Association of leptin receptor polymorphisms Lys109Arg and Gln223Arg with serum leptin profile and bone mineral density in Korean women

Effect of adipokine and ghrelin levels on BMD and fracture risk: an updated systematic review and meta-analysis

Context

Circulating adipokines and ghrelin affect bone remodeling by regulating the activation and differentiation of osteoblasts and osteoclasts. Although the correlation between adipokines, ghrelin, and bone mineral density (BMD) has been studied over the decades, its correlations are still controversial. Accordingly, an updated meta-analysis with new findings is needed.

Objective

This study aimed to explore the impact of serum adipokine and ghrelin levels on BMD and osteoporotic fractures through a meta-analysis.

Data sources

Studies published till October 2020 in Medline, Embase, and the Cochrane Library were reviewed.

Study selection

We included studies that measured at least one serum adipokine level and BMD or fracture risk in healthy individuals. We excluded studies with one or more of the following: patients less than 18 years old, patients with comorbidities, who had undergone metabolic treatment, obese patients, patients with high physical activities, and a study that did not distinguish sex or menopausal status.

Data extraction

We extracted the data that include the correlation coefficient between adipokines (leptin, adiponectin, and resistin) and ghrelin and BMD, fracture risk by osteoporotic status from eligible studies.

Data synthesis

A meta-analysis of the pooled correlations between adipokines and BMD was performed, demonstrating that the correlation between leptin and BMD was prominent in postmenopausal women. In most cases, adiponectin levels were inversely correlated with BMD. A meta-analysis was conducted by pooling the mean differences in adipokine levels according to the osteoporotic status. In postmenopausal women, significantly lower leptin (SMD = -0.88) and higher adiponectin (SMD = 0.94) levels were seen in the osteoporosis group than in the control group. By predicting fracture risk, higher leptin levels were associated with lower fracture risk (HR = 0.68), whereas higher adiponectin levels were associated with an increased fracture risk in men (HR = 1.94) and incident vertebral fracture in postmenopausal women (HR = 1.18).

Conclusions

Serum adipokines levels can utilize to predict osteoporotic status and fracture risk of patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021224855, identifier CRD42021224855.

Effects of Natural Progesterone and Synthetic Progestin on Germ Layer Gene Expression in a Human Embryoid Body Model

Natural progesterone and synthetic progestin are widely used for the treatment of threatened abortion or in in vitro fertilization (IVF) cycles. This in vitro study aimed to assess whether the treatment with natural progesterone or synthetic progestin influences the germ layer gene expression on the early human embryonic development using human embryonic stem cells (hESCs)-derived embryoid bodies (hEBs) as a surrogate of early stage human embryonic development. Human EBs derived from hESCs were cultured for nine days, and were treated with natural progesterone (P4) or synthetic progestin, medroxyprogesterone acetate (MPA) at 10–7 M for five days. To reverse the effects of treatment, mifepristone (RU486) as progesterone antagonist was added to the hEBs for four days starting one day after the initiation of treatment. Mouse blastocysts (mBLs) were cultured in vitro for 24 h, and P4 or MPA at 10⁻⁷ M was treated for an additional 24 h. The treated embryos were further transferred onto in vitro cultured endometrial cells to evaluate chorionic gonadotropin (CG) expression. To analyze the effects of P4 or MPA, the expression of differentiation genes representing the three germ layers was investigated, GATA-binding factor 4 (GATA4), α-fetoprotein (AFP), hepatocyte nuclear factor (HNF)-3β, hepatocyte nuclear factor (HNF)-4α (endoderm), Brachyury, cardiac actin (cACT) (mesoderm), and Nestin (ectoderm), using quantitative reverse transcription PCR (qRT-PCR) and immunostaining. Significantly lower expressions of HNF-3β, HNF-4α, Brachyury, and Nestin were observed in MPA-treated hEBs (all p < 0.05), which was negated by RU486 treatment. This inhibitory effect of MPA was also observed in mouse embryos. Conclusively, the effects of natural progesterone and synthetic progestin may differ in the germ layer gene expression in the hEB model, which suggests that caution is necessary in the use of progestogen.

Correlation between Ovarian Reserve and Incidence of Ectopic Pregnancy after In Vitro Fertilization and Embryo Transfer

PURPOSE

To elucidate the correlation between ovarian reserve and the incidence of ectopic pregnancy (EP) following in vitro fertilization and embryo transfer (IVF/ET) cycles.

