Obesity and Male Fertility

S.J. Parekattil and A. Agarwal (eds.), Male Infertility: Contemporary Clinical Approaches, Andrology, ART & Antioxidants, DOI 10.1007/978-1-4614-3335-4_33, © Springer Science+Business Media, LLC 2012 In the past 5–10 years, obesity has become a worldwide epidemic that has brought attention to learning more about the various causes, effects, and treatments. A combination of an increasingly acceptable sedentary lifestyle and unhealthy diet in the Western world has resulted in an increasing number of overweight and obese children and adults. According to the WHO, approximately 1.6 billion adults were classi fi ed as being overweight and 400 million adults were obese in 2005 [ 1 ] . It is predicted that globally, in the next 5 years, more than 700 million adults will suffer from obesity [ 1 ] . Once considered a problem only in high-income countries, overweight and Abstract The obesity pandemic has grown to concerning proportions in recent years, not only in the Western world but in developing countries as well. The corresponding decrease in male fertility and fecundity may be explained partially by obesity, and obesity should be considered an etiology of male subfertility. Studies show that obesity contributes to infertility by reducing semen quality, changing sperm proteomes, contributing to erectile dysfunction, and inducing other physical problems related to obesity. Mechanisms for explaining the effect of obesity on male infertility include abnormal reproductive hormone levels, an increased release of adipose-derived hormones and adipokines associated with obesity, and other physical problems including sleep apnea and increased scrotal temperatures. Recently, genetic factors and markers for an obesity-related infertility have been discovered and may explain the difference between fertile obese and infertile obese men. Treatments are available for not only infertility related to obesity but also for the other comorbidities arising from obesity. Natural weight loss and bariatric surgery are options for obese patients and have shown promising results in restoring fertility and normal hormonal pro fi les. Therapeutic interventions including aromatase inhibitors, exogenous testosterone replacement therapy and maintenance, and regulation of adipose-derived hormones, particularly leptin, may also be able to restore fertility in obese males. The increasing prevalence of obesity calls for greater clinical awareness of its effects on fertility, better understanding of underlying mechanisms, and exploration into avenues of treatment.