Association between the leptin gene 2548G/A polymorphism, the plasma leptin and the metabolic syndrome with psoriasis

Changes in Cells Associated with Insulin Resistance

Insulin is a polypeptide hormone synthesized and secreted by pancreatic β-cells. It plays an important role as a metabolic hormone. Insulin influences the metabolism of glucose, regulating plasma glucose levels and stimulating glucose storage in organs such as the liver, muscles and adipose tissue. It is involved in fat metabolism, increasing the storage of triglycerides and decreasing lipolysis. Ketone body metabolism also depends on insulin action, as insulin reduces ketone body concentrations and influences protein metabolism. It increases nitrogen retention, facilitates the transport of amino acids into cells and increases the synthesis of proteins. Insulin also inhibits protein breakdown and is involved in cellular growth and proliferation. On the other hand, defects in the intracellular signaling pathways of insulin may cause several disturbances in human metabolism, resulting in several chronic diseases. Insulin resistance, also known as impaired insulin sensitivity, is due to the decreased reaction of insulin signaling for glucose levels, seen when glucose use in response to an adequate concentration of insulin is impaired. Insulin resistance may cause, for example, increased plasma insulin levels. That state, called hyperinsulinemia, impairs metabolic processes and is observed in patients with type 2 diabetes mellitus and obesity. Hyperinsulinemia may increase the risk of initiation, progression and metastasis of several cancers and may cause poor cancer outcomes. Insulin resistance is a health problem worldwide; therefore, mechanisms of insulin resistance, causes and types of insulin resistance and strategies against insulin resistance are described in this review. Attention is also paid to factors that are associated with the development of insulin resistance, the main and characteristic symptoms of particular syndromes, plus other aspects of severe insulin resistance. This review mainly focuses on the description and analysis of changes in cells due to insulin resistance.

A quantitative systems pharmacology model for certolizumab pegol treatment in moderate-to-severe psoriasis

Background

Psoriasis is a chronic immune-mediated inflammatory systemic disease with skin manifestations characterized by erythematous, scaly, itchy and/or painful plaques resulting from hyperproliferation of keratinocytes. Certolizumab pegol [CZP], a PEGylated antigen binding fragment of a humanized monoclonal antibody against TNF-alpha, is approved for the treatment of moderate-to-severe plaque psoriasis. Patients with psoriasis present clinical and molecular variability, affecting response to treatment. Herein, we utilized an in silico approach to model the effects of CZP in a virtual population (vPop) with moderate-to-severe psoriasis. Our proof-of-concept study aims to assess the performance of our model in generating a vPop and defining CZP response variability based on patient profiles.

Methods

We built a quantitative systems pharmacology (QSP) model of a clinical trial-like vPop with moderate-to-severe psoriasis treated with two dosing schemes of CZP (200 mg and 400 mg, both every two weeks for 16 weeks, starting with a loading dose of CZP 400 mg at weeks 0, 2, and 4). We applied different modelling approaches: (i) an algorithm to generate vPop according to reference population values and comorbidity frequencies in real-world populations; (ii) physiologically based pharmacokinetic (PBPK) models of CZP dosing schemes in each virtual patient; and (iii) systems biology-based models of the mechanism of action (MoA) of the drug.

Results

The combination of our different modelling approaches yielded a vPop distribution and a PBPK model that aligned with existing literature. Our systems biology and QSP models reproduced known biological and clinical activity, presenting outcomes correlating with clinical efficacy measures. We identified distinct clusters of virtual patients based on their psoriasis-related protein predicted activity when treated with CZP, which could help unravel differences in drug efficacy in diverse subpopulations. Moreover, our models revealed clusters of MoA solutions irrespective of the dosing regimen employed.

Conclusion

Our study provided patient specific QSP models that reproduced clinical and molecular efficacy features, supporting the use of computational methods as modelling strategy to explore drug response variability. This might shed light on the differences in drug efficacy in diverse subpopulations, especially useful in complex diseases such as psoriasis, through the generation of mechanistically based hypotheses.

A Pilot Genome-Wide Association Study Identifies Novel Markers of Metabolic Syndrome in Patients with Psoriasis

BACKGROUND

Recent studies have reported that psoriasis is associated with the development of metabolic syndrome. Genome-wide association studies have been used to discover gene variant markers that occur frequently in case group in relation to specific diseases.

OBJECTIVE

The aim of the present study was to investigate the variants of specific genes involved in metabolic syndrome associated with psoriasis.

METHODS

A total of 95 psoriasis patients were recruited and divided into two groups: one with metabolic syndrome (38 patients) and the other without (57 patients). After genotyping, imputation, and quality checking, the association between the several single nucleotide polymorphisms and metabolic syndrome in psoriasis was tested, followed by gene set enrichment analysis.

RESULTS

We found 76 gene polymorphisms that conferred an increased risk for metabolic syndrome in patients with psoriasis. Four single nucleotide polymorphisms (rs17154774 of FRMD4A, rs77498336 of GPR116, rs75949580 and rs187682251 of MAPK4) showed the strongest association between metabolic syndrome and psoriasis. The epidermal growth factor receptor protein was located at the center of the protein interactions for the gene polymorphisms.

CONCLUSION

This study identified several previously unknown polymorphisms associated with metabolic syndrome in psoriasis. These results highlight the potential for future genetic studies to elucidate the development, and ultimately prevent the onset, of metabolic syndrome in patients with psoriasis.

Considerations of the Genetic Background of Obesity among Patients with Psoriasis

Psoriasis comorbidities may emerge from pleiotropic mechanisms, including common proinflammatory pathways, cellular mediators or genetic predisposition. Obesity is considered to be an independent risk factor of psoriasis, which may influence the severity of the disease and its early onset, decrease patients’ quality of life, alter response to psoriasis therapies and affect morbidity by reduced life expectancy due to cardiovascular events. Although novel approaches, including genetic techniques, have provided a wide range of new research, there are still scarce studies elaborating on the common genetic background of psoriasis and obesity. The aim of this study was to present and evaluate a possible common genetic background of psoriasis and concomitant increased body mass based on the review of the available literature.

