Frailty trajectories before and after diabetes: a prospective cohort study in the UK and the US

BACKGROUNDS: Frailty trajectories around diabetes onset remain unclear, particularly across countries. We investigated frailty progression before, during, and after diagnosis in the UK and the US. METHODS: Data were drawn from the English Longitudinal Study of Ageing (2008-2018; n = 8012) and the US Health and Retirement Study (2010-2020; n = 13,072). Frailty was assessed using a 27-item index. Diabetes onset was defined by self-report, medication, or HbA1c ≥6.5%. Trajectories were estimated using linear mixed-effects models, and results were combined via random-effects meta-analysis. RESULTS: Meta-analysis confirmed accelerated progression pre-diagnosis and acute worsening at onset, but no further acceleration afterward (β = 0.0016; 95% CI: -0.0006, 0.0038; P = 0.165). Subgroups showed stronger acute effects in UK men and older US adults, and faster post-diagnosis decline in older participants in both cohorts. CONCLUSION: Incident diabetes is linked to faster frailty progression before and at diagnosis, whereas post-diagnosis trajectories diverged between the UK and US - showing continued acceleration in the UK but largely stable frailty in the US - with no overall evidence of further acceleration in pooled analyses. These findings indicate that diabetes diagnosis is a turning point in the frailty trajectory and highlight the need for stage- and context-specific prevention.