Acute isometric handgrip exercise enhances cardiac baroreflex sensitivity and lowers systolic blood pressure in chronic kidney disease

Chronic kidney disease (CKD) impairs cardiac baroreflex sensitivity (cBRS), contributing to poor blood pressure (BP) control and heightened cardiovascular risk. Emerging evidence indicates that isometric handgrip (IHG) exercise may enhance cBRS in healthy individuals; however, its effects in CKD remain unclear. Therefore, this study tested the hypothesis that a single IHG session increases cBRS and reduces beat-to-beat BP variability (BPV) in CKD patients. In 21 patients (61 ± 12 yr; stages III-IV), beat-to-beat BP (finger photoplethysmography), heart rate (HR, electrocardiography), and respiration were continuously measured before and 10-, 20-, and 30-min post IHG vs. sham exercise in a crossover design. cBRS was assessed via the sequence technique and cardiac autonomic modulation via time- and frequency-domain HR variability (HRV). BPV was quantified using time domain indexes. cBRS increased following IHG exercise (10-min: Δ20 ± 4%; 20-min: Δ23 ± 5%; 30-min: Δ17 ± 5%; all P < 0.004 vs rest). This increase was significantly different from sham at 10-min and 20-min (all P < 0.006 vs sham), but not at 30-min post-IHG (P = 0.074). HR decreased throughout recovery (all P = 0.001 vs rest). Systolic BP decreased 30-min following IHG exercise (Δ-5 ± 2 mmHg; P = 0.047 vs. rest). Time-domain HRV increased during recovery (P = 0.005) whereas BPV remained unchanged following IHG exercise. After sham, all variables remained similar to rest, except systolic BP was significantly higher 20-min after sham. A single IHG session increased cBRS and vagal modulation, with a modest reduction in systolic BP and no change in BPV, in CKD patients. Overall, these findings suggest that IHG may serve as a non-pharmacological intervention for cardiovascular regulation in CKD.