Obesity is considered a worldwide epidemic disease. Many pathological conditions have been associated to obesity but the evidence relating to impaired fertility in males with obesity are contrasting. The aim of this review was to evaluate the interplay between obesity and male fertility, analyzing evidence from in vitro and in vivo studies to clinical trials. Obesity seems to be responsible of secondary hypogonadism. Here, we propose a new classification including central, peripheral and testicular factors that may affect the hypothalamic-pituitary-gonadal axis. Moreover, some studies demonstrated a direct action of obesity on sperm count and sperm characteristics, mediated by impaired Sertoli cells function, increased scrotal temperature, oxidative stress and accumulation of toxic substances and liposoluble endocrine disruptors in fat tissue. Recent studies have explored obesity-related epigenetic effects in sperm cells which may cause diseases in offspring. Moreover, not only in females but also males, obesity has been linked to reduced outcomes of in vitro fertilization, with a reduction of pregnancy rate and an increase of pregnancy loss. Finally, we reviewed the effects of weight modifications through diet or bariatric surgery on obesity-related reproductive dysfunction. In this regard, several studies have demonstrated that weight loss has been associated with a restoration of gonadal hormones levels.

肥胖被认为是世界范围内的流行病。肥胖与许多病理状况有关，但与肥胖男性生育能力受损有关的证据却相反。这篇综述的目的是评估肥胖与男性生育能力之间的相互作用，分析从体内和体外研究到临床试验的证据。肥胖似乎是继发性腺功能减退的原因。在这里，我们提出了一个新的分类法，包括可能影响下丘脑-垂体-性腺轴的中心，外周和睾丸因素。此外，一些研究表明肥胖症是由Sertoli细胞功能受损，阴囊温度升高，氧化应激以及有毒物质和脂溶性内分泌干扰物在脂肪组织中的积累介导的，对精子数量和精子特征具有直接作用。最近的研究已经探索了与肥胖相关的表观遗传效应，这些效应可能导致子代疾病。此外，不仅在女性中，而且在男性中，肥胖都与体外受精的结果降低，妊娠率降低和妊娠流失的增加有关。最后，我们回顾了通过饮食或减肥手术减轻体重对肥胖相关的生殖功能障碍的影响。在这方面，多项研究表明，体重减轻与性腺激素水平的恢复有关。降低了怀孕率，增加了流产的风险。最后，我们回顾了通过饮食或减肥手术减轻体重对肥胖相关的生殖功能障碍的影响。在这方面，多项研究表明，体重减轻与性腺激素水平的恢复有关。降低了怀孕率，增加了流产的风险。最后，我们回顾了通过饮食或减肥手术减轻体重对肥胖相关的生殖功能障碍的影响。在这方面，多项研究表明，体重减轻与性腺激素水平的恢复有关。