title: Association of estrogen receptor alpha gene polymorphisms with autonomic modulation of heart rate in users and nonusers of oral contraceptives.
abstract: BACKGROUND
  This study examined the association between estrogen receptor α gene (ESR1) polymorphisms and blood pressure (BP), heart rate (HR) and autonomic modulation of HR in a sample population.
  
  
  METHODS
  Two hundred thirty-two young healthy women were selected, and those using oral contraceptives (OC) were compared with nonusers (control group). Short-term HR variability (HRV) was evaluated in both the supine and sitting positions using temporal indices rMSSD [square root of the mean squared differences of successive R-R intervals (RRi) divided by the number of RRi minus one], SDNN (root mean square of differences from mean RRi, divided by the number of RRi) and frequency domain methods. Power spectral components were reported at low frequency (LF) and high frequency (HF) and as LF/HF ratio. ESR1 c.454-397T>C (rs2234693) and c.454-351A>G (rs9340799) polymorphisms were determined by polymerase chain reaction and fragment restriction analysis.
  
  
  RESULTS
  The ESR1 T>C and A>G polymorphisms had no effect on HR, rMSSD, SDNN, LF, HF or LF/HF ratio (supine or sitting), independently of OC use. The ESR1 T-A, T-G, C-A and C-G haplotypes were not associated with HR, BP or HRV.
  
  
  CONCLUSIONS
  ESR1 variants had no effect on the autonomic modulation of HR in young women users and nonusers of OC and may not be implicated in cardiovascular risk in young women.
authors.affiliation: Federal University of Goiás, Department of Morphology, (Campus II), 74001-970 - Caixa Postal: 13, Goiânia, GO, Brazil. anacristina.silvarebelo@gmail.com
authors.forename: Ana Cristina S
authors.initials: AC
authors.lastname: Rebelo
authors.forename: Rozangela
authors.initials: R
authors.lastname: Verlengia
authors.forename: Vandeni C
authors.initials: VC
authors.lastname: Kunz
authors.forename: Nayara Y
authors.initials: NY
authors.lastname: Tamburus
authors.forename: Marcos Felipe
authors.initials: MF
authors.lastname: Silva de Sá
authors.forename: Rosario D C
authors.initials: RD
authors.lastname: Hirata
authors.forename: Alvaro
authors.initials: A
authors.lastname: Cerda
authors.forename: Mario H
authors.initials: MH
authors.lastname: Hirata
authors.forename: Ester
authors.initials: E
authors.lastname: da Silva
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D001938:Brazil / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D017135:Desogestrel / Q000009:adverse effects; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D004967:Estrogens / Q000009:adverse effects*; D004997:Ethinyl Estradiol / Q000009:adverse effects; D005260:Female; D056726:Genetic Association Studies; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007438:Introns; D016912:Levonorgestrel / Q000009:adverse effects; D009652:Norpregnenes / Q000009:adverse effects; D020641:Polymorphism, Single Nucleotide; D011372:Progestins / Q000009:adverse effects*; D012307:Risk Factors
chemical_list: D003277:Contraceptives, Oral, Combined; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D004967:Estrogens; D009652:Norpregnenes; D011372:Progestins; C033273:Gestodene; D004997:Ethinyl Estradiol; D016912:Levonorgestrel; D017135:Desogestrel