Genetic polymorphisms in adipokine genes and the risk of obesity: a systematic review and meta-analysis

The Future of Obesity Management through Precision Nutrition: Putting the Individual at the Center

PURPOSE OF REVIEW: The prevalence of obesity continues to rise steadily. While obesity management typically relies on dietary and lifestyle modifications, individual responses to these interventions vary widely. Clinical guidelines for overweight and obesity stress the importance of personalized approaches to care. This review aims to underscore the role of precision nutrition in delivering tailored interventions for obesity management. RECENT FINDINGS: Recent technological strides have expanded our ability to detect obesity-related genetic polymorphisms, with machine learning algorithms proving pivotal in analyzing intricate genomic data. Machine learning algorithms can also predict postprandial glucose, triglyceride, and insulin levels, facilitating customized dietary interventions and ultimately leading to successful weight loss. Additionally, given that adherence to dietary recommendations is one of the key predictors of weight loss success, employing more objective methods for dietary assessment and monitoring can enhance sustained long-term compliance. Biomarkers of food intake hold promise for a more objective dietary assessment. Acknowledging the multifaceted nature of obesity, precision nutrition stands poised to transform obesity management by tailoring dietary interventions to individuals' genetic backgrounds, gut microbiota, metabolic profiles, and behavioral patterns. However, there is insufficient evidence demonstrating the superiority of precision nutrition over traditional dietary recommendations. The integration of precision nutrition into routine clinical practice requires further validation through randomized controlled trials and the accumulation of a larger body of evidence to strengthen its foundation.

Association of the C3953T (rs1143634) variant of the interleukin 1 beta gene with the features of a complicated course of COVID-19-associated pneumonia

BACKGROUND

The pro-inflammatory cytokine IL-1 plays an important role in severe COVID-19. A change in IL-1 production may be associated with a mutation in the IL1Β gene. Our study analyzed the impact of the IL1Β gene variants (rs1143634) on disease progression in patients with severe COVID-19 pneumonia, taking into account treatment strategies.

METHODS AND RESULTS

The study enrolled 117 patients with severe COVID-19 pneumonia. The IL1Β gene variants were identified using the polymerase chain reaction-restriction fragment length polymorphism method. In the group of patients, the following genotype frequencies were found based on the investigated rs1143634 variant of the IL1Β gene: CC-65.8%, CT-28.2%, and TT-6.0%. Our results showed that the group of patients with the T allele of the IL1Β gene had higher leukocyte counts (p = 0.040) and more pronounced lymphopenia (p = 0.007). It was determined that patients carrying the T allele stayed on ventilators significantly longer (p = 0.049) and required longer treatment with corticosteroids (p = 0.045).

CONCLUSION

Identifying variants of the IL1Β gene can be used as a predictive tool for assessing the severity of COVID-19 pneumonia and tailoring personalized treatment strategies. Further research with a larger patient cohort is required to validate these findings.

Hypoxia as a Double-Edged Sword to Combat Obesity and Comorbidities

The global epidemic of obesity is tightly associated with numerous comorbidities, such as type II diabetes, cardiovascular diseases and the metabolic syndrome. Among the key features of obesity, some studies have suggested the abnormal expansion of adipose-tissue-induced local endogenous hypoxic, while other studies indicated endogenous hyperoxia as the opposite trend. Endogenous hypoxic aggravates dysfunction in adipose tissue and stimulates secretion of inflammatory molecules, which contribute to obesity. In contrast, hypoxic exposure combined with training effectively generate exogenous hypoxic to reduce body weight and downregulate metabolic risks. The (patho)physiological effects in adipose tissue are distinct from those of endogenous hypoxic. We critically assess the latest advances on the molecular mediators of endogenous hypoxic that regulate the dysfunction in adipose tissue. Subsequently we propose potential therapeutic targets in adipose tissues and the small molecules that may reverse the detrimental effect of local endogenous hypoxic. More importantly, we discuss alterations of metabolic pathways in adipose tissue and the metabolic benefits brought by hypoxic exercise. In terms of therapeutic intervention, numerous approaches have been developed to treat obesity, nevertheless durability and safety remain the major concern. Thus, a combination of the therapies that suppress endogenous hypoxic with exercise plans that augment exogenous hypoxic may accelerate the development of more effective and durable medications to treat obesity and comorbidities.

Dietary total antioxidant capacity interacts with a variant of chromosome 5q13-14 locus to influence cardio-metabolic risk factors among obese adults

Background

The association between cocaine- and amphetamine-regulated transcript prepropeptide gene (CARTPT) and obesity-related outcomes has shown in the epidemiological studies. Nevertheless, there is lack of data regarding the CARTPT gene-diet interactions in terms of antioxidant potential of diet. So, this study aimed to test CARTPT gene-dietary non-enzymatic antioxidant capacity (NEAC) interactions on cardio-metabolic risk factors in obese individuals.

Methods and material

The present cross-sectional study was carried out among 288 apparently healthy obese adults within age range of 20-50 years. Antioxidant capacity of diet was estimated by calculating the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), total radical-trapping antioxidant parameter (TRAP) and Trolox equivalent antioxidant capacity (TEAC) using a semiquantitative food frequency questionnaire (FFQ). Genotyping for CARTPT rs2239670 polymorphism was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

A significant interaction was revealed between CARTPT rs2239670 and dietary ORAC on BMI (PInteraction = 0.048) and fat mass percent (FM%) (PInteraction = 0.008); in A allele carriers, higher adherence to the dietary ORAC was related to lower level of BMI and FM%. And, the significant interactions were observed between FRAP index and rs2239670 in relation to HOMA (PInteraction = 0.049) and QUICKI (PInteraction = 0.048). Moreover, there were significant interactions of rs2239670 with TRAP (PInteraction = 0.029) and TEAC (PInteraction = 0.034) on the serum glucose level; individuals with AG genotype were more respondent to higher intake of TRAP.

Conclusion

The present study indicated that the relationships between CARTPT rs2239670 and obesity and its-related metabolic parameters depend on adherence to the dietary NEAC. Large prospective studies are needed to confirm our findings.

