We made longitudinal measurements of bone mineral density (BMD) in 139 normal women (ages 20-88 yr) at midradius (99% cortical bone) and lumbar spine (approximately 70% trabecular bone) by single- and dual-photon absorptiometry. BMD was measured 2-6 (median, 3) times over an interval of 0.8-3.4 yr (median, 2.1 yr). For midradius, BMD did not change (+0.48%/yr, NS) before menopause but decreased (-1.01%/yr, P less than 0.001) after menopause. For lumbar spine, there was significant bone loss both before (-1.32%/yr, P less than 0.001) and after (-0.97%/yr, P = 0.006) menopause; these rates did not differ significantly from each other. Our data show that before menopause little, if any, bone is lost from the appendicular skeleton but substantial amounts are lost from the axial skeleton. Thus, factors in addition to estrogen deficiency must contribute to pathogenesis of involutional osteoporosis in women because about half of overall vertebral bone loss occurs premenopausally.
B L Riggs, H W Wahner, L J Melton 3rd, L S Richelson, H L Judd, K P Offord
Usage data is cumulative from March 2024 through March 2025.
Usage | JCI | PMC |
---|---|---|
Text version | 296 | 21 |
89 | 45 | |
Scanned page | 215 | 14 |
Citation downloads | 54 | 0 |
Totals | 654 | 80 |
Total Views | 734 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.