The Effect of Age and Obesity on Male Infertility:

Male infertility is a multi factorial complex disease with multiple genetic and clinical etiologies.

The causes of male infertility are widely varied and linked with a reduction in sperm concentration and motility, an increase in sperm DNA damage and changes in reproductive hormones. One of the potential underlying pathological mechanisms behind diminished reproductive performance in obese men is sperm oxidative stress.

How does age affect male infertility?

Age is the single biggest factor affecting the rate of fertility. It is widely known that aging in women steadily decline fertility as ovarian reserve diminishes. The vast majority of women gradually lose the natural power of fertility by the time they reach 35, even pregnancies following ART may fail after 40.

However, the adverse effects of male aging on fertility are less known. A slightly general disturbance in sperm parameters and high sperm DNA Fragmentation Index (DFI) is reported after 40. Male fertility decline is a slow process in men. In fact, it is never too late for men to father a baby.

Nonetheless, aging-related decline in physiological function of men and certain underlying medical conditions such as blood sugar and blood pressure lead to sexual dysfunction. As a result, a reduced sexual desire and erectile dysfunction occur. In this respect, subsequent infertility can have major effects on marital intimacy too.

In conclusion, age plays an important factor in infertility and deciding the treatment method for infertile couples. But it should be noted that the most significant factor in the reproductive potential of a couple is female age.

How does obesity affect fertility in males?

Obesity refers to excessive and abnormal accumulation of fat in the body impairing health. According to the WHO definition, a body mass index (BMI) of 25.0 or more indicates that you are overweight. if your BMI is 30.0 or higher, it falls within the obese range. There is emerging evidence that male obesity can be associated with sexual dysfunction and infertility. The possible mechanisms that contribute to obesity are:

1. Further peripheral fat accumulation in obese men increases expression of the aromatase enzyme which transforms testosterone (male hormone) to estradiol (female hormone). Therefore, with the decrease in testosterone, low libido in men and consequently erectile dysfunction are inevitable. Low testosterone can affect fertility by decreasing sperm production.
2. Due to negative inhibitory action of estradiol increase on hypothalamus–pituitary–testis axis, LH and testosterone production from the testicular tissue decrease. And this reduction of testosterone inside the testicular parenchyma will lead to a decrease in sperm synthesis in the seminiferous tubules.
3. In obese men, more leptin produced by the adipose tissue in obese men inhibits Leydig cells which appears substantially result in low levels of testosterone and decreased production of sperm.

How does obesity affect infertility?

Obese men are more likely to have higher estrogen levels, combined with lower levels of sperm-producing hormones like inhibin b and androgen. This can mess with sperm count, sperm concentration and the sperm’s ability to swim well.

Obesity and its related complications can be prevented with proper diet (decreasing the consumption of carbohydrates and fats and increasing the consumption of fresh fruits, vegetables and nuts), sufficient physical activity and regular exercise (at least 30 minutes per day). It is possible to achieve and maintain a healthy weight with a right lifestyle.