Knowledge Mapping and Research Hotspots of Comorbidities in Psoriasis: A Bibliometric Analysis from 2004 to 2022

Background and Objectives: Psoriasis is a chronic inflammatory disease whose impact on health is not only limited to the skin, but is also associated with multiple comorbidities. Early screening for comorbidities along with appropriate treatment plans can provide a positive prognosis for patients. This study aimed to summarize the knowledge structure in the field of psoriasis comorbidities and further explore its research hotspots and trends through bibliometrics. Materials and Methods: A search was conducted in the core collection of the Web of Science for literature on comorbidities of psoriasis from 2004 to 2022. VOSviewer and CiteSpace software were used for collaborative network analysis, co-citation analysis of references, and keyword co-occurrence analysis on these publications. Results: A total of 1803 papers written by 6741 authors from 81 countries was included. The publications have shown a progressive increase since 2004. The United States and Europe were at the forefront of this field. The most prolific institution was the University of California, and the most productive author was A. Armstrong. Research has focused on "psoriatic arthritis", "metabolic syndrome", "cardiovascular disease", "psychosomatic disease", "inflammatory bowel disease", "prevalence", "quality of life", and "risk factor" in the past 18 years. Keywords such as "biologics" and "systemic inflammation", have been widely used recently, suggesting current research hotspots and trends. Conclusions: Over the past 18 years, tremendous progress has been made in research on psoriasis comorbidity. However, collaborations among countries, institutions, and investigators are inadequate, and the study of the mechanisms of interaction between psoriasis and comorbidities and management of comorbidities is insufficient. The treatment of comorbidities with biologic agents, screening of comorbidities, and multidisciplinary co-management are predicted to be the focus of future research.

Study of leptin gene polymorphism and leptin serum level in alopecia areata patients

Leptin, produced by adipocytes, regulates metabolism, hunger, and immune response. The inflammatory role of leptin has been linked to autoimmune diseases. To assess leptin gene polymorphism and serum level in alopecia areata and their relation to metabolic syndrome (MS). This case-control study was conducted on 100 alopecia areata patients (50 with MS and 50 without MS) and 50 age- and gender-matched controls. Leptin gene polymorphism and serum level were assessed through the use of PCR and ELISA, respectively. GG genotype was the highest in AA with MS (54%), lower in AA without MS (42%), and the lowest in controls (20%). G allele was more expressed in cases, than in controls (P < .001). The serum leptin level was the highest in AA with MS, lower in AA without MS, and the lowest in controls (P value = 0.001). Leptin level was significantly higher in GG polymorphism than AG and AA. Leptin gene polymorphism (GG genotype) and serum level appear to play a significant role in AA. Absent difference regarding leptin gene polymorphism and MS might indicate a separate inflammatory role of leptin or the future risk of MS development in AA patients.

Cognitive Process of Psoriasis and Its Comorbidities: From Epidemiology to Genetics

Psoriasis (PsO) is a chronic inflammatory skin disease that affects approximately 2% of the population all over the world. Comorbidities of PsO have increasingly garnered more interest in the past decades. Compared with the normal population, the incidences of comorbidities are higher among patients with PsO. In the last 20 years, researchers have focused on studying the genetic components of PsO, and genetic associations between PsO and its comorbidities were elucidated. This review provides an in-depth understanding and summarization of the connection between PsO and its comorbidities from the perspectives of epidemiology and genetics. Further understanding of PsO and its comorbidities will promote research on the pathogenesis, drug development, novel therapy methods, and personalized and precision treatment of PsO and its comorbidities.

Leptin Receptor (rs1137101) and Brain-Derived Neurotrophic Factor (rs925946) Gene Variants Are Associated with Obesity in the Early- but Not in the Late-Onset Population of Hungarian Psoriatic Patients

Background: Psoriatic patients have considerably higher odds of being obese compared with the general population; however, the exact pathophysiological link between psoriasis and obesity needs to be elucidated. Methods: To investigate the association of psoriasis with established obesity-related gene variants, we conducted a population-based case-control study including 3541 subjects (574 psoriasis cases and 2967 controls from the general Hungarian population). Genotyping of 20 SNPs at ADIPOQ, BDNF, FTO, GNPDA2, LEPR, MC4R, NEGR1, NPY, PPARG, TMEM18, and UCP2 were determined, and differences in genotype and allele distributions were investigated. Multiple logistic regression analyses were implemented. Results: Analysis revealed an association between the G allele of the rs1137101 polymorphism (LEPR gene) and obesity risk (OR: 3.30 (1.45; 7.50), p = 0.004) in the early-onset group of psoriatic patients. Furthermore, the T allele of rs925946 polymorphism (BDNF gene) was also associated with increased risk of obesity in early-onset psoriasis (OR: 2.26 (1.24; 4.14), p = 0.008). Conclusions: Our results suggest that in psoriatic patients, there are prominent differences in the causes of obesity that should be accounted for, including not only environmental factors but also patient characteristics, such as the time of disease onset as well as genetic factors.

Analysis of the Potential Genetic Links between Psoriasis and Cardiovascular Risk Factors

Cardiovascular risk factors are one of the most common comorbidities in psoriasis. A higher prevalence of hypertension, insulin resistance and type 2 diabetes, dyslipidemia, obesity, metabolic syndrome, depression, as well as cardiovascular disease was confirmed in psoriatic patients in comparison to the general population. Data suggest that psoriasis and systemic inflammatory disorders may originate from the pleiotropic interactions with many genetic pathways. In this review, the authors present the current state of knowledge on the potential genetic links between psoriasis and cardiovascular risk factors. The understanding of the processes linking psoriasis with cardiovascular risk factors can lead to improvement of psoriasis management in the future.

