Physical activity can improve health-related quality of life (HRQoL); however, it is not clear whether this association is direct or indirect. The aims of this study were to examine the associations o Show more
Physical activity can improve health-related quality of life (HRQoL); however, it is not clear whether this association is direct or indirect. The aims of this study were to examine the associations of daily movement behaviours with physical and mental HRQoL in older adults, and the mediating role of muscle strength and body composition on it. Three hundred thirty-four community-dwelling older adults wore the Intelligent Device for Energy Expenditure and Activity for two consecutive days to quantify time spent in sedentary behaviour (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA). HRQoL was assessed using the 12-Item Short-Form Health Survey, yielding physical (PCS) and mental (MCS) component scores. For muscle strength, a handgrip dynamometer and the Sit-to-Stand test were used. Body mass index (BMI), waist circumference, and estimates of skeletal muscle mass and fat mass by bioelectrical impedance were included as body composition variables. Association analyses were examined using linear regression models, and for mediation analysis, structural equation modelling was used. MVPA was positively associated with PCS [β (95%CI): 0.39 (0.19, 0.59)], whereas no significant associations were observed between MVPA, LPA, or SB and MCS. The association between MVPA and PCS was partially mediated by lower-limb muscle strength and fat mass percentage [8.5% (z = 1.753, p = 0.080) and 28.9% (z = 1.912, p = 0.056), respectively], and fully mediated by skeletal muscle mass normalized by BMI [28.2% (z = 2.016, p = 0.044)].Regular engagement in MVPA is positively associated with the physical component of HRQoL in older adults, both directly and indirectly through muscle strength and skeletal muscle mass. Show less
The preservation of the chondrogenic phenotype and hypoxia-related physiological microenvironment are major challenges in the 2D culture of primary human chondrocytes. To address this problem, we deve Show more
The preservation of the chondrogenic phenotype and hypoxia-related physiological microenvironment are major challenges in the 2D culture of primary human chondrocytes. To address this problem, we develop a 3D culture system generating scaffold-free spheroids from human chondrocytes. Our results highlight the chondrogenic potential of cultured human articular chondrocytes in a 3D system combined with hypoxia independently of the cartilage source. After 14 days of culture, we developed spheroids with homogenous diameter and shape from hyaline cartilage donors. Spheroids generated in hypoxia showed a significantly increased glycosaminoglycans synthesis and up-regulated the expression of Show less