title: High body mass index has a deleterious effect on semen parameters except morphology: results from a large cohort study.
abstract: OBJECTIVE
  To evaluate the influence of body mass index (BMI) on semen characteristics.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Single private andrology laboratory.
  
  
  METHODS
  All patients (n=10,665) consulting for a semen analysis from October 9, 2010, to October 8, 2011. When analyses were repeated on the same patient, only the first was included.
  
  
  METHODS
  Recording of self-reported weight and height and of semen analysis.
  
  
  METHODS
  All parameters of standard semen analysis: pH, volume, sperm concentration per mL, total sperm count per ejaculate, motility (%) within 1 hour after ejaculation (overall and progressive), viability (%), and normal sperm morphology (%). Parametric and nonparametric statistical methods were applied, and results are given either with mean±SD, or 10th, 50th, and 90th percentiles.
  
  
  RESULTS
  Semen volume decreased from 3.3±1.6 to 2.7±1.6 mL when BMI increased from normal (20-25 kg/m2) to extreme obesity (>40 kg/m2). The same was true for semen concentration (56.4±54.9 to 39.4±51.0 million/mL), total sperm count (171±170 to 92±95 million), and progressive motility (36.9±16.8% to 34.7±17.1%). The percentage of cases with azoospermia and cryptozoospermia increased from 1.9% to 9.1% and from 4.7% to 15.2%, respectively. The other semen characteristics were not affected. Multivariate models including age and abstinence duration confirmed these results.
  
  
  CONCLUSIONS
  In this study, on a large patient sample size, increased BMI was associated with decreased semen quality, affecting volume, concentration, and motility. The percentage of normal forms was not decreased.
authors.affiliation: Laboratoire Eylau Unilabs, Paris, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Belloc
authors.affiliation: Laboratoire Eylau Unilabs, Paris, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Cohen-Bacrie
authors.affiliation: Clinique de la Muette, Paris, France.
authors.forename: Edouard
authors.initials: E
authors.lastname: Amar
authors.affiliation: Clinique Pierre Chérest, Neuilly sur Seine, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Izard
authors.affiliation: Service de Biologie de la Reproduction et Cytogénétique, Centre Hospitalier Universitaire, Amiens, France.
authors.forename: Moncef
authors.initials: M
authors.lastname: Benkhalifa
authors.affiliation: Laboratoire Eylau Unilabs, Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Dalléac
authors.affiliation: INSERM, Université Paris Descartes, Faculté de Médecine, Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Universitaire Ouest, Centre Hospitalier Universitaire Cochin Port Royal, Service de Gynécologie Obstétrique II et Médecine de la Reproduction, Paris, France. Electronic address: jacques.de-mouzon@inserm.fr.
authors.forename: Jacques
authors.initials: J
authors.lastname: de Mouzon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007248:Infertility, Male / Q000453:epidemiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000473:pathology*; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012661:Semen / Q000166:cytology* / Q000502:physiology; D055101:Semen Analysis / Q000706:statistics & numerical data*; D012680:Sensitivity and Specificity; D013851:Thinness / Q000453:epidemiology / Q000473:pathology*; D055815:Young Adult
keywords: BMI; concentration; morphology; motility; obesity; semen volume