Sugita, Yousuke; Faculty of Health Sciences, Tsukuba University of Technology, Ibaraki, Japan.
Kudo, Ayano;Arakawa, Sota;Sakai, Satoshi
Heart and vessels,2025 Dec 29
Background Reduced exercise capacity is a hallmark of heart failure with preserved ejection fraction (HFpEF), and this limitation is particularly pronounced in older patients with coexisting type 2 diabetes mellitus (T2DM), a high-risk population characterized by poor prognosis. Although previous studies have demonstrated that exercise training (ET) can improve exercise capacity in patients with HFpEF, its efficacy in older patients with coexisting HFpEF and T2DM remains unclear.
Methods Therefore, we evaluated the effects of ET on peak oxygen uptake (peakVO 2 ) and 6-min walk distance (6MWD) in older patients with HFpEF and investigated whether these effects differ based on T2DM status. A total of 99 stable outpatients with HFpEF aged 65 to 80 years were enrolled. Participants were classified into four groups based on T2DM and ET status: T2DM-ET (n = 25), non-T2DM-ET (n = 24), T2DM-usual-care (UC; n = 26), and non-T2DM-UC (n = 24). PeakVO 2 and hemodynamic responses during exercise were assessed using cardiopulmonary exercise testing and impedance cardiography. Additionally, walking distance, cadence, step length, and metabolic cost were assessed during the 6-min walk test. The interaction between T2DM and ET on changes in these parameters was analyzed using multivariable-adjusted linear regression.
Results ET significantly improved peakVO 2 after 5 months; however, the magnitude of improvement was attenuated in the T2DM group (0.5 mL/kg/min) compared with that in the non-T2DM group (1.9 mL/kg/min; p < 0.001). This difference was primarily attributable to a blunted increase in arteriovenous oxygen difference, which increased by only 0.2 mL/100 mL in the T2DM group vs. 0.4 mL/100 mL in the non-T2DM group (p < 0.001). In contrast, improvements in 6MWD were similar between the groups (29 vs. 31 m; p = 0.651). Step length remained unchanged, whereas cadence increased in the T2DM and non-T2DM groups (11 vs. 8 steps/min, respectively), accompanied by a reduction in metabolic cost (- 0.06 vs. – 0.04 mL/kg/m), indicating enhanced walking efficiency regardless of T2DM status. Although T2DM attenuated improvements in peakVO 2 , the walking efficiency and functional capacity improved with ET regardless of T2DM status.
Conclusions These findings highlight the potential value of ET in older patients with HFpEF, irrespective of T2DM status.