated using Cox proportional hazard regression.

During a median follow-up of 3.1 years among 12 992 people with diabetes, mortality rates per 10 000 person-years were 67.7 in adult type 1 diabetes and 324.2 in type 2 diabetes. The major cause of non-cardiovascular death was malignancy. During the pandemic years of influenza (2018) and COVID (2020), mortality rates peaked. Age, smoking and an estimated glomerular filtration rate of <60 ml/min were associated with all-cause mortality. In type 2 diabetes, additional factors were male sex, body mass index <20 kg/m², diabetes duration <1 year and hypertension.

Mortality among Dutch outpatients with diabetes is high. Smoking and renal failure were associated with mortality in both types. Further focus on early detection and treatment of mortality-associated factors may improve clinical outcomes.