RESPIRATORY MUSCLE STRENGTH AS A DISCRIMINATOR OF SARCOPENIA IN COMMUNITY-DWELLING ELDERLY: A CROSS-SECTIONAL STUDY

Objectives: To compare the values obtained from maximum respiratory pressures (MRP) between sarcopenic and non-sarcopenic elderly; to verify the association of maximum respiratory pressures with sarcopenia and its indicators; and to establish cut-off points for MRP as a discriminator of sarcopenia. Design: Cross-sectional study. Location: Macapa, Brazil. Participants: Community-dwelling elderly >= 60 years old, both sexes. Measures: Evaluation of respiratory muscle strength (maximal inspiratory pressure - MIP and maximal expiratory pressure - MEP) and sarcopenia, according to the European Working Group on Sarcopenia in Older People (EWGSOP), in which the diagnosis of this condition considered the reduction of muscle mass (muscle mass index - MMI) associated with muscle strength reduction (hand grip strength - HGS) and / or impairment in physical performance (gait speed - GS). Results: The sample consisted of 383 elderly individuals, with a mean age of 70.02 +/- 7.3 years and a prevalence of sarcopenia of 12.53% (n = 48). Sarcopenic individuals presented significantly lower (obtained, obtained versus predicted) mean values for the maximal respiratory pressures compared to the non-sarcopenic elderly, and these were inversely associated with sarcopenia (an increase by 1 cmH2O in MIP and MEP reduced by 5% and 3%, respectively, the probability of sarcopenia). In relation to the association with the sarcopenia indicators, the increase by 1 cmH2O in MIP and MEP decreased, respectively, the probability of decreasing muscle strength (3% and 2%), GS (3% and 4%) and MMI (3 % - MIP). Cut-off points <= 60 cmH2O and <= 50 cmH2O for MEP and <= 55 cmH2O and <= 45 cmH2O for MEP, respectively for elderly men and women, served as a discriminant criterion for the presence of sarcopenia (area under the ROC curve superior to 0.70). Conclusions: Elderly patients with sarcopenia had lower MIP and MEP values when compared to non-sarcopenic individuals, and respiratory muscle strength was inversely associated with the diagnosis of sarcopenia and its indicators (HGS, gait speed and MMI). Furthermore, cut-off points for MIP and MEP can be used in clinical practice as discriminators of sarcopenia in community-dwelling elderly.