Muscle mass and intramuscular fat of the quadriceps are related to muscle strength in non-ambulatory chronic stroke survivors: A cross-sectional study

Abstract

ObjectiveImproving muscle mass and intramuscular fat in the mid-thigh increases the muscle strength of the paretic and non-paretic limbs in ambulatory chronic stroke survivors. There is a remarkable decrease in muscle mass and muscle strength and an increase in intramuscular fat in the quadriceps of both limbs of non-ambulatory compared with ambulatory survivors. Therefore, given that paretic lower extremity function does not recover sufficiently in the chronic phase, it may be helpful to improve muscle mass and intramuscular fat to increase muscle strength in the quadriceps of non-ambulatory chronic stroke survivors. However, these relationships remain unclear. The purpose of this study was to clarify the relationships between muscle strength, muscle mass, and intramuscular fat of the quadriceps in non-ambulatory chronic stroke survivors.MethodsStudy design: A cross-sectional study.Participants: Fifty non-ambulatory chronic stroke survivors.Main outcome measures: Quadriceps muscle strength was measured using a handheld dynamometer. Transverse ultrasound images were acquired using B-mode ultrasound imaging. Muscle mass and intramuscular fat of the quadriceps were assessed based on muscle thickness and echo intensity, respectively.Data analysis: Stepwise multiple regression analyses were used to identify the factors independently associated with the quadriceps muscle strength of the paretic and non-paretic limbs. To avoid multicollinearity, muscle thickness and echo intensity were entered into separate multiple regression models. Muscle thickness or echo intensity of the paretic or non-paretic limbs and other confounding factors were set as the independent variables.ResultsMuscle thickness was positively related and echo intensity was negatively related to the quadriceps muscle strength of the paretic and non-paretic limbs.ConclusionsMuscle mass and intramuscular fat of the quadriceps are related to muscle strength in non-ambulatory chronic stroke survivors. Increasing muscle mass and decreasing intramuscular fat of the quadriceps of both limbs may improve muscle strength.

Relationship of Quadriceps Muscle Thickness with Motor Paralysis and Muscle Echo Intensity in Post-Stroke Patients

“…The reliability and validity of the MT and RF EI at the anterior mid-thigh have been repeatedly confirmed in previous studies [19,20,[24][25][26][27]29]. The MT reflects the quadriceps muscle volume (r = 0.46, p < 0.05) [26] and cross-sectional area (r = 0.91, p < 0.001) [24].…”

“…The intraclass correlation coefficient (ICC) of the MT was 0.88-0.95 [29]. The ICC of the RF EI was 0.86-0.89 [27].…”

“…US is an ideal technique for the measurement of muscle quality and quantity, which are frequently assessed according to the muscle thickness (MT) and echo intensity (EI) [9,17,20,21,[24][25][26][27]. The advantages of US are that it is noninvasive as well as less expensive and more portable than other medical imaging modalities such as magnetic resonance imaging, computed tomography, and dual-energy X-ray absorptiometry.…”

Zebrafish models of sarcopenia

“…Genetic, epigenetic and environmental factors significantly alter structural, biochemical and functional properties, indicating that accumulation of intramuscular fat may cause damage and dysfunction of a muscle network system (Akazawa et al, 2018). Nevertheless, it is not yet clear whether intramuscular fat decreases muscle fiber number, size and muscle volume, thus leading to muscle wasting in sarcopenia.…”

Future Ultrasound Biomarkers for Sarcopenia: Elastography, Contrast-Enhanced Ultrasound, and Speed of Sound Ultrasound Imaging

“…53 Intramuscular fat increases with aging and is significantly higher among the elderly population. 54,55 It has a negative correlation with muscle strength and muscle function 56,57 and is an important factor in sarcopenia progression. Muscle and adipose tissues have different SoS times (1440 m/s for adipose tissue; 1585 m/s for muscle).…”