Leptin Receptor Gene Polymorphisms Research Articles

The Arg/Arg genotype of leptin receptor gene Gln223Arg polymorphism may be an independent risk factor for nonalcoholic fatty liver disease.

Given that obesity and insulin resistance play key roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the connection between leptin and these metabolic diseases, the association between NAFLD and a leptin receptor gene (LEPR) polymorphism was examined. In this genetic case-control association study, 144 biopsy-proven NAFLD patients and 144 controls were genotyped for the LEPR gene Gln223Arg (rs1137101) polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. The distributions of genotypes and alleles of Gln223Arg variant were in accordance with the Hardy-Weinberg equilibrium in the study groups (P>.05). Multivariate logistic regression analysis showed that the LEPR Gln223Arg Arg/Arg genotype was an independent risk factor for NAFLD; the Arg/Arg genotype, compared with the Gln/Gln genotype, was associated with a 2.09-fold increased risk for NAFLD (P=.036, odds ratio=2.09 [95% CI = 1.31-5.95]). We found that the LEPR Gln223Arg Arg/Arg genotype was independently associated with a more than 2-fold rise in biopsy-proven NAFLD risk. Our findings, however, need to be corroborated by further studies.

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.

Leptin receptor gene polymorphisms in kidney transplant patients with post-transplant diabetes mellitus treated with tacrolimus

Post-transplant diabetes mellitus (PTDM) is a metabolic complication that often occurs after kidney transplantation. Factors that increase the risk of this complication are currently being researched, including polymorphisms in genes affecting carbohydrate-lipid metabolism. Leptin is a hormone that affects appetite and adipose tissue and plays an important role in regulating insulin secretion as well as glucose and lipid metabolism. The aim of this study was to examine the association between leptin receptor gene polymorphisms and the development of post-transplant diabetes mellitus in patients treated with tacrolimus. The study was carried out in a group of 201 patients who underwent kidney transplantation. The follow-up period was 12 months. PTDM was diagnosed in 35 patients. Analysing the LEPR gene rs1137101 polymorphism, we observed in patients with PTDM an increased frequency of GG genotype carriers (GG vs AA, OR 3.36; 95 % CI 0.99–11.46; p = 0.04). There were no statistically significant differences in the distribution of the LEPR rs1137100 and LEPR rs1805094 polymorphisms between patients with and without PTDM. Multivariate regression analysis confirmed that female sex, advanced age, increased BMI and a higher number of LEPR rs1137101 G alleles were independent risk factors for PTDM development. The risk of PTDM development was almost 3.5 times greater in LEPR rs1137101 G allele carriers than in AA homozygotes (GG + AG vs AA; OR 3.48; 95 %CI (1.09–11.18), p = 0.035). The results suggest that patients after kidney transplantation with the LEPR gene rs1137101 G allele may have an increased risk of post-transplant diabetes development.

Research Note: Association of LEPR gene polymorphism with growth and carcass traits in Savimalt and French Giant meat-type quails

The leptin receptor (LEPR) gene is a member of the class I cytokine receptor family, which plays an important role in weight regulation, fat accumulation and neuroendocrine function in animals. This study aimed to explore the association of single nucleotide polymorphisms (SNPs) of the LEPR gene with growth and carcass traits in meat-type quail by PCR amplification and DNA direct sequencing. In this study, genomic DNA was extracted from blood samples of 36 female Savimalt (SV) quails and 49 female French Giant (FG) quails. Growth traits (measured at 3 or 5 wk) and carcass traits (measured at 5 wk) were used for LEPR gene association analysis. The results showed the existence of 9 SNPs (T81C, G90T, C187A, A191G, A219G, G258A, C286T, G346A, and G373A) of the LEPR gene in the 2 quail strains. The statistical analyses indicated that these SNPs of LEPR gene was significantly associated with shank circumference (SC), shank length (SL), breastbone length (BBL), heart rate (HR), and whole net carcass rate (WNCR) of FG (P < 0.05); chest width (CW), body length (BL), leg muscle rate (LMR), whole net carcass rate (WNCR), and heart rate (HR) of SV (P < 0.05). While haplotypes showed significant effect on SL, BBL, heart weight (HW), WNCR, and HR of FG (P < 0.05). Therefore, the LEPR gene may serve as a molecular genetic marker for improving growth and carcass traits in quails.

