Trends in cause-specific mortality among people with and without diabetes in high-income settings: a multinational, population-based study

Background — Cardiovascular disease has historically been the most common cause of death (COD) among people with and without diabetes. However, substantial progress has been made in the management of cardiovascular disease. We conducted a multinational analysis to establish whether this trend is still the case.

Methods — In this multinational, population-based study, we assembled aggregated annual mortality data collected during routine clinical care from nationally or regionally representative administrative datasets in high-income jurisdictions between 2000 and 2023. For inclusion, datasets must have ongoing enrolment of new patients with diabetes, cause-specific death counts in people with and without diabetes, and sex-specific and age-specific data. We collected population size, counts of prevalent diabetes (type 1 and type 2), death counts, and person-years of follow-up in people with and without diagnosed diabetes by sex and 10-year age group. We estimated cause-specific trends in mortality rates, proportional mortality, and mortality rate ratios (MRR) for people with versus those without diabetes (type 1 and type 2) using Poisson models standardised for age and sex.

Findings — Using data from 11 jurisdictions, we identified 2·7 million deaths in people with diabetes and 11·0 million deaths in people without diabetes during a total of 1·7 billion person-years of follow-up. Cardiovascular disease mortality decreased in all jurisdictions in populations with and without diabetes. Mean 5-year declines in cardiovascular disease mortality among people with diabetes ranged from 8·3% (95% CI 5·9 to 10·7) to 25·4% (22·8 to 28·0). Mortality due to diabetes declined in most jurisdictions. Dementia mortality increased in people with and without diabetes in six (86%) of seven jurisdictions. Cancer mortality declined in people with diabetes in three (33%) of nine jurisdictions and in people without diabetes in six (67%). At the end of the observation period, cancer was the leading COD in people with diabetes in four (36%) of 11 jurisdictions. MRRs were generally stable for all CODs. Exceptions include Lithuania, where the mean 5-year change in MRR for cardiovascular disease was –7·6% (–10·1 to –5·1), indicating a more rapid fall in cardiovascular disease mortality in people with diabetes than in people without. For dementia, the MRR increased in Denmark (5-year change 8·0% [5·0 to 11·1]) and Scotland (11·4% [8·5 to 14·3]).

Interpretation — Mortality from cardiovascular disease and diabetes has declined among people with diabetes in most jurisdictions, whereas mortality from dementia has increased markedly, independent of age. Cardiovascular disease is no longer universally the most common COD among people with diabetes in high-income countries.