Association between Adiponectin and Leptin Receptor Genetic Polymorphisms and Clinical Manifestations of Metabolic Syndrome

Abdominal obesity coupled with polygenic hereditary defects is considered the initial event in the development of metabolic syndrome (MS). The purpose of this study was to analyse the frequency with which polymorphic loci of adiponectin (ADIPOQ) and leptin (LEP) genes occur in patients with MS and the association between the symptoms of MS and these polymorphisms. DNA was isolated from the whole blood of 207 patients with MS and 100 healthy individuals (control group) using the phenol-chloroform method. Gene polymorphisms were determined using real-time polymerase chain reaction (PCR). The most common variant of the ADIPOQ (rs2241766) gene among MS patients was the GT genotype. The A allele of the LEP (rs7799039) gene was found to be the most frequent in MS patients. The highest systolic blood pressure was found in carriers of the GG genotype of the LEP (rs7799039) gene. The carriers of the ADIPOQ (rs2241766) GT genotype were associated with the highest systolic blood pressure and body mass index (BMI); carriers of the ADIPOQ (rs2241766) GG genotype were associated with the highest diastolic blood pressure, hyperglycaemia, and elevated glycated haemoglobin (HbA1c). The results of this study allowed us to establish the unique gene variants associated with the risk of developing MS in the Crimean population.

A GWAS top hit for circulating leptin is associated with weight gain but not with leptin protein levels in lithium-augmented patients with major depression

Lithium-treated patients often suffer from weight gain as a common adverse event. In an earlier investigation, we found an impact of two single-nucleotide polymorphisms (rs10487506 and rs2278815) at the leptin gene on weight gain but not on leptin protein levels in serum under lithium augmentation. A recent genome-wide association study identified a polymorphism at the leptin gene locus (rs10487505) associated with circulating leptin protein levels. To characterize potential effects of this variant in acute major depressive disorder, we investigated body mass indices from 180 lithium-augmented patients and serum concentrations of leptin protein from 89 patients using linear mixed model analyses and rs6979832, a proxy SNP of rs10487505. Body mass index was measured before and after 4 weeks of lithium augmentation, in a subsample also after 4 and 7 months. Leptin serum levels were measured before and during lithium augmentation. G-allele homozygotes of rs6979832 had a significantly lower body mass index increase during observation compared to A-allele hetero- and homozygotes. However, we found no influence on leptin serum levels. Joint analyses of rs6979832 with the previously investigated polymorphisms rs10487506 and rs2278815, and expressed quantitative trait data, suggest a complex interplay between SNP alleles at the leptin locus. These results strongly support our earlier findings that common genetic variation at the leptin gene locus may be involved in lithium augmentation-associated weight gain in major depressive disorder.

Innate-Immunity Genes in Obesity

The main functions of adipose tissue are thought to be storage and mobilization of the body’s energy reserves, active and passive thermoregulation, participation in the spatial organization of internal organs, protection of the body from lipotoxicity, and ectopic lipid deposition. After the discovery of adipokines, the endocrine function was added to the above list, and after the identification of crosstalk between adipocytes and immune cells, an immune function was suggested. Nonetheless, it turned out that the mechanisms underlying mutual regulatory relations of adipocytes, preadipocytes, immune cells, and their microenvironment are complex and redundant at many levels. One possible way to elucidate the picture of adipose-tissue regulation is to determine genetic variants correlating with obesity. In this review, we examine various aspects of adipose-tissue involvement in innate immune responses as well as variants of immune-response genes associated with obesity.

Associations between perceived stress and BMI and waist circumference in Chinese adults: data from the 2015 China Health and Nutrition Survey

OBJECTIVES

To assess the association between perceived stress and adiposity among Chinese adults.

DESIGN

Cross-sectional study. Perceived stress was assessed using the 14-item perceived stress scale. Associations between quintiles of perceived stress and BMI and waist circumference were assessed using linear regression models and multinomial regression models. Estimates were adjusted for sociodemographic characteristics.

SETTING

2015 China Health and Nutrition Survey: 12 provinces covering a variety of geographic, economic development and health indicator situations.

PARTICIPANTS

A total of 8385 adults of both sexes, aged 18-99 years, were included.

RESULTS

Overall, the mean perceived stress score was 22·7 (6·2), mean BMI was 24·3 (3·6) kg/m2 and prevalence of obesity (BMI ≥ 30 kg/m2) was 6·0 %. There were inverse associations between perceived stress quintiles with continuous BMI (P < 0·001), BMI categories (P = 0·015) and waist circumference (P = 0·047). Compared to adults in the lowest quintile of perceived stress, adults in the highest quintile of perceived stress had 0·44 kg/m2 lower mean BMI (95 % CI: -0·67, -0·21), 0·72 times the prevalence of obesity (95 % CI: 0·55, 0·94) and 0·73 times the prevalence of abdominal obesity (95 % CI: 0·61, 0·88). Results were similar when using Chinese-specific cut-points.

CONCLUSION

Our results showed inverse associations between perceived stress quintiles and adiposity among Chinese adults. Future studies should aim to better understand the directionality of the observed associations and the potential biological and behavioural mechanisms underlying these associations in the Chinese population.

Urinary metals and adipokines in midlife women: The Study of Women's Health Across the nation (SWAN)

BACKGROUND

Information on the associations between metal exposures and adipokines in human populations is limited and results are inconsistent. We evaluated the associations between metals and adipokines.

METHODS

Urinary concentrations of 15 metals (arsenic, barium, cadmium, cobalt, cesium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, tin, thallium, and zinc) were measured in 1999-2000 among 1228 women of the Study of Women's Health Across the Nation Multi-Pollutant Study. Serum adipokines including high molecular weight (HMW)-adiponectin, leptin, and soluble leptin receptor (sOB-R) were measured at the follow-up visit (2002-2003). Linear regression models with adaptive elastic-net (AENET) were fit to identify metals associated with adipokines and to compute estimated percent changes in adipokines for one standard deviation increase in log-transformed urinary metal concentrations.

RESULTS

After adjustment for confounders, urinary molybdenum was associated with a 5.54% higher level (95% CI: 1.36%, 9.90%), whereas cadmium was associated with a 4.53% lower level (95% CI: -8.17%, -0.76%) of HMW-adiponectin. Urinary molybdenum was also associated with a 5.95% lower leptin level (95% CI: -10.15%, -1.56%) and a 2.98% (95% CI: 0.69%, 5.32%) higher sOB-R level. Urinary cesium and lead were associated with a 3.58% (95% CI: -6.06%, -1.03%) and a 2.53% (95% CI: -4.80%, -0.21%) lower level of sOB-R, respectively.