Analysis of leptin, adiponectin and adiponectin gene polymorphism and leptin receptor in obese children and adolescents

Background: The aim of this study was to determine serum levels of leptin and adiponectin of obese children to identify the influence of leptin receptor gene polymorphisms on leptin resistance and leptin levels, as well as the association between the polymorphisms of adiponectin gene and adiponectin levels.Materials and methods: A case-control study comparing a study group of 74 obese children (age 13.34±2.60 years) to a normal weight-age matched (age 13.39±2.64 years) control group of 69 children. In both groups, body mass index (BMI) and waist/hip circumference, systolic and diastolic blood pressure were measured. Also, the leptin and adiponectin levels, as well as glucose and lipid metabolism parameters, and highly sensitive C-reactive protein (hs-CRP) were measured. Insulin sensitivity was evaluated using fasting insulinemia and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). All subjects were tested for gene-tic polymorphisms in LEPRQ223R (rs1137101), ADIPOQ G276T (rs1501299) and ADIPOT45G (rs2241766).Results: The phenotypes of the obese children study group were significantly higher than in the control group in weight, BMI, waist/hip circumferences and systolic blood pressure (SBP) (P&amp;lt;0.001). We confirmed that in obese children the levels of leptin in the blood are increased and levels of adiponectin are decreased (P&amp;lt;0.001). The differences of the genotype distributions of leptin receptor (LEPRQ223R) and adiponectin (ADIPOG276T and ADIPOT45G) gene polymorphisms in the study group of obese chil-dren and a control group was not observed.Conclusion: In this study, we demonstrated increased leptin level and significantly decreased level of adiponectin in the obese children group compared with the control group. The results of the analysis of glucose metabolism and lipidogram between the two groups showed that insulin, HOMA-IR, and triglycerides, as well as hsCRP were increased and significantly different in the group of obese children compared to the control group, as expected. However, by including a significantly larger number of tested and control samples of both sexes and age-specific groups, with a larger number of tested SNPs, the genes investigated in this study would probably give better insight into a multicomplex disease such as obesity.

Correlation of Q223R and K109R polymorphisms in leptin receptor gene with susceptibility of breast cancer: A systematic review and meta-analysis.

Increasing evidence has suggested a strong association of Q223R (rs1137101) and K109R (rs1137100) polymorphisms in leptin receptor (LEPR) gene with susceptibility of breast cancer (BC), but inconsistent results were obtained. To provide a quantitative assessment of this association, a systematic review and meta-analysis was performed. A literature search of PubMed, EMBASE, Google Scholar, and the Chinese National Knowledge Infrastructure was collected. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. A total of 20 case-control studies for Q223R polymorphism and 8 case-control studies for K109R polymorphism were included. Significant association between Q223R polymorphism and BC risk was not found in total, Asian or Caucasian population, but in African population: allelic model, OR = 0.72, 95% CI = 0.60-0.86, p < 0.001; recessive model, OR = 0.67, 95%CI = 0.52-0.87, P = 0.003; dominant model, OR = 1.58, 95% CI = 1.15-2.17, p = 0.004; homozygous model, OR = 0.51, 95% CI = 0.36-0.78, p < 0.001. Significant association between K109R polymorphism and BC risk was not found in total or Caucasian population, but in Asian population: dominant model, OR = 0.24, 95% CI = 0.07-0.84, p = 0.03; heterozygous model, OR = 1.87, 95% CI = 1.07-3.26, p = 0.03. The available evidence suggests that Q223R polymorphism may be significantly associated with BC risk in African population. K109R polymorphism may be significantly associated with BC risk in Asian population.

Metabolic Status in Patients with Ischemic Heart Disease and Obesity with Different Genotypes of Leptin Receptor Gene (Arg223Glu)

