Associations between Physical Function, Bone Density, Muscle Mass and Muscle Morphology in Older Men with Sarcopenia: A Pilot Study.

Background and Objectives: It is thought that muscle and bone interact only on a biomechanical level, however, some research is now emerging that links bone and muscle on a cellular level. The aim of this study was to explore associations between physical function, muscle mass and bone density in community-dwelling elderly men with sarcopenia. A secondary goal was to analyze if muscle morphology was associated with bone density and physical functioning. Materials and Methods: Body composition was measured by dual-energy X-ray absorptiometry (DXA). Bone density was evaluated according to WHO criteria. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People (EWGSOP) criteria: low muscle mass and low muscle strength or low physical performance. Microbiopsy of musculus vastus lateralis was performed with a disposable muscle microbiopsy system. The perimeter and cross-sectional area of muscle fibers were calculated using image analysis software in whole slide images; type of fibers and their distribution were evaluated as well. Results: A total of 151 men, 60 years or older were included in this study. Mean age of the subjects was 72.9 ± 8.02 years. Sarcopenia was diagnosed in 45 (29.8%) men. Multiple significant correlations were found between bone mineral density, lean mass, appendicular lean mass, arm and leg lean mass, gait speed, balance test and handgrip strength in sarcopenic men. Lean mass was associated with femoral neck BMD (bone mineral density; r = 0.418, p = 0.006) and handgrip strength (r = 0.553, p < 0.001). In the sarcopenia group, 25 muscle biopsies were examined. In 9 sarcopenic men with T-scores equal or below -2.5, the muscle fiber area had a significant correlation with the balance test (r = 0.73, p = 0.025). Conclusions: In men with sarcopenia, low lean muscle mass was associated with low femoral neck BMD and low muscle strength. In sarcopenic men with osteoporosis, low muscle fiber area was associated with low scores in a balance test.

Bibliometric and scientometric analysis on biomarkers and molecular mechanisms for physical frailty and sarcopenia.

Introduction: The influence of physical frailty and sarcopenia (PFS) on the well-being of older people and continuous pressure on the healthcare systems has prompted a research on the pathophysiology and molecular mechanisms of these conditions. Nonetheless some biomarkers have been suggested as potential markers for PFS none of them have been shown to highlight the complex nature of PFS, which reveals that there is a need for an understanding of the possible biomarker candidates. The aim of this study was to identify the current research hotspots, status, and trends in the field of biomarkers and molecular mechanisms for PFS. Methods: The bibliometric and scientometric analyses were performed using VOSviewer (version 1.6.18) and open source software platform Cytoscape v.3.9 (for visualizing and constructing a network of keywords). Data of publications (from 1997 to 2023) related to biomarkers and molecular mechanisms of PFS were obtained (in May 2023) from the database of Science Citation Index Expanded of Web of Science, Scopus, and PubMed. The keywords obtained from the Scopus database were used to perform a meaningful keyword analysis. A network of keyword relationships was build using Cytoscape. Results: In this study, we present biomarker keywords for PFS in relation to other keywords potentially designating processes and mechanisms and reveal the biomarker identities and current contexts in which these biomarker identities are discussed. Conclusions: Over recent years, scientific interest in the field of PFS has increased and focused on the inflammatory process and probably will be concentrated on myokines (such as cytokines and small proteins) that are synthetized and released by skeletal muscles in response to physical activity. Moreover, proteomic and genetic markers are deeply involved in PFS.

Quality of life in sarcopenia measured with the SarQoL questionnaire: A meta-analysis of individual patient data.

Age-related sarcopenia, resulting from a gradual loss in skeletal muscle mass and strength, is pivotal to the increased prevalence of functional limitation among the older adult community. The purpose of this meta-analysis of individual patient data is to investigate the difference in health-related quality of life between sarcopenic individuals and those without the condition using the Sarcopenia Quality of Life (SarQoL) questionnaire. A protocol was published on PROSPERO. Multiple databases and the grey literature were searched until March 2023 for studies reporting quality of life assessed with the SarQoL for patients with and without sarcopenia. Two researchers conducted the systematic review independently. A two-stage meta-analysis was performed. First, crude (mean difference) and adjusted (beta coefficient) effect sizes were calculated within each database; then, a random effect meta-analysis was applied to pool them. Heterogeneity was measured using the Q-test and I2 value. Subgroup analyses were performed to investigate the source of potential heterogeneity. The strength of evidence of this association was assessed using GRADE. From the 413 studies identified, 32 were eventually included, of which 10 were unpublished data studies. Sarcopenic participants displayed significantly reduced health-related quality of life compared with non-sarcopenic individuals (mean difference = -12.32; 95 % CI = [-15.27; -9.37]). The model revealed significant heterogeneity. Subgroup analyses revealed a substantial impact of regions, clinical settings, and diagnostic criteria on the difference in health-related quality of life between sarcopenic and non-sarcopenic individuals. The level of evidence was moderate. This meta-analysis of individual patient data suggested that sarcopenia is associated with lower health-related quality of life measured with SarQoL.

