Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women.

Certain cut-off points for sarcopenia screening and diagnosis are arbitrary and based on European populations, with normative references often obtained from healthy young adults. Although respiratory skeletal muscle strength tests represent low-cost clinical measures commonly performed in clinical practice by health professionals, a gap remains regarding whether respiratory skeletal muscle strength tests are adequate and sensitive measures for sarcopenia screening. This study aimed to verify the value of handgrip and respiratory muscle strength as possible discriminators to identify sarcopenia and to establish cut-off points for sarcopenia screening in community-dwelling, Brazilian women. In a cross-sectional study, 154 community-dwelling, Brazilian women (65-96 years) were assessed for appendicular skeletal muscle mass, handgrip (HGS), and respiratory muscular strength, including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). The data were analyzed using the ROC curve and the Youden Index determined cut-off points. Statistical significance was set at 5%. 88 participants (57%) were sarcopenic. MEP (OR 0.98 [95%CI 0.97, 1.00], p = 0.023) and HGS (OR 0.82 [95% CI 0.75, 0.90], p < 0.001) were independent factors for sarcopenia in older. The optimal cut-off points for identifying sarcopenia were ≤ 77 cmH2O for MEP (AUC = 0.72), and ≤ 20 kg for HGS (AUC = 0.80). Simple muscular strength tests, including HGS and MEP, may be considered in the identification of sarcopenia in older, community-dwelling, Brazilian women. Future work is still needed to assess external validation of the proposed cut-offs before the clinical application.

Are oxidative stress biomarkers and respiratory muscles strength associated with COPD-related sarcopenia in older adults?

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often present with sarcopenia, a condition marked by the loss in quality and quantity of muscle mass that can affect the strength of respiratory muscles. COPD and sarcopenia are also independently associated with oxidative stress. This study aimed to investigate whether oxidative stress biomarkers and respiratory muscle strength are associated with sarcopenia in COPD patients. METHODS: In a cross-sectional study, 86 elderly subjects, including subjects with and without COPD were assessed for body composition, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) and oxidative stress parameters [substances reactive to thiobarbituric acid (TBARS), ferric reducing ability of plasma (FRAP), superoxide dismutase (SOD), and catalase (CAT)]. RESULTS: The sample was mainly composed by males (72.1%) and eutrophic subjects. COPD-related sarcopenia was evidenced in 51.1% (22/43) of subjects with COPD. The highest TBARS and CAT, and lower MIP and MEP were associated with a high probability of having COPD-related sarcopenia. In the multivariate analysis, TBARS (OR: 4.89, 95% CI 1.52 to 15.54, p = 0.006), CAT (OR: 1.22, 95% CI 1.03 to 1.45, p = 0.020) and MEP (OR: 0.97, 95% CI 0.95 to 0.99, p = 0.020) were independent determinants of COPD-related sarcopenia. CONCLUSION: The increase in oxidative stress-related factors and the reduction of respiratory muscle strength are associated with COPD-related sarcopenia.

Plasma levels of myokines and inflammatory markers are related with functional and respiratory performance in older adults with COPD and sarcopenia.

This study investigated whether blood-based biomarkers were related to functional test performance and respiratory muscle strength in older adults with COPD and sarcopenia. The participants included in this cross-sectional study were from both sexes and sixty years or older. Based on clinical assessment, participants were categorized in COPD (n = 43) and non-COPD (NCOPD) (n = 43) groups. They were also assessed for body composition and muscular mass by dual-energy X-ray absorptiometry, using the relative skeletal muscle index for the diagnosis of sarcopenia. A series of functional tests, including short physical performance battery (SPPB), 6-minute walking test (6MWT), maximal inspiratory and expiratory pressures (MIP and MEP), were carried out. Plasma levels of myokines (Irisin and BDNF), and soluble TNF receptors (sTNFR1 and sTNFR2) were determined by ELISA. In the multivariate analysis, 6MWD was associated with age, COPD-related sarcopenia and BDNF (R2 = 0.29; f2 = 0.41). SPPB score was associated with COPD-related sarcopenia and sTNFR1 (R2 = 0.25; f2 = 0.33). MIP value was associated with sex, COPD-related sarcopenia, sTNFR2 and Irisin (R2 = 0.24; f2 = 0.31). Finally, MEP value was associated with sex COPD-related sarcopenia (R2 = 0.18; f2 = 0.22). Plasma levels of myokines and inflammatory markers are related with functional and respiratory performance in older adults with COPD and sarcopenia.

Immediate Effects of Whole-Body Vibration Associated with Squatting Exercises on Hemodynamic Parameters in Sarcopenic Older People: A Randomized Controlled Trial.

Whole-body vibration (WBV) exercises have recently been introduced as a nonpharmacological therapeutic strategy for sarcopenic older people. The present study aimed to evaluate the effect of WBV exercise on hemodynamic parameters in sarcopenic older people. Forty older people, divided into groups of nonsarcopenic (NSG = 20) and sarcopenic (SG = 20), participated in the study and were cross randomized into two interventions of eight sets of 40 s each, these being squatting with WBV and squatting without WBV. Heart rate (HR), peak heart rate (peak HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), mean arterial pressure (MAP), and subjective perception of effort (SPE), were assessed at baseline, during, and after a single WBV session. The HR, peak HR, and DP variables were similar at baseline between groups. WBV exercise increased all the hemodynamic parameters both during and immediately after the intervention, in both groups (SG and NSG). The MAP values were similar at baseline between groups; however, in the NSG there was a significant increase during and immediately after the squatting with WBV intervention (p < 0.05). The HR behavior, in both groups, showed that there was an increase in HR after the first set of exercises with vibration and this increase was maintained until the final set. The absence of adverse effects of WBV exercise on the cardiovascular system and fatigue suggests this exercise modality is adequate and safe for sarcopenic older people.