The purpose of the study was to assess the metabolic status, namely carbohydrate and lipid metabolism, in patients with coronary heart disease and obesity with different genotypes of the leptin receptor gene (Arg223Glu). Materials and methods. The study included 220 patients with coronary heart disease and obesity. The comparison group consisted of 113 patients with coronary heart disease with normal body weight. The control group included 35 healthy individuals. Additionally, patients with coronary heart disease and obesity were divided into subgroups depending on the genotype of the leptin receptor gene (Arg223Glu): the first subgroup included carriers of the A/A genotype (n=57), the second – G/A genotype (n=90), the third – G/G genotype (n=73). Results and discussion. The analysis of carbohydrate metabolism depending on the genotypes of the leptin receptor gene (Arg223Gln) in patients with coronary heart disease and obesity showed that carriers of the G/G genotype have more pronounced disorders of carbohydrate metabolism in the form of hyperinsulinemia and decreased tissue sensitivity to insulin while carriers of the genotypes G/A and A/A have greater resistance to glucose-metabolic disorders. Body mass index in carriers of G/G genotype had the highest value, which is 19.19% and 19.53% more than in carriers of genotypes G/A and A/A. Thus, the G/G genotype in patients with coronary heart disease and obesity was associated with body mass index. The impaired lipid metabolism in patients with coronary heart disease in combination with obesity was defined as hypertriglyceridemia, which is associated with the G/G genotype of the leptin receptor gene polymorphism (Arg223Gln). The results obtained in our work indicate the involvement of the polymorphic locus of the leptin receptor gene (Arg223Gln) in the formation of disorders of carbohydrate and lipid metabolism, which corresponds to the literature. It has been suggested that structural changes in the leptin receptor gene are associated not only with the development of obesity but also with the development of type 2 diabetes mellitus. Conclusion. The features of the combined course of coronary heart disease and obesity were identified: hyperinsulinemia and insulin resistance are associated with the G allele and G/G genotype of the polymorphic locus Arg223Gln leptin receptor gene (r=0.76, p&lt;0.05); the rearrangement of the lipid spectrum due to hypertriglyceridemia is influenced by the homogeny of the G allele of the polymorphic locus of the Arg223Gln gene of the leptin receptor gene (r=0.73, p&lt;0.05)

GHRL, LEP, LEPR genes polymorphism and their association with the metabolic syndrome in the Ukrainian population.

Objective. Many conflicting results have been obtained in the study of leptin (LEP) and leptin receptor (LEPR) gene variants that are associated with the obesity and diabetes possibly due to differences in the study populations. The aim of this study was to evaluate changes in the metabolic hormones (leptin, ghrelin, adiponectin, resistin) levels in the blood of obese patients in relation to the GHRL (rs696217), LEP (rs7799039), LEPR (rs1137100, rs1137101, rs1805094) polymorphism in Ukrainian population. Methods. The study involved 53 obesity cases and 48 non-obesity subjects (controls). The GHRL, LEP, and LEPR genes polymorphism (rs696217, rs7799039, rs1137100, rs1137101, rs1805094) was genotyped using a TaqMan real-time polymerase chain reaction method. Blood hormones (leptin, ghrelin, adiponectin, resistin) were determined with commercially available kits using a Multiskan FC analyzer. Results. The study of the effect of genotypes of the GHRL (rs696217), LEP (rs7799039), and LEPR (rs1137100, rs1805094) polymorphisms on the level of metabolic hormones (leptin, ghrelin, adiponectin, resistin) in the blood of obese patients did not show reliably significant results. Thus, the presence of the LEPR genes (rs1137101) polymorphism in the Ukrainian population indicates an increased risk of the metabolic syndrome development regardless of the homozygous or heterozygous genotype (genotypes AA, AG, GG). Conclusions. We established a significant effect of the presence of the A allele and G allele of the LEPR gene polymorphism (rs1137101) on the level of leptin, ghrelin, adiponectin, and resistin in the serum of patients diagnosed with the metabolic syndrome in the Ukrainian population.

The Effects of BMI and Genetic Variation of Adipokines on Serum Concentrations of Hormones in Untreated Individuals with Breast Cancer; a Pilot Study

Background: Numerous studies have shown an association between hormones secreted by adipose tissues and cancer development. Objectives: This study aimed at investigating the effect of body mass index (BMI) and genetic variation of leptin and adiponectin on serum concentrations of leptin, adiponectin, and estradiol among untreated breast cancer. Methods: This case-control study was performed on 350 women (175 women with breast cancer and 175 healthy controls), who had not taken any medications. Serum levels of estradiol (17-beta estradiol), leptin, and adiponectin were measured, using the ELISA technique. Single-nucleotide polymorphisms of leptin gene (LepG2548A), leptin receptor (Q223, K109R, and K656N), and adiponectin gene (T45G, G276T, C11377G, and 11391A) in blood-isolated DNA were evaluated, using RFLP-PCR technique. Results: Body mass index can affect serum concentrations of hormones and is associated with breast cancer. Also, except for adiponectin C11377G polymorphism, other all genetic variations showed significant relationships with breast cancer. In both groups, BMI was significantly correlated with the mean serum concentrations of hormones, and the risk of breast cancer increased in G2548A, Q223R, K656N, and G276T polymorphisms. The effect of risk allele genotypes on serum concentration of hormones showed that changes in serum concentration of estrogen and leptin in all studied polymorphisms were associated with breast cancer in postmenopausal women. But adiponectin level was only affected by polymorphisms K109R, K656N, and G276 and G11391A. Conclusions: High BMI and genetic variation can affect cancer development by changing the serum concentrations of hormones in different genotypes. Studying various populations’ genetics and lifestyle can help definitive conclusions about genetics and obesity.

