Renal Function Responses to Steady-State Moderate-Intensity and High-Intensity Interval Exercise in Mid-Spectrum Chronic Kidney Disease

Efficacy of exercise to improve renal function remains understudied in adults with mid-spectrum chronic kidney disease (CKD). In addition, a comparison of steady-state exercise (SSE) and high-intensity interval exercise (HIIE) may contribute clinically-relevant information for exercise-related augmentation of renal function in mid-spectrum CKD. PURPOSE: To determine the influence of SSE and a comparable amount of HIIE on indicators of post-exercise renal function in patients diagnosed with secondary Stage 3 or 4 CKD. METHODS: Twenty participants (n = 6 men; n = 14 women; age 62.0 + 9.9 yr; weight 80.9 + 16.2 kg; body fat 37.3 + 8.5% of weight; VO2max 19.4 + 4.7 ml/kg/min) completed 30 min of SSE at 65% VO2reserve or HIIE by treadmill walking (90% and 20% of VO2reserve in 3:2 min ratio) in a randomized crossover design. Both exercise conditions averaged ~ 65% VO2reserve. Blood and urine samples were obtained by the same technician under standardized conditions just before, 1hr and 24hrs after exercise. Serum creatinine (sCR), urine epidermal growth factor ratio (uEGFr), cystatin C and estimates of glomerular filtration rate - modification of diet in renal disease (MDRD) and the CKD-EPI - responses were analyzed using 2 (condition) by 3 (sample point) repeated measures ANOVAs. RESULTS: sCR decreased from 1.45 + 0.05 pre-exercise to 1.26 + 0.05 mg/dl (-13%) 1hr after exercise and returned to pre-exercise levels by 24hr (p = 0.009). Both MDRD and CKD-EPI estimates of glomerular filtration rate were 16 to 19% higher at 1hr, returning to pre-exercise values by 24hrs after exercise. The MDRD estimate increased from 43.1 + 1.9 pre-exercise to 50.3 + 2.1 ml/min/1.73m2 1hr after exercise (p = 0.007) and CKD-EPI from 45.2 + 2.1 to 53.8 + 2.4 ml/min/1.73m2 at 1hr post-exercise (p = 0.009). Relative to pre-exercise measures, uEGFr remained stable with SSE but was 5.4% greater 24hr after HIIE (p = 0.052). Cystatin C remained stable in the hours after exercise (p \u3e 0.05). CONCLUSION: By clinical estimates, renal function was not normalized but transiently improved with SSE and HIIE in mid-spectrum CKD

Circulating Inflammatory and Oxidative Stress Responses to Steady-State Moderate-Intensity and High-Intensity Interval Exercise in Mid-Spectrum Chronic Kidney Disease

Inflammation and oxidative stress can be potent modulators of vascular function. These factors may transiently respond to moderate-intensity steady state exercise (SSE) in a manner that improves post-exercise vascular function in healthy adults. Whether exercise imparts similar effects in adults with Stage 3 or 4 chronic kidney disease (CKD) remains understudied. Moreover, a comparison of SSE and high-intensity interval exercise (HIIE) may add to clinically-relevant findings for improving vascular function in mid-spectrum CKD. PURPOSE: To determine the influence of SSE and a comparable amount of HIIE on post-exercise inflammation and oxidative stress in patients diagnosed with secondary Stage 3 or 4 CKD. METHODS: Twenty participants (n = 6 men; n = 14 women; age 62.0 + 9.9 yr; weight 80.9 + 16.2 kg; body fat 37.3 + 8.5% of weight; VO2max 19.4 + 4.7 ml/kg/min) completed 30 min of SSE at 65% VO2reserve or HIIE by treadmill walking (90% and 20% of VO2reserve in 3:2 min ratio) in a randomized crossover design. Both exercise conditions averaged ~ 65% VO2reserve. Blood samples were obtained by the same technician under standardized conditions just before, 1hr and 24hrs after exercise. Total antioxidant capacity (TAC), paraoxonase1 (PON1), asymmetric dimethylarginine (ADMA), 3nitrotyrosine (3NT) and interleukin-6 (IL6) responses were analyzed using 2 (condition) by 3 (sample point) repeated measures ANOVAs. RESULTS: Relative to pre-exercise measures: TAC increased by 4.3% 24hr after exercise (p = 0.012). PON1 was maintained 1hr and elevated by 6.1% 24hr after SSE, but not HIIE (p = 0.035). When corrected for plasma volume shifts, ADMA increased 30 ng/ml at 1hr but was 58 ng/ml lower 24hrs after exercise (p = 0.0006). 3NT and IL6 remained stable in the hours after exercise (p \u3e 0.05). CONCLUSION: Modest inflammatory and oxidative stress marker responses to either SSE and HIIE may contribute to improved vascular function in mid-spectrum CKD