Abstract 1816: Diabetes Reduces Reactivation of Vagal Tone after Peak Exercise in Heart Failure Patients
Background: Heart rate recovery (HRR) after peak exercise is a function of the reactivation of vagal tone and is known to be diminished in HF. Common comorbidities associated with HF (diabetes [DM] and depression) may have reduced HRR. However, the effect of these comorbitities on HRR in HF patients has not been evaluated. The study objective was to determine if HRR recovery after peak exercise was lower in HF patients with and without DM and depression.
Methodology: A comparative design was used to study 74 HF (73[99%] male; mean age 62.7 ± 10.7 years; EF 27 ± 9%; 59 [80%] NYHA II, 15 [20%] NYHA III–IV). Patients were classified into 4 groups: No DM and no depression (n= 23); no DM but depressed (n=22); DM but not depressed (n= 13); and DM and depressed (n = 16). All underwent maximal CPX bicycle ergometry at a VA medical center. HRR was defined HR at 1 minute after CPX. Depression was measured by the Multiple Affect Adjective Checklist and depression was defined as scores > 11. Groups were compared by 2-way ANOVA after controlling for age, beta-blocker use and smoking pack year history.
Results: HRR 1-minute post maximal exercise was lower in both groups with DM compared to those without (p = .007) (Table⇓). There were main effects for DM (F = 4.53. p =.03), but, not for depression. There were no interactive effects of DM and depression on HRR.
Conclusion: HF patients with DM demonstrated lowered reactivation of vagal tone than those without DM. This finding suggests that diminished vagal tone may be exacerbated when both HF and DM are present and may be accompanied by exaggerated sympathetic activation. Diabetic HF patients may require extra treatment to restore autonomic balance.