Calcif Tissue Int (1995) 56:410--414 Calcified Tissue International 9 1995 Springer-Verlag New York Inc. Appendicular Cortical Bone Loss After Age 65: Sex-Dependent Event? D. Maggio, 1 R. Pacifici, 2 A. Cherubini, 1 M. C. Aisa, 3 C. Santucci, 4 D. Cucinotta, s U. Senin 1 1Department of Gerontology and Geriatrics, University of Perugia, Italy 2Division of Bone and Mineral Diseases, Washington University School of Medicine, The Jewish Hospital of St. Louis, St. Louis, Missouri ~Department of Biochemistry, University of Perugia, Italy 4Department of Biometrics and Statistics, University of Perugia, Italy 5Geriatrics Division, Malpighi Hospital, Bologna, Italy Received: 29 September 1994 / Accepted: 15 November 1994 Abstract. Distal radius photodensitometric and second metacarpal radiogrammetric measurements were obtained from computerized analyses of standard hand X-Ray films of 296 Caucasian subjects (189 women and 107 men). This sam- ple included 134 subjects >/65 years old (75 women and 59 men). Distal radius bone density and metacarpal index showed a significant linear decrease with age in both sexes. Rates of bone loss, calculated from the regression curves, were -0.7% per year in women and -0.5% per year in men by distal radial photodensitometry, and -0.49% per year in women and -0.33% per year in men by metacarpal radio- grammetry. In the elderly subgroup, women />65 years of age showed an even faster bone loss, with an annual de- crease of -1.4% by distal radial photodensitometry. Con- versely, men ~>65 years of age had no significant bone loss, not even by metacarpal radiogrammetry. In conclusion, these data suggest that appendicular cortical bone loss oc- curs at a higher rate in elderly females than in the elderly males, both at the distal radial and at the metacarpal site. Key words: Cortical bone -- Trabecular bone -- Radiogram- metry -- Photodensitometry. Cortical bone loss is largely dependent on a series of age- related metabolic changes [1]. Among them are calcium and vitamin D deficiency, impaired calcium absorption, impaired target tissue responsiveness to calcitriol, and diminished re- nal 1-alpha-hydroxylase activity [1-7]. These events trigger a mild form of secondary hyperparathyroidism, which leads to cortical bone loss and porosity, and to a resulting increase in hip fracture risk [8-11]. Though this metabolic pattern in- creases the risk of cortical demineralization in the elderly, longitudinal studies suggest that the rate of bone loss con- siderably slows in the majority of women after age 70 [12, 13]. However, these data have been obtained from small cohorts of elderly subjects of either sex, followed for several years. The information is limited on cortical demineraliza- tion rate in males and in the last decades of life [14]. The Correspondence to: D. Maggio present cross-sectional study was conducted on a sample including a sufficiently large subgroup of both normal men and women above 65, in order to obtain additional data on cortical bone loss in the elderly. Materials and Methods Subjects Bone mineral density of the distal radius and cortical index of the second metacarpal bone were measured in 296 Caucasian subjects by photodensitometry and radiogrammetry, respectively. All gave their informed consent and the project was approved by our Insti- tution Ethics Committee. There were 189 women aged 59.8 - 13.0 (mean +- SD) years, range 30-87, and 107 men aged 62.9 - 12.9 (mean -+ SD) years, range 36-88. Of these, 134 subjects were 65 years of age or older (75 women and 59 men). True cross-secti0nal sampling was not possible, but the subjects were generally repre- sentative of the normal Italian population. Most of the younger sub- jects were hospital employees and their friends. The more elderly subjects were recruited from local social clubs. All persons were ambulatory, and had at least one intact forearm hand. None of them had chronic illnesses or recognized disorders of calcium metabo- lism, and none had given a history of alcohol and tobacco abuse or had taken drugs with a negative impact on bone. No subject had suffered from diseases and/or conditions (such as stroke or periph- eral palsy) potentially limiting motility in the upper limbs. Height, weight, body mass index (BMI), and age at menopause were mea- sured and recorded. Height, weight, and BMI were tested and proved to belong to a sample with a normal distribution. Bone Mass Measurements Radial Photodensitometry. Bone density was measured with an in- strument (QR OSTEORADIOMETER, Verona, Italy) capable of deriving photodensitometric and radiogrammetric readings of the distal radius and of the second metacarpal bone, respectively, from a hand X-Ray image [15, 16]. With this device, a standard A-P X-Ray image of the nondominant hand and distal forearm is cap- tured by a video camera and digitalized. Grey levels of this image can be modified and quantified against a proper reference standard. Radiographs are taken at a standard kilovoltage setting (45 Kvp for 1 second, at 300 mA) using nonscreened 3M film. Focus-film dis- tance is maintained within a narrow range (120-130 cm). An alumi- num alloy reference wedge (phantom) is placed parallel to the distal