Sarcopenia is Associated With Lower Skeletal Muscle Capillarization and Exercise Capacity in Older Adults

Abstract

Background: Skeletal muscle capillary rarefaction limits the transcapillary transport of nutrients and oxygen to muscle and may contribute to sarcopenia and functional impairment in older adults. We tested the hypothesis that skeletal muscle capillarization and exercise capacity (VO2max) are lower in sarcopenic than in nonsarcopenic older adults and that the degree of sarcopenia is related to lower skeletal muscle capillarization. Methods: Body composition, VO2max, and vastus lateralis capillarization were determined in 76 middle-aged and older men and women (age = 61±1 years, body mass index [BMI] = 30.7±0.5kg/m2 [mean ± SEM]). Participants were classified as sarcopenic if appendicular lean mass divided by BMI (ALMBMI) was less than 0.789 for men or less than 0.512 for women. Results: Sarcopenic subjects (ALMBMI = 0.65±0.04, n = 16) had 20% lower capillary-to-fiber ratio, as well as 13% and 15% lower VO2max expressed as mL/kg/min or L/min, respectively, compared with sex-, race-, and age-matched participants without sarcopenia (ALMBMI = 0.81±0.05, n = 16; p