INTRODUCTION AND OBJECTIVE: The body composition has been intensively investigated as a determinant of bone mineral density. The present study was developed in order to propose a predictive equation to calculate body fat percentage by means of skin folds thickness using bone densitometry (DXA) as a reference in a group of elderly women with osteoporosis and osteopenia. METHODOLOGY: Twenty-nine women, mean age 67 to 84 years old, in attendance at the Osteoporosis Clinic at Rheumatology Division, School of Medicine, University of Sao Paulo, were evaluated. Four skin folds thickness were measured (biceps, triceps, subscapular and suprailiac) and body composition by DXA was evaluated. The statistical analysis consisted of Kolmogorov-Smirnov test, Pearson's coefficient correlation, simple linear regression analysis, intra-class correlation coefficient, t Student test, Bland-Altman test and calculus of equation total error according to Lohman (1992). RESULTS: The best skinfold model that explained the percentage of body fat mass included the suprailiac, bicipital and tricipital values, determining up to 72% of body fat mass. The fat mass average values in kilograms estimated by the skin folds and measured by DXA were not statistically different and had been highly correlated (r = 0.82; p < 0.001). Comparing the fat mass percentage evaluated by the proposed equation and the percentage measured by DXA, the total error was of 0.7% and 0.4 kg. CONCLUSION: In view of the presented results, the resultant equation of the regression model is adequate for elderly women with osteoporosis and osteopenia, and may be an alternative for the body fat mass estimate in this population.
Body composition; Bone mineral density; Elderly
