Abstract
Objective: The present retrospective study aimed to clarify the involvement of knee extensor strength and autonomic indices （ΔHR) in the improvement of exercise capacity (peak VO2) in acute myocardial infarction (AMI) patients with type 2 diabetes mellitus (DM) undergoing cardiac rehabilitation (CR) -related exercise training. Methods: A total of 41 consecutive male AMI patients with type 2 DM were divided into the supervised outpatient CR group (n = 24) and the non-CR group (control, n = 17). Physical training was prescribed for 8 weeks in the CR group. Cardiopulmonary exercise testing (peak VO2, ΔHR) and isokinetic knee extension strength measurements were performed on all subjects at 1 (T1) and 3 (T2) months after AMI onset. Results: Significantly greater improvements in peak VO2 (26.1→29.4 vs 23.5→24.4 ml/kg/min, F = 7.5， p ＜0.01), knee extension strength (1.7 →1.9 vs 1.7 →1.7 Nm/kg，F=5.1，p = 0.02), and ΔHR (71.3 →77.2 vs 63.5 →62.5 bpm, F = 5.5, p = 0.02) were measured from T1 to T2 in the CR group versus the nonCR group. Conclusions: In patients with AMI complicated by DM, only the exercise group showed significant improvements in knee extensor strength and ΔHR. Therefore, improvement in exercise capacity in such patients was considered to be related to improvements in knee extensor strength and ΔHR.
