Inflammatory mediators, muscle and functional performance of community-dwelling elderly women.

The purpose of this study was to investigate the correlation and association between inflammatory mediators and muscle and functional performance in elderly women. We conducted a cross-sectional study. Plasma concentrations of interleukin-6 (IL-6) and soluble receptor for tumor necrosis factor alpha (sTNFR1) were determined by enzyme-linked immune sorbent assay. The muscle performance was measured using a isokinetic dynamometer and assessment of handgrip strength was performed using a Jamar® dynamometer. Functional performance was assessed through a walking speed test. Statistical analysis was performed using the Pearson or Spearman correlation. The association between the variables was determined by multiple regression analysis. 221 volunteers (71.07±4.93 years) participated in the study. Plasma levels of IL-6 (0.87pg/mL) correlated with the power of the knee extensors (r=0.14; p=0.03) and the power of the knee flexors (r=0.16; p=0.01); the plasma levels of sTNFR1 (1051.70pg/mL) did not correlate with any dependent variable. The regression models showed that the variables IL-6, level of physical activity and depressive status explained 5.5% (R(2)=0.055, p<0.01) of average power of knee extensors variability. For the average power of knee flexors, the final model showed that the factors IL-6 and level of physical activity explained 4.1% (R(2)=0.041, p<0.01). There was no negative correlation between inflammatory mediators and muscle or physical performance in elderly women. These results may be explained by the fact that the cytokine levels did not reach the threshold needed to influence the muscle tissue and functionality of the participants.

Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women.

AIM: To investigate the correlation between handgrip strength and performance of knee flexor and extensor muscles determined using an isokinetic dynamometer in community-dwelling elderly women. METHODS: This was a cross-sectional study. Sample selection for the study was made by convenience, and 221 (71.07 ± 4.93 years) community-dwelling elderly women were included. Knee flexor and extensor muscle performance was measured using an isokinetic dynamometer Biodex System 3 Pro. The isokinetic variables chosen for analysis were peak torque, peak torque/bodyweight, total work/bodyweight, total work, average power, and agonist/antagonist ratio at the angular velocities of 60°/s and 180°/s. Assessment of handgrip strength was carried out using the Jamar dynamometer. Spearman's correlation coefficient was calculated to identify intervariable correlations. RESULTS: Only knee flexor peak torque (60°/s) and average power (60°/s), and knee extensor peak torque (180°/s) and total work (180°/s) were significantly (P < 0.05), yet poorly, correlated with handgrip strength (r < 0.30). CONCLUSION: The majority of analyses did not show any correlation between variables assessed by isokinetic dynamometer and handgrip dynamometer. Caution is required when generalizing handgrip strength as a predictor of global muscle strength in community-dwelling elderly women.

TNF-α, IL6, and IL10 polymorphisms and the effect of physical exercise on inflammatory parameters and physical performance in elderly women.

High levels of inflammatory mediators are associated with reduced physical capabilities and muscle function in the elderly. Single nucleotide polymorphisms (SNPs) may affect the expression and synthesis of these molecules, thus influencing the intensity of the inflammatory response and susceptibility to certain diseases. Physical exercise may attenuate age-related chronic inflammation and improve physical performance. This study evaluated the interaction between the SNP rs1800629 in TNF-α, rs1800795 in IL6, and rs1800896 in IL10 and the effect of physical exercise on physical performance and inflammation in elderly women. There was a significant interaction between rs1800629 and the effect of exercise on physical performance and between the combined 3-SNP genotype and changes in physical performance in response to exercise. These SNPs did not influence the effect of exercise on inflammatory parameters. Elderly women with a combination of genotypes associated with an anti-inflammatory profile (low TNF-α and IL-6 production, high IL-10 production) showed better physical performance independent of exercise modality, evidence of an interactive influence of genetic and environmental factors on improving physical performance in elderly women.