Effects of muscle strength training with blood flow restriction on glomerular function in people with stage 3 chronic...

Stage 3 chronic kidney disease (CKD) represents a critical juncture in clinical management. However, muscle strength training (MST) combined with blood flow restriction (BFR) has shown benefits as an adjunctive treatment, but its renal effects remain unclear.

To analyze the effects of MST+BFR on markers of glomerular function in individuals with CKD-3.

A randomized, longitudinal clinical trial with 40 participants divided into 4 groups: control (G1); low-load MST (G2); high-load MST (G3); and low-load MST combined with BFR (G4). Serum creatinine, cystatin C, microalbuminuria, and estimated eGFR were used as dependent variables. The MST protocol was conducted over 12 weeks, 3 times per week, for 30-40 minutes, with 3 exercises (single- and multi-joint) per day at progressive intensities. Data analysis (intention-to-treat) was performed using the Shapiro-Wilk test (normality), paired t-test/Wilcoxon test (within-group comparisons), ANOVA/Kruskal-Wallis tests (between-group comparisons), Bonferroni test (post hoc corrections), and Cohen's d (effect size) with a p-value ≤ 0.05.

The participants were predominantly male (52.5%) with low levels of physical activity (60%), hypertension (87.5%), and some with diabetes (37.5%). Group 4 showed a significant increase in albuminuria levels (p = 0.048), as well as significant differences compared with Group 1 (creatinine, p = 0.032) and Group 2 (creatinine, p = 0.036; and eGFR-Cr, p = 0.032).

MST+BFR was not associated with severe adverse effects on serum creatinine/cystatin C levels, eGFR estimates, or urinary creatinine and microalbuminuria levels, but it may significantly increase albuminuria levels.