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

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.

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.

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.

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.