Metabolic disorders represent a major public health burden nowadays. From
these metabolic disorders, obesity and diabetes mellitus (DM) may be considered the
most significant ones. Obesity is characterized by an excess of body fat, where body
mass index (BMI) is used for its classification. When an individual has a BMI between
25 and 30 kg/m2 is considered overweight, while a BMI over 30 kg/m2 classifies an
individual as obese. This excessive fat is very harmful and may even reduce life
expectancy. On the other hand, DM encompasses a cluster of disorders characterized
by chronic hyperglycemia that are a result of defects in insulin action, insulin secretion,
or both. The exponential increase of these metabolic disorders is, in part, due to
erroneous dietary habits that lead to an inadequate intake of essential nutrients.
Moreover, while the prevalence of metabolic diseases increases, the fertility trends
decrease, illustrating an association that may, or may not, be direct. In fact, there is an
increasing number of children, adolescent and men in reproductive age suffering from
metabolic disorders. It is well known that the occurrence of a normal spermatogenesis
is dependent on the metabolic cooperation established between testicular cells,
particularly concerning glucose metabolism and insulin signaling. Therefore, it is
crucial to unveil these mechanisms in individuals with metabolic disorders, how they
are affected by the disease and how they change the fertility of males. In recent years,
several studies have provided new information concerning alterations induced by
metabolic disorders in male reproductive health. In addition, it was highlighted that
testicular cells possess several mechanisms that react to hormonal fluctuations to
counteract hyper- and hypoglycemic events. In this chapter, we will discuss the effects
of DM and obesity in the regulation of testicular insulin signaling and glucose
metabolism as well as the importance of an adequate diet and how these events are
implicated in the reproductive health of males.
Keywords: Antioxidants, Diabetes mellitus, Fertility, Glucose, Insulin,
Micronutrients, Nutrition, Obesity, Oxidative Stress, Sperm, Vitamins.