CONCLUSIONS

Our findings suggest that molybdenum was associated with favorable profiles of HMW-adiponectin, leptin, and sOB-R. Exposures to cadmium, cesium, and lead were associated with adverse adipokine profiles.

Pharmacological Therapy Determines the Gut Microbiota Modulation by a Pomegranate Extract Nutraceutical in Metabolic Syndrome: A Randomized Clinical Trial

SCOPE

Poly-pharmacological therapy shapes the gut microbiota (GM) in metabolic syndrome (MetS) patients. The effects of polyphenols in poly-medicated MetS patients are unknown.

METHODS AND RESULTS

A randomized, placebo-controlled, double-blinded, and crossover trial in poly-medicated MetS patients (n=50) explored whether the effects of a pomegranate extract nutraceutical (PE, 320 mg phenolics/day for 1 month) are affected by the drug therapy. Considering the lipid-lowering (LL-), anti-hypertensive (HP-) and(or) anti-diabetic (AD-) treatments: GM (16S rRNA sequencing), short-chain fatty acids, 40 inflammatory-metabolic and endotoxemia-related biomarkers, associations between biomarkers and GM with 53 cardiometabolic dysfunctions-related single-nucleotide polymorphisms (SNPs), and urolithin metabotypes (UMs) influence are evaluated. Representative SNPs-GM associations after PE include Lactococcus and ClostridiumXIVa with rs5443-GNB3 (G-protein-β-polypeptide-3) and ClostridiumXIVa with rs7903146-TCF7L2 (transcription-factor-7-like-2) and rs1137101-LEPR (leptin-receptor). PE decreases sICAM-1 in LL-patients and the lipopolysaccharide-binding protein in all the patients. PE does not affect the other patients' markers as a group or stratifying by UMs. After PE, Lactococcus increases in AD-, LL-, and HP-patients, Bifidobacterium increases in LL- and AD-, while Clostridium XIVa decreases in non-LL- and non-HP-patients.

CONCLUSION

The prebiotic effect of PE depends on the medication, mainly on HP-treatments. Targeting GM can complement MetS therapy, but the patients' drug therapy should be considered individually.

Role of Dietary Amino Acids and Nutrient Sensing System in Pregnancy Associated Disorders

Defective implantation is related to pregnancy-associated disorders such as spontaneous miscarriage, intrauterine fetal growth restriction and others. Several factors proclaimed to be involved such as physiological, nutritional, environmental and managemental that leads to cause oxidative stress. Overloading of free radicals promotes oxidative stress, and the internal body system could not combat its ability to encounter the damaging effects and subsequently leading to pregnancy-related disorders. During pregnancy, essential amino acids display important role for optimum fetal growth and other necessary functions for continuing fruitful pregnancy. In this context, dietary amino acids have received much attention regarding the nutritional concerns during pregnancy. Arginine, glutamine, tryptophan and taurine play a crucial role in fetal growth, development and survival while ornithine and proline are important players for the regulation of gene expression, protein synthesis and angiogenesis. Moreover, amino acids also stimulate the mammalian target of rapamycin (mTOR) signaling pathway which plays a central role in the synthesis of proteins in placenta, uterus and fetus. This review article explores the significances of dietary amino acids in pregnancy development, regulation of nutrient-sensing pathways such as mTOR, peroxisome proliferator-activated receptors (PPARs), insulin/insulin-like growth factor signaling pathway (IIS) and 5' adenosine monophosphate-activated protein kinase (AMPK) which exhibit important role in reproduction and its related problems. In addition, the antioxidant function of dietary amino acids against oxidative stress triggering pregnancy disorders and their possible outcomes will also be enlightened. Dietary supplementation of amino acids during pregnancy could help mitigate reproductive disorders and thereby improving fertility in animals as well as humans.

Causal Relationship between Plasma Adiponectin and Body Mass Index: One- and Two-Sample Bidirectional Mendelian Randomization Analyses in 460 397 Individuals

BACKGROUND

Adiponectin is a protein hormone produced by adipocytes that may play an important role in obesity. However, the causal interrelation between plasma adiponectin and body mass index (BMI) is still uncertain. We tested the hypotheses that (a) plasma adiponectin and BMI are inversely associated observationally, (b) genetically high BMI is associated with lower plasma adiponectin, and (c) genetically high plasma adiponectin is associated with lower BMI.

METHODS

Information on 108 896 individuals from the Copenhagen General Population Study was used in observational and bidirectional one-sample Mendelian randomization analyses, using 5 genetic variants for BMI and 3 for adiponectin. For independent confirmation, information on 322 154 individuals from the GIANT consortium, and 29 347 individuals from the ADIPOGen consortium was used in bidirectional two-sample Mendelian randomization analysis, using 68 genetic variants for BMI and 14 for adiponectin.

RESULTS

In observational analyses, a 1 kg/m2 increase in BMI was associated with -0.44 µg/mL (95% confidence interval: -0.46, -0.42) in plasma adiponectin, whereas a 1 µg/mL increase in plasma adiponectin was associated with -0.11 kg/m2 (-0.12, -0.11) in BMI. In causal genetic analyses, no associations were observed between BMI and plasma adiponectin and vice versa. In one-sample Mendelian randomization analyses, a 1 kg/m2 genetically determined increase in BMI was associated with -0.13 µg/mL (-0.53, 0.28) in plasma adiponectin, whereas a 1 µg/mL genetically determined increase in plasma adiponectin was associated with 0.01 kg/m2 (-0.05, 0.07) in BMI. Corresponding estimates in the two-sample Mendelian randomization analyses were 0.03 µg/mL (-0.02, 0.07) and 0.03 kg/m2(-0.02, 0.07), respectively.

CONCLUSIONS

Observationally, plasma adiponectin and BMI are inversely associated. In contrast, genetically high plasma adiponectin is unlikely to influence BMI, and genetically high BMI is unlikely to influence plasma adiponectin.