Association of Leptin and Leptin receptor Gene polymorphisms with Insulin resistance in pregnant women: A cross-sectional study

Introduction: Leptin is an adipokine hormone that regulates insulin sensitivity and lipid profile, which may contribute to complications like gestational diabetes.The goal of the study was to examine if there was a link between the leptin (LEP)/leptin receptor (LEPR) gene polymorphism and insulin resistance in pregnant women, and to determine the extent to which the leptin gene polymorphism could cause insulin resistance.. Methods: 208 pregnant women participated in this cross-sectional study of which 74 were insulin resistant cases and 134 were insulin sensitive controls. The study was carried out from December 2018 to December 2020 at a charitable hospital in Mangalore, Karnataka, India. Genotyping of leptin and its receptor gene were carried out using the Polymerase Chain Reaction- Restriction fragment Length Polymorphism (PCR-RFLP) method. Serum levels of leptin, insulin, and C peptide were assayed using Enzyme Linked Immuno Sorbent Assay (ELISA) and lipid profile by automated chemistry analyzer. Statistical analysis was carried out using SPSS 23. Results: Insignificant association was observed between leptin receptor gene polymorphisms and insulin resistance, and leptin gene and insulin resistant women. There was no significant difference in the serum leptin levels among the cases and control (61.62±29.23 and 59.88±22.25). However, fasting blood sugar, insulin, C peptide, Triglycerides (TG), and very low-density Lipoprotein (VLDL) levels were significantly higher in cases as compared to controls (p=0.0068, p&lt;0.0001, p&lt;0.0001 and 0.01 respectively). Homeostatic Model Assessment for Insulin Resistance (HOMA IR) was greater in subjects with homozygous dominant, 'GG' of LEPR (p=0.0409) and hyperinsulinemia (p=0.023) as compared to other genotypes. However, hyperglycaemia was observed in subjects with homozygous dominant, ‘AA’ of leptin gene (p=0.0173). Conclusion: No significant association was found between leptin and leptin receptor gene polymorphisms with insulin resistance in pregnancy. However, genotyping of these genes may be useful in predicting insulin resistance and gestational diabetes in pregnancy.

Association of Leptin and Leptin receptor Gene polymorphisms with Insulin resistance in pregnant women: A cross-sectional study

Introduction: Leptin is an adipokine hormone that regulates insulin sensitivity and lipid profile, which may contribute to complications like gestational diabetes.The goal of the study was to examine if there was a link between the leptin (LEP)/leptin receptor (LEPR) gene polymorphism and insulin resistance in pregnant women, and to determine the extent to which the leptin gene polymorphism could cause insulin resistance.. Methods: 208 pregnant women participated in this cross-sectional study of which 74 were insulin resistant cases and 134 were insulin sensitive controls. The study was carried out from December 2018 to December 2020 at a charitable hospital in Mangalore, Karnataka, India. Genotyping of leptin and its receptor gene were carried out using the Polymerase Chain Reaction- Restriction fragment Length Polymorphism (PCR-RFLP) method. Serum levels of leptin, insulin, and C peptide were assayed using Enzyme Linked Immuno Sorbent Assay (ELISA) and lipid profile by automated chemistry analyzer. Statistical analysis was carried out using SPSS 23. Results: Insignificant association was observed between leptin receptor gene polymorphisms and insulin resistance, and leptin gene and insulin resistant women. There was no significant difference in the serum leptin levels among the cases and control (61.62±29.23 and 59.88±22.25). However, fasting blood sugar, insulin, C peptide, Triglycerides (TG), and very low-density Lipoprotein (VLDL) levels were significantly higher in cases as compared to controls (p=0.0068, p<0.0001, p<0.0001 and 0.01 respectively). Homeostatic Model Assessment for Insulin Resistance (HOMA IR) was greater in subjects with homozygous dominant, 'GG' of LEPR (p=0.0409) and hyperinsulinemia (p=0.023) as compared to other genotypes. However, hyperglycaemia was observed in subjects with homozygous dominant, ‘AA’ of leptin gene (p=0.0173). Conclusion: No significant association was found between leptin and leptin receptor gene polymorphisms with insulin resistance in pregnancy. However, genotyping of these genes may be useful in predicting insulin resistance and gestational diabetes in pregnancy.