MATERIALS AND METHODS

In this observational study, 430 fresh IVF/ET cycles were examined from patient data of two university hospital infertility clinics. All included patients were positive for β-human chorionic gonadotropin (hCG) at 2 weeks after oocyte retrieval via controlled ovarian stimulation. For each cycle, information on age, duration of infertility, basal follicle stimulating hormone (FSH), anti-Müllerian hormone (AMH), days of ovarian stimulation, numbers of retrieved oocytes and transferred embryos, and pregnancy outcomes was collected. Patients with AMH lower than 1.0 ng/dL or basal FSH higher than 10 mIU/mL were classified into the decreased ovarian reserve (DOR) group, and the remaining patients were classified into the normal ovarian reserve (NOR) group.

RESULTS

In total, 355 cycles showed NOR, and 75 cycles DOR. There were no significant differences between the DOR and NOR groups regarding intrauterine (74.7% vs. 83.4%, respectively) or chemical (14.7% vs. 14.1%, respectively) pregnancies. The DOR group had a higher EP than that of NOR group [10.7% (8/75) vs. 2.5% (9/355), p=0.004]. In both univariate [odds ratio (OR) 5.6, 95% confidence interval (CI) 1.4-9.6, p=0.011] and multivariate (adjusted OR 5.1, 95 % CI 1.1-18.7, p=0.012) analysis, DOR was associated with a higher risk of EP.

CONCLUSION

DOR may be associated with a higher risk of EP in IVF/ET cycles with controlled ovarian stimulation. More careful monitoring may be necessary for pregnant women with DOR.

Proliferation Profile of Uterine Endometrial Stromal Cells during In Vitro Culture with Gonadotropins: Recombinant versus Urinary Follicle Stimulating Hormone

Background

Provision of optimal endometrial stromal cells is essential in uterine tissue engineering. Culture of these cells is significantly influenced by gonadotropin hormones. This investigation attempted to define the proliferation profiles of murine uterine endometrial stromal cells during in vitro culture with recombinant follicle stimulating hormone (rFSH), urinary follicle stimulating hormone (uFSH), and human chorionic gonadotropin (hCG).

Methods

Murine uterine endometrial stromal cells were collected from 8-week-old mice and cultured in vitro up to 72 h, with rFSH, uFSH, or hCG. Cell cycles were analyzed by BrdU assay, and cyclin D1 expression was evaluated according to dose and duration of gonadotropin treatment.

Results

BrdU assay showed a further inhibitory effect on murine uterine endometrial stromal cell proliferation when cultured with rFSH compared to uFSH, and a similar inhibitory proliferation profile when cultured with hCG at a specific range of concentrations. The expression of cyclin D1 of murine uterine endometrial stromal cells was down-regulated when cultured with rFSH, uFSH, or hCG, compared to control.

Conclusions

FSH may inhibit the proliferation of murine uterine endometrial stromal cells during in vitro culture. rFSH may have more significant inhibitory effects on the proliferation of endometrial stromal cells than uFSH. Establishing an optimal endocrine milieu is necessary using more advanced combination of female hormones for in vitro culture of this type of cells.

Efficient Production of Murine Uterine Damage Model

Background

Thin or damaged endometrium causes uterine factor-derived infertility resulting in a failure of embryonic implantation. Regeneration of endometrium is a major issue in gynecology and reproductive medicine. Various types of cells and scaffolds were studied to establish an effective therapeutic strategy. For this type of investigations, production of optimal animal models is indispensable. In this study, we tried to establish various murine uterine damage models and compared their features.

Methods

Three to ten-week-old C57BL/6 female mice were anesthetized using isoflurane. Chemical and mechanical methods using ethanol (EtOH) at 70 or 100% and copper scraper were compared to determine the most efficient condition. Damage of uterine tissue was induced either by vaginal or dorsal surgical approach. After 7-10 days, gross and microscopic morphology, safety and efficiency were compared among the groups.

Results

Both chemical and mechanical methods resulted in thinner endometrium and reduced number of glands. Gross morphology assessment revealed that the damaged regions of uteri showed various shapes including shrinkage or cystic dilatation of uterine horns. The duration of anesthesia significantly affected recovery after procedure. Uterine damage was most effectively induced by dorsal approach using 100% EtOH treatment compared to mechanical methods.

