ELSEVIER SCIENCE IRELAND Maturitas 18 (1994) 199-206 Relationship between skin collagen and bone changes during aging Camil Castelo-Branco* a, Francesca Ponsb, Eduard Gratac6sa, Albert Fortunya, Juan Antonio Vanrell”, Jestis Gonzhlez-Merle” “Department of Gynaecology and Obstetrics, hDepartment of Nuclear Medicine, Hospital Clinic i Provincial de Barcelona, School of Medicine, University of Barcelona, C/Villarroel 170 08036Barcelona. Spain (Received 5 March 1993; revision received I5 July 1993: accepted 19 September 1993) zyxwvutsrqponmlkjihg Abstract There is evidence that skin collagen content and bone mass are influenced by estrogen de& ciency, both of them declining in the years following menopause. The aim of our study was to analyze the relationship between changes in skin collagen content and bone mass during aging. A total of 76 nulliparous women who had been admitted for surgery of non-malignant processes were studied. All subjects were arranged into five age-groups (from 20 to 60 years). Bone mineral density was measured by dual photon absorptiometry and expressed in g/cm* as the mean of the second to fourth lumbar vertebrae. Additionally, in all patients skin biop- sies were taken from a non-sun exposed site in the lower abdomen (4 cm above the pubic sym- physis) and osteocalcin levels were determined. Collagen decreased significantly with age after the 40s (P < 0.001) and after menopause (P < 0.001). Changes in bone mass were closely related to those detected in collagen (r = 0.586; P <O.OOOl). In conclusion, our data suggest that bone mass and skin collagen decline in parallel with aging and that the hypoestrogenism developing in postmenopausal years has a significant effect on skin collagen content. Never- theless, the question of whether osteoporosis is an intrinsic collagen disorder remains to be demonstrated. Key words: Skin; Collagen; Bone mass; Bone absorptiometry; Aging; Menopause 1. introduction Skin collagen content and bone mass density share comparable regressive changes during aging. Several studies have pointed out that skin collagen is influenced by the * Corresponding author. 0378-5122/94/.$07.00 0 1994 Elsevier Science Ireland Ltd. All rights reserved SSDI 0378-5122(93)00781-N