title: Low-dose combined oral contraceptive use is associated with lower bone mineral content variation in adolescents over a 1-year period.
abstract: BACKGROUND
  Low-dose combined oral contraceptives (COCs) can interfere with bone mass acquisition during adolescence. This study aimed to evaluate bone mineral density (BMD) and bone mineral content (BMC) in female adolescents taking a standard low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) over a 1-year period and to compare their data with those of healthy adolescents from the same age group not taking COCs.
  
  
  METHODS
  This was a non-randomized parallel-control study with a 1-year follow-up. Sixty-seven adolescents aged from 12 to 19 years, divided into COC users (n = 41) taking 20 μg ethinylestradiol/150 μg desogestrel and COC non-user controls (n = 26), were evaluated by bone densitometry examinations at baseline and after 12 months. Comparisons between the groups at the study onset were performed using the Mann-Whitney test with the significance level fixed at 5% or p < 0.05. Comparisons between the groups at the study onset and after 12 months were based on variations in the median percentages for bone mass variables.
  
  
  RESULTS
  The COC users presented with low bone mass acquisition in the lumbar spine, and had BMD and BMC median variations of 2.07% and +1.57%, respectively, between the measurements at baseline and 12 months. The control group had median variations of +12.16% and +16.84% for BMD and BMC, respectively, over the same period. The total body BMD and BMC showed similar evolutions during the study in both groups. Statistical significance (p < 0.05) was seen for the BMC percentage variation between COC users and non-users.
  
  
  CONCLUSIONS
  Use of a low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) was associated with lower bone mass acquisition in adolescents during the study period.
  
  
  BACKGROUND
  Registry Number, RBR-5h9b3c.
authors.affiliation: Department of Pediatrics, Adolescent Medicine Discipline, Graduate Program in Gynecology, Obstetrics, and Mastology, Botucatu School of Medicine, São Paulo State University (UNESP), São Paulo, Brazil. talitapoli@uol.com.br.
authors.forename: Talita Poli
authors.initials: TP
authors.lastname: Biason
authors.affiliation: Department of Pediatrics, Adolescent Medicine Discipline, Graduate Program in Gynecology, Obstetrics, and Mastology, Botucatu School of Medicine, São Paulo State University (UNESP), São Paulo, Brazil. tamara@fmb.unesp.br.
authors.forename: Tamara Beres Lederer
authors.initials: TB
authors.lastname: Goldberg
authors.affiliation: Clinical and Experimental Pediatrics Research Center, Department of Pediatrics, Botucatu Medical School, São Paulo State University (UNESP), São Paulo, Brazil. kurokawa@fmb.unesp.br.
authors.forename: Cilmery Suemi
authors.initials: CS
authors.lastname: Kurokawa
authors.affiliation: Clinical and Experimental Pediatrics Research Center, Department of Pediatrics, Botucatu Medical School, São Paulo State University (UNESP), São Paulo, Brazil. rmoretto@fmb.unesp.br.
authors.forename: Maria Regina
authors.initials: MR
authors.lastname: Moretto
authors.affiliation: Department of Tropical Diseases and Diagnostic Imaging, Botucatu School of Medicine, São Paulo State University (UNESP), São Paulo, Brazil. altamirsteixeira@gmail.com.
authors.forename: Altamir Santos
authors.initials: AS
authors.lastname: Teixeira
authors.affiliation: Statistical Consultant, Botucatu School of Medicine, São Paulo State University (UNESP), São Paulo, Brazil. helio@conspart.com.br.
authors.forename: Hélio Rubens de Carvalho
authors.initials: HR
authors.lastname: Nunes
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000187:drug effects*; D002648:Child; D003276:Contraceptives, Oral / Q000627:therapeutic use*; D003277:Contraceptives, Oral, Combined / Q000627:therapeutic use*; D017135:Desogestrel / Q000008:administration & dosage; D004997:Ethinyl Estradiol / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D004997:Ethinyl Estradiol; D017135:Desogestrel