Effects of levonorgestrel-releasing subdermal contraceptive implants on bone density and bone metabolism

A prospective, randomized clinical trial observed the effects of Norplant(R ) long-term contraceptive implants and domestic implants similar to Norplan t on bone mineral density cmd bone metabolism in female accepters for 1 yea r. Bone mineral density (BMD) and bone mineral content (BMC) of lumbar 2-4 and proximal femur of 61 normal women of child-bearing age were measured by dual energy x-ray absorptiometry (DEXA) before and 12 months after implant s insertion in both groups. BMD and BMC of lumbar 2-4 in both groups 12 mon ths after implant insertion significantly increased (p <0.01); with an aver age increase of 2.40% and 3.34%, respectively in the Norplant implant group , and 2.75% and 4.47%, respectively in the domestic implant group. Urine hy droxyproline and creatinine ratio (Hop/Cr) in the domestic implant group si gnificantly decreased (p <0.01). There was no significant differences in th e effects on BMD and BMC of lumbar spine and femur and on bone metabolism b etween the two groups of contraceptive implants (p >0.05). Levonorgestrel r eleasing contraceptive subdermal implants were not deleterious to the skele ton in women of child-bearing age. There was no significant effect on achie ving maximum bone mass in young women.