Role of Insulin in Health and Disease: An Update

Insulin is a polypeptide hormone mainly secreted by β cells in the islets of Langerhans of the pancreas. The hormone potentially coordinates with glucagon to modulate blood glucose levels; insulin acts via an anabolic pathway, while glucagon performs catabolic functions. Insulin regulates glucose levels in the bloodstream and induces glucose storage in the liver, muscles, and adipose tissue, resulting in overall weight gain. The modulation of a wide range of physiological processes by insulin makes its synthesis and levels critical in the onset and progression of several chronic diseases. Although clinical and basic research has made significant progress in understanding the role of insulin in several pathophysiological processes, many aspects of these functions have yet to be elucidated. This review provides an update on insulin secretion and regulation, and its physiological roles and functions in different organs and cells, and implications to overall health. We cast light on recent advances in insulin-signaling targeted therapies, the protective effects of insulin signaling activators against disease, and recommendations and directions for future research.

The Important Role of Leptin in Modulating the Risk of Dermatological Diseases

It is an indisputable fact that obesity is associated with a series of health problems. One important hallmark of obesity is excessive accumulation of lipids in the adipocyte, especially triglyceride (TG). Currently, the adipocyte has been considered not only as a huge repository of excess energy in the form of fat but also as an important source of multiple hormones and cytokines called adipokines. In obesity, the adipocyte is dysfunctional with excessive production and secretion of pro-inflammatory adipokines, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and leptin. On the other hand, accumulating evidence has shown that leptin plays a vital role in stimulating angiogenesis, controlling lipid metabolism, and modulating the production of pro-inflammatory cytokines. Furthermore, the various activities of leptin are related to the wide distribution of leptin receptors. Notably, it has been reported that enhanced leptin levels and dysfunction of the leptin signaling pathway can influence diverse skin diseases. Recently, several studies revealed the roles of leptin in wound healing, the hair cycle, and the pathogenic development of skin diseases, such as psoriasis, lupus erythematosus, and dermatological cancers. However, the exact mechanisms of leptin in modulating the dermatological diseases are still under investigation. Therefore, in the present review, we summarized the regulatory roles of leptin in the pathological progression of diverse diseases of skin and skin appendages. Furthermore, we also provided evidence to elucidate the complicated relationship between leptin and different dermatological diseases, such as systemic lupus erythematosus (SLE), psoriasis, hidradenitis suppurativa, and some skin tumors.

Leptin in skin disease modulation

In obesity, adipocytes are dysfunctional with excessive production and secretion of pro-inflammatory hormones and cytokines, ie, adipokines, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and leptin. Accumulating evidence has shown that leptin possesses pleiotropic functions including stimulation of angiogenesis and production of pro-inflammatory cytokines. Furthermore, various leptin associated activities involve a wide distribution of leptin receptors. For example, increased serum leptin was associated with tissue receptor resistance in metabolic syndrome. Although increased serum leptin, receptor and signaling impairment are involved in wound healing, hair cycle and the pathogenesis of many skin diseases such as psoriasis and lupus erythematosus as well as skin cancer, its exact role remains unclear. In the present article, we discuss the biochemistry of leptin action and its potential role in the pathophysiology of diverse skin diseases.

Quantile-specific heritability of sibling leptin concentrations and its implications for gene-environment interactions

"Quantile-dependent expressivity" occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., leptin) is high or low relative to its distribution. Leptin concentrations are strongly related to adiposity, whose heritability is quantile dependent. Whether inheritance of leptin concentrations is quantile dependent, and whether this explains the greater heritability in women than men in accordance with their greater adiposity, and explains other gene-environment interactions, remains to be determined. Therefore, leptin and leptin receptor concentrations from 3068 siblings in 1133 sibships from the Framingham Heart Study Third Generation Cohort were analyzed. Free leptin index (FLI) was calculated as the ratio of leptin to soluble leptin receptor concentrations. Full-sib (β_FS) regression slopes were robustly estimated by quantile regression with nonparametric significance assigned from 1000 bootstrap samples. The analyses showed β_FS increased significantly with increasing percentiles of the offspring's age- and sex-adjusted leptin distribution (P_linear = 0.0001), which was accelerated at the higher concentrations (P_quadratic = 0.0003). β_FS at the 90th percentile (0.418 ± 0.066) was 4.7-fold greater than at the 10th percentile (0.089 ± 0.032, P_difference = 3.6 × 10^-6). Consistent with quantile-dependent expressivity, the β_FS was greater in female sibs, which was attributable to their higher leptin concentrations. Reported gene-environment interactions involving adiposity and LEP, LEPR, MnSOD, PPARγ, PPARγ2, and IRS-1 polymorphisms were consistent with quantile-dependent expressivity of leptin concentrations. β_FS for leptin receptor concentrations and free leptin index also increased significantly with increasing percentiles of their distributions (P_linear = 0.04 and P_linear = 8.5 × 10^-6, respectively). In conclusion, inherited genetic and shared environmental effects on leptin concentrations were quantile dependent, which likely explains male-female differences in heritability and some gene-environment interactions.

Adipokines in the Skin and in Dermatological Diseases

Adipokines are the primary mediators of adipose tissue-induced and regulated systemic inflammatory diseases; however, recent findings revealed that serum levels of various adipokines correlate also with the onset and the severity of dermatological diseases. Importantly, further data confirmed that the skin serves not only as a target for adipokine signaling, but may serve as a source too. In this review, we aim to provide a complex overview on how adipokines may integrate into the (patho) physiological conditions of the skin by introducing the cell types, such as keratinocytes, fibroblasts, and sebocytes, which are known to produce adipokines as well as the signals that target them. Moreover, we discuss data from in vivo and in vitro murine and human studies as well as genetic data on how adipokines may contribute to various aspects of the homeostasis of the skin, e.g., melanogenesis, hair growth, or wound healing, just as to the pathogenesis of dermatological diseases such as psoriasis, atopic dermatitis, acne, rosacea, and melanoma.

The role of leptin in selected skin diseases

Leptin is an adipokine, adipocyte-derived compound, which acts both as a hormone and cytokine. It is mainly synthesized by adipocytes of white adipose tissue. Leptin possesses pleiotropic functions including, among others, stimulation of angiogenesis and production of proinflammatory cytokines. The various types of leptin activity are related to the wide distribution of leptin receptors. This adipokine acts by activating intracellular signaling cascades such as JAKs (Janus kinases), STATs (signal transducers and activators of transcription), and others.In a course of obesity, an increased serum level of leptin coexists with tissue receptor resistance. It has been reported that enhanced leptin levels, leptin receptor impairment, and dysfunction of leptin signaling can influence skin and hair. The previous studies revealed the role of leptin in wound healing, hair cycle, and pathogenesis of skin diseases like psoriasis, lupus erythematosus, and skin cancers. However, the exact mechanism of leptin's impact on the skin is still under investigation. Herein, we present the current knowledge concerning the role of leptin in psoriasis and selected skin diseases.