Association of the Human Leptin Receptor Gene (rs1137101; Gln223Arg) Polymorphism and Circulating Leptin in Patients with Metabolic Syndrome in the Indian Population.

Phenotypic expression of metabolic syndrome is precipitated by environmental variables along with the individual genetic susceptibility to the obesogenic environment and growing body of evidence suggest a paramount role of adipocytokines. Therefore, identifying the genetic influence on circulation leptin levels and clarifying genotype-phenotype correlation of rs1137101 {Leptin receptor gene (LEPR) Gln223Arg (Q223R; A668G)} in metabolic syndrome were the primary objective of this study. A total of 447 adult participants, including 214 metabolic syndrome patients and 233 healthy controls, were genotyped using polymerase chain reaction-restriction fragment length polymorphism method to unravel the effects of genetic risk loci {Leptin receptor gene; Gln223Arg (Q223R; A668G); rs1137101} on the occurrence of metabolic syndrome in consort with circulation leptin levels. Suitable descriptive statistics was used for different variables. The genotype frequencies were found to be in Hardy-Weinberg equilibrium for both cases (p > 0.2722) as well as in controls (p > 0.2331). However, genotype (x2: 11.26, 2 d.f. p = 0.0036) and allele distribution (x2: 10.51, 2 d.f. p: 0.0012) of the LEPR Gln223Arg (Q223R; A668G) differed significantly between cases and controls. Gln/Arg genotype (OR = 1.6099; 95% CI = 1.0847-2.3893; p value = 0.0181), Arg/Arg genotype (OR = 2.8121; 95% CI = 1.4103-5.6074; p value = 0.0033) and R allele (OR = 1.5875; 95% CI = 1.1996-2.1008; p value = 0.0012) were significantly associated with increased risk of metabolic syndrome in univariate analysis. Further a multivariate logistic regression adjusted for potential confounders showed that Arg/Arg genotype (OR = 1.9; 95% CI = 1.271-2.639; p-value < 0.05) and Gln/Arg (OR: 1.3; 95% CI = 0.873-2.034; p value < 0.05) have a significant risk for the occurrence of the metabolic syndrome. A progressive increase in the serum leptin levels from major homozygous alleles to minor homozygous alleles were observed indicating that rs1137101 modify the serum leptin concentrations in patients with metabolic syndrome. These findings provide enough evidence of a significant association of LEPR Gln223Arg (Q223R; A668G) polymorphism in the LepR gene in Indian patients with increased risk of metabolic syndrome for R allele and Arg/Arg homozygote. Thus, rs1137101 might be a pleiotropic locus for metabolic syndrome and its components in studied population.

Association study of leptin receptor polymorphisms in women with obesity and their impact on protein domains: a case-control study and in silico analyses

Leptin receptor (LEPR) is a member of the class I cytokine receptor family that receives and transmits leptin signals. It is primarily involved in the regulation of energy expenditure and food intake. This study aimed to evaluate the association of LEPR gene polymorphisms, Lys109Arg, Gln223Arg and Lys656Asn, with obesity in Moroccan women and to explore the structural and functional consequences of these SNPs. The variants were genotyped using the Sanger sequencing method. The three-dimensional structures of LEPR extracellular domains were determined using a template-based tertiary structure modeling web server and the protein variants were generated using in silico mutagenesis. The amino acids conservation analysis in the variants region was performed based on a protein’s evolutionary profile. The molecular dynamics simulations of the wild-types and variants N-terminal, cytokine receptor homology I and fibronectin type III domains of LEPR protein were performed to investigate their impact on the domain structures. We identified that only Lys656Asn polymorphism is associated with obesity in Moroccan women (P = 0.024). In silico analyses revealed that Lys109, Gln223 and Lys656 are exposed residues and their substitution leads to changes in protein structure through loss or gain of hydrogen bonds and hydrophobic interactions. Lys656Asn increases the stability and decreased flexibility of the fibronectin type III domain. Lys109Arg highly decreases the stability and increases flexibility and the overall dimension of N-terminal and cytokine receptor homology I domains. Gln223Arg increases the stability and the compaction level of these domains. These results provide insight into the involvement of LEPR variants in obesity development. Communicated by Ramaswamy H. Sarma

Association of Leptin and Leptin receptor Gene polymorphisms with Insulin resistance in pregnant women: A cross-sectional study.

