Relationships between bone and skin atrophies during aging.

Bone mineral density (BMD) was measured in 133 female subjects (age: 61.7 +/- 16.3 years) by dual energy X-ray absorptiometry (DEXA). Vertebral bone mineral density (BMD; L1-L4) and BMD of the whole upper femoral extremity were taken into account. In addition, skinfold thickness was measured with a callipers on the dorsum of the nondominant hand. A significant negative correlation was found between skinfold thickness and age (r = -0.623, p less than 0.0001). Both vertebral and femoral BMD decreased with age and the slopes were similar to those observed by other authors. Skinfold thickness was significantly correlated with vertebral (r = 0.364, p less than 0.0001) and femoral BMD (r = 0.486, p less than 0.0001). Skin and bone are connective tissues whose extracellular matrix mainly contains type I collagen. It is postulated that age-related skin atrophy and bone atrophy have a common genetic mechanism. Skinfold thickness measurement may help in defining the women at risk for osteoporotic bone fractures who should be referred for a DEXA examination.