The Genetic Basis of Obesity and Related Metabolic Diseases in Humans and Companion Animals

Obesity is one of the most prevalent health conditions in humans and companion animals globally. It is associated with premature mortality, metabolic dysfunction, and multiple health conditions across species. Obesity is, therefore, of importance in the fields of medicine and veterinary medicine. The regulation of adiposity is a homeostatic process vulnerable to disruption by a multitude of genetic and environmental factors. It is well established that the heritability of obesity is high in humans and laboratory animals, with ample evidence that the same is true in companion animals. In this review, we provide an overview of how genes link to obesity in humans, drawing on a wealth of information from laboratory animal models, and summarise the mechanisms by which obesity causes related disease. Throughout, we focus on how large-scale human studies and niche investigations of rare mutations in severely affected patients have improved our understanding of obesity biology and can inform our ability to interpret results of animal studies. For dogs, cats, and horses, we compare the similarities in obesity pathophysiology to humans and review the genetic studies that have been previously reported in those species. Finally, we discuss how veterinary genetics may learn from humans about studying precise, nuanced phenotypes and implementing large-scale studies, but also how veterinary studies may be able to look past clinical findings to mechanistic ones and demonstrate translational benefits to human research.

Genetic Polymorphisms, Mediterranean Diet and Microbiota-Associated Urolithin Metabotypes can Predict Obesity in Childhood-Adolescence

Environmental and genetic factors are associated with pandemic obesity since childhood. However, the association of overweight-obesity with these factors, acting as a consortium, has been scarcely studied in children. We aimed here to assess the probabilities of being overweighed-obese in a randomly recruited cohort of Spanish children and adolescents (n = 415, 5−17 years-old) by estimating the odds ratios for different predictor variables, and their relative importance in the prediction. The predictor variables were ethnicity, age, sex, adherence to the Mediterranean diet (KIDMED), physical activity, urolithin metabotypes (UM-A, UM-B and UM-0) as biomarkers of the gut microbiota, and 53 single-nucleotide polymorphisms (SNPs) from 43 genes mainly related to obesity and cardiometabolic diseases. A proportional-odds logistic ordinal regression, validated through bootstrap, was used to model the data. While every variable was not independently associated with overweight-obesity, however, the ordinal logistic model revealed that overweight-obesity prevalence was related to being a young boy with either UM-B or UM-0, low KIDMED score and high contribution of a consortium of 24 SNPs, being rs1801253-ADRB1, rs4343-ACE, rs8061518-FTO, rs1130864-CRP, rs659366-UCP2, rs6131-SELP, rs12535708-LEP, rs1501299-ADIPOQ, rs708272-CETP and rs2241766-ADIPOQ the top-ten contributing SNPs. Additional research should confirm and complete this model by including dietary interventions and the individuals’ gut microbiota composition.

Converging Relationships of Obesity and Hyperuricemia with Special Reference to Metabolic Disorders and Plausible Therapeutic Implications

BACKGROUND

Obesity and hyperuricemia mutually influence metabolic syndrome. This study discusses the metabolic relationships between obesity and hyperuricemia in terms of pathophysiology, complications, and treatments.

METHODS

We searched for preclinical or clinical studies on the pathophysiology, complications, and therapy of obesity and hyperuricemia on the PubMed database.

RESULTS

In this systemic review, we summarized our searching results on topics of pathophysiology, complications and therapeutic strategy. In pathophysiology, we firstly introduce genetic variations for obesity, hyperuricemia and their relationships by genetic studies. Secondly, we talk about the epigenetic influences on obesity and hyperuricemia. Thirdly, we describe the central metabolic regulation and the role of hyperuricemia. Then, we refer to the character of adipose tissue inflammation and oxidative stress in the obesity and hyperuricemia. In the last part of this topic, we reviewed the critical links of gut microbiota in the obesity and hyperuricemia. In the following part, we review the pathophysiology of major complications in obesity and hyperuricemia including insulin resistance and type 2 diabetes mellitus, chronic kidney disease, cardiovascular diseases, and cancers. Finally, we recapitulate the therapeutic strategies especially the novel pharmaceutic interventions for obesity and hyperuricemia, which concurrently show the mutual metabolic influences between two diseases.

CONCLUSION

The data reviewed here delineate the metabolic relationships between obesity and hyperuricemia, and provide a comprehensive overview of the therapeutic targets for the management of metabolic syndromes.

Leptin gene polymorphisms are associated with weight gain during lithium augmentation in patients with major depression

Weight gain is a common adverse effect of lithium augmentation. Previous studies indicate an impact of genetic variants at the leptin gene on weight gain as a consequence of psychopharmacological treatment. The primary aim of our study was to identify variants at the leptin locus that might predict lithium-induced weight gain. The secondary aim was to investigate if these variants modulate leptin levels. In 180 patients with acute major depressive disorder, body mass index was measured before and after 4 weeks of lithium augmentation, in a subsample also after 4 and/or 7 months. In a subsample of 89 patients, leptin serum concentrations were measured before and during lithium augmentation. We used linear mixed model analyzes to investigate the effects of 2 polymorphisms at the leptin locus (rs4731426 and rs7799039, employing the respective proxy SNPs rs2278815 and rs10487506) on changes in body mass index and leptin levels. For both polymorphisms, which are in high linkage disequilibrium, body mass index was significantly lower in homozygous A-allele carriers than in carriers of other genotypes at baseline. Over the follow-up period, body mass index increased less in homozygous A-allele carriers of rs4731426 than in carriers of other genotypes. This was not the case for rs7799039. Neither polymorphism modulated leptin protein expression. Our study strongly supports the hypothesis that genetic variability at the leptin locus is involved in lithium augmentation-associated weight gain in major depressive disorder. Furthermore, Genotype-Tissue Expression data provide strong evidence that rs4731426 influences the expression of leptin messenger ribonucleic acid in fibroblasts.