Leptin Gene G2548A Polymorphism among Mongolians with Metabolic Syndrome

Metabolic syndrome (MetS) corresponds with multiple risk factors. Many studies have indicated that MetS significantly increases the risk of cardiovascular diseases and type 2 diabetes (T2D). The prevalence of MetS was estimated to be one third of the general Mongolian population in 2015. The purpose of our study was to determine polymorphisms of the LEP (Leptin) and LEPR (Leptin receptor) genes that show susceptibility to MetS and to predict the genetic risk of MetS. We selected 160 cases with MetS and 144 with healthy controls. The G2548A polymorphism of the LEP gene and the A668G (Q223R) polymorphism of the LEPR gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results of the regression analysis showed that the 2548 amino acids (AA) of LEP gene carriers had increased incidences of MetS (OR = 3.23; p = 0.035). Patients with MetS who were 2548A allele carriers had an increased concentration of serum leptin (p = 0.011). Moreover, G2548A of LEP polymorphism was associated with elevated body mass index (BMI) and fasting blood glucose (FBG) in the case group. Our results confirm that the LEP G2548A loci is the independent risk factor of MetS.

Prevalence of psoriatic arthritis in patients with psoriasis: A systematic review and meta-analysis of observational and clinical studies

BACKGROUND

Wide-ranging prevalence estimates of psoriatic arthritis (PsA) in patients with psoriasis have been reported.

OBJECTIVES

To assess the prevalence and incidence of PsA in patients with psoriasis.

METHODS

Two authors independently searched 3 databases for studies reporting on the prevalence or incidence of PsA in patients with psoriasis. A proportion meta-analysis was performed to calculate the pooled proportion estimates of PsA in patients with psoriasis.

RESULTS

A total of 266 studies examining 976,408 patients with psoriasis were included. Overall, the pooled proportion (95% confidence interval [CI]) of PsA among patients with psoriasis was 19.7% (95% CI, 18.5%-20.9%). In children and adolescents (<18 years of age), the pooled prevalence was 3.3% (95% CI, 2.1%-4.9%). The PsA prevalence was 22.7% (95% CI, 20.6%-25.0%) in European patients with psoriasis, 21.5% (95% CI, 15.4%-28.2%) in South American patients with psoriasis, 19.5% (95% CI, 17.1%-22.1%) in North American patients with psoriasis, 15.5% (95% CI, 0.009%-51.5%) in African patients with psoriasis, and 14.0% (95% CI, 95% CI, 11.7%-16.3%) in Asian patients with psoriasis. The prevalence of PsA was 23.8% (95% CI, 20.1%-27.6%) in studies in which the Classification Criteria for Psoriatic Arthritis were applied. The incidence of PsA among patients with psoriasis ranged from 0.27 to 2.7 per 100 person-years.

LIMITATIONS

Between-study heterogeneity may have affected the estimates.

CONCLUSIONS

We found that 1 in 4 patients with psoriasis have PsA. With the growing recognition of the Classification Criteria for Psoriatic Arthritis, more homogenous and comparable prevalence estimates are expected to be reported.

Gender-Specific Association of Leptin and Adiponectin Genes With Multiple Sclerosis

BACKGROUND

Adipocytokines such as leptin (LEP) and adiponectin (ADIPOQ) represent a link between metabolism, nutritional status and immune responses. The present study aimed to determine the possible association between single nucleotide polymorphisms of LEP and ADIPOQ genes with multiple sclerosis (MS).

MATERIALS AND METHODS

Single nucleotide polymorphisms in LEP (rs2167270 or 19G > A and rs7799039 or -2,548G > A) and ADIPOQ (rs1501299 or +276G > T and rs266729 or -11,377C > G) were genotyped in 305 patients and 255 healthy individuals using polymerase chain reaction-restriction fragment length polymorphism. Sera levels of leptin and adiponectin were measured using enzyme-linked immunosorbent assay.

RESULTS

The frequencies of low leptin producer rs2167270GG genotype and rs2167270G allele were significantly lower in patients with MS compared to those of controls (for GG genotype: 39.7% and 49.8%, respectively; P = 0.01; for G allele: 63.3% and 68.8%, respectively; P = 0.05). Both polymorphisms in ADIPOQ did not show any significant association with disease susceptibility, though after gender categorization the frequency of high adiponectin producer rs1501299TT genotype and rs1501299T allele were significantly higher in male controls compared to male patients (TT genotype: P = 0.006; T allele: P = 0.006). Additionally, rs1501299TT genotype in ADIPOQ was associated with susceptibility to primary progressive multiple sclerosis (PP-MS) (P = 0.02). Moreover, while the sera levels of leptin were only different between male patients and controls (P = 0.05), adiponectin levels were significantly higher in total and female healthy controls (P < 0.001, P = 0.002, respectively).

CONCLUSIONS

Our findings provide evidence to support the hypothesis that functional ADIPOQ and LEP gene polymorphisms are associated with susceptibility to MS and its clinical forms.

Mismatch Amplification Mutation Assay Real-Time PCR Analysis of the Leptin Gene G2548A and A19G Polymorphisms and Serum Leptin in Infancy: A Preliminary Investigation

Leptin is a hormone that regulates food intake and energy metabolism. Its coding gene (LEP) is one of the most promising candidates for obesity. Although some studies have detected associations of different single nucleotide polymorphisms (SNPs) in the LEP gene with serum leptin levels and obesity-related traits, the results are still conflicting. We investigated two SNPs to find relationships with leptin concentrations. Thirty healthy Caucasian infants younger than 6 months were genotyped for the SNPs G2548A and A19G with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system-mismatch amplification mutation assay (ARMS- MAMA) real-time PCR, and serum leptin concentrations were measured with a radioimmunoassay method. Considering the significant linkage disequilibrium observed between the two SNPs, we divided the sample according to the number of GG haplotypes and observed that individuals homozygous for the GG haplotype had higher serum leptin levels in early infancy than the others. Although these preliminary results are based on a limited sample, they suggest that the genetic background seems to play a role in modulating leptin levels in infancy, but changes in leptin levels over infancy and their correlation with obesity need to be further explored. We describe an ARMS-MAMA real-time PCR procedure which could be profitably applied in routine genetic screening.