Introduction: Leptin, along with its receptor, are linked with mechanisms affecting a diverse array of pregnancy-specific pathologies that include gestational diabetes and intrauterine growth restriction. The goal of the study was to examine if there was a link between the leptin (LEP)/leptin receptor (LEPR) gene polymorphism and insulin resistance in pregnant women, and to determine the extent to which the leptin gene polymorphism could cause insulin resistance.. Methods: 208 pregnant women participated in this cross-sectional study of which 74 were insulin resistant cases and 134 were insulin sensitive controls. The study was carried out from December 2018 to December 2020 at a charitable hospital in Mangalore, Karnataka, India. Genotyping of leptin and its receptor gene were carried out using the Polymerase Chain Reaction- Restriction fragment Length Polymorphism (PCR-RFLP) method. Serum levels of leptin, insulin, and C peptide were assayed using Enzyme Linked Immuno Sorbent Assay (ELISA). Statistical analysis was carried out using SPSS 23. Results: Insignificant association was observed between leptin receptor gene polymorphisms and insulin resistance, and leptin gene and insulin resistant women. There was no significant difference in the serum leptin levels among the cases and control (61.62±29.23 and 59.88±22.25). However, fasting blood sugar, insulin, C peptide, Triglycerides (TG), and very low-density Lipoprotein (VLDL) levels were significantly higher in cases as compared to controls (p=0.0068, p<0.0001, p<0.0001 and 0.01 respectively). Homeostatic Model Assessment for Insulin Resistance (HOMA IR) was greater in subjects with homozygous dominant, 'GG' of LEPR (p=0.0409) and hyperinsulinemia (p=0.023) as compared to other genotypes. However, hyperglycaemia was observed in subjects with homozygous dominant, 'AA' of leptin gene (p=0.0173). Conclusion: No significant association was found between leptin and leptin receptor gene polymorphisms with insulin resistance in pregnancy. However, genotyping of these genes may be useful in predicting insulin resistance and gestational diabetes in pregnancy.

Implication of Leptin and Leptin Receptor Gene Variations in Type 2 Diabetes Mellitus: A Case-Control Study

Background: Global increase in the prevalence of type 2 diabetes mellitus (T2DM) has affected about 6% of the population and is one of the major healthcare challenges worldwide. Apart from other factors, genetics play a pivotal role in the development of diabetes. Recent studies have drawn attention to the role of leptin ( LEP ) and leptin receptor ( LEPR ) gene polymorphisms in the pathogenesis of T2DM, that being the reason for the uptake of this study. Methods: A total of 390 T2DM cases and 408 controls matched with respect to age and gender were taken for the study. Biochemical analysis was performed on all study subjects. Polymerase chain reaction (PCR) amplification of the genomic regions encompassing the single nucleotide polymorphisms (SNPs) under study was followed by digestion using specific restriction enzymes to analyze the SNP genotype through restriction fragment length polymorphism (RFLP). Results: Serum leptin levels were elevated in 57.9% (226 of 390) of cases as compared to 11.8% (48 of 408) of controls (P &lt; 0.0001). Cases had significant homeostatic model assessment-insulin resistance (HOMA-IR) as compared to controls (5.3 ± 5.9 vs. 1.4 ± 0.4; P &lt; 0.0001). In case of LEP G2548A SNP, the frequency of a variant genotype (GA + AA) was found to be higher for cases than controls (69.7% vs. 29.4%; P &lt; 0.0001). For LEPR Q223R SNP, the frequency of a variant genotype (AG + GG) was found to be higher for cases than controls (69.2% vs. 23.6%; P &lt; 0.0001). Conclusion: We observed a significant association between the LEP/LEPR polymorphisms and T2DM in the ethnic population of Kashmir indicating that genetic susceptibility may play an important role in the pathogenesis of T2DM. J Endocrinol Metab. 2022;12(1):19-31 doi: https://doi.org/10.14740/jem785

