16-year excess all-cause mortality of newly diagnosed type 2 diabetic patients: a cohort study

BACKGROUND Studies have shown that type 2 diabetic patients have higher all-cause mortality than people without diabetes, but it is less clear how diabetes affects mortality in elderly patients and to what degree mortality differs between diabetic men and women. The aim of the present study is to investigate the age- and sex-specific all-cause mortality pattern in patients with type 2 diabetes in comparison with the Danish background population. METHODS Population-based cohort study of 1323 patients, diagnosed with clinical type 2 diabetes in 1989-92 and followed for 16 years. Median (interquartile range) age at diagnosis was 65.3 (55.8-73.6) years. The age- and sex-specific hazard rates were estimated for the cohort using the life table method and compared with the expected hazard rates calculated with Danish register data from the general population. RESULTS In comparison with the general population, diabetic patients had a 1.5-2.5 fold higher risk of dying depending on age. The over-mortality was higher for men than for women. It decreased with age in both sexes, and among patients over 80 years at diagnosis the difference between the observed and the expected survival was small. CONCLUSION We found an excess mortality of type 2 diabetic patients compared with the background population in all age groups. The excess mortality was most pronounced in men and in young patients.