New onset diabetes in adulthood is associated with a substantial risk for mortality at all ages: a population based historical cohort study with a decade-long follow-up.

BACKGROUND: Diabetes has been reported to be associated with an increased relative risk for mortality, with estimates ranging from 1.1 to 2.1. Findings are inconsistent regarding modification of the risk by gender and by age. The aim of this study was to estimate the mortality risk associated with new-onset diabetes in adulthood, by age group and gender.

METHODS: From the database of a large health care provider, we identified 31,987 individuals diagnosed with diabetes during 2003-2005; and 162,656 individuals without diabetes, group-matched by age. We used Cox regression to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall mortality adjusted for age, gender, socioeconomic (SE) level, obesity, smoking and comorbidities at baseline.

RESULTS: During a median follow-up of 9.5 years, 4464 (14%) of persons with diabetes and 13,327 (8.2%) of those without died. Among persons with incident diabetes, the proportion of men, smokers, obese and patients of low SE level was higher, as was the prevalence of cardiovascular disease and renal impairment at baseline. Incident diabetes was associated with an adjusted HR for mortality of 1.38 (95% CI 1.32-1.43). Mortality HR for DM was comparable with hypertension (1.42; 1.37-1.46), smoking (1.65; 1.58-1.71) and atherosclerosis (1.40; 1.35-1.46). Diabetes associated mortality HR was somewhat higher among women 1.78 (95% CI 1.58-2.08) as compared with men 1.51 (95% CI 1.41-1.62).

CONCLUSIONS: Incident diabetes in adults is associated with a substantial risk for mortality, especially in younger adults. Further efforts should be allocated to diabetes primary prevention.