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A Prospective Study Evaluating the Effects of Depo Proveba® on Bone Mineral Density in Adolescent Females: A Preliminary Report

1998; Elsevier BV; Volume: 11; Issue: 4 Linguagem: Inglês

10.1016/s1083-3188(98)70278-5

1873-4332

Catherine Pamela Edwards, S. Paige Hertweck, Sally E. Perlman, L. Jane Goldsmith, Joseph S. Sanfilippo,

Pharmacological Effects and Toxicity Studies

Background Depot medroxyprogesterone acetate (Depo Provera®) is a popular contraceptive method among adolescents. Little is known, however, about the long term effects of Depo Provera® on bone mineral density in adolescent females. This ongoing study prospectively evaluates the effects of Depo Provera® and oral contraceptive pills on bone mineral density, compared to normally menstruating adolescents receiving no hormonal contraception. Methods From March 1, 1995 to December 31, 1997, 55 patients aged 12 to 17 presenting for new start hormonal contraception (Depo Provera®: n = 30, oral contraceptive pills: n = 25) received baseline lumbar vertebral bone mineral density evaluation by dual energy x-ray absorptiometry (DEXA). Patients continuing with their original contraceptive method received bone mineral density evaluation every six months. Patients who subsequently discontinued hormonal contraception, became, pregnant or switched to an alternative contraceptive method were removed from the study. Exclusion criteria included prior use of hormonal contraception, previous pregnancy, and pre-existing risk factors for osteoporosis. Results Baseline DEXA scans revealed no significant difference in bone mineral density between the three groups. After 1 year, bone mineral density decreased from baseline by 0.017 gm/cm2 or 1.8% in the Depo Provera® group (n = 15), and increased by 0.030 gm/cm2 or 3.0% in the oral contraceptive group (n = 8), p = 0.013. Bone mineral density increased by 0.0093 gm/cm2 or 1.2% in the normally menstruating group over 1 year. After 18 months, bone mineral density decreased from baseline by 0.036 gm/cm2 or 3.8% in the Depo Provera® group (n = 10), and increased by 0.062 gm/cm2 or 6.1% in the oral contraceptive group (n = 4), p < 0.05. Normally menstruating adolescents (n = 6) experienced an increase of 0.0165 gm/cm2 (2.0%) in the same time period. A subset of patients receiving Depo Provera® over 24 months (n = 5) experienced a decrease of 0.222 gm/cm2 or 4.8% in bone mineral density from baseline. There were no significant differences between the Depo Provera® and oral contraceptive groups with respect to body mass index, race, smoking, alcohol consumption, or osteoporosis risk factors. Conclusions Depo Provera® administration in adolescent females appears to be associated with a decrease in bone mineral density which becomes more pronounced with long term use. This is particularly significant as peak bone mineral density is accrued during the adolescent years. Further research is needed to determine whether decreased skeletal bone mineralization induced by Depo Provera® is reversible on discontinuation of Depo Provera®, or may be prevented by the concurrent administration of anti resorptive/bone forming agents. Depot medroxyprogesterone acetate (Depo Provera®) is a popular contraceptive method among adolescents. Little is known, however, about the long term effects of Depo Provera® on bone mineral density in adolescent females. This ongoing study prospectively evaluates the effects of Depo Provera® and oral contraceptive pills on bone mineral density, compared to normally menstruating adolescents receiving no hormonal contraception. From March 1, 1995 to December 31, 1997, 55 patients aged 12 to 17 presenting for new start hormonal contraception (Depo Provera®: n = 30, oral contraceptive pills: n = 25) received baseline lumbar vertebral bone mineral density evaluation by dual energy x-ray absorptiometry (DEXA). Patients continuing with their original contraceptive method received bone mineral density evaluation every six months. Patients who subsequently discontinued hormonal contraception, became, pregnant or switched to an alternative contraceptive method were removed from the study. Exclusion criteria included prior use of hormonal contraception, previous pregnancy, and pre-existing risk factors for osteoporosis. Baseline DEXA scans revealed no significant difference in bone mineral density between the three groups. After 1 year, bone mineral density decreased from baseline by 0.017 gm/cm2 or 1.8% in the Depo Provera® group (n = 15), and increased by 0.030 gm/cm2 or 3.0% in the oral contraceptive group (n = 8), p = 0.013. Bone mineral density increased by 0.0093 gm/cm2 or 1.2% in the normally menstruating group over 1 year. After 18 months, bone mineral density decreased from baseline by 0.036 gm/cm2 or 3.8% in the Depo Provera® group (n = 10), and increased by 0.062 gm/cm2 or 6.1% in the oral contraceptive group (n = 4), p < 0.05. Normally menstruating adolescents (n = 6) experienced an increase of 0.0165 gm/cm2 (2.0%) in the same time period. A subset of patients receiving Depo Provera® over 24 months (n = 5) experienced a decrease of 0.222 gm/cm2 or 4.8% in bone mineral density from baseline. There were no significant differences between the Depo Provera® and oral contraceptive groups with respect to body mass index, race, smoking, alcohol consumption, or osteoporosis risk factors. Depo Provera® administration in adolescent females appears to be associated with a decrease in bone mineral density which becomes more pronounced with long term use. This is particularly significant as peak bone mineral density is accrued during the adolescent years. Further research is needed to determine whether decreased skeletal bone mineralization induced by Depo Provera® is reversible on discontinuation of Depo Provera®, or may be prevented by the concurrent administration of anti resorptive/bone forming agents.