Objectives: To study, prospectively, in young adult patients, the mortality during the first years after the diagnosis of diabetes.
Design: The Diabetes Incidence Study in Sweden (DISS) aims to register all incident cases aged 15-34 years. During a 10-year period all deaths were identified by record linkage to the national Cause of Death Registry.
Subjects: During the period, 4097 new cases were registered and classified as type 1 diabetes (73%), type 2 (16%), secondary (2%) and unclassified (9%). The median follow-up was 5 years (21 001 person-years).
Main outcome measures: Calculation of the standardized mortality ratio (SMR) and 95% confidence interval (CI). Evaluation of all deceased by scrutiny of clinical records, death certificates and autopsy protocols.
Results: Fifty-eight patients died, corresponding to an SMR of 3.5 (CI=2.7-4.5), which increased from 1.5 at 15-19 years to 4.1 at 30-34 years. SMR was 2.7 in primary diabetes: 2.3 (1.6-3.3) in type 1 and 4.1 (2.6-6.7) in type 2. In secondary diabetes, alcohol-associated pancreatitis a common cause, SMR was 32 (CI=24-45). Evidence of alcohol or drug misuse, mental dysfunction or suicide was found in 40 of all 58 deceased cases. Less often, hypoglycaemia (n=7) or hyperglycaemia-ketoacidosis (n=11) was present at death. Unexplained 'dead in bed' was found once.
Conclusions: In the investigated population-based cohort the early mortality was about threefold increased. Hypoglycaemia and ketoacidosis per se played a relatively small role compared with a heavy impact from social and mental dysfunction, and from careless use of alcohol or drugs.