Association of interleukin-6 polymorphisms with obesity: A systematic review and meta-analysis

Obesity is a common metabolic disorder with increasing trend all around the world. Owing to the role of pro-inflammatory cytokines on obesity, we aimed to investigate the role of interleukin-6 (IL-6) polymorphisms on risk of obesity. Electronic literatures were searched in Web of Science, PubMed, Embase, and Scopus. The references of relevant reviews and included studies were also manually checked. All types of observational studies from 1 January 1992 to 28 February 2018 were included. Odds ratio (OR) was estimated by fixed and random effect model. Subgroup analysis was carried out based on age statues. Pooling analysis of eligible studies have been considered for rs2069845 and rs1800796, and no significant results were observed. Minor allele of IL-6 rs1800797polymorphism decreased the risk of obesity/overweight in allelic 0.74 (0.59-0.92), dominant 0.65 (0.49-0.85), and over-dominant 0.66 (0.51-0.87) models. Fourteen eligible studies were included for rs1800795. According to BMI, C allele showed increased risk of obesity in genetic models containing homozygote model 1.47 (1.02-2.12) for body mass index (BMI) ≥ 25 vs. BMI < 25, recessive model 1.32 (1.07-1.63) for BMI ≥ 30 vs. BMI < 25, and homozygote model 1.35 (1.10-1.66) for BMI ≥ 30 vs. BMI < 30. In overall definition of obesity more significant results were observed, including homozygote model in obese vs. normal 1.71 (1.14-2.56). Similarly, subgroups analysis revealed additional significant results. Minor alleles of rs1800795 raised and rs1800797 reduced the risk of obesity, while rs1800796 and rs2069845 may not be associated. However, more observational studies are recommended to confirm these results.

The Effect of Habitual Fat Intake, IL6 Polymorphism, and Different Diet Strategies on Inflammation in Postmenopausal Women with Central Obesity

The hypothesis that habitual fat intake, the IL6 genotype, the Mediterranean diet or the central European diet for 16 weeks affect biomarkers of inflammation in centrally obese postmenopausal women, was tested in a randomized controlled trial. Dietary intake was assessed using a three-day food diary. Lipid parameters were measured using a Beckman Coulter AU analyzer. Transcription of TNF and IL6 genes was analyzed in peripheral blood mononuclear cells using real-time PCR. Concentrations of tumor necrosis factor alpha (TNFα) and interleukin 6 (IL6) were measured with ELISA. rs1800795 polymorphism of IL6 was analyzed using hydrolyzing probes. Higher energy intake from fat was associated with higher IL6 levels (p < 0.05). Significantly (p < 0.01) lower total cholesterol (T-C) and low-density lipoprotein cholesterol (LDL-C) concentrations were observed in the GG IL6 rs1800795 genotype group. Both diets significantly (p < 0.001) decreased TNFα concentrations. Neither IL6 gene transcription levels nor blood IL6 concentrations were affected by them. Our findings confirm that habitual fat intake may affect inflammation. The rs1800795 IL6 polymorphism alone did not significantly affect body weight or body composition in aimed group, but C-allele carriers had higher levels of T-C and LDL-C. This polymorphism did not affect inflammation. Both diets may lead to a decrease in TNFα concentration.

Polymorphisms in Adipokines in Mexican Children with Obesity

The high prevalence of childhood obesity in Mexico is alarming in the health-science field. We propose to investigate the contribution of adipokines and cytokines polymorphisms and common BMI/obesity-associated loci, revealed in genome-wide association studies in Caucasian adult cohorts, with childhood obesity. This study included 773 Mexican-Mestizo children (5-15 years old) in a case-control study. The polymorphisms included were ADIPOQ (rs6444174), TNF-α (rs1800750), IL-1β (rs1143643), IL-6 (rs1524107; rs2069845), NEGR1 (rs34305371), SEC16B-RASAL2 (rs10913469), TMEM18 (rs6548238; rs7561317), GNPDA2 (rs16857402), LEP (rs2167270), MTCH2 (rs10838738), LGR4-LIN7C-BDNF (rs925946), BCDIN3D-FAIM2 (rs7138803), FTO (rs62033400), MC4R (rs11872992), MC4R (rs17782313), and KCTD15 (rs29942). No significant contribution was found with adipokines and cytokines polymorphisms in this study. Only both TMEM18 (rs6548238; rs7561317) polymorphisms were found associated with obesity (OR=0.5, P=0.008) and were in linkage disequilibrium (r2=0.87). The linear regression showed that the rs7561317 polymorphism of TMEM18 is negatively associated with obesity. This report highlights the influence of TMEM18 in Mexican-Mestizo children obesity, while adipokine and cytokine polymorphisms were not associated with it.

Pharmacogenetic Correlates of Antipsychotic-Induced Weight Gain in the Chinese Population

Antipsychotic-induced weight gain (AIWG) is a common adverse effect of this treatment, particularly with second-generation antipsychotics, and it is a major health problem around the world. We aimed to review the progress of pharmacogenetic studies on AIWG in the Chinese population to compare the results for Chinese with other ethnic populations, identify the limitations and problems of current studies, and provide future research directions in China. Both English and Chinese electronic databases were searched to identify eligible studies. We determined that > 25 single-nucleotide polymorphisms in 19 genes have been investigated in association with AIWG in Chinese patients over the past few decades. HTR2C rs3813929 is the most frequently studied single-nucleotide polymorphism, and it seems to be the most strongly associated with AIWG in the Chinese population. However, many genes that have been reported to be associated with AIWG in other ethnic populations have not been included in Chinese studies. To explain the pharmacogenetic reasons for AIWG in the Chinese population, genome-wide association studies and multiple-center, standard, unified, and large samples are needed.

Genetic association of ADIPOQ gene variants (-3971A>G and +276G>T) with obesity and metabolic syndrome in North Indian Punjabi population

BACKGROUND AND AIMS

At present obesity and metabolic syndrome (MetS) in India are the most challenging health problems. It is also well accepted that obesity is a significant risk factor for the development of metabolic syndrome and other degenerative diseases. Many studies have reported that single-nucleotide polymorphisms (SNPs) of the adiponectin (ADIPOQ) gene have been associated with obesity and its related disorders. Here, we aimed to investigate the association of two intronic variants in ADIPOQ gene, -3971A>G (rs822396) and +276G>T (rs1501299) with obesity and metabolic syndrome.

