This analysis indicates that the current body of literature does not support a de facto decrease of in vivo muscle oxidative capacity in old age .
The heterogeneity of study results and identification of significant moderators provide clarity regarding apparent discrepancies in the literature , and indicate the importance of accounting for these variables when examining purported age-related differences in muscle oxidative capacity
Despite intensive efforts to underst and the extent to which skeletal muscle mitochondrial capacity changes in older humans , the answer to this important question remains unclear .
To determine what the preponderance of evidence from in vivo studies suggests , we conducted a systematic review and meta- analysis of the effects of age on muscle oxidative capacity as measured noninvasively by magnetic resonance spectroscopy .
A secondary aim was to examine potential moderators contributing to differences in results across studies , including muscle group , physical activity status , and sex .
Skeletal muscle mitochondrial function and lean body mass in healthy exercising elderly
BACKGROUND The decline in muscle mass ( sarcopenia ) with aging may be related to a decline in mitochondrial function . However , investigators have yet to reach a consensus as to whether a decline in mitochondrial function can be attenuated by physical activity has yet to reach a consensus . METHODS Using dynamic 31PMRS to measure mitochondrial function , we measured baseline Phosphocreatine ( PCr ) , inorganic phosphate ( Pi ) , phosphodiester ( PDE ) , [ ADP ] , pH and recovery times ( t(1/2 ) ) for PCr and [ ADP ] following exercise , in 45 older ( 73+/-4 years , SD ) , and 20 younger subjects ( 25+/-4 years , SD ) who were matched for body mass across high and low activity levels and within age and sex groupings . RESULTS Baseline PCr , and Pi , were lower , and PDE higher in the older subjects compared to younger subjects ( all P<0.01 ) . The t(1/2)(ADP ) was longer in older subjects ( P<0.001 ) controlling for age and sex in the low activity group ( P=0.02 ) . In the older low activity groups , t(1/2)(PCr ) was longer than high activity groups . Higher PDE levels were positively correlated with longer t(1/2)(PCr ) in the older low activity females ( both P<0.05 ) . CONCLUSIONS Our data suggests that mitochondrial function declines with age in healthy , exercising elderly adults and that the decline appears to be influenced by the level of physical activity
This analysis indicates that the current body of literature does not support a de facto decrease of in vivo muscle oxidative capacity in old age .
The heterogeneity of study results and identification of significant moderators provide clarity regarding apparent discrepancies in the literature , and indicate the importance of accounting for these variables when examining purported age-related differences in muscle oxidative capacity
Despite intensive efforts to underst and the extent to which skeletal muscle mitochondrial capacity changes in older humans , the answer to this important question remains unclear .
To determine what the preponderance of evidence from in vivo studies suggests , we conducted a systematic review and meta- analysis of the effects of age on muscle oxidative capacity as measured noninvasively by magnetic resonance spectroscopy .
A secondary aim was to examine potential moderators contributing to differences in results across studies , including muscle group , physical activity status , and sex .