Effect of miRNA-27a and Leptin Polymorphisms on Risk of Recurrent Spontaneous Abortion

Background

The aim of this study was to investigate the possible associations of miRNA-27a and Leptin polymorphisms with the risk of recurrent spontaneous abortion (RSA).

Material/Methods

Between May 2013 and April 2015 at Shenzhen Longhua New District Central Hospital, we randomly recruited 138 RSA patients as the case group and another 142 normal pregnancy women as the control group. We used denaturing high-performance liquid chromatography (DHPLC) to determine the genotypes and allele frequencies of miRNA-27a rs895819 A/G and Leptin rs7799039 G/A.

Results

The GG genotype and G allele frequencies of miRNA-27a rs895819 A/G were higher in the case group than in the control group, and the AA genotype and A allele frequencies of Leptin rs7799039 G/A were also higher in the case group than in the control group (all P<0.05). MiRNA-27a rs895819 A/G and Leptin rs7799039 G/A polymorphisms increased the risk of RSA (Exp (B)=2.732, 95% CI=1.625~4.596, P=0.000; Exp (B)=4.081, 95% CI=1.817~9.164, P=0.001). GG-AA or AG-AA carriers had a higher risk of RSA. The miRNA-27a expression of AA carriers of miRNA-27a rs895819 was lower than that of AG+GG carriers both in the case and control groups (all P=0.024). The plasma leptin concentration of GG carriers was lower than that of GA+AA carriers in the case group (P=0.026).

Conclusions

The polymorphisms of miRNA-27a rs895819 A/G and Leptin rs7799039 G/A may contribute to an increased risk of RSA.

Relationships between plasma leptin levels, leptin G2548A, leptin receptor Gln223Arg polymorphisms and gestational diabetes mellitus in Chinese population

The purposes of this study were to examine concentrations of leptin and biochemical parameters in gestational diabetes mellitus (GDM) patients and normal glucose tolerance (NGT) individuals, and also to explore the links of leptin (LEP) G2548A and leptin receptor (LEPR) Gln223Arg polymorphisms with leptin levels and GDM risk among Chinese. Our study included 357 GDM and 355 NGT individuals who were at 24~30 gestational weeks. Plasma leptin and insulin levels were analyzed by ELISA. Gene polymorphisms were genotyped using TaqMan real-time polymerase chain reaction assay. The results showed that plasma leptin levels were significantly higher in the impaired fasting glucose (IFG) group than NGT group (34.35 (26.54, 56.48) ng/mL vs 26.31 (17.99, 37.87) ng/mL, P < 0.05). Plasma leptin levels correlated with plasma fasting insulin levels, pre-pregnant body mass index, homeostasis model assessment-insulin resistance and quantitative insulin sensitivity check index both in GDM and NGT group (P < 0.05). However, neither LEP G2548A nor LEPR Gln223Arg polymorphisms were significantly associated with GDM risk and plasma leptin levels (P > 0.05). Our findings showed that high leptin level was associated with GDM. And larger and more rigorous researches were needed to further explore the association of LEP and LEPR gene polymorphisms and GDM among Chinese population.

Insulin resistance and skin diseases

In medical practice, almost every clinician may encounter patients with skin disease. However, it is not always easy for physicians of all specialties to face the daily task of determining the nature and clinical implication of dermatologic manifestations. Are they confined to the skin, representing a pure dermatologic event? Or are they also markers of internal conditions relating to the patient's overall health? In this review, we will discuss the principal cutaneous conditions which have been linked to metabolic alterations. Particularly, since insulin has an important role in homeostasis and physiology of the skin, we will focus on the relationships between insulin resistance (IR) and skin diseases, analyzing strongly IR-associated conditions such as acanthosis nigricans, acne, and psoriasis, without neglecting emerging and potential scenarios as the ones represented by hidradenitis suppurativa, androgenetic alopecia, and hirsutism.

Effect of psoriasis activity on serum adiponectin and leptin levels

INTRODUCTION

Psoriasis is an inflammatory and chronic skin disease associated with obesity, cardiovascular diseases, diabetes and metabolic syndrome. Adipokines, as bioactive substances secreted from adipose tissue, are involved in various metabolic diseases.

AIM

To investigate the association between psoriasis severity and serum adiponectin and leptin levels in patients with psoriasis.

MATERIAL AND METHODS

Serum fasting adiponectin and leptin levels were examined by an enzyme-linked immunosorbent assay in 49 patients with relapse of plaque-type psoriasis and 16 healthy controls. The results were correlated with the Psoriasis Area and Severity Index (PASI), body mass index (BMI), several inflammatory markers, duration of the disease and present relapse.

RESULTS

Serum adiponectin and leptin levels were significantly decreased in psoriatic patients in comparison to the control group. There were no correlations between the above measures and PASI scores, patients' age, duration of the disease, present relapse and hospitalization, neither between white blood cells or platelets counts. Serum adiponectin levels significantly correlated with C-reactive protein (CRP) levels. Adiponectin was negatively and leptin positively correlated to BMI at statistical significance. Multivariate analysis demonstrated a significant positive correlation between adiponectin and CRP or PASI concentrations as well as between BMI and leptin concentration.

CONCLUSIONS

The data showed that serum adiponectin levels increase and serum leptin levels decrease with psoriasis severity. Leptin might be useful in assessing severity and the risk of complications of psoriasis. Moreover, these results confirmed the relationship between leptin, obesity and psoriasis.

