Non-invasive assessment of peripheral skeletal muscle weakness in idiopathic pulmonary fibrosis: a pilot study with multiparametric MRI of the rectus femoris muscle

Abstract

Background: To investigate differences in magnetic resonance imaging (MRI) features of rectus femoris muscle between idiopathic pulmonary fibrosis (IPF) patients and healthy volunteers.Methods: Thirteen IPF patients with GAP Index stage II disease were subjected to pulmonary function tests, 6-minute walk test (6MWT), quadriceps femoris muscle strength measurement and MRI of the thigh at rest. At MRI, muscle cross-sectional areas, T2 and T2* relaxometry, and 3-point Dixon fat fraction were measured. The results were compared to those of eight healthy sedentary volunteers.Results: IPF patients had significantly lower %predicted FVC, FEV1 and DLCO (p<0.001 for the three variables) and walked significantly less in the 6MWT (p=0.008). Mean quadriceps femoris muscle strength also was significantly lower in IPF patients (p=0.041). Rectus femoris muscle T2* measurements were significantly shorter in IPF patients (p=0.027). No significant intergroup difference was found regarding average muscle cross-sectional areas (p=0.790 for quadriceps and p=0.816 for rectus femoris) or rectus femoris fat fraction (p=0.901). Rectus femoris T2 values showed a non-significant trend to be shorter in IPF patients (p=0.055).Conclusions: Our preliminary findings suggest that, besides disuse atrophy, other factors such as hypoxia (but not inflammation) may play a role in the peripheral skeletal muscle dysfunction observed in IPF patients. This might impact the rehabilitation strategies for IPF patients and warrants further investigation.

Management of musculoskeletal pain in patients with idiopathic pulmonary fibrosis: a review

“…Respiratory and limb muscle dysfunction can be caused by several different mechanisms, such as chronic lack of oxygen in the blood, inflammatory, and oxidative stress in the muscle; chronic corticosteroid administration; physical inactivity; ageing; and malnutrition (34). These claims are supported by the findings of several studies, where the force of quadriceps femoris muscle (36) or rectus femoris muscle (37) was reduced in patients with IPF. Chronic hypoxia may potentially cause nerve injury, but additional pathways for nerve damage have not been thoroughly examined.…”

Rectus Femoris Cross-Sectional Area and Phase Angle asPredictors of 12-Month Mortality in Idiopathic Pulmonary Fibrosis Patients

“…The nutritional ultrasound technique yields an RF-CSA value with adequate sensitivity and specificity to predict 12-month mortality. Other techniques, such as CT [39] or MRI [40], have already established their prognostic value for IPF patients and other pulmonary diseases [41]. De Paula et al [40] have obtained preliminary findings suggesting that other factors, such as hypoxia (but not inflammation), may play a role in the peripheral skeletal muscle dysfunction observed in IPF patients, in addition to disuse atrophy.…”

Multiform-based Baduanjin exercise prevention and treatment for idiopathic pulmonary fibrosis: study protocol for a randomized controlled trial

“…This may fulfill the function of acute oxygen supplementation, which increases supplemental oxygen tolerance and alleviates dyspnea in individuals with idiopathic pulmonary fibrosis who do not have hypoxemia at rest [ 23 ]. At the same time, hypoxia may be related to the peripheral skeletal muscle dysfunction observed in IPF patients [ 24 ], so in the rehabilitation of IPF patients, hypoxia and skeletal muscle may have a mutual influence rather than an independent relationship. The fifth pose of Sitting Baduanjin is a combination of the traditional Baduanjin and Yijinjing movements of “drawing the knife”.…”