Abstract
OBJECTIVE: To investigate the association between 24-h minimum heart rate (MHR) and deceleration capacity (DC) in patients with type 2 diabetes mellitus (T2DM) and essential hypertension (EH) and to explore DC differences across sex-stratified MHR categories. METHODS: In this single-center cross-sectional study, 123 patients with T2DM and EH were stratified by sex-specific 24-h MHR thresholds (reduced/normal/elevated) based on previous studies. DC and heart rate variability (HRV) indices were derived from 24-h Holter recordings. Bivariate correlation analysis was performed to examine the relationship between MHR and DC. Subsequently, multiple linear regression analysis was conducted with DC as the dependent variable to identify independent predictors of DC. Demographics, HRV indices, echocardiographic parameters, and laboratory findings were included as independent variables. Subgroup analyses stratified by sex and MHR categories were also performed. RESULTS: MHR showed a significant negative correlation with DC (r = -0.484, p < 0.001). Stepwise multiple linear regression identified age (β = -0.264, p < 0.001), MHR (β = -0.320, p = 0.001), and SDNN_INDX (β = 0.316, p = 0.001) as independent DC predictors. Sex-MHR subgroup analysis revealed: In Group B (normal MHR), age predicted reduced DC in both sexes (males: β = -0.375, p = 0.041; females: β = -0.612, p = 0.009). In Group C (elevated MHR), SDNN_INDX correlated with higher DC in both sexes (males: β = 0.363, p = 0.027; females: β = 0.808, p < 0.001). MHR negatively impacted DC only in males with elevated MHR (β = -0.386, p = 0.019). CONCLUSION: Age predicts reduced DC within normal MHR ranges, while preserved SDNN_INDX correlates with higher DC in elevated MHR subgroups. This sex- and MHR-stratified approach enables personalized risk stratification in T2DM and EH patients.