MUSCLE MASS AND PHYSICAL FUNCTION IN ELDERLY GASTROINTESTINAL CANCER PATIENTS
Sarcopenia, muscle radiodensity, skeletal muscle, handgrip, gait speed.
Skeletal muscle loss, commonly known as sarcopenia, is highly prevalent in aging and associated with adverse outcomes in the elderly with cancer. However, studies of cancer patients only analyze the amount of muscle mass for the definition of sarcopenia, and lack collaborative information on muscle quality and physical function associated with this diagnosis. Therefore, the objective of the present study was to explore the association between skeletal muscle parameters and physical function in elderly individuals with cancer, from two different cut-off points in the literature. As a methodology, a cross-sectional study was performed with elderly patients with gastrointestinal cancer under treatment. Physical function was assessed by palmar grip strength (dynamometry) and gait velocity test. In order to evaluate muscle quality and quantity, computed tomographic images of the abdominal region were analyzed using O-Matic slice software (Tomovision, CA), using skeletal muscle index (SMI, cm2 / m2) and radidensity Hounsenfield - HU). The classification was made from two different cut-off points in the literature. Individuals were classified into four musculature phenotypes: SMI and normal radiodensities, low SMI only, low radiodensity only and low SMI and radiodensity. In order to compare the physical function variables among the four different phenotypes, the analysis of variance (ANOVA One Way) was used, and the Regression models were used to test the associations between muscle mass and physical function. A significance level of 5% was adopted. We evaluated 167 patients, with a higher prevalence of males (58.1%) and mean age of 69.17 ± 7.97 years. The majority of the patients were sedentary (xx%) and had low muscularity. The elderly with low radiodensity presented lower values of hand grip strength and walking speed, especially in males, but this finding was observed only in one of the cut-off points proposed in the literature. In the regression analysis, radiodensity influences physical function more, explaining 15% muscle strength and 12% walking speed. We conclude that radiodensity strongly influences the physical function of elderly patients with neoplasias of the gastrointestinal tract, and that the currently available cutoff points may not be suitable for use in the present sample.