Muscle strength, muscle balance, physical function and plasma interleukin-6 (IL-6) levels in elderly women with knee osteoarthritis (OA).

An increased circulating level of inflammatory cytokines has been associated with sarcopenia, functional disability, chronic diseases, and mortality in the elderly. Osteoarthritis (OA) is a disease common to this population, the seriousness of articular degeneration has been associated to the increase in some cytokines, IL-6 among them. The aim of the present study was to correlate IL-6 plasma levels with muscle strength, endurance, muscle balance hamstring/quadriceps (H/Q) and physical function in 80 elderly women (71.2 ± 5.3) with knee OA. IL-6 was measured using enzyme-linked immunosorbent assay (ELISA). Quadriceps and hamstring muscle strength, endurance and hamstring-quadriceps muscle balance were assessed using a Biodex system 3 pro(®) isokinetic dynamometer. Physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Spearman's correlation coefficient was used to explore the relationship between the outcomes at the significance level of α=0.05. IL-6 was inversely correlated to the endurance of the hamstring muscles (r=-0.232; p=0.03) and muscle balance (H/Q) on the lower right side at 180°/s (r=-0.254; p=0.023). No significant correlation between IL-6, muscle strength and physical function was found. Our results show that elevated levels of IL-6 may possibly contribute to the reduction of the endurance of hamstring muscles and H/Q muscle balance in the elderly studied.

sTNFR-1 is an early inflammatory marker in community versus institutionalized elderly women.

OBJECTIVE AND DESIGN: To evaluate plasma sTNFR-1 and IL-6 levels and correlate with hand grip in the institutionalized and community living Brazilian elderly. MATERIAL: A convenience sample of 110 elderly women (71.17 + or - 7.44 years) was selected. Plasma sTNFR-1 and IL-6 levels were measured by ELISA. For the measurement of hand grip, a JAMAR dynamometer was used. RESULTS: Plasma concentrations of inflammatory markers were significantly higher in institutionalized elderly (sTNFR-1: 479 + or - 22 pg/mL; IL-6: 6.3 + or - 0.8 pg/mL) than in community-dwelling elderly (sTNFR-1: 329 + or - 24 pg/mL; IL-6: 2.5 + or - 0.4 pg/mL; P < 0.0001). Institutionalized elderly had reduced hand grip (15 + or - 0.8 Kgf) in comparison to community dwelling elderly (23 + or - 0.6 Kgf; P < 0.05). When individuals were subdivided in age groups, sTNFR-1 was higher in community dwelling versus institutionalized elderly in the 60-70 age range. CONCLUSIONS: Our results demonstrate that being institutionalized has an impact on levels of inflammatory markers.

Muscle strength but not functional capacity is associated with plasma interleukin-6 levels of community-dwelling elderly women

The association of plasma interleukin-6 (IL-6) levels, muscle strength and functional capacity was investigated in a cross-sectional study of community-dwelling elderly women from Belo Horizonte, Brazil. Elderly people who present controlled chronic diseases with no negative impact on physical, psychosocial and mental functionality are considered to be community-dwelling. Psychological and social stress due to unsuccessfully aging can represent a risk for immune system disfunctions. IL-6 levels, isokinetic muscle strength of knee flexion/extension, and functional tests to determine time required to rise from a chair and gait velocity were measured in 57 participants (71.21 ± 7.38 years). Serum levels of IL-6 were measured in duplicate and were performed within one single assay (mouse monoclonal antibody against IL-6; High-Sensitivity, Quantikine®, R & D Systems, USA; intra-assay coefficient of variance = 6.9-7.4 percent; interassay coefficient of variance = 9.6-6.5 percent; sensitivity = 0.016-0.110 pg/mL; mean = 0.039 pg/mL). Muscle strength was assessed with the isokinetic dynamometer Biodex System 3 Pro®. After the Shapiro-Wilk normality test was applied, correlations were investigated using Spearman and Kruskal-Wallis tests. Post hoc analysis was performed using the Dunn test. A significant negative correlation was observed between plasma IL-6 levels (1.95 ± 1.77 pg/mL) and muscle strength for knee flexion (70.70 ± 21.14 percent; r = -0.265; P = 0.047) and extension (271.84 ± 67.85 percent; r = -0.315; P = 0.017). No significant correlation was observed between IL-6 levels and the functional tests (time to rise from a chair = 14.65 ± 2.82 s and gait velocity = 0.95 ± 0.14 m/s). These results suggest that IL-6 is associated with reduced muscle strength.

Muscle strength but not functional capacity is associated with plasma interleukin-6 levels of community-dwelling elderly women.

The association of plasma interleukin-6 (IL-6) levels, muscle strength and functional capacity was investigated in a cross-sectional study of community-dwelling elderly women from Belo Horizonte, Brazil. Elderly people who present controlled chronic diseases with no negative impact on physical, psychosocial and mental functionality are considered to be community-dwelling. Psychological and social stress due to unsuccessfully aging can represent a risk for immune system disfunctions. IL-6 levels, isokinetic muscle strength of knee flexion/extension, and functional tests to determine time required to rise from a chair and gait velocity were measured in 57 participants (71.21 +/- 7.38 years). Serum levels of IL-6 were measured in duplicate and were performed within one single assay (mouse monoclonal antibody against IL-6; High-Sensitivity, Quantikine, R & D Systems, USA; intra-assay coefficient of variance = 6.9-7.4%; interassay coefficient of variance = 9.6-6.5%; sensitivity = 0.016-0.110 pg/mL; mean = 0.039 pg/mL). Muscle strength was assessed with the isokinetic dynamometer Biodex System 3 Pro. After the Shapiro-Wilk normality test was applied, correlations were investigated using Spearman and Kruskal-Wallis tests. Post hoc analysis was performed using the Dunn test. A significant negative correlation was observed between plasma IL-6 levels (1.95 +/- 1.77 pg/mL) and muscle strength for knee flexion (70.70 +/- 21.14%; r = -0.265; P = 0.047) and extension (271.84 +/- 67.85%; r = -0.315; P = 0.017). No significant correlation was observed between IL-6 levels and the functional tests (time to rise from a chair = 14.65 +/- 2.82 s and gait velocity = 0.95 +/- 0.14 m/s). These results suggest that IL-6 is associated with reduced muscle strength.