Lack of association between leptin, leptin receptor, adiponectin gene polymorphisms and epicardial adipose tissue, abdominal visceral fat volume and atherosclerotic burden in psoriasis patients

CONTEXT

Identifying psoriasis patients who present a higher risk of developing cardiovascular co-morbidities is of upmost importance. Two key adipokines, leptin and adiponectin, may play a role connecting psoriasis and its major co-morbidities.

OBJECTIVE

To evaluate the potential contribution of LEPrs2167270(19 G/A), LEPRrs1137100(326 A/G) and ADIPOQrs1501299(276 G/T) gene polymorphisms in psoriasis susceptibility and their influence in epicardial adipose tissue and abdominal visceral fat volume and subclinical atherosclerosis in severe psoriasis patients.

MATERIALS AND METHODS

One hundred severe psoriasis patients underwent clinical and laboratory evaluation, DNA genotyping and multi-detector computed tomography scan for epicardial adipose tissue, abdominal visceral fat and coronary artery calcification assessment. DNA control group was obtained from a previously anonymized biobank of 206 adult subjects without psoriasis.

RESULTS

No association was observed between the studied gene polymorphisms and psoriasis susceptibility, CAC or increased EAT or AVF volume.

DISCUSSION AND CONCLUSION

The studied polymorphisms do not seem, at least in this cohort of patients, to be a genetic risk factor for the development of atherosclerosis or increased adiposity in psoriasis.

Psoriasis is associated with decreased plasma adiponectin levels independently of cardiometabolic risk factors

BACKGROUND

Psoriasis is an inflammatory skin disease that may be associated with an adverse cardiometabolic profile including modulated plasma adiponectin and leptin levels. Whether these levels are independent of cardiometabolic risk factors, which are also prevalent in psoriasis, is not known.

METHODS

A consecutive sample of 122 participants with varying degrees of psoriasis severity, and a random sample of 134 participants without psoriasis, were recruited for this case-control study. Cardiometabolic risk factors including traditional cardiovascular risk factors, waist circumference, insulin resistance, and total plasma adiponectin and leptin were measured. Total plasma adiponectin and leptin levels were compared in unadjusted and adjusted analyses by psoriasis status.

RESULTS

Participants with psoriasis had mostly mild disease and were mainly on topical therapies, but still had a more adverse cardiometabolic profile compared with those without psoriasis. Furthermore, plasma adiponectin levels were significantly lower in participants with psoriasis than those without {7.13 μg/mL [interquartile range (IQR) 4.9-11.3) vs. 14.5 μg/mL (IQR 8.4-24.1); P < 0.001]}. Plasma leptin (ng/mL) levels were higher in the psoriasis group but this did not reach statistical significance [11.3 (IQR 6.4-21.8) vs. 9.8 (IQR 4.9-20.5); P = 0.07]. In multivariable modelling, plasma adiponectin levels were still negatively associated with psoriasis status after adjusting for waist size (% difference = -41.2%, P < 0.001), insulin resistance (% difference = -39.5%, P < 0.001), and both waist size and insulin resistance (% difference = -38.5%, P < 0.001).

CONCLUSIONS

Plasma levels of adiponectin were lower in psoriasis, and this relationship persisted after adjusting for cardiometabolic risk factors known to decrease adiponectin levels. These findings suggest that inflammation present in psoriasis may be associated with adipose tissue dysfunction; however, direct studies of adipose tissue are needed to confirm this.

Hair cycle control by leptin as a new anagen inducer

Our purpose is to clarify the physiological role of leptin in hair cycle as leptin reportedly causes activation of Stat3, which is indispensable for hair cycling. While hair follicles in dorsal skin of 5-week-old C57/BL6 mice had progressed to late anagen phase, those in dorsal skin of 5-week-old leptin receptor deficient db/db mice remained in the first telogen and later entered the anagen at postnatal day 40, indicating that deficiency in leptin receptor signalling delayed the second hair cycle progression. Next, we shaved dorsal hairs on wild-type mice at postnatal 7 weeks and injected skin with mouse leptin or a mock. After 20 days, although mock injection showed no effect, hair growth occurred around leptin injection area. Human leptin fragment (aa22-56) had similar effects. Although the hair cycle of ob/ob mice was similar to that of wild-type mice, injection of mouse leptin on ob/ob mice at postnatal 7 weeks induced anagen transition. Immunohistochemically, leptin is expressed in hair follicles from catagen to early anagen in wild-type mice, suggesting that leptin is an anagen inducer in vivo. Phosphorylation of Erk, Jak2 and Stat3 in human keratinocytes was stimulated by leptin and leptin fragment. In addition, RT-PCR and ELISA showed that the production of leptin by human dermal papilla cells increased under hypoxic condition, suggesting that hypoxia in catagen/telogen phase promotes leptin production, preparing for entry into the next anagen. In conclusion, leptin, a well-known adipokine, acts as an anagen inducer and represents a new player in hair biology.

Serum adiponectin and leptin levels in psoriatic patients according to topical treatment

OBJECTIVES

Psoriasis has been considered as a systemic disease associated with obesity, cardiovascular diseases and metabolic syndrome. Adipokines have influence on many metabolic processes. Aim of this study was to evaluate the effect of conventional topical treatment on serum adiponectin and leptin levels in patients with psoriasis.

METHODS

Forty-nine patients with relapse of plaque-type psoriasis and 16 healthy controls were examined. Blood samples were collected before therapy and after 14 days of application. Serum adiponectin and leptin concentrations were examined by enzyme-linked immunosorbent assay for correlations with effectiveness of topical treatment.

RESULTS

Adiponectin and leptin serum levels were significantly decreased in psoriatic patients in comparison to the controls. As a result of the topical treatment, serum adiponectin level did not significantly change. Serum leptin level increased significantly, still remaining lower than in the controls.

CONCLUSIONS

Leptin might be a useful marker in assessing the efficacy of the treatment for psoriasis.

Genetic variation in adipokine genes and associations with adiponectin and leptin concentrations in plasma and breast tissue

BACKGROUND

Circulating adipokines may be associated with breast cancer risk. Genetic variants governing adipokines and adipokine receptors may also predict risk, but their effect on breast adipokine concentrations is unknown.

