Skeletal muscle mitochondrial capacity in people with multiple sclerosis

Abstract

Background People with multiple sclerosis (MS) have functional disability and may have reduced muscle mitochondrial capacity. Objective The objective of this paper is to measure muscle mitochondrial capacity of leg muscles using near-infrared spectroscopy (NIRS) and compare to functional status. Materials and methods People with MS ( n = 16) and a control (CON) group ( n = 9) were evaluated for 25-ft walk time. Mitochondrial capacity of both gastrocnemius muscles were measured with NIRS as the rate of recovery of oxygen consumption in after exercise. Results Mitochondrial capacity was lower in the MS group compared to the CON group (rate constants: 1.13 ± 0.29 vs. 1.68 ± 0.37 min−1, p < 0.05). There was a tendency for people with MS who used assistive devices to have lower mitochondrial capacity in the weaker leg ( p = 0.07). Conclusion NIRS measurements of mitochondrial capacity suggest a 40% deficit in people with MS compared to CONs and this may contribute to walking disability.