title: Axonal degeneration affects muscle density in older men and women.
abstract: Using data from InCHIANTI, a prospective population-based survey of older persons, we examined the relationship of peroneal nerve conduction velocity (NCV, a measure of nerve myelination) and compound muscle action potential (CMAP, a measure of axonal degeneration) with calf muscle mass and density, two complementary measures of sarcopenia. NCV and CMAP were assessed by surface electroneurography of the right peroneal nerve conducted in 1162 participants, 515 men and 647 women, age 21-96 years, free of major neurological diseases. Cross-sectional muscle area and calf muscle density were measured using peripheral quantitative computerized tomography (pQCT). Both nerve and muscle parameters declined with age although in most cases the decline was not linear. In both sexes, CMAP, but not NCV, was independently and significantly associated with calf muscle density. These findings suggest that intrinsic changes in the muscle tissue are partially caused by a reduction in the number of motor axons.
authors.affiliation: Laboratory of Clinical Epidemiology, Italian National Institute of Research and Care on Aging (INRCA), Geriatric Department, Florence, Italy; Tuscany Regional Health Agency, Florence, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Lauretani
authors.forename: Stefania
authors.initials: S
authors.lastname: Bandinelli
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bartali
authors.forename: Angelo
authors.initials: A
authors.lastname: Di Iorio
authors.forename: Vittoria
authors.initials: V
authors.lastname: Giacomini
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Corsi
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D003711:Demyelinating Diseases / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000473:pathology* / Q000503:physiopathology*; D009431:Neural Conduction; D019636:Neurodegenerative Diseases / Q000473:pathology / Q000503:physiopathology; D010543:Peroneal Nerve / Q000473:pathology / Q000503:physiopathology