METHODS

We conducted a cross-sectional analysis of functional SNPs in 5 adipokine genes [adiponectin, leptin (LEP), and their receptors] among 85 cancer-free women who were undergoing reduction mammoplasty.

RESULTS

In multivariable-adjusted regression models, compared with the common GG genotype, the AA genotype of the LEP A19G SNP was associated with 27% lower plasma adiponectin [ratio, 0.73; 95% confidence interval (CI), 0.54-0.98] and leptin (ratio, 0.73; 95% CI, 0.55-0.96). Women with the AG genotype of LEP A19G had 39% lower breast leptin (ratio, 0.61; 95% CI, 0.39-0.97) compared with those with the GG genotype. No associations were observed for SNPs in the remaining genes.

CONCLUSIONS

Genetic variation in LEP may alter endogenous adipokine concentrations in circulation and in breast tissues.

IMPACT

These preliminary findings may support the hypothesis that genetic variation in adipokine genes modifies circulating adipokine concentrations and possibly leptin concentrations in local breast tissues, which may be associated with breast cancer risk.

Serum leptin and adiponectin levels in Korean patients with psoriasis

Psoriasis is a disorder caused by genetic and immunological factors. Leptin, a peptide hormone secreted predominantly from adipose tissue, regulates energy intake and expenditure, as well as the T-helper response. There have been conflicting reports regarding serum levels of leptin and adiponectin in patients with psoriasis. In the present study, we measured serum levels of leptin and adiponectin in Korean patients with psoriasis. Twenty-four patients with psoriasis and fifteen control subjects were included in the study. Serum leptin and adiponectin levels were determined by an immunometric sandwich enzyme-linked immunosorbent assay (ELISA). The mean serum leptin concentration in patients with psoriasis was higher than in controls, and the difference was statistically significant. In contrast, serum adiponectin levels in patients with psoriasis were significantly decreased compared with healthy controls. Leptin levels in vitamin D-deficient patients were statistically significantly higher than in vitamin D-sufficient patients. Serum adiponectin concentrations showed a negative correlation with body mass index (BMI) and psoriasis area and severity index (PASI) in patients with psoriasis. In conclusion, the present study demonstrated that leptin and adiponectin may play a role in the immunopathogenesis of psoriasis and may be useful biomarkers indicating severity of psoriasis in Korean patients.

Assessment of Leptin Gene Polymorphism rs2060713 in Psoriasis Vulgaris

Psoriasis is a lifelong disorder characterized by approximately 8-fold reduction of the duration of normal skin keratinocyte cell cycle and 2-fold increase of the number of dividing cells. Multiple genes, several environmental factors, and immune system alterations are involved in the pathogenesis of psoriasis. Hyperleptinemia is associated with psoriasis and leptin acts as an angiogenic factor. Angiogenetic processes precede the epidermal hyperplasia in psoriasis, indicating possible involvement of leptin in the pathogenesis of psoriasis. Leptin gene polymorphisms and their association with psoriasis have been given very little attention. We present a study of the rs2060713C/T genetic polymorphism in the pathogenesis of psoriasis vulgaris in 263 vulgaris patients and 252 unrelated matched healthy controls. No statistically significant differences were observed between patients and controls. A statistically nonsignificant trend was observed in males with the early onset type of psoriasis (11.1% C/T in patients versus 5.6% in controls) and in females with the late onset type of the disease (12.8% C/T in patients versus 3.3% in controls). Still, there is no hard evidence on correlation of psoriasis vulgaris with this polymorphism. Possible association with specific forms of the disease and either gender needs further investigation in larger studies.

Measurement of the levels of leptin, BDNF associated with polymorphisms LEP G2548A, LEPR Gln223Arg and BDNF Val66Met in Thai with metabolic syndrome

BACKGROUND

Metabolic syndrome is a cluster of metabolic risk factors including dyslipidemia, impaired glucose tolerance, hypertension and central obesity. BDNF (Brain-derived neurotrophic factor) and leptin have been implied in the energy homeostasis. The purposes of this study were to examine concentrations of leptin, BDNF and biochemical parameters in metabolic-syndrome subjects and healthy controls, and also to search for associations of leptin gene (LEP) G2548A, leptin receptor gene (LEPR) Gln223Arg, and BDNF gene (BDNF) Val66Met polymorphisms with leptin levels, BDNF levels and metabolic syndrome among Thais.

METHODS

The case-controlled design was performed using 322 Thai volunteers (160 metabolic-syndrome subjects; 162 controls) during the health screening program. Metabolic syndrome was assessed by using the modified National Cholesterol Education Program, Adult Treatment Panel III criteria. The levels of leptin, BDNF, insulin, glucose and lipids were measured in samples. Genotyping of LEP G2548A, LEPR Gln223Arg and BDNF Val66Met was carried out using polymerase chain reaction-restriction fragment length polymorphism technique.

RESULTS

Serum leptin levels were significantly higher in the metabolic-syndrome group than the control group (p < 0.01), but the BDNF difference between them was not significant. Significant associations of LEPR Gln223Arg polymorphism were found with leptin and glucose levels (p < 0.05), after adjusting for potential covariates. This LEPR polymorphism in the metabolic-syndrome group was also significantly more frequent than in the control group (p < 0.05). However, other gene polymorphisms, LEP G2548A and BDNF Val66Met, showed no significant relationship with leptin levels, BDNF levels or metabolic syndrome.

CONCLUSION

These findings suggest leptin levels are linked with metabolic syndrome. LEPR Gln223Arg polymorphism impacted leptin concentrations, and this gene polymorphism may influence susceptibility to metabolic syndrome among Thais.

Leptin levels in patients with psoriasis: a meta-analysis

BACKGROUND

There have been inconsistent results reported for leptin levels in patients with psoriasis.

AIM

To evaluate leptin levels in patients with psoriasis using a meta-analysis of studies comparing leptin levels in controls and in patients with psoriasis.

METHODS

PubMed (MEDLINE), EMBASE and the Cochrane Library were searched for relevant papers published in English. Pooled weighted mean differences (WMDs) and 95% CIs were calculated using random-effects and fixed-effects models. Heterogeneity between studies was assessed using the Cochran Q and I(2) statistics.