Conclusion

Taken together, murine uterine damage models were most successfully established by chemical treatment. This production protocols could be applied further to larger animals such as non-human primate.

Circulating leptin, soluble leptin receptor, free leptin index, visfatin and selected leptin and leptin receptor gene polymorphisms in sporadic breast cancer

Leptin and visfatin are implicated in breast cancer risk but studies accounting for bioavailability of leptin are sparse. Reports on the association of leptin gene (LEP) and leptin receptor gene (LEPR) polymorphisms with breast cancer are also inconsistent. Only a very few studies have examined biochemical and genetic variables concomitantly in the same cohort. A matched pairs study was carried out to ascertain whether plasma leptin, soluble leptin receptor, free leptin index (leptin/soluble leptin receptor), serum visfatin and selected LEP and LEPR polymorphisms are risk factors for sporadic breast cancer. Newly diagnosed sporadic breast cancer patients (N=80) were matched for age, body mass index (BMI) and menopausal status with healthy controls. Plasma leptin, soluble leptin receptor and serum visfatin were measured by enzyme-immunoassay. LEP -2548 A/G and LEPR K109R, LEPR Q223R polymorphisms were determined by genotyping. Leptin (p=0.0234), leptin/BMI (p=0.0468), free leptin index (p<0.0001) and visfatin (p=0.0002) were significantly higher and soluble leptin receptor (p<0.0001) was significantly lower in patients. LEPR gene K109R A/G polymorphism increased breast cancer risk (odds ratio: 4.125). Multivariate analysis confirmed that leptin, soluble leptin receptor, free leptin index and G109 (R109) allele of the LEPR gene K109R polymorphism are risk factors for breast cancer. When stratified by menopausal status free leptin index and soluble leptin receptor remained as risk factors irrespective of menopausal status while LEPR gene K109R A/G polymorphism remained as a risk factor only in the postmenopausal group.

High-Carbohydrate/Low-Fat Diet-Induced Gender-Specific Serum Lipid Profile Changes Are Associated with LEPR Polymorphisms in Chinese Youth

BACKGROUND/AIMS

The study aimed to investigate the interactions of genetic variants in the leptin receptor (LEPR) gene with lipid profile changes following a high-carbohydrate/low-fat (HC/LF) diet in a Chinese Han population.

METHODS

Fifty-six healthy young subjects were given washout diets, followed by HC/LF diets consisting of 15% fat and 70% carbohydrate for 6 days. Serum lipid profiles and insulin levels before and after HC/LF diets were analyzed.

RESULTS

Statistically elevated high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-1 (apoA-I), and insulin levels were only observed in the GG genotype of LEPR Lys109Arg but not in the A carriers after HC/LF diet. When gender was taken into account, significantly increased HDL-C, apoA-I, and insulin levels were found in women with the GG genotype. Moreover, lower low-density lipoprotein cholesterol (LDL-C) and higher insulin levels were only observed in subjects with the GG genotype of LEPR Gln223Arg, while higher HDL-C and apoA-I were only found in the A allele carriers. Additionally, the lower LDL-C and body mass index (BMI), and higher HDL-C and insulin levels were only observed in subjects with the GG genotype of LEPR Lys656Asn.

CONCLUSIONS

LEPR polymorphisms contribute to the heterogeneities in BMI, LDL-C, and HDL-C responsiveness that are induced by a HC/LF diet in healthy young Chinese adults.

Association of the I264T variant in the sulfide quinone reductase-like (SQRDL) gene with osteoporosis in Korean postmenopausal women

