Glycemia control in older diabetic adults is complicated by uncertainty regarding how intensive glycemic control should be, particularly in those with frailty. This study investigated the association between HbA1c levels and all-cause mortality, assessing the modifying effect of frailty. This retrospective study used Hong Kong hospitalization data (2012–2021) for older adults. Patients with first-recorded diabetes during 2014–2020 were classified as index cases. Frailty was evaluated using the Hospital Frailty Risk Score (HFRS), derived from two years of hospitalization diagnoses before the index diabetes and categorized as follows: no (HFRS = 0), mild (HFRS <5), and moderate andsevere frailty (HFRS ≥5). Glycemic control was assessed via time-weighted mean HbA1c and early variability of the first three measurements. The relationship between HbA1c, variability, and mortality was examined using multivariable Cox regression, with nonlinear relationships modeled via restricted cubic splines. A J-shaped curve was observed for HbA1c-mortality association (p-nonlinearity <0.001), with increased risk at low/high extremes, significantly influenced by frailty (p-interaction <0.001). In non-frail patients, lower mortality was noted across an HbA1c range of 5.4%–10.5%, with a minimum at 7.8% (HR = 0.59, 95% CI: 0.56–0.61). For those with moderate andsevere frailty, the safety zone narrowed to 6.1%–9.3%, with a nadir at 7.7% (HR = 0.73, 95% CI: 0.68–0.79). Early glycemic variability significantly affected mortality risk only in non-frail individuals. Frailty alters the mortality risk associated with glycemic control, highlighting the need for frailty-stratified management strategies in older diabetic adults to optimize health outcomes.
Yu et al. (Thu,) studied this question.