Abstract
OBJECTIVE: Hypertensive patients are prone to frailty, but the exact link between them remains unclear. This study aims to evaluate the HbA1c glycated index (HGI) as a biomarker for frailty and mortality in hypertensive patients. METHODS: 1773 hypertensive participants were included in the CHARLS database. HGI was calculated as measured HbA1c minus predicted HbA1c. Associations with frailty and mortality were evaluated via multivariable logistic regression, Cox regression, mediation analysis, and threshold detection. RESULTS: HGI was independently associated with frailty (adjusted OR = 1.28, 95% CI:1.03-1.60), with diabetes mediating 27.8% of this association. It also showed a U-shaped relationship with all-cause mortality (inflection point: HGI=-0.15). In the overall hypertensive population, when HGI ≥ -0.15, there is no significant association between HGI and mortality risk (adjusted HR = 1.17, 95% CI: 0.92-1.50). But in the frailty subgroup with HGI ≥-0.15, per 1-unit HGI increase 60% higher mortality risk (HR = 1.60, 95% CI:1.11-2.32). For HGI <-0.15, higher HGI was linked to lower mortality (adjusted HR = 0.68, 95% CI:0.49-0.95), with a similar trend in the frailty subgroup (adjusted HR = 0.36, 95% CI:0.13-0.97). CONCLUSION: This study demonstrates that the HGI serves as a biomarker for both frailty and mortality in hypertensive patients. Elevated HGI is associated with increased frailty risk, while its U-shaped relationship with all-cause mortality highlights critical implications for risk stratification.