On 12 June at 15 Kristel Ehala Aleksejev will defend her doctoral thesis "The reproductive consequences of obesity including obesity-related health and lifestyle conditions in male infertility".
Supervisor:
Associate Professor Margus Punab (dr. med. ), Institute of Clinical Medicine, University of Tartu
Opponent:
Professor Stefan Arver (PhD), Department of Medicine, Huddinge, Unit for Metabolism, Karolinska Universitetssjukhuset Huddinge, Stockholm, Sweden.
Summary:
About 15% of couples in fertile age have experienced fertility problems and males are found to be contribute to 50% of cases overall. Men's semen quality has dropped dramatically over the last century. The possible reasons for the decline of fertility parameters can be the rapidly changed lifestyle, altered physical activity and eating habits along with other factors. The proportion of overweight men has tripled in parallel with the increase in fertility problems. Overweight is also a problem for Estonian men. There are studies that link fertility with obesity and those who deny it. Furthermore, there are also a few studies that have found a negative relationship between central obesity-related metabolic syndrome (MS) and sperm quality. There is, however, an almost unanimous agreement that increased weight has a negative correlation with testosterone levels. Semen analysis are mostly used to investigate fertility, but one of the easiest methods for determining fertility potential is the measurement of testicular volumes (TTV). Nevertheless, a critical TTV that would ensure adequate reproductive function has not been formally established. Altogether, a better understanding of the relationship between lifestyle, weight gain and overweight related health parameters and fertility would increase the quality of counseling. Investigating and comparing the results of a group of provenly fertile men and male partners of infertile couples showed that a significantly higher prevalence of adiposity and MS was found among male partners of infertile couples. Central obesity was associated with a decline in fertility parameters in both groups. Importantly, our analysis revealed that men with smaller testicles were more affected by changes in body composition. MS had no independent effect on major fertility parameters in different subgroups of men, but MS was negatively correlated to testosterone levels. The present results revealed an association between semen quality and GGT for the first time. In both groups, alcohol consumption was positively correlated to adiposity parameters. Alcohol consumption together with elevated GGT was negatively related to semen quality.