Frailty is a dynamic state of vulnerability in the elderly. We examined whether individuals with overt diabetes or higher levels of HbA 1c or fasting plasma glucose (FG) experience different frailty trajectories with aging. RESEARCH DESIGN AND METHODS Diabetes, HbA 1c , and FG were assessed at baseline, and frailty status was evaluated with a 36-item frailty index every 2 years during a 10-year follow-up among participants from the English Longitudinal Study of Ageing (ELSA). Mixed-effects models with age as time scale were used to assess whether age trajectories of frailty differed as a function of diabetes, HbA 1c , and FG. RESULTS Among 5,377 participants (median age [interquartile range] 70 [65, 77] years, 45% men), 35% were frail at baseline. In a model adjusted for sex, participants with baseline diabetes had an increased frailty index over aging compared with those without diabetes. Similar findings were observed with higher levels of HbA 1c , while FG was not associated with frailty. In a model additionally adjusted for income, social class, smoking, alcohol, and hemoglobin, only diabetes was associated with an increased frailty index. Among nonfrail participants at baseline, both diabetes and HbA 1c level were associated with a higher increased frailty index over time. CONCLUSIONS People with diabetes or higher HbA 1c levels at baseline had a higher frailty level throughout later life. Nonfrail participants with diabetes or higher HbA 1c also experienced more rapid deterioration of frailty level with aging. This observation could reflect a role of diabetes complications in frailty trajectories or earlier shared determinants that contribute to diabetes and frailty risk in later life. Life expectancy is increasing worldwide. However, the aging process is heterogeneous with a large interindividual variability in health status and disability (1). This heterogeneity in aging can also affect people with diabetes, who are also living longer than before. Although the age-specific prevalence of diabetic complications is lower now than in the past, the cumulative lifetime prevalence of complications in older adults with diabetes and the co-occurrence of multiple medical conditions are higher (2).