APPENDICULAR LEAN SOFT TISSUE: DEVELOPMENT AND CROSS-VALIDATION OF PREDICTIVE MODELS FOR OLDER MEN AND WOMEN
I.C. Gomes, L.A. Gobbo, A.M. Silva, I.F. Freitas Junior, Y.A.O. Duarte, M.F.N. Marucci, V.R. dos Santos, M.L. Lebrão
J Frailty Aging 2013;2(2):62-67
Background: Sarcopenia may explain, in a large proportion, physical disability, falls and fractures, especially in aged elderly. However, a diagnosis in an operationally systematic, simple and low cost way is extremely important, particularly for home-based, epidemiological studies. Objective: The purpose of this study was to develop and validate predictive equations of appendicular lean soft tissue (ALST) in elderly older than 80 years. Design and settings: A validation study was performed in 106 elderly (men and women) aged 80 years and older. Measurements: Body weight, height, circumference (arm, midcalf, hip and waist) and triceps skinfold were measured in the elderly. ALST were measured using as the reference method dual-energy X-ray absorptiometry (DXA). Results: Two models were predicted. The first model (ALST, in kg = 0.074*height + 0.277*weight – 0.144*triceps skinfold – 0.103*waist circumference + 1.831*gender -0.966), which considered all possible variables in stepwise multiple regression, presented better statistical performance (r2 = 0.82; SEE = 1.67 kg), compared to the second model (ALST, in kg = 0.138*height + 0.103*weight + 3.061*gender – 12.489), a more practical equation, due to a lesser quantity of predictive variables (r2 = 0.75; SEE = 1.94 kg). Both models were validated, however, it was verified trend (p<0.05) for overestimation of predicted ALST. Conclusion: In summary, two models for predicting ALST in men and women with age ≥ 80 years were developed and cross-validated. Model 1, with a greater number of predictive variables, presented a better accuracy than did the model with only three variables (height, weight, and gender). Validation studies are needed to test the usefulness of both models in other populations.
I.C. Gomes ; L.A. Gobbo ; A.M. Silva ; I.F. Freitas Junior ; Y.A.O. Duarte ; M.F.N. Marucci ; V.R. dos Santos ; M.L. Lebrão (2013): Appendicular lean soft tissue: development and cross-validation of predictive models for older men and women . The Journal of Frailty and Aging (JFA). http://dx.doi.org/10.14283/jfa.2013.10