Greater Aortic Hemodynamic Responses to Muscle Metaboreflex Activation In Older Adults with Prediabetes than Diabetes

Abstract

PURPOSE: Wave reflection measures (augmentation pressure [AP] and index [AIx]) are similarly increased in adults with type 2 diabetes (T2D) and prediabetes (PRET2D) suggesting high cardiovascular risk. An exaggerated blood pressure (BP) response to muscle metaboreflex activation induced via post-exercise muscle ischemia (PEMI) following isometric handgrip exercise has been reported in patients with T2D. The purpose of this study was to examine the wave reflection responses to PEMI in adults with PRET2D and T2D. METHODS: Aortic hemodynamics were obtained using pulse wave analysis at rest and during PEMI following isometric handgrip at 30% of maximal voluntary contraction in adults (age, 59.7 ± 6.3 y) with PRET2D (n= 12) and T2D (n= 12). RESULTS: Vascular parameters were similar at rest. Aortic systolic BP (PRET2D Δ42 ± 13 mmHg vs. T2D Δ31 ± 10 mmHg, P < 0.001 for both), pulse pressure (PRET2D Δ22± 9 mmHg vs. T2D Δ13 ± 10 mmHg, P < 0.001 and P < 0.01, respectively) and AP (PRET2D Δ13 ± 5 mmHg vs. T2D Δ9 ± 5 mmHg, P < 0.001 for both) responses to PEMI were greater (P < 0.05) in PRET2D compared with T2D patients. The aortic diastolic BP, AIx, AIx adjusted at 75 bpm, and time to reflection responses to PEMI were similar in PRET2D and T2D. CONCLUSIONS: Our findings show that aortic hemodynamic responses to exercise-related metabolites are exaggerated in PRET2D. These findings suggest that an increased left ventricular afterload during muscle metaboreflex activation may contribute to augment cardiovascular risk in adults with PRET2D.