title: Male fertility is reduced by chronic intermittent hypoxia mimicking sleep apnea in mice.
abstract: OBJECTIVE
  Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia and oxidative stress. However, it is unknown whether intermittent hypoxia mimicking OSA modifies male fertility. We tested the hypothesis that male fertility is reduced by chronic intermittent hypoxia mimicking OSA in a mouse model.
  
  
  METHODS
  Case-control comparison in a murine model.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Eighteen F1 (C57BL/6xCBA) male mice.
  
  
  METHODS
  Mice were subjected to a pattern of periodic hypoxia (20 sec at 5% O2 followed by 40 sec of room air) 6 h/day for 60 days or normoxia. After this period, mice performed a mating trial to determine effective fertility by assessing the number of pregnant females and fetuses.
  
  
  RESULTS
  After euthanasia, oxidative stress in testes was assessed by measuring the expression of glutathione peroxidase 1 (Gpx1) and superoxide dismutase-1 (Sod1) by reverse-transcription polymerase chain reaction. Sperm motility was determined by Integrated Semen Analysis System (ISAS). Intermittent hypoxia significantly increased testicular oxidative stress, showing a reduction in the expression of Gpx1 and Sod1 by 38.9% and 34.4%, respectively, as compared with normoxia (P < 0.05). Progressive sperm motility was significantly reduced from 27.0 ± 6.4% in normoxia to 12.8 ± 1.8% in the intermittent hypoxia group (P = 0.04). The proportion of pregnant females and number of fetuses per mating was significantly lower in the intermittent hypoxia group (0.33 ± 0.10 and 2.45 ± 0.73, respectively) than in normoxic controls (0.72 ± 0.16 and 5.80 ± 1.24, respectively).
  
  
  CONCLUSIONS
  These results suggest that the intermittent hypoxia associated with obstructive sleep apnea (OSA) could induce fertility reduction in male patients with this sleep breathing disorder.
authors.affiliation: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Torres
authors.affiliation: INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Laguna-Barraza
authors.affiliation: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Dalmases
authors.affiliation: INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Calle
authors.affiliation: INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid.
authors.forename: Eva
authors.initials: E
authors.lastname: Pericuesta
authors.affiliation: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain ; Institut Investigacions Biomèdiques August Pi Sunyer, Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Montserrat
authors.affiliation: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Unitat Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain ; Institut Bioenginyeria Catalunya, Barcelona, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Navajas
authors.affiliation: INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Gutierrez-Adan
authors.affiliation: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Institut Investigacions Biomèdiques August Pi Sunyer, Barcelona, Spain ; Unitat Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Farré
mesh_terms: D000818:Animals; D001947:Breeding; D016022:Case-Control Studies; D004195:Disease Models, Animal; D005260:Female; D005979:Glutathione Peroxidase / Q000235:genetics; D006801:Humans; D000860:Hypoxia / Q000150:complications* / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D007248:Infertility, Male / Q000150:complications* / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress; D011247:Pregnancy; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D013081:Sperm Motility; D013482:Superoxide Dismutase / Q000235:genetics; D000072105:Superoxide Dismutase-1; D013737:Testis / Q000201:enzymology / Q000378:metabolism; D000094765:Glutathione Peroxidase GPX1
chemical_list: C000606290:SOD1 protein, human; D005979:Glutathione Peroxidase; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000094765:Glutathione Peroxidase GPX1
keywords: hypoxia; male fertility; obstructive sleep apnea; oxidative stress