title: The relationship between sperm viability and DNA fragmentation rates.
abstract: BACKGROUND
  In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation rate of >30% indicating subfertility. We postulated that in some men, the sperm viability assay could predict the sperm DNA fragmentation rates. This in turn could reduce the need for sperm DNA fragmentation assay testing, simplifying the infertility investigation and saving money for infertile couples.
  
  
  METHODS
  All men having semen analyses with both viability and DNA fragmentation testing were identified via a prospectively collected database. Viability was measured by eosin-nigrosin assay. DNA fragmentation was measured using the sperm chromosome structure assay. The relationship between DNA fragmentation and viability was assessed using Pearson's correlation coefficient.
  
  
  RESULTS
  From 2008-2013, 3049 semen analyses had both viability and DNA fragmentation testing. A strong inverse relationship was seen between sperm viability and DNA fragmentation rates, with r=-0.83. If viability was ≤50% (n=301) then DNA fragmentation was ≥ 30% for 95% of the samples. If viability was ≥75% (n=1736), then the DNA fragmentation was ≤30% for 95% of the patients. Sperm viability correlates strongly with DNA fragmentation rates.
  
  
  CONCLUSIONS
  In men with high levels of sperm viability≥75%, or low levels of sperm viability≤ 30%, DFI testing may be not be routinely necessary. Given that DNA fragmentation testing is substantially more expensive than vitality testing, this may represent a valuable cost-saving measure for couples undergoing a fertility evaluation.
authors.affiliation: Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. msamplaski@gmail.com.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Samplaski
authors.affiliation: Department of Pathology, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. dimitromanolakis@gmail.com.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Dimitromanolakis
authors.affiliation: Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. klo@mtsinai.on.ca.|Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada. klo@mtsinai.on.ca.
authors.forename: Kirk C
authors.initials: KC
authors.lastname: Lo
authors.affiliation: Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. egrober@mtsinai.on.ca.
authors.forename: Ethan D
authors.initials: ED
authors.lastname: Grober
authors.affiliation: Department of Pathology, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. bmullen@mtsinai.on.ca.
authors.forename: Brendan
authors.initials: B
authors.lastname: Mullen
authors.affiliation: Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. alaina.garbens@utoronto.ca.
authors.forename: Alaina
authors.initials: A
authors.lastname: Garbens
authors.affiliation: Division of Urology, Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. kjarvi@mtsinai.on.ca.|Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada. kjarvi@mtsinai.on.ca.|Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada. kjarvi@mtsinai.on.ca.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Jarvi
mesh_terms: D053938:DNA Fragmentation; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis / Q000235:genetics; D008297:Male; D055101:Semen Analysis