Maturitas 55 (2006) 317–324 Influence of pattern of menopausal transition on the amount of trabecular bone loss Results from a 6-year prospective longitudinal study V. Seifert-Klauss a,∗ , T. Link c , C. Heumann d , P. Luppa b , M. Haseitl a , J. Laakmann a , J. Rattenhuber a , M. Kiechle a a Frauenklinik und Poliklinik, Technische Universit¨ at M ¨ unchen, Klinikum rechts der Isar, Ismaninger Str. 22, 81675 M¨ unchen, Germany b Institut f ¨ ur Klinische Chemie und Pathobiochemie, Technische Universit¨ at M ¨ unchen, Germany c Department of Radiology, University of San Francisco, United States d Institut f ¨ ur Statistik, Ludwig-Maximilian-Universit¨ at, M ¨ unchen, Germany Received 11 November 2005; received in revised form 22 April 2006; accepted 26 April 2006 Abstract Introduction: Bone density is lower in postmenopausal than in premenopausal women. Recent findings have suggested that accelerated bone loss already begins before menopause. Despite numerous cross-sectional studies on menopause-related bone density, longitudinal data on perimenopausal bone density changes are scarce. This study sought to characterize the dynam- ics of changes leading to postmenopausal osteopenia and to possibly find the time point at which accelarated bone loss begins. Methods: We prospectively followed 34 pre-, peri- and early postmenopausal women without prior external hormone use, measuring their lumbar spine trabecular bone density with quantitative computer tomography at 0, 2 and 6 years. The analysis of the changes over time was done in a tri-parted fashion, since menopausal status changed variably for individual subjects: we grouped the participants according to their currently valid menopausal classification for prospective (baseline classification), interim (2 years) and retrospective (6-year classification) analysis. Results: Six different patterns of menopausal transition were identified in our sample. Bone loss in the groups not reaching postmenopause during 6 years of observation was >50% of the maximum bone loss observed during the study period. Invariably for all analyses, the perimenopausal phase with estrogen levels still adequate was associated with the greatest reduction of trabecular bone mineral density, reaching 6.3% loss annually in the lumbar spine. By comparison, the average rate of loss was slower in the early postmenopause; total bone loss differed by pattern of menopausal transition (one-way ANOVA p < 0.05). ∗ Corresponding author. Tel.: +49 89 4140 5434; fax: +49 89 4140 4912. E-mail address: vanadin.seifert-klauss@lrz.tum.de (V. Seifert-Klauss). 0378-5122/$ – see front matter © 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2006.04.024