Resistance training increases muscle mitochondrial biogenesis in patients with chronic kidney disease.
OBJECTIVE
Muscle wasting, a common complication in chronic kidney disease (CKD), contributes to poor outcomes. Mitochondrial biogenesis is critical for the maintenance of skeletal muscle function and structural integrity. The present study--a secondary analysis from a published randomized controlled trial--examined the effect of resistance exercise training on skeletal muscle mitochondrial (mt)DNA copy number and determined its association with skeletal muscle phenotype (muscle mass and strength).


METHODS
Twenty-three patients with moderate-to-severe CKD were randomized to resistance training (n = 13) or an attention-control (n = 10) group for 12 weeks. After a run-in period of a low-protein diet that continued during the intervention, mtDNA copy number in the vastus lateralis muscle was estimated by quantitative real-time PCR at baseline and 12 weeks.


RESULTS
Participants mean age was 64 +/- 10 (SD) years and median (interquartile range, IQR) GFR 27.5 (37.0) ml/min. There were no differences between groups at baseline. Median (IQR) mtDNA copy number was 13,713 (10,618). There was a significant increase in muscle mtDNA with exercise compared with controls (1306 [13306] versus -3747 [15467], P = 0.01). The change in muscle mtDNA copy number was positively correlated with previously reported changes in types I and II muscle fiber cross-sectional area.


CONCLUSIONS
In this pilot study, resistance training was highly effective in enhancing mitochondrial content in patients with moderate-to-severe CKD. This finding suggests that the mitochondrial dysfunction observed with chronic disease could potentially be restored with this exercise modality and should be investigated further.
Balakrishnan
Vaidyanatha S
VS
Division of Nephrology, Tufts Medical Center, Boston, Massachusetts, USA.
Rao
Madhumathi
M
Menon
Vandana
V
Gordon
Patricia L
PL
Pilichowska
Monika
M
Castaneda
Francisco
F
Castaneda-Sceppa
Carmen
C
D000368:Aged; D001706:Biopsy; D002908:Chronic Disease; D004272:DNA, Mitochondrial / Q000096:biosynthesis*; D018753:Diet, Protein-Restricted; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000378:metabolism*; D053580:Muscle Strength; D009133:Muscular Atrophy / Q000209:etiology / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D009929:Organ Size; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D052097:Quadriceps Muscle / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D055070:Resistance Training; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
D004272:DNA, Mitochondrial