METHODS

Biochemical and anthropometric measurements were obtained from a total of 550 unrelated subjects (obese = 250 and non-obese = 300) of North Indian Punjabi population. Genotyping for the intron variants were performed by polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP) methods. After genotyping, as a quality control measure 10% of the samples for each polymorphism were confirmed by Sanger Sequencing method. The distributions of genotypic and allelic frequencies among obese and non-obese groups were compared by chi-square test and the corresponding risk was calculated using binary logistic regression. The effects of multiple testing were controlled by applying Bonferroni corrections.

RESULTS

All the anthropometric and biochemical parameters except triglycerides (TG) and very low-density lipoproteins cholesterol (VLDL-C) have shown significant association with both GG and TT genotypes of -3971A>G (rs822396) and +276G>T (rs1501299) polymorphisms respectively. The frequencies of GG (-3971A>G) and TT (+276G>T) genotypes were higher among obese cases (p = 0.008 and p = 0.035 respectively). However, no significant association was found between allelic frequencies of ADIPOQ rs822396 and obesity, whereas the association of ADIPOQ rs1501299 attenuated and became marginally significant after Bonferroni correction (p>0.025). Both the variant genotypes of ADIPOQ gene polymorphisms (-3971GG and +276TT) significantly increased the risk of development of obesity (OR: 1.52, p = 0.03; OR: 1.58, p = 0.04 respectively) and MetS (OR: 1.42, p = 0.03; OR: 1.57, p = 0.01 respectively) in the present population, after adjusting the various covariates. The G-T haplotype model (possessing -3971G and +276T alleles) was shown toprovide ~ 3 fold risk towards the obesity susceptibility (OR: 2.69, p = 0.009) and MetS risk (OR: 2.73, p = 0.009) and the association persisted after adjusting for different confounding variables.

CONCLUSION

The present study has confirmed that ADIPOQ -3971A>G (rs822396) and +276G>T (rs1501299) polymorphism may be clinically helpful to estimate obesity and MetS risk in North Indian Punjabi population.

Association between -174G>C polymorphism in the IL-6 promoter region and the risk of obesity: A meta-analysis

BACKGROUND

Many researchers have suggested that the -174G>C polymorphism in the interleukin-6 (IL-6) promoter region contributes to the risk of obesity; however, this hypothesis is still inconclusive. Therefore, we conducted a meta-analysis to combine the data from several studies to arrive at a conclusion regarding the association between -174G>C polymorphism and the risk of obesity.

METHODS

The PubMed and Embase databases were searched up to February 20, 2018. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random-effects model. Subgroup analysis and sensitivity were also performed.

RESULTS

Ten eligible studies involving 7210 cases were performed to identify the association strength. The association strength was measured by the ORs and 95% CIs. By pooling the eligible studies, we found a significant association between the -174G>C polymorphism and obesity risk (C vs G: OR = 1.37; 95% CI, 1.08-1.74; Pheterogeneity < .01). Overall, individuals with the variant CC (OR = 1.58; 95% CI, 1.09-2.28; Pheterogeneity < 0.01) and GC/CC (OR = 1.61; 95% CI, 1.13-2.29; Pheterogeneity < .01) were associated with a significantly increased risk of obesity.

CONCLUSION

The meta-analysis results suggested that the polymorphism -174G>C in the IL-6 promoter region was associated with a significantly increased risk of obesity.

The Role of Adipokines in the Establishment and Progression of Head and Neck Neoplasms

Adipokines constitute a family of protein factors secreted by white adipose tissue (WAT), that regulate the functions of WAT and other sites. Leptin, adiponectin and resistin, are the main adipokines present in serum and saliva, targeting several tissues and organs, including vessels, muscles, liver and pancreas. Besides body mass regulation, adipokines affect glucose homeostasis, inflammation, angiogenesis, cell proliferation and apoptosis, and other crucial cell procedures. Their involvement in tumor formation and growth is well established and deregulation of adipokine and adipokine receptors' expression is observed in several malignancies including those located in the head and neck region. Intracellular effects of adipokines are mediated by a plethora of receptors that activate several signaling cascades including Janus kinase/ Signal transducer and activator of transcription (JAK/ STAT pathway), Phospatidylinositol kinase (PI3/ Akt/ mTOR) and Peroxisome proliferator-activated receptor (PPAR). The present review summarizes the current knowledge on the role of adipokines family members in carcinogenesis of the head and neck region. The diagnostic and prognostic significance of adipokines and their potential role as serum and saliva biomarkers are also discussed.

Tissue expression and variation analysis of three bovine adipokine genes revealed their effect on growth traits in native Chinese cattle

Adipokines play a crucial role in the regulation of energy homeostasis; however, little is known about genetic alterations in this family that may contribute to economic traits in cattle. Therefore, this study conducts transcript profiles, variations and association studies of three major adipokines, leptin (LEP), tumour necrosis factor (TNF) and angiopoietin-like protein 8 (ANGPTL8), to evaluate their effects on native Chinese cattle. Using quantitative real-time PCR, the study revealed that the bovine LEP was expressed primarily in the back and visceral fat, while TNF was predominantly expressed in spleen and ANGPTL8 was mainly expressed in back fat and liver. Five single nucleotide polymorphisms (SNPs) including two missense SNPs (SNP1: g.12254T>C and SNP2: g.14177C>T) in LEP, a synonymous SNP (SNP3: g.2130A>G) in TNF and two SNPs (SNP4: g.629G>A and SNP5: g.884T>C) in the 5'UTR of ANGPTL8 were identified and genotyped in 537 individuals from six Chinese cattle breeds. Bioinformatics analysis revealed that SNP1 might disrupt the efficient binding of LEP to its receptor, SNP3 might affect translation efficiency of TNF, and SNP4 and SNP5 were likely to affect stability, splicing and nuclear export of ANGPTL8 mRNA. Consistently, association studies indicated that three SNPs (SNP1, SNP3 and SNP5) were significantly associated with body weight, heart girth, average daily gain, hip width and body length in 100 Nanyang cattle (p < 0.05). Overall, our results support the view that LEP, TNF and ANGPTL8 could be used as biomarkers to improve the growth performance in Chinese cattle selection programmes.

