Cardiovascular outcomes and mortality risk at diagnosis of type 2 diabetes in older adults: a retrospective population-based study using health records from Spain
TL;DR
Diabetes-associated relative excess risks for cardiovascular outcomes and mortality differed by age at first recorded type 2 diabetes diagnosis, with lower relative excess risks among those diagnosed at older ages, however, absolute cardiovascular and mortality burdens remained substantial in older adults.
Abstract
Summary Background Older-onset diabetes is often accompanied by multimorbidity, frailty, and variable metabolic profiles that complicate treatment decisions and alter risk-benefit considerations. Emerging evidence suggests that age at diagnosis is a major determinant of prognosis, with younger-onset cases showing higher lifetime risks of vascular complications. However, the prognostic implications of diabetes first diagnosed at older ages remain insufficiently characterised, particularly within Mediterranean populations. We investigated cardiovascular and mortality risks associated with type 2 diabetes diagnosed at older ages in Catalonia, Spain. Methods We conducted a retrospective, population-based study using electronic health records from primary care centres in Catalonia, Northeast Spain. Data were collected from 1 January 2010 to 30 June 2023. We included adult participants with newly recorded type 2 diabetes between 1 January 2010 and 31 December 2021 and excluded individuals with other types of diabetes or sustained insulin monotherapy during the first year after diagnosis. Individuals with type 2 diabetes were stratified by age at diagnosis (<65 vs ≥65 years), with follow-up for up to 10 years. Sex- and birth year-matched individuals without diabetes were included at a 1:3 ratio. Outcomes were cardiovascular events and all-cause mortality. Cox regression models were used to estimate hazard ratios and relative hazard ratios (RHRs), with sex-stratified analyses. Findings Among 481,709 individuals with type 2 diabetes, 241,472 were diagnosed between ages 18 and 64 years and 240,237 at age ≥65 years. These individuals were matched with 1,398,836 individuals without diabetes. At 10 years, individuals diagnosed before age 65 had higher diabetes-associated excess risk of heart failure than those diagnosed at age ≥65 years (RHR 1.18, 95% CI: 1.10–1.26). Within the older-onset population, individuals diagnosed at age 65–74 years had higher 10-year diabetes-associated excess risks than those diagnosed at age ≥75 years for ischaemic heart disease (RHR 1.14, 95% CI: 1.07–1.20), heart failure (RHR 1.20, 95% CI: 1.14–1.26), and all-cause mortality (RHR 1.16, 95% CI: 1.11–1.20). Interpretation Diabetes-associated relative excess risks for cardiovascular outcomes and mortality differed by age at first recorded type 2 diabetes diagnosis, with lower relative excess risks among those diagnosed at older ages. However, absolute cardiovascular and mortality burdens remained substantial in older adults. These findings should be interpreted as prognostic associations based on routine clinical recognition of diabetes rather than biological onset, and they support age-informed, but individualised, cardiovascular prevention rather than treatment decisions based on chronological age alone. Future research should clarify the mechanisms underlying age-specific differences in diabetes-associated cardiovascular and mortality risk, and determine how these findings can inform individualised prevention strategies for older adults. Funding This research received financial support from the Instituto de Salud Carlos III, Ministry of Health, and by the Catalan Agency for Management of University and Research Grants (AGAUR, Generalitat de Catalunya), under the consolidated research group DAP.cat.group. This research was also supported by the Consorcio Centro de Investigación Biomédica en Red (CIBER), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea—European Regional Development Fund.