To identify novel susceptibility variants for osteoporosis in Korean postmenopausal women, we performed a genome-wide association analysis of 1180 nonsynonymous single nucleotide polymorphisms (nsSNPs) in 405 individuals with osteoporosis and 722 normal controls of the Korean Association Resource cohort. A logistic regression analysis revealed 72 nsSNPs that showed a significant association with osteoporosis (p<0.05). The top 10 nsSNPs showing the lowest p-values (p = 5.2×10-4-8.5×10-3) were further studied to investigate their effects at the protein level. Based on the results of an in silico prediction of the protein's functional effect based on amino acid alterations and a sequence conservation evaluation of the amino acid residues at the positions of the nsSNPs among orthologues, we selected one nsSNP in the SQRDL gene (rs1044032, SQRDL I264T) as a meaningful genetic variant associated with postmenopausal osteoporosis. To assess whether the SQRDL I264T variant played a functional role in the pathogenesis of osteoporosis, we examined the in vitro effect of the nsSNP on bone remodeling. Overexpression of the SQRDL I264T variant in the preosteoblast MC3T3-E1 cells significantly increased alkaline phosphatase activity, mineralization, and the mRNA expression of osteoblastogenesis markers, Runx2, Sp7, and Bglap genes, whereas the SQRDL wild type had no effect or a negative effect on osteoblast differentiation. Overexpression of the SQRDL I264T variant did not affect osteoclast differentiation of the primary-cultured monocytes. The known effects of hydrogen sulfide (H2S) on bone remodeling may explain the findings of the current study, which demonstrated the functional role of the H2S-catalyzing enzyme SQRDL I264T variant in osteoblast differentiation. In conclusion, the results of the statistical and experimental analyses indicate that the SQRDL I264T nsSNP may be a significant susceptibility variant for osteoporosis in Korean postmenopausal women that is involved in osteoblast differentiation.

Association of Leptin Receptor Gene Polymorphisms with Genetic Susceptibility to Ischemic Stroke

BACKGROUND

Ischemic stroke is a multifactorial disease that is influenced by both genetic and environmental factors. Identification of the genetic factors that are underlining this disease is important. Leptin receptor (LEPR) mediates the leptin-regulated human energy homeostasis, and mutations of LEPR can increase cardiovascular risks and may predispose an individual to ischemic stroke.

METHODS

We analyzed distribution of 3 single nucleotide polymorphisms (SNPs) of LEPR gene (Lys109Arg, Gln223Arg, and Lys656Asn) in 101 patients with ischemic stroke and 105 controls by polymerase chain reaction-restriction fragment length polymorphism strategy.

RESULTS

Our results showed that there were significant differences in the genotype and allele distribution of Lys109Arg and Gln223Arg polymorphisms of the LEPR gene between case and control. The 109GG and 223GG genotype were associated with a significantly increased risk of ischemic stroke (odds ratio [OR], 3.23; P = .001 and OR, 2.87; P = .008, respectively). The 109G and 223G alleles carriers were correlated with an increased incidence of ischemic stroke (OR, 2.72; P = .001; OR, 2.94; P = .004). By haplotype analyses, we found that 109A/223G/656G haplotype was associated with an increased risk of ischemic stroke although this was not observed in the control group (OR, 3.86; P = .029).

CONCLUSIONS

LEPR 109GG and 223GG genotypes and the 109G and 223G alleles are associated with the risk of ischemic stroke. Our data suggest that LEPR Lys109Arg and Gln223Arg polymorphisms could be used as genetic predictive factor for ischemic stroke.

Relationship between serum leptin levels and bone mineral density: a systematic review and meta-analysis

BACKGROUND

The association between leptin and bone mineral density (BMD) is controversial because of conflicting findings from previous studies.

METHODS

This meta-analysis aimed to provide an overview of the serum leptin levels and BMD in a healthy population. We reviewed the PubMed, Embase, and Cochrane Library databases until July 2014 for research on the association between leptin levels and BMD in healthy people.

RESULTS

We included and analyzed 45 studies in this systematic review and meta-analysis. The pooled correlations between leptin and BMD were analyzed by using the method of the inverse of the variance. Leptin was positively associated with BMD and the bone mineral content (BMC), especially in postmenopausal women (pooled r: 0.13-0.49). Overall, high serum leptin levels were associated with higher BMD levels.

CONCLUSIONS

This meta-analysis suggests that serum leptin levels are positively associated with BMD and BMC, especially in postmenopausal women.

Does Q223R Polymorphism of Leptin Receptor Influence on Anthropometric Parameters and Bone Density in Childhood Cancer Survivors?

Childhood cancer survivors are in augmented risk for developing obesity. For many factors leptin and leptin receptor gene polymorphism play an important role in the development and metabolism not only of fat, but also, bone tissue. The aim of the analysis was to find the relationships between Q223R, leptin levels, and anthropometric parameters. Patients and Methods. In the study 74 cancer survivors participated (ALL n = 64, lymphomas n = 10), and the control group consisted of 51 healthy peers. Leptin blood concentration was determined by ELISA method. To estimate leptin receptor gene polymorphism, RFLP method was used. Bone mineral density (BMD) and content (BMC), fat, and lean tissue measurements were obtained by DXA. Results. We found no correlations between serum leptin concentrations and anthropometric parameters nor BMD. Serum leptin concentrations were significantly lower in the group of cancer survivors compared to controls; however, in those overweight from examined group we found leptin levels higher than those in nonoverweight. Genotype Q223R was not associated with higher leptin levels, BMI, BMD, body fat or lean tissue. Conclusion. To our knowledge, this is the first report describing the relationship between BMD and Q223R polymorphism in childhood cancer survivors. Further analysis, based on a larger group of patients, is needed to confirm these findings.

