Globally, the prevalence of type 2 diabetes is increasing, with 537 million adults estimated to have diabetes in 2021. There is an increasing trend for a lower age at type 2 diabetes diagnosis and, although previous work has estimated that adults with type 2 diabetes die on average six years younger than their counterparts, studies were not sufficiently powered to analyse age at diagnosis.

This study by the Emerging Risk Factors Collaboration aimed to estimate the associations of age at type 2 diabetes diagnosis with all-cause mortality, cause-specific mortality and reductions in life expectancy, in high income countries. Individual records were analysed from 97 long term, prospective, UK, EU, Canadian and USA cohorts, with 1,515,718 participants followed up for a total of 23.1 million person-years. 

They found a steep linear dose–response association between earlier age at diagnosis of diabetes and higher risk of all-cause mortality, with every decade of earlier diabetes diagnosis associated with a reduction in life expectancy of approximately 3–4 years. Interestingly, this reduction in life expectancy associated with diabetes was slightly greater for women than for men. 

Read the full article in Lancet Diabetes & Endocrinology 11 731–742