The effects of depot medroxyprogesterone acetate and intrauterine device use on fracture risk in Danish women.
BACKGROUND
Depot medroxyprogesterone acetate (DMPA) use may be associated with an increased risk of fractures; however, nothing is known about the risk associated with intrauterine contraceptive device (IUD) use.


METHODS
Case-control study. All women with a fracture (n=64,548) in the year 2000 in Denmark served as cases. For each case, three age-matched controls were randomly drawn from the general population (n=193,641). Exposure was present or previous DMPA or IUD use (only IUD coated with hormones, not those coated solely with copper). Adjustments were made for confounders.


RESULTS
DMPA use seemed to be associated with an increased risk of fractures [odds ratio (OR)=1.44, 95% confidence interval (CI): 1.01-2.06], while IUD use appeared to be associated with a decreased risk of fractures (OR=0.75, 95% CI: 0.64-0.87).


CONCLUSIONS
DMPA use may cause an increased risk of fracture. However, the fact that use of DMPA is rare in Danish women and the lack of baseline data including smoking status and BMI does not allow causal inferences to be made. Likewise, the seemingly decreased risk of fractures with IUD use is probably not a pharmacological effect but rather the effect of residual confounding related to nonincluded confounders regarding lifestyle.
Vestergaard
Peter
P
Department of Endocrinology and Metabolism C, Aarhus Amtssygehus, DK-8000 Aarhus, Denmark. p-vest@post4.tele.dk
Rejnmark
Lars
L
Mosekilde
Leif
L
D015992:Body Mass Index; D016022:Case-Control Studies; D016001:Confidence Intervals; D015986:Confounding Factors, Epidemiologic; D003692:Delayed-Action Preparations; D003718:Denmark / Q000453:epidemiology; D005260:Female; D050723:Fractures, Bone / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D007436:Intrauterine Devices, Medicated / Q000009:adverse effects*; D008019:Life Style; D017258:Medroxyprogesterone Acetate / Q000009:adverse effects* / Q000494:pharmacology*; D008875:Middle Aged; D016017:Odds Ratio; D012042:Registries; D018570:Risk Assessment; D013997:Time Factors
D003692:Delayed-Action Preparations; D017258:Medroxyprogesterone Acetate