title: Detrimental effect of oral contraceptives on parameters of bone mass and geometry in a cohort of 248 young women.
abstract: The aim of this cross-sectional analysis was to examine the skeletal effects of low-dose monophasic oral contraceptive (OC) use in a cohort of 248 young Caucasian women aged 18-24 years. Areal bone mineral density (BMD) of the femoral neck and lumbar spine was evaluated by dual-energy X-ray absorptiometry. Volumetric BMD, bone mineral content (BMC), and bone geometry were assessed in the tibia by peripheral quantitative computed tomography (pQCT). The women were allocated into ever or never OC users, and also into 5 different OC groups according to duration and time of initiation of OC use. Women with >2 years of OC use and OC initiation within 3 years after menarche were characterized by 10% lower femoral neck areal BMD (P<0.001), 5% lower spine areal BMD (not significant, P=0.101), 7% lower distal tibial total BMC (P<0.05), and 6% lower total BMC at the tibial shaft (P<0.05) relative to never users. In addition, women who had ever used OCs had lower bone mass at the femoral neck and tibial shaft, despite similar age, height, weight, BMI, hours of exercise, and calcium intake compared with never users. At the tibial shaft, OC users showed reduced total cross-sectional area, and increased cortical BMD. In conclusion, our data suggest that OC use is associated with a detrimental effect on bone mass in young women, and provide further insight into the pathophysiological mechanisms involved.
authors.affiliation: Working Group MusculoSkeletal Interactions, Department of Gynecology and Obstetrics, Faculty of Medicine, Klinikum Grosshadern, Ludwig Maximilians Universität, 81377 Munich, Germany. Manfred.Hartard@t-online.de
authors.forename: Manfred
authors.initials: M
authors.lastname: Hartard
authors.forename: Christine
authors.initials: C
authors.lastname: Kleinmond
authors.forename: Michael
authors.initials: M
authors.lastname: Wiseman
authors.forename: Ernst R
authors.initials: ER
authors.lastname: Weissenbacher
authors.forename: Dieter
authors.initials: D
authors.lastname: Felsenberg
authors.forename: Reinhold G
authors.initials: RG
authors.lastname: Erben
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D003276:Contraceptives, Oral / Q000008:administration & dosage / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000187:drug effects*; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects*
chemical_list: D003276:Contraceptives, Oral