RESULTS

In total, 11 studies, comprising 773 patients with psoriasis and 570 healthy controls, were identified. Leptin levels were significantly higher in patients with psoriasis compared with controls (WMD = 7.24, 95% CI 4.55-9.93; P < 0.001). On stratified analysis, significant differences in leptin levels between patients with psoriasis and controls were reported only in serum samples (P < 0.001), and not in plasma samples (P = 0.025). Sensitivity analysis showed that there were no changes in the direction of effect when any one study was excluded. No publication bias was detected.

CONCLUSIONS

Leptin levels are higher in patients with psoriasis compared with those in controls. Future studies are warranted to clarify the association between leptin levels and the pathomechanism of psoriasis.

The effect of acitretin treatment on insulin resistance, retinol-binding protein-4, leptin, and adiponectin in psoriasis vulgaris: a noncontrolled study

BACKGROUND/AIM

To investigate the effects of acitretin treatment on insulin resistance (IR) and adipokines, particularly retinol-binding protein (RBP)-4.

METHODS

Thirty-four patients with chronic plaque psoriasis and a control group of 34 healthy volunteers were recruited in the study. Screening for the parameters was performed before starting and after 3 months of acitretin treatment in the psoriasis group. The control group was only evaluated at the beginning of the study and did not receive placebo. We could not compare our results with a placebo control group because of ethical reasons.

RESULTS

Basal adiponectin (p = 0.01), insulin (p < 0.0001) levels and homeostasis model assessment (HOMA) IR (p < 0.0001) were significantly higher in psoriasis patients. After the treatment, insulin (p = 0.014), C peptide (p = 0.011), RBP-4 (p < 0.0001) levels and HOMA-IR (p = 0.008) decreased significantly. Posttreatment leptin (p = 0.036) levels were significantly lower than those of the controls. Posttreatment adiponectin (p = 0.005) and insulin (p = 0.048) levels were higher than those of the controls.

CONCLUSIONS

This study showed for the first time that RBP-4 levels and IR are decreased significantly with acitretin treatment. This finding is very important in psoriasis patients because psoriasis may cause insulin resistance and diabetes. Further experimental and clinical studies are needed to clarify the effect of acitretin on adipocyte structure and behavior.

Prevalence of metabolic syndrome in obese Chilean children and association with gene variants of the leptin-melanocortin system

Metabolic syndrome (MS) related to adult type 2 diabetes mellitus and cardiovascular disease is prevalent among obese children/adolescents. Genetic variants of the leptin-melanocortin system have been associated with components of MS. The aim of our study is to estimate the prevalence of MS (according to Cook's criteria) in a Chilean cross-sectional sample of 259 obese children (47.1% girls, aged 6-12 years), and to assess the association between common genetic variants of leptin-melanocortin pathway genes (LEP, LEPR, POMC, MC3R and MC4R) with components of the MS using logistic regression. We observed an overall MS prevalence of 26.3% (32.2% in girls and 21.1% in boys) in obese Chilean children. No associations were detected between genetic variants of leptin-melanocortin genes and MS components. MS prevalence among our obese children sample is similar to those previously described in Chile, demonstrating the increased risk of diseases in adulthood that obese children carry.

Leptin, adiponectin, visfatin and retinol-binding protein-4 - mediators of comorbidities in patients with psoriasis?

White adipose tissue is known to be involved in numerous physiological processes such as insulin-mediated functions, lipid and glucose metabolism, vascular changes and coagulation. These processes are mainly mediated by adipokines that are secreted either from adipocytes or cells of the stromal-vascular fraction of adipose tissue. In obesity, a shift in the production of adipokines can mediate the development of associated diseases, such as metabolic syndrome, and vascular complications, such as artherosclerosis, myocardial infarction or stroke, which are known comorbidities of psoriasis too. As obesity is a frequently seen comorbidity in psoriasis patients, adipokines could be involved in the pathogenesis of psoriasis and/or its comorbidities either dependently or independently from obesity. Therefore, this study investigates the levels of four major adipokines in psoriasis patients compared with a control group of healthy volunteers without chronic inflammatory diseases in relation to body composition. Leptin, adiponectin (high molecular weight (HMW) and total adiponectin), visfatin and retinol-binding protein 4 (RBP4) have been analysed in 79 psoriasis patients and in 80 healthy volunteers. It was shown that HMW adiponectin (OR 1.3755; P = 0.0094) and visfatin (OR 1.1267; P = 0.0472) are independently increased, and RBP4 (OR 0.9884; P < 0.0001) is independently decreased in psoriasis. In conclusion, increased levels of HMW adiponectin and decreased levels of RBP4 could be a mechanism in a chronic inflammatory state that helps to protect against vascular and metabolic disorders, whereas the increase of the pro-inflammatory adipokine visfatin could lead to atherosclerosis and vascular disorders found in psoriasis.

Psoriasis and physical activity: a review

Psoriasis is a common, chronic inflammatory skin disease that can cause significant discomfort and impairment to quality of life. Recent research indicates that individuals with moderate-to-severe psoriasis are likely at greater risk for chronic cardiometabolic co-morbidities such as cardiovascular disease, type 2 diabetes, obesity and metabolic syndrome. Physical activity can be an effective primary and adjunctive treatment for these maladies in other populations. Unfortunately, only a limited number of studies have examined physical activity in psoriasis, which are limited by poor design and lack of validated physical activity assessment methodologies. A variety of data suggest shared physiologic pathways between physical activity, psoriasis, and psoriasis cardiometabolic co-morbidities. Increased adiposity, inflammation, oxidative stress, adhesion molecules and lipids are physiologically linked to psoriasis, the risk of psoriasis cardiometabolic co-morbidities, and low levels of physical activity. In addition, epigenetic pathways are involved in psoriasis and could be influenced by physical activity. The physical and psychosocial impairments common in psoriasis may make it difficult to participate in regular physical activity, and future studies should aim to determine if physical activity interventions improve functioning and reduce co-morbidities in psoriasis.