Validation of the Lithuanian version of sarcopenia-specific quality of life questionnaire (SarQoL®).

PURPOSE: The aim of this study was to translate and culturally adapt the SarQoL® questionnaire into Lithuanian and investigate its main psychometric properties. METHODS: A cross-sectional study was performed on community-dwelling Lithuanian people aged ≥ 60 years. The revised criteria of the European Working Group on Sarcopenia in Older People were used. A forward-backward methodology was used for the translation, with a pre-test of the final version of the Lithuanian SarQoL® questionnaire. Adjusted logistic regression analysis was used to compare sarcopenic and non-sarcopenic subjects. Internal consistency was determined using Cronbach's alpha coefficient. The correlation of total score of the SarQoL® and each domain of the Short-form General Health Survey (SF-36) and EuroQol-5D (EQ-5D) questionnaires was measured using Spearman's correlations. Test-retest reliability was measured by the intraclass correlation coefficient. RESULTS: The study was performed on 176 subjects. Fifty-eight subjects were diagnosed with sarcopenia. After adjustment for confounders, the total score of the SarQoL® questionnaire was significantly lower for sarcopenic subjects compared to non-sarcopenic subjects (50.32 ± 8.58 vs 73.75 ± 13.51, p < 0.001). Cronbach's alpha coefficient was 0.95. Neither floor nor ceiling effects were found. The SarQoL® questionnaire revealed good correlation with similar domains of the SF-36 and EQ-5D questionnaires for convergent validity and weak correlations with different domains for divergent validity, confirming its construct validity. An excellent agreement between test and retest was found with an ICC of 0.976 (95% CI 0.959-0.986). CONCLUSIONS: Lithuanian version of the SarQoL® is valid, reliable and consistent and could be used to assess quality of life in sarcopenic population.

Vitamin D Level and Activities of Daily Living in Octogenarians: Cross-Sectional Study.

INTRODUCTION: Despite the growing number of octogenarians, little is known about their vitamin D status and activities of daily living (ADL) relations. OBJECTIVE: The aim of this study was to investigate peculiarities of vitamin D and ADL and to assess their relations in octogenarians. METHODS: A cross-sectional study was performed at the National Osteoporosis Centre located in Vilnius, Lithuania. Community-dwelling ambulatory persons aged ≥80 years were included. Current users of vitamin D supplements were excluded. Total 25 hydroxyvitamin D concentration in serum was measured with Cobas E411. Functional status was assessed by Katz ADL and the Lawton Instrumental Activities of Daily Living (IADL) scales. Subjects were divided into three groups according to age and into two groups according to vitamin D level. One-way analysis of variance with post hoc test was used to determine between-group comparisons. Associations between vitamin D and ADL score, and IADL score were assessed using Spearman's correlation. RESULTS: The study was performed on 153 octogenarians: 81 (52.9%) women and 72 (47.1%) men. The average age of subjects was 83.9 ± 3.2 years. Mean total 25 hydroxyvitamin D concentration was 11.2 ± 7.0 ng/ml; 137 (89.5%) persons had vitamin D deficiency, 12 (7.8%) had insufficiency, and only 4 (2.6%) persons were vitamin D sufficient. Positive weak correlation between total 25 hydroxyvitamin D and ADL score (r = 0.2, p = 0.01) and very weak correlation between total 25 hydroxyvitamin D and IADL score (r = 0.19, p = 0.02) were found. Total 25 hydroxyvitamin D level was correlated with ADL score in women (r = 0.23, p = 0.04). In the 80-84 years group ADL score correlated with total 25 hydroxyvitamin D level (r = 0.23, p = 0.02). CONCLUSION: The majority of investigated octogenarians had vitamin D deficiency. The level of vitamin D was associated with the ADL score. There was no association between the vitamin D level and the IADL score, although a weak correlation was found between vitamin D level and category of food preparation.