Study of leptin levels and gene polymorphisms in patients with central precocious puberty

INTRODUCTION

Three single-nucleotide polymorphisms (SNPs) in the leptin (LEP) or leptin receptor (LEPR) genes were assessed for their association with central precocious puberty (CPP).

RESULTS

The control group with the A/G SNP at LEPR 223 or A/G SNP at LEPR 109 exhibited significantly higher peak luteinizing hormone (LH) levels. The leptin level in the CPP group was significantly higher than that in the control group, but SNPs in either LEP or LEPR gene could not explain this observation.

DISCUSSION

In conclusion, SNPs at LEPR 223 and LEPR 109 were significantly associated with higher levels of LH in girls without CPP, but none of the genotypes at these SNPs were significantly associated with CPP.

METHODS

The SNP genotypes of LEP (polymorphism at promoter at nt-2548) and LEPR (223A/G, 109A/G) of 219 healthy girls and 249 girls diagnosed with CPP were compared. Allele frequencies in SNPs were compared with anthropometric measures, circulating leptin, hormones (estradiol, follicle-stimulating hormone, and LH), and lipid concentrations for CPP risk.

Common genetic variation in adiponectin, leptin, and leptin receptor and association with breast cancer subtypes

Adipocytokines are produced by visceral fat, and levels may be associated with breast cancer risk. We investigated whether single nucleotide polymorphisms (SNPs) in adipocytokine genes adiponectin (ADIPOQ), leptin (LEP), and the leptin receptor (LEPR) were associated with basal-like or luminal A breast cancer subtypes. 104 candidate and tag SNPs were genotyped in 1776 of 2022 controls and 1972 (200 basal-like, 679 luminal A) of 2311 cases from the Carolina Breast Cancer Study (CBCS), a population-based case-control study of whites and African Americans. Breast cancer molecular subtypes were determined by immunohistochemistry. Genotype odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. Haplotype ORs and 95% CIs were estimated using Hapstat. Interactions with waist-hip ratio were evaluated using a multiplicative interaction term. Ancestry was estimated from 144 ancestry informative markers (AIMs), and included in models to control for population stratification. Candidate SNPs LEPR K109R (rs1137100) and LEPR Q223R (rs1137101) were positively associated with luminal A breast cancer, whereas ADIPOQ +45 T/G (rs2241766), ADIPOQ +276 G/T (rs1501299), and LEPR K656N (rs8129183) were not associated with either subtype. Few patterns were observed among tag SNPs, with the exception of 3 LEPR SNPs (rs17412175, rs9436746, and rs9436748) that were in moderate LD and inversely associated with basal-like breast cancer. However, no SNP associations were statistically significant after adjustment for multiple comparisons. Haplotypes in LEP and LEPR were associated with both basal-like and luminal A subtypes. There was no evidence of interaction with waist-hip ratio. Data suggest associations between LEPR candidate SNPs and luminal A breast cancer in the CBCS and LEPR intron 2 tag SNPs and basal-like breast cancer. Replication in additional studies where breast cancer subtypes have been defined is necessary to confirm these potential associations.

Associations between serum leptin level and bone turnover in kidney transplant recipients

BACKGROUND AND OBJECTIVES

Obesity is associated with increased parathyroid hormone (PTH) in the general population and in patients with chronic kidney disease (CKD). A direct effect of adipose tissue on bone turnover through leptin production has been suggested, but such an association has not been explored in kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined associations of serum leptin with PTH and with biomarkers of bone turnover (serum beta crosslaps [CTX, a marker of bone resorption] and osteocalcin [OC, a marker of bone formation]) in 978 kidney transplant recipients. Associations were examined in multivariable regression models. Path analyses were used to determine if the association of leptin with bone turnover is independent of PTH.

