Age, sex, and grip strength determine architectural bone parameters assessed by peripheral quantitative computed tomography (pQCT) at the human radius

The purpose of this study was to estimate the relation of some noninvasivel y derived mechanical characteristics of radial bone including architectural parameters for bone strength to grip strength and muscle cross-section. Si xty-three males between 21 and 78 yr of age and 101 females between 18 and 80 yr of age were measured at the nondominant forearm using peripheral quan titative computed tomography (pQCT). We assessed the integral bone mineral density (BMDI) and content (BMCI) by pQCT at the distal and at the mid-shaf t radius. Integral bone area (Area(I)), cortical thickness (C-th), and a ne wly proposed index for bone strength; the stress-strain index (SSI) were al so calculated. The dynamometrically measured maximum grip strength was take n as a mechanical loading parameter and muscle cross-section as a substitut e for it. Sex, grip strength, BMCI and BMDI (distal radius) were identified in a multiple regression analysis to significantly predict bone strength a s expressed by SSI, after adjusting for all other independent variables, in cluding age and sex (p < 0.0001). Grip strength was closest related to age, sex, BMDI and SSIp of the distal radius. The cross-sectional area of muscl e was not significantly determining the grip strength within the analysis m odel. In conclusion, our results suggested that architectural parameters at the distal radius were better related to grip strength than to cross-secti onal muscle area in both males and females. Maximum muscle strength as esti mated by grip strength might be a stronger determinant of mechanical charac teristics of bones as compared with cross-sectional muscle area. (C) 2001 E lsevier Science Ltd. All rights reserved.