Our meta analysis of a homogeneous set of studies is the first to provide valuable LLNs for fiber CSA according to fiber type and gender .
Skeletal muscle atrophy is a major systemic impairment in chronic diseases .
Yet its determinants have been hard to identify because a clear research definition has not been agreed upon .
The reduction in muscle fiber cross-sectional area ( CSA ) is a widely acknowledged marker of muscle atrophy , but no reference values for the muscle fiber CSA at the age of the onset of chronic disease have ever been published .
Skeletal muscle microbiopsy: a validation study of a minimally invasive technique
The study of the peripheral skeletal muscle function in patients with chronic obstructive pulmonary disease ( COPD ) is of growing interest , but often requires biopsies , usually with the Bergström technique . The current study was design ed to test the validity of a minimally invasive technique : the microbiopsy . In 17 patients with COPD and four normal subjects , two specimens of the vastus lateralis were taken percutaneously under local anaesthesia , one with a 16-gauge needle ( microbiopsy ) and the other with the Bergström needle .  The enzymatic activity of citrate synthase ( CS ) and phosphofructokinase ( PFK ) , and the myosin heavy chain ( MyoHC ) composition were measured for both techniques . The subjects reported no pain or much less with the microbiopsy compared with the Bergström biopsy . The microbiopsy sample weight reached 55±17 mg . The two techniques showed excellent agreement for CS activity and MyoHC composition . The PFK activity did not differ statistically between the techniques , but the agreement was moderate . The agreement between both biopsy techniques was stable over time . The median ( range ) fibre number within the microbiopsy specimens was 144 ( 38–286 ) . In conclusion , the current study shows the feasibility and validity of a minimally invasive muscle biopsy technique that appears more comfortable for subjects , compared with the Bergström technique
Our meta analysis of a homogeneous set of studies is the first to provide valuable LLNs for fiber CSA according to fiber type and gender .
Skeletal muscle atrophy is a major systemic impairment in chronic diseases .
Yet its determinants have been hard to identify because a clear research definition has not been agreed upon .
The reduction in muscle fiber cross-sectional area ( CSA ) is a widely acknowledged marker of muscle atrophy , but no reference values for the muscle fiber CSA at the age of the onset of chronic disease have ever been published .