Association between LEPR polymorphism and susceptibility of osteoporosis in Chinese Mulao people

To explore the association between the single nucleotide polymorphism (SNP) of leptin receptor (LEPR) gene and the susceptibility to osteoporosis (OP) among Chinese Mulao people. A total of 738 people were involved. Bone mineral density (BMD) was examined by calcaneus ultrasound attenuation measurement. Six SNPs of LEPR were detected. The genotypes, allele frequencies, linkage disequilibrium, and haplotype were analyzed. BMD decreased with age and males had higher BMD than women. The proportion of normal bone mass decreased with age, and morbidity of OP increased. Three out of six SNPs showed a difference between OP and normal group. Individuals with AA genotype of rs1137100 in OP group outnumber the normal group, AA increased the risk of OP. In rs2767485, CT increased the risk of OP, C allele may be susceptible to OP. TT genotype of rs465555 was susceptible genotype of OP, T locus may be associated with OP. Strong linkage disequilibrium was detected among rs1137100, rs1137101, and rs4655555. Four haplotypes were constructed, among which, AACGCT and GGTGTA increased the risk of OP by 3.9 and 4.2 times, respectively, whereas, GGCGTA reduced 74% of OP susceptibility. The rs1137100, rs2767485, and rs465555 of LEPR were associated with OP in Chinese Mulao people.

A cross-sectional study on the association of single nucleotide polymorphism of leptin receptor (Gln223Arg) and insulin resistance in gestational diabetes mellitus

BackgroundThe role of genetics in pathophysiology of gestational diabetes mellitus (GDM) is least explored. Objective of the study is to find the association of leptin receptor (LEPR) gene polymorphism with GDM and its role in altered leptin levels, insulin resistance, and dyslipidemia in GDM. MethodsHundred GDM patients and an equal number of BMI and gestational age matched normal glucose tolerant pregnant women were recruited as cases and controls. Five milliliters of venous blood was drawn for biochemical and genetic analysis. Genotyping of LEPR (Gln223Arg) was performed by PCR-RFLP. Fasting blood sugar, leptin, insulin, C-peptide, and lipid profile estimations were done. Various insulin resistance models were constructed using suitable formulae. The statistical analysis was performed using SPSS 23.0 software. ResultsThere was no significant association found between LEPR gene polymorphism with leptin levels and insulin resistance in GDM. However, Odd’s ratio showed that individuals with the “A” allele were at 1.25 times higher risk of developing GDM. HOMA B-cell significantly varied among LEPR genotypes (p < 0.0001), values being double in AA genotype, compared to AG (p < 0.05), ten times higher in AA compared to GG (p < 0.0001). There was no significant deviation of the genotype frequency distributions for rs1137101 variants from HWE in GDM cases, suggesting that alleles were in equilibrium. ConclusionThe study established a cycle of gene polymorphism altering leptin levels which in turn can alter insulin secretion and insulin resistance, contributing to dyslipidemia of pregnancy as well as gestational diabetes.

Association of leptin receptor gene polymorphisms and meta-inflammation markers with metabolically unhealthy obesity in children