RESULTS

Higher leptin levels were associated with higher PTH and lower vitamin D levels, and adjustment for vitamin D attenuated the association between leptin and PTH. However, higher leptin was also significantly associated with lower levels of the bone turnover markers: 1 SD higher leptin was associated with 0.13 lower log-OC (-0.17, -0.08, P < 0.001) and 0.030 lower log-CTX (-0.045, -0.016, P < 0.001) after multivariable adjustments. Path analysis indicated that the association of leptin with PTH was mostly mediated through vitamin D, and that the association between leptin and bone turnover was independent of PTH and vitamin D.

CONCLUSIONS

Elevated leptin level is associated with lower bone turnover independent of its effects on serum PTH in kidney transplant recipients.

Molecular genetic studies of gene identification for osteoporosis: the 2009 update

Osteoporosis is a complex human disease that results in increased susceptibility to fragility fractures. It can be phenotypically characterized using several traits, including bone mineral density, bone size, bone strength, and bone turnover markers. The identification of gene variants that contribute to osteoporosis phenotypes, or responses to therapy, can eventually help individualize the prognosis, treatment, and prevention of fractures and their adverse outcomes. Our previously published reviews have comprehensively summarized the progress of molecular genetic studies of gene identification for osteoporosis and have covered the data available to the end of September 2007. This review represents our continuing efforts to summarize the important and representative findings published between October 2007 and November 2009. The topics covered include genetic association and linkage studies in humans, transgenic and knockout mouse models, as well as gene-expression microarray and proteomics studies. Major results are tabulated for comparison and ease of reference. Comments are made on the notable findings and representative studies for their potential influence and implications on our present understanding of the genetics of osteoporosis.

Fat targets for skeletal health

Emerging evidence points to a critical role for the skeleton in several homeostatic processes, including energy balance. The connection between fuel utilization and skeletal remodeling begins in the bone marrow with lineage allocation of mesenchymal stem cells to adipocytes or osteoblasts. Mature bone cells secrete factors that influence insulin sensitivity, and fat cells synthesize cytokines that regulate osteoblast differentiation; thus, these two pathways are closely linked. The emerging importance of the bone-fat interaction suggests that novel molecules could be used as targets to enhance bone formation and possibly prevent fractures. In this article, we discuss three pathways that could be pharmacologically targeted for the ultimate goal of enhancing bone mass and reducing osteoporotic fracture risk: the leptin, peroxisome proliferator-activated receptor gamma and osteocalcin pathways. Not surprisingly, because of the complex interactions across homeostatic networks, other pathways will probably be activated by this targeting, which could prove to be beneficial or detrimental for the organism. Hence, a more complete picture of energy utilization and skeletal remodeling will be required to bring any potential agents into the future clinical armamentarium.

Leptin levels and leptin receptor polymorphism frequency in healthy populations

BACKGROUND

The leptin receptor gene (LEPR) polymorphism Q223R is one of the most common in the general population, and is thought to be associated with an impaired signaling capacity of the leptin receptor and with higher mean circulating levels of leptin. Leptin is a hormone primarily produced in adipose tissue. Increased levels of leptin have been positively correlated with obesity. We have determined the frequency of the leptin receptor polymorphism (LEPR Q223R) in healthy populations from various ethnic groups, and compared plasma leptin levels across the LEPR Q223R polymorphism in healthy African-Caribbean and Caucasian women.

RESULTS

The study population consists of 1,418 healthy subjects from various ethnic groups. The LEPR Q223R homozygous variant was observed overall in 19% of subjects (n = 1,418), with significant differences based on self reported ethnicity: the proportion of subjects with the homozygous variant was lower in Caucasians (14%, n = 883) than in African-Caribbean (n = 194), African-American (n = 36) and Asian/other ethnic groups (n = 26), (35%, 33% and 34.6% respectively); the frequency in Africans (20%), was similar to the overall study population. The mean +/- standard deviation (SD), circulating leptin levels for African-Caribbean women was 44.7 +/- 31.4 ng/ml, while for Caucasian women the mean was 42.4 +/- 34.8 ng/ml. Adjusted circulating leptin levels in post-menopausal Caucasian women who were LEPR Q223R homozygous variant were marginally statistically significantly higher than in women with the wild-type genotype (p = 0.098). No significant differences in leptin levels by genotype were observed for African-Caribbean women, (heterozygous: p = 0.765, homozygous variant: p = 0.485).

CONCLUSION

These findings suggest an association between mean circulating leptin levels and the LEPR Q223R genotype among post-menopausal Caucasian women.