Older Men And DNA Sperm Damage
According to research presented at a conference of the European Society of Human Reproduction and Embryology, the amount of DNA damage to the sperm of older men is far higher than that of younger men. Study author Dr. Sergey Moskovtsev of Toronto, Canada's Mount Sinai Hospital explained to those at the conference that the ages of the partners at the time a first pregnancy is attempted makes these findings of particular significance. "Older men tend to reproduce with older women", said Moskovtsev, "and the combination of increased female factor infertility, increased sperm DNA damage, low levels of DNA repair, and increased abnormalities in conventional semen parameters present in this population will have a pronounced impact on their reproductive potential."
Moskovtsev and his team of colleagues looked at the relationship of age to DNA integrity. At the time of the study, this was a new parameter for examining male fertility capabilities. The study included 2134 men who had come to the hospital to have their fertility evaluated.
The scientists were able to identify both normal and damaged sperm through the use of a type of fluorescent dye that can stick to DNA, turning red when adhering to damaged DNA, and turning green when sticking to normal sperm DNA. The scientists used 20,000 sperm for each sample tested and were thus able to calculate the amount of DNA damage by examining the ratio of red to green.
The researchers discovered that the DNA damage was greatest in the participants who were over the age of 45 when compared to the younger participants. The damage was seen to double in the men who were 45 years and up when compared to study participants under the age of 30. Moskovtsev commented that sperm DNA damage is not something that can be repaired. He explained that this damage can be used to predict the decline of fertility potential as opposed to seeing the damage as a predictor of male fertility.
On the other hand, men who are infertile, yet have good DNA integrity may have other factors causing their infertility. Moskovtsev is pressing for a technique by which technicians could choose only the sperm without DNA damage for use in assisted reproduction techniques (ART) such as ICSI and IVF. He comments that this field of research has gained importance because of the relative older age of first time parents.