[Changes with age in adiposity and lean body mass in a healthy Spanish population]

The reduction in muscular mass with age is well-known, and thus in order to obtain reference values, the behaviour of the LBM and corporal adiposity (FM) in a standard population was studied. Of a total of 217 patients considered a priori as healthy, 172 were selected following a strict application of criteria based on clinical examination, haematological analysis and biochemical parameters, as well as hormone concentrations, aimed showed urinary elimination of creatinine (Cro) of between (+ - DE) within the theoretical level for their weight and age. In this standard population, the behaviour of the LBM and FM was studied depending on age, using for this purpose creatinine at 24 hours, weight and size, and different calculation procedures. The reduction in LBM showed a better correlation with age when calculated based on Cro (r = 0.47; p < 0.01) than on height (r = -0.27; p < 0.01). The age correlation was similar for both sexes (women: r = -0.60; men: r = -0.65) and reduction in LBM started to be considerable from the fifth decade and could be calculated from the regression equation LBM = 64.6 - 0.00069. age (days). At the same time as this reduction in LBM, there was an increase in FM (p < 0.0001). Our results show that the reduction of LBM and increase in FM with age in a healthy Spanish population is similar to other foreign studies published. It is preferable to correct the LBM with age using Cro, which can be calculated using the above-mentioned linear regression equation, regardless of sex.