The aim: to study the contribution of single-nucleotide polymorphisms (SNP) of the leptin receptor (LEPR) gene and meta-inflammation markers to the formation of metabolically unhealthy obesity (MUO) in children. Materials and methods. A total of 109 obese children aged 6–18 years were examined. Based on the recommendations of the National Heart, Lung, and Blood Institute (NHLBI), 2 observation groups were formed. The main group (n = 56) was represented by patients with MUO. The control group (n = 53) comprised children with metabolically healthy obesity (MHO). Serum levels of interleukin-1β (IL-1β) were measured using a chemiluminescent immunoassay (CLIA) method, interleukin-6, leptin, adiponectin – by enzyme-linked immunosorbent assay (ELISA) and the serum level of C-reactive protein were quantified by latex turbidimetric method (Synevo, Ukraine). The method of next-generation sequencing (NGS) (CeXGat, Germany) was used to identify LEPR SNP. Statistical methods were used: analysis of variance, Spearman’s correlation analysis and multiple discriminant analysis. Results. In obese children aged 6 to 18 years, there was an increase in pro-inflammatory adipokines IL-6 and leptin and a decrease in anti-inflammatory adiponectin. Statistically significant changes in these indicators were more expressed in the main group: IL-6 – 7.4 ± 0.5 pg/ml (ρ = 0.65; P ≤ 0.001); adiponectin – 3.9 ± 0.8 μg/ml (ρ = -0.27; P = 0.007) among all the children examined, leptin in girls – 47.8 ± 4.4 ng/ml (ρ = -0.28; P = 0.003) compared with the results of patients in the control group: IL-6 – 4.3 ± 0.3 pg/ml, adiponectin – 7.7 ± 2.4 μg/ml, leptin in girls – 32.5 ± 4.3 ng/ml, P ≤ 0.05. The most important in the development of MUO were the following SNP of the LEPR gene: rs3790435 (CiMUO = 0.939), rs2186248 (CiMUO = 0.862), P &lt; 0.05. A strong correlation was found between MUO and serum IL-6 level (ρ = 0.7), LEPR SNP rs3790435 (ρ = 0.7), basal hyperinsulinemia (ρ = 0.72); Р ≤ 0.001. The risk of IL-6-dependent meta-inflammation in the presence of SNP rs3790435 of the LEPR gene: OR = 17.11; 95 % CI 2.8–20.4. Conclusions. Meta-inflammation in MUO is IL-6-dependent. Among the 10 SNPs of the LEPR gene that we identified, SNP rs3790435 of the LEPR gene has a strong association with the formation of MUO. SNP rs2186248 LEPR was described by us for the first time when it was found in 94.1 % of obese children, but it was characterized by the presence of a weak association with MUO.

Integration of association and computational methods reveals functional variants of LEPR gene for abdominal fat content in chickens

Leptin receptor (LEPR) plays a vital role in obesity in humans and animals. The objective of this study is to assess LEPR functional variants for chicken adipose deposition by integration of association and in-silico analysis using a unique chicken population, the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF). Five online bioinformatics tools were used to predict the functionality of the single nucleotide polymorphisms (SNPs) in coding region. Further, the possible structure–function relationship of high confidence SNPs was determined by bioinformatics analyses, including the conservation and stability analysis based on amino acid residues, prediction of protein ligand-binding sites, and the superposition of protein tertiary structure. Meanwhile, we analyzed the association between abdominal fat traits and 20 polymorphisms of chicken LEPR gene. The integrated results showed that rs731962924 (N867I) and rs13684622 (C1002R) could lead to striking changes in the structure and function of proteins, of which rs13684622 (C1002R) was significantly associated with abdominal fat weight (AFW, P=0.0413) and abdominal fat percentage (AFP, P=0.0260) in chickens. Therefore, we are of the opinion that rs13684622 (C1002R) may be an essential functional SNP affecting chicken abdominal fat deposition, and potentially applied to improvement of broiler abdominal fat in molecular marker-assisted selection (MAS) program. Additionally, the coupling of association with computer electronic predictive analysis provides a new avenue to identify important molecular markers for breeders.

Association of insulin resistance and leptin receptor gene polymorphism in type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a chronic disease that is characterized by impaired glucose metabolism and insulin resistance. The objectives of the study were to evaluate the pattern of leptin receptor gene polymorphism Gln223Arg in T2DM and to identify its association with the serum leptin and insulin levels as well as with insulin resistance in diabetes. In this cross-sectional study, genotyping of leptin receptor was done for Gln223Arg alleles by PCR-restriction fragment length polymorphism in 39 patients with type 2 diabetes. Serum leptin and insulin levels were assayed using enzyme linked sorbent assay in 39 cases and 45 nondiabetic controls. Insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) formula. Statistical analysis was performed with Graph pad Instat version 3. Hardy-Weinberg Equilibrium for the leptin receptor (LEPR) gene variants showed that alleles were in equilibrium. Leptin levels were insignificantly low in patients with diabetes compared to those in controls. Women in the control group showed significantly higher leptin levels (p < 0.05) compared with men. There was a significant difference in the serum insulin levels and insulin resistance (HOMA-IR) among patients with different genotypes (p = 0.04 and p = 0.0378, respectively). Leptin receptor gene polymorphism affected glucose metabolism by altering insulin resistance and pancreatic beta cells. Thus, single-nucleotide polymorphism of LEPR may affect the pathogenesis of T2DM.