Leptin receptor variant in women with polycystic ovary syndrome

Association between leptin receptor polymorphisms and polycystic ovary syndrome risk: a meta-analysis based on 11 studies

OBJECTIVE

Published evidence indicated that the leptin receptor (LEPR) gene polymorphisms are associated with polycystic ovary syndrome (PCOS) risk. However, studies on the association between the polymorphisms of LEPR gene are inconsistent or even controversial.

MATERIAL AND METHODS

We conducted this meta-analysis to explore the more precise relationship between LEPR polymorphisms and PCOS risk. Relevant articles were searched with five online databases up to March 1 2023. Odds ratios (OR) with 95% confidence intervals (CI) were selected to examine the statistical strength of each genetic model. Moreover, RNA secondary structure and variant effects of these loci were examined with in silico analysis.

RESULTS

Overall, 11 publications were analyzed, and the pooled results did not present any significant association between rs1137101 A/G polymorphism and PCOS risk in general population and some subgroup analysis. But the significant association were observed in Asian population (AG vs. AA: OR = 0.51, 95%CI = 0.32-0.81, p = .01, I2=0%; AG + GG vs. AA: OR = 0.41, 95%CI = 0.26-0.65, p < .01, I2=25.9%). Moreover, similar positive associations were also observed in rs1805096 polymorphism with PCOS risk.

CONCLUSION

In summary, our meta-analysis suggested that the LEPR gene polymorphisms might be associated with PCOS susceptibility. Owing to the limited studies and small sample size in our meta-analysis, more well-designed studies from different races were needed to be conducted to verify the current results.

Expression of leptin long-form receptor mRNA in luteinized granulosa cells of obese women with polycystic ovary syndrome

To investigate the expression of mRNA of leptin long-form receptor (OB-Rb) in luteinized granulosa cells of obese women with polycystic ovary syndrome (PCOS), and to determine the role of leptin in the physiopathology of PCOS, luteinized granulosa cells were collected from the follicle fluid of 10 obese women who met the diagnostic criteria for PCOS and their BMI was equal to or greater than 25 kg/m(2), and at the same time, granulosa cells were collected from 10 normal women undergoing IVF-ET who served as the control group. Some luteinized granulosa cells were taken from normal women for in-vitro culture, into which human leptin of different concentrations was added (0, 10, 100 and 1000 ng/mL). After stimulation with leptin for 48 h, RT-PCR was employed for the detection of the expression of OB-RLmRNA in the luteinized granulosa cells. Our results showed that the level of OB-RLmRNA in luteinized granulosa cells of obese PCOS women was higher than those in the control (P<0.05). In luteinized granulosa cells cultured in vitro and stimulated by human leptin for 48 h, the level of OB-RLmRNA was higher than those without leptin stimulation (P<0.01), and when leptin concentration was at 100 ng/mL, and the level of OB-R(L)mRNA reached a peak. It is concluded that in obese PCOS women, the level of serum leptin is increased, which promotes the expression of OB-R(L) in luteinized granulosa cells and increases the sensitivity of the granulosa cells to leptin. Leptin may contribute to anovulation in obese women with PCOS.

The impact of body mass index on assisted reproduction

PURPOSE OF REVIEW

Obesity is a worldwide problem. The effect of obesity on the outcome of assisted reproductive techniques is quite controversial.

RECENT FINDINGS

Although there is not an absolute consensus based on evidence, obesity may lengthen the duration of ovulation induction, increase the gonadotrophin dose, decrease the peak estradiol levels, number of mature follicles and number of oocytes retrieved, and increase the cycle cancellation rate. Moreover, obesity may have a negative impact on oocyte and embryo quality. Thus, fertilization, embryo transfer, implantation and pregnancy rates have been usually found to be low in many studies. In addition, oocyte retrieval and embryo transfer procedures can be difficult due to obesity itself. Finally, miscarriage rate is found to be high. None of the studies related with obesity and assisted reproduction has been designed as a randomized controlled trial, yet. Definition of obesity, cause of infertility, protocols used for ovulation induction, starting dose for gonadotrophins, oocyte and embryo-grading systems are not standardized among the studies. Some confounding factors, such as polycystic ovary syndrome status and age, are not taken into consideration.

SUMMARY

Obesity has a negative impact on the outcomes of assisted reproductive techniques.

Interactions of the hormones leptin, ghrelin, adiponectin, resistin, and PYY3-36 with the reproductive system

OBJECTIVE

To summarize the effects of novel hormones (leptin, ghrelin, adiponectin, resistin, and PYY3-36) secreted from adipose tissue and the gastrointestinal tract that have been discovered to exert different effects on several reproductive functions, such as the hypothalamic-pituitary-gonadal axis, embryo development, implantation physiology, and clinically relevant conditions.

DESIGN

A MEDLINE computer search was performed to identify relevant articles.

RESULT(S)

Leptin and ghrelin exert important roles on body weight regulation, eating behavior, and reproduction, acting on the central nervous system and target reproductive organs. As a marker of adequate nutritional stores, these hormones may act on the central nervous system to initiate the complex process of puberty and maintain normal reproductive function. In addition, leptin and ghrelin and their receptors are involved in reproductive events such as gonadal function, embryo development, and embryo-endometrial interaction.

CONCLUSION(S)

Leptin and ghrelin and other adipose tissue-secreted hormones have significant effects on reproduction. Acting through the brain, these hormones may serve as links between adipose tissue and the reproductive system to supply and regulate energy needs for normal reproduction and pregnancy. Future studies are needed to further clarify the role of these hormones in reproductive events and other related gynecological conditions.