In healthy older adults, the two-minute step test (2MST) does not have its concurrent validity tested against the six-minute walk test (6MWT), which is a valid cardiorespiratory fitness test frequently applied in geriatric samples. To derive an equation to predict 6MWT from 2MST and to observe the agreement between observed and estimated 6MWT distances. 6MWT and 2MST were measured in 51 older adults (72.9±4.6 years) from community multicomponent exercise programs. Multiple linear regression derives the predictive equation of 6MWT walked distance (dependent outcome) from steps obtained in 2MST, age, sex, and body mass index (independent outcomes). Correlation between 6MWT and 2MST was strong (r=0.696, p<0.001). The regression equation showed good agreement with measured values, when 6MWT was below 600 m. The equation stands as a novel approach to obtaining a valid 6MWT estimation from the 2MST. 2MST is easier and faster, representing an alternative approach when time and space are limited.
1 July 2020 in Archives of Gerontology and Geriatrics
Body composition alterations, or lipodystrophy, can lead to serious health problems in people living with HIV/AIDS (PLWHA). The objectives of this study are to predict and validate sex-specific anthropometric predictive models for the diagnosis of lipodystrophy in PLWHA. A cross-sectional design was employed to recruit 106 PLWHA (men = 65 and women = 41) in Brazil during 2013–2014. They were evaluated using dual-energy X-ray absorptiometry, and 19 regions of body perimeters and 6 skinfold thicknesses were taken. Sex-specific predictive models for lipodystrophy diagnosis were developed through stepwise linear regression analysis. Cross-validations using predicted residual error sum of squares was performed to validate each predictive model. Results support the use of anthropometry for the diagnosis of lipodystrophy in men and women living with HIV/AIDS. A high power of determination with a small degree of error was observed for lipodystrophy diagnosis for men in model six (r2 = 0.77, SEE = 0.14, r2PRESS = 0.73, SEE PRESS = 0.15), that included ratio of skinfold thickness of subscapular to medial calf, skinfold thickness of thigh, body circumference of waist, formal education years, time of diagnosis to HIV months, and type of combined antiretroviral therapy (cART) (with protease inhibitor “WI/PI = 1” or without protease inhibitor “WO/PI = 0”); and model five for women (r2 = 0.78, SEE = 0.11, r2PRESS = 0.71, SEE PRESS = 0.12), that included skinfold thickness of thigh, skinfold thickness of subscapular, time of exposure to cART months, body circumference of chest, and race (Asian) (“Yes” for Asian race = 1; “No” = 0). The proposed anthropometric models advance the field of public health by facilitating early diagnosis and better management of lipodystrophy, a serious adverse health effect experienced by PLWHA.
24 February 2023 in Archives of Gerontology and Geriatrics
Background: Dynamic knee extensor muscle strength is a valid measure among healthy older adults but has not been tested in the sarcopenia condition. This study’s objective was to test the validity of a one-repetition submaximal strength protocol to measure dynamic knee extension strength in older adults with and without sarcopenia. Methods: Ninety-four physically independent older adults (female: n = 64, 60 to 85 years; male: n = 29, 60 to 85 years) participated in this study in Brazil during 2016–2017. Sarcopenia was classified and isokinetic unilateral knee extension strength was measured at 60°/s. Bilateral dynamic knee extension strength was estimated with an extensor chair using one-repetition submaximal protocol. Validity was determined using Spearman’s correlation with isokinetic muscle strength. Results: The frequency of sarcopenia was 11.7%. Sarcopenic individuals presented lower body mass, body mass index and skeletal muscle index. Only chronological age was higher among the sarcopenic individuals. A high correlation was found between isokinetic unilateral knee extension strength and bilateral estimated one-repetition with submaximal protocol (r = 0.74; p < 0.001), when the presence (r = 0.71; p = 0.014) and absence of sarcopenia (r = 0.74; p < 0.001) were considered. The validity of the one-repetition submaximal protocol for bilateral knee extension was confirmed. Conclusions: The estimated measure of bilateral knee extension muscle strength can be used to monitor adaptations promoted by physical exercise for older adults with and without sarcopenia. The validation enable studies that will propose cutoff points to identify sarcopenia with this submaximal protocol. This will enable early diagnosis and better management of sarcopenia, a disease with adverse impacts for older adults.
2 March 2022 in Journal of the American Medical Directors Association