reduction of soluble leptin receptor levels in women with unexplained infertility and the effect of leptin receptor gln223arg polymorphism on its serum level

Background and objectives: soluble leptin receptor (sob-r) is the most important leptin-binding protein that can affect the level of active biological leptin. the gln223arg polymorphism in the leptin receptor gene is associated with obesity, which can be a factor for infertility. the purpose of this study was to evaluate the sob-r levels in women with unexplained infertility and to investigate the effect of leptin receptor (lepr) gene polymorphism on sob-r serum level.methods: one hundred and two women with unexplained infertility and 112 fertile women were studied in this case-control study. the subjects in both groups had a normal hormonal profile with the age below 40 years. the sob-r levels were measured using elisa method.results: there was a 2-fold decrease in sob-r level in the infertile group compared to the control group (p < /em>=0.001). although sob-r levels were lower in overweight and obese infertile subjects, this difference was not significant. however, this difference was significant compared to the control group. there was a direct correlation between bmi, age, and infertility. although sob-r levels in arg/arg genotypes were higher in the infertile group than gln/gln and arg/gln genotypes, they were not statistically significant. a significant decrease was observed in sob-r levels of gln/gln and arg/gln genotypes in the infertile group compared to the control.conclusion: there was a reverse correlation between sob-r levels and unexplained infertility. it seems that by a decrease in serum sob-r, the serum leptin levels increase which can enhance leptin inhibitory effects in infertility.