Association between obesity and alteration of sperm DNA integrity and mitochondrial activity

Abstract

What ' s known on the subject? and What does the study add?The relationship between high levels of BMI and changes in altered standard semen analysis parameters are described in the literature. However, the functional characteristics of the sperm are essential to complete the evaluation of male infertility. Thus, this study provides important information about the functionality of the sperm of men with different levels of BMI.Study Type -Prognosis (cohort) Level of Evidence 3a OBJECTIVE• To assess the effect of obesity on semen analysis, sperm mitochondrial activity and DNA fragmentation. MATERIALS AND METHODS• A transversal study of 305 male patients, presenting for clinical evaluation, was carried out. The patients were divided into three groups according to body mass index (BMI) as follows: eutrophic (BMI < 25 kg/ m 2 , n = 82), overweight (BMI ≥ 25 kg/m 2 and < 30, n = 187) and obese (BMI ≥ 30 kg/ m 2 , n = 36).• The variables analysed were semen analysis, rate of sperm DNA fragmentation and sperm mitochondrial activity.• Groups were compared using one-way analysis of variance followed by a least signifi cant difference post-hoc test. A P -value of < 0.05 was considered to indicate statistical signifi cance. RESULTS• No differences were observed in age, ejaculatory abstinence, ejaculate volume, sperm vitality, morphology or round cell and neutrophil count among the groups.• The eutrophic group had a higher percentage of sperm with progressive motility ( P = 0.001). Mitochondrial activity was lower in the obese group ( P = 0.037) when compared to the eutrophic, and the percentage of sperm with DNA damage was higher in the obese group ( P = 0.004) than the other two groups. CONCLUSION• Increased BMI values are associated with decreased mitochondrial activity and progressive motility and increased DNA fragmentation.

Acrosome reaction is impaired in spermatozoa of obese men: a preliminary study

“…Indeed, some studies pointed out alterations in other functional aspects, such as DNA integrity. A significant increase in DNA fragmentation has been reported in spermatozoa of obese vs. lean subjects (8,24,30,31). Conversely, no significant association has been found between BMI and another functional marker of sperm fertilization potential, ZP binding (32).…”

Obesity and reproduction: a committee opinion

“…Moreover, increased abdominal adiposity in men of subfertile couples has been associated with reduced sperm count, concentration, and motility (90). Evidence, however, varies as to whether male obesity alters sperm function (98), increases sperm DNA damage (91,(99)(100)(101)(102)(103), decreases sperm mitochondrial activity (101,102), induces seminal oxidative stress (104), impairs blastocyst development (85), reduces pregnancy outcome, or increases miscarriage following assisted reproduction (85,87,91,98,(105)(106)(107)(108). These discrepancies likely represent differences in data acquisition, study populations, patient lifestyles, and comorbidities (98).…”

Paternal obesity negatively affects male fertility and assisted reproduction outcomes: a systematic review and meta-analysis

“…The non-random recruitment of participants (appraisal criteria 1, Supplementary Table S1) was a characteristic failing of studies on this topic, with only two of the 35 utilizing any form randomized patient selection. The included studies were conducted in a range of different countries, including: the USA (9) (Chavarro et al, 2010;Colaci et al, 2012;Eisenberg et al, 2014;Hammoud et al, 2008;Jokela et al, 2008;Keltz et al, 2010;Kort et al, 2006;Linabery et al, 2012;Schliep et al, 2015), Denmark (3) (Aggerholm et al, 2009;Petersen et al, 2013;Ramlau-Hansen et al, 2007), the UK (2) (Pacey et al, 2014;Shayeb et al, 2011), Australia (2) (Bakos et al, 2011a;Tunc et al, 2011), Italy (2) (La Vignera et al, 2012;Lotti et al, 2011), The Netherlands (2) (Duits et al, 2010;Hammiche et al, 2012), Brazil (1) (Fariello et al, 2012), China (1) (Qin et al, 2007), New Zealand (1) (Macdonald et al, 2013), Hungary (1) (Koloszar et al, 2005), the Czech republic (1) (Rybar et al, 2011), Argentina (1) (Martini et al, 2010), Norway (1) (Nguyen et al, 2007), Turkey (1) (Umul et al, 2015), Russia (1) (Gutorova et al, 2014), and France (1) (Dupont et al, 2013). A total of 115,158 participants were ultimately included in this systematic review, with a range of 81 to 47,835 participants per study.…”