Objectives: Investigate the presence of a correlation between systemic inflammatory profile of community-dwelling individuals and the loss of muscular mass and performance in old age over a 4.5y follow-up, focusing on the role of anti-inflammatory cytokines in muscular changes in elderly.
Design: Longitudinal clinical study.
Setting: Subjects were randomly selected from lists of 11 general practitioners in the city of Verona, Italy.
Participants: The study included 120 subjects, 92 women and 28 men aged 72.27±2.06 years and with BMI of 26.52±4.07 kg/m2 at baseline.
Measurements: Six minutes walking test (6MWT), appendicular and leg fat free mass (FFM) as measured with Dual Energy X-ray absorptiometry, were obtained at baseline and after 4.5 years (4.5y) of mean follow-up. Height, weight, body mass index (BMI), and circulating levels of TNFα, IL-4, IL-10, and IL-13 were evaluated at baseline.
Results: A significant reduction of appendicular FFM, leg FFM and 6MWT performance (all p<0.001) was observed after 4.5 y follow-up. In a stepwise regression model, considering appendicular FFM decline as dependent variable, lnIL-4, BMI, baseline appendicular FFM, lnTNFα and lnIL-13 were significant predictors of appendicular FFM decline explaining 30.8% of the variance. While building a stepwise multiple regression considering leg FFM as a dependent variable, lnIL-4, BMI and leg FFM were significant predictors of leg FFM decline and explained 27.4% of variance. When considering 6MWT decline as a dependent variable, baseline 6MWT, lnIL-13 and lnTNFα were significant predictors of 6MWT decline to explain 22.9% of variance.
Conclusions: Our study suggest that higher serum levels of anti-inflammatory markers, and in particular IL-4 and IL-13, may play a protective role on FFM and performance maintenance in elderly subjects.
Keywords: Muscle mass; anti-inflammatory cytokines; physical performance.