The Role of Motivation to Reduce Obesity among Elderly People: Response to Priming Temptation in Obese Individuals

The risk of obesity-related disorders is increased among the elderly, so changing eating habits can be an important element of prevention. The main aim of this article is to consider whether looking at pictures that present either fattening food or healthy food may motivate elderly people to change their nutrition habits. Might priming different kinds of food influence the attractiveness of the food for people in late adulthood undergoing obesity therapy? Based on priming theories, we analysed the effects of the conscious processing of stimuli associated with dietary habits in individuals aged with BMI ≥ 30 kg/m². Our experiments confirmed the influence of a higher-priority goal of "slimming" on the perception and internalization of nutrition-related stimuli. In response to such stimuli, individuals who are actively involved in weight reduction and health-oriented programs use strategies for resisting temptation and to effectively "slim". We present our findings in the context of their theoretical background and practical application.

Influence of Interleukin-6 (174G/C) Gene Polymorphism on Obesity in Egyptian Children

BACKGROUND:

Obesity is a multi-factorial chronic disorder. A considerable number of studies have been performed to figure out whether there is an association between obesity and polymorphisms of gene IL-6 (174G/C), but the results are equivocal.

AIM:

This study aimed to find out whether the IL-6 (174G/C) gene was associated with the risk of developing obesity in Egyptian children.

SUBJECTS AND METHODS:

The study included 149 children and adolescents with age ranged between 9.5 – 18 years. Eighty-five of them were obese which BMIZ-score is > 2, and sixty-four children with BMIZ-score ≤ 2 served as control group. Serum level of IL-6 and genetic analysis for IL-6 (174G/C) gene polymorphism were done.

RESULTS:

Obese children had significantly higher serum levels of IL-6 as compared to those of control children (P = 0.003). A high percentage of IL-6 polymorphism GC was found in obese subjects (93.7%), while the control group had a higher percentage of IL-6 polymorphism GG (70.6 %).

CONCLUSION:

Our study showed that carriers of the C allele for the IL-6 (174G/C) polymorphism have higher BMI. As the G174C polymorphism is likely to affect IL-6 expression and its physiological regulation; consequently this polymorphism may affect adiposity.

The joint effects of family risk of obesity and neighborhood environment on obesity among women

Obesity is a significant health problem in the United States that has encouraged a search for modifiable risk factors, such as walkable neighborhood designs. Prior research has shown linkages between a family history of obesity (i.e., due to either genetic or non-genetic factors) and an individual's risk of elevated body mass index (BMI). Yet, we know little about the possible interactions between neighborhood walkability and family susceptibility to unhealthy BMI in predicting individual BMI. This paper addresses this important research gap using a sample of 9918 women, derived from vital and administrative data in the Utah Population Database. We use a novel indicator of familial risk (a summary measure of siblings' BMI) and a neighborhood walkability score to capture familial susceptibility and environmental exposures, respectively. The analysis focuses on distinct risk combinations of familial susceptibility and neighborhood walkability. Compared with the "best" combination of lean family BMI history and more walkable neighborhoods, women in all of the other three family weight history/neighborhood categories show greater risks of obesity. Our results also indicate that the neighborhood environment has a strong association with individual obesity among women with higher family risk of obesity but that the association between neighborhood environment and individual obesity is even stronger for women with a lower family risk of obesity.

Polymorphisms in the leptin (rs7799039) gene are associated with an increased risk of excessive gestational weight gain but not with leptin concentration during pregnancy

Single nucleotide polymorphisms (SNPs) in leptin (LEP) and leptin receptor (LEPR) have been shown to be linked to obesity-related metabolic markers and phenotype. Therefore, we hypothesized that the LEP-rs7799039 and LEPR-rs1137101 SNPs are related to the risk of pre-pregnancy overweight/obesity (body mass index ≥25 kg/m²) as well as to excessive gestational weight gain (GWG) and high concentrations of leptin throughout pregnancy. We investigated a prospective cohort of 147 Brazilian pregnant women through weeks 5-13, 20-26, and 30-36 of gestation. Genetic variants of LEP and LEPR were analyzed by real-time polymerase chain reaction and leptin by enzyme-linked immunosorbent assay. Statistical analyses included multiple linear regression, linear mixed effects, and Poisson regression models. Genotype AA carriers for the LEP-rs7799039 gene maintained a lower body weight throughout pregnancy compared with those with genotypes GG or GA + GG (β_AAvsGG = -7.91 kg; 95% confidence interval [CI], -14.21 to -1.61; P = .01; and β_{AAvsGA + GG} = -7.66 kg; 95% CI, -14.07 to -1.25; P = .02). The A allele was significantly associated with an increased risk for excessive GWG (relative risk_LEP-GAvsGG, 2.16; 95% CI, 1.23-3.80; and relative risk_LEP-AAvsGG, 2.37; 95% CI, 1.04-5.39). Neither the LEP-rs7799039 nor LEPR-rs1137101 SNP was significantly associated with pre-pregnancy overweight/obesity risk and leptin concentrations during pregnancy. In conclusion, our results indicate that women who had the AA genotype for LEP-rs7799039 displayed a lower body weight throughout pregnancy compared with GG or GA + GG carriers. LEP-rs7799039 was significantly associated with an increased risk for excessive GWG, but the results do not support significant associations of the LEP-rs7799039 and LEPR-rs1137101 polymorphisms with pre-pregnancy overweight/obesity risk and leptin concentrations throughout pregnancy.

Adipokine genes and radiographic hand osteoarthritis in Finnish women: a cross-sectional study

OBJECTIVES

Available evidence suggests that genetic factors and overweight play major roles in the aetiology of osteoarthritis (OA). We analysed the association of 18 single-nucleotide polymorphisms (SNPs) from nine adipokine and adipokine receptor genes (LEP, LEPR, ADIPOQ, RETN, NAMPT, SERPINA12, ITLN1, RARRES2, and APLN) with radiographic hand OA.

METHOD

The study design was cross-sectional. Bilateral hand radiographs of 542 occupationally active Finnish female dentists and teachers aged 45-63 years were examined and classified for the presence of hand OA using reference images. Hand OA was defined as at least three finger joints with radiographic OA of grade 2-4. The genotypes were determined using polymerase chain reaction-based methods. Body mass index (BMI) was calculated based on self-reported height and measured weight. Associations of the individual SNPs and their haplotypes with hand OA were tested using logistic regression analysis.

