A cross-sectional study of the forearm bone density of long-term users of levonorgestrel-releasing intrauterine system.
BACKGROUND
There are concerns about the effect of hormonal contraceptives on bone mineral density (BMD), but there is currently no information available on the effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) on BMD. The objective of this study was to compare the BMD of LNG-IUS users with that of controls using the TCu380A intrauterine device (IUD).


METHODS
A cross-sectional study paired 53 women, aged 25-51 years, who had been using the LNG-IUS for 7 years, with 53 IUD users, according to age (+/-1 year) and body mass index (BMI; kg/m2) (+/-1). BMD was evaluated at the midshaft of the ulna and the distal radius of the nondominant forearm using double X-ray absorptiometry.


RESULTS
Mean age of women was 34 years. BMI was slightly over 25 in both groups. Estradiol was normal. Mean BMD was 0.469 +/- 0.008 and 0.467 +/- 0.009 and 0.409 +/- 0.009 and 0.411 +/- 0.009 at the midshaft of the ulna and distal radius in LNG-IUS and IUD users, respectively, without significant differences.


CONCLUSIONS
Women aged 25-51 years, using the LNG-IUS for 7 years, had a mean BMD similar to that of the control group of TCu380A IUD users.
Bahamondes
Luis
L
Human Reproduction Unit, Department of Obstetrics and Gynaecology, School of Medicine, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil. bahamond@caism.unicamp.br
Espejo-Arce
Ximena
X
Hidalgo
Maria M
MM
Hidalgo-Regina
Creusa
C
Teatin-Juliato
Cássia
C
Petta
Carlos A
CA
D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood; D005260:Female; D005542:Forearm / Q000000981:diagnostic imaging; D006801:Humans; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage*; D008875:Middle Aged; D011884:Radius / Q000528:radiation effects*; D014457:Ulna / Q000528:radiation effects*
D003271:Contraceptive Agents, Female; D004958:Estradiol; D016912:Levonorgestrel