Diabetes and obesity appear to be major risk factors for male infertility. At the recent 24th annual conference of the European Society of Human Reproduction and Embryology, two separate studies presented these results, one concerning reduced sperm count due to obesity, and the other dealing with sperm DNA damage due to diabetes.
The study dealing with diabetes, which was conducted at Queen’s University in Belfast, Ireland, was based on the idea that male infertility and diabetes have both been on the rise, suggesting a potential connection. While there has been little research in the past that supported the view that diabetes could lead to male infertility, this current study found significant evidence that diabetes can cause damage to sperm DNA.
The study considering obesity and it’s relation to male infertility was conducted at the University of Aberdeen in Aberdeen, Scotland. This study ended up showing that obese individuals had lower sperm counts and more occurrences of “abnormal sperm.”
The first study looked at semen samples from diabetic individuals who are treated by the administration of insulin. As far as sperm count, diabetics appear to be within normal range, but the actual structure of the sperm DNA is significantly different than in healthy non-diabetics. Lead researcher Dr. Con Mallidis states that “sperm RNA was significantly altered, and many of the changes we observed are in RNA transcripts involved in DNA repair. And comparison with a database of men of proven fertility confirmed our findings. Diabetics have a significant decrease in their ability to repair sperm DNA, and once this is damaged it cannot be restored.”
What does this sperm DNA damage mean exactly when it comes to producing offspring? The study mentions that poor quality of sperm DNA increases the likelihood of miscarriages, decreases embryo quality, lowers likelihood of conception, and increases the likelihood for childhood diseases such as cancer.
Obese individuals, or those with high body mass index’s (BMI’s), on the other hand, were observed to have lower sperm counts and more abnormal sperm. These characteristics lead to lesser rates of conception and more problems during and after pregnancy. Sperm DNA was not considered in this study. Past studies though have connected obesity to damage to sperm DNA, much like in the above diabetes study. Past research has also indicated that overweight women are less likely to conceive than normal weight individuals.
While these two studies were not connected, they both represent a common problem. Obesity is one of the leading risk factors for type 2 diabetes, and is often caused by poor eating habits and lack of physical activity. These unhealthy lifestyle choices, besides increasing the likelihood of potentially fatal conditions like diabetes and cardiovascular disease for oneself, appear to limit the likelihood of producing a healthy child.
Source: Defeat Diabetes Foundation: Rice, Mary. European Society of Human Reproduction and Embryology news releases. July 2008.