RESULTS

The minor allele of RETN rs10401670 was associated with a decreased [odds ratio (OR) = 0.73, 95% confidence interval (CI) 0.55-0.97, p = 0.03] and RARRES2 rs4721 with an increased (OR 1.41, 95% CI 1.07-1.87, p = 0.01) prevalence of hand OA. Also, LEPR AC (OR 1.54, 95% CI 1.01-2.35, p = 0.05) and RETN GGTT (OR 0.58, 95% CI 0.37-0.93, p = 0.02) haplotypes were associated with hand OA. These associations were modified by BMI when comparing normal and overweight women. However, the associations lost their statistical significance after adjusting for multiple testing.

CONCLUSION

Our results suggest weak associations between the studied variations in LEPR, RARRES2, and RETN genes and hand OA in Finnish women, and that the associations are modified by BMI. However, these associations could not be verified in the current study.

Leptin Receptor Gene Variant rs11804091 Is Associated with BMI and Insulin Resistance in Spanish Female Obese Children: A Case-Control Study

Leptin is an endocrine hormone that has a critical role in body weight homoeostasis and mediates its effects via the leptin receptor (LEPR). Common polymorphisms in the genes coding leptin receptors have been associated with metabolic abnormalities. We assessed the association of 28 LEPR polymorphisms with body mass index (BMI) and their relationship with obesity-related phenotypes, inflammation and cardiovascular disease risk biomarkers. A multicentre case-control study was conducted in 522 children (286 with obesity and 236 with normal-BMI). All anthropometric, metabolic factors and biomarkers were higher in children with obesity except apolipoprotein (Apo)-AI, cholesterol, high-density lipoprotein cholesterol (HDL-c), and adiponectin, which were lower in the obesity group; and glucose, low-density lipoprotein cholesterol (LDL-c), and matrix metalloproteinase-9 that did not differ between groups. We identified the associations between rs11208659, rs11804091, rs10157275, rs9436303 and rs1627238, and BMI in the whole population, as well as the association of rs11804091, rs10157275, and rs1327118 with BMI in the female group, although only the rs11804091 remained associated after Bonferroni correction (p = 0.038). This single nucleotide polymorphisms (SNP) was also associated with insulin (p = 0.004), homeostasis model assessment for insulin resistance (HOMA-IR) (p = 0.006), quantitative insulin sensitivity check index (QUICKI) (p = 0.005) and adiponectin (p = 0.046) after adjusting for age, Tanner stage and BMI. Our results show a sex-specific association between the rs11804091 and obesity suggesting an influence of this SNP on insulin resistance.

Association of circulating leptin and adiponectin with periodontitis: a systematic review and meta-analysis

BACKGROUND

This study aimed to assess the difference in serum levels of leptin and adiponectin in patients with periodontitis and in periodontally healthy individuals and evaluate the changes in circulating leptin and adiponectin after periodontal therapy. Leptin and adiponectin are the most generally studied adipokines that function as inflammatory cytokines. Although the association between periodontitis and serum levels of leptin and adiponectin has been studied extensively, the results were not consistent.

METHODS

A systematic search of the Pubmed, Embase, Web of Science, and Cochrane Library up to September 2016 was conducted. The studies were screened and selected by two writers according to the specific eligibility criteria. The quality of included cross-sectional studies was assessed using the quality assessment form recommended by the Agency for Healthcare Research and Quality and Methodological Index for Nonrandomized Studies. The meta-analyses were conducted using the STATA 12.0 software.

RESULTS

A total of 399 manuscripts were yielded and 25 studies were included in the present meta-analysis. Significantly elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis were observed in the subgroup analysis of body mass index (BMI) <30. The overall and subgroup analyses showed no significant change in the serum levels of leptin in patients with periodontitis after periodontal treatment. The subgroup analysis of systemically healthy patients showed no significant change in serum levels of adiponectin in patients with periodontitis after periodontal treatment.

CONCLUSIONS

The present meta-analysis supported elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis compared with controls in the BMI <30 population. In systemically healthy patients with periodontitis, serum levels of leptin and adiponectin do not significantly change after periodontal treatment.

The IL-6 Gene Promoter SNP and Plasma IL-6 in Response to Diet Intervention

We recently reported that interleukin-6 (IL-6), an inflammatory marker associated with breast pathology and the development of breast cancer, decreases with diet intervention and weight loss in both insulin-sensitive and insulin-resistant obese women. Here, we tested whether an individual’s genotype at an IL6 SNP, rs1800795, which has previously been associated with circulating IL-6 levels, contributes to changes in IL-6 levels or modifies the effect of diet composition on IL-6 in these women. We genotyped rs1800795 in overweight/obese women (N = 242) who were randomly assigned to a lower fat (20% energy), higher carbohydrate (65% energy) diet; a lower carbohydrate (45% energy), higher fat (35% energy) diet; or a walnut-rich (18% energy), higher fat (35% energy), lower carbohydrate (45% energy) diet in a 1-year weight loss intervention study of obesity-related biomarkers for breast cancer incidence and mortality. Plasma IL-6 levels were measured at baseline, 6 and 12 months. At baseline, individuals with a CC genotype had significantly lower IL-6 levels than individuals with either a GC or GG genotype (p < 0.03; 2.72 pg/mL vs. 2.04 pg/mL), but this result was not significant when body mass index (BMI) was accounted for; the CC genotype group had lower BMI (p = 0.03; 32.5 kg/m² vs. 33.6 kg/m²). We did not observe a 2-way interaction of time*rs1800795 genotype or diet*rs1800795 genotype. Our findings provide evidence that rs1800795 is associated with IL-6 levels, but do not support a differential interaction effect of rs1800795 and diet composition or time on changes in circulating IL-6 levels. Diet intervention and weight loss are an important strategy for reducing plasma IL-6, a risk factor of breast cancer in women, regardless of their rs1800795 genotype.

Translating the biology of adipokines in atherosclerosis and cardiovascular diseases: Gaps and open questions

AIM

Critically discuss the available data, to identify the current gaps and to provide key concepts that will help clinicians in translating the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

DATA SYNTHESIS

Adipose tissue is nowadays recognized as an active endocrine organ, a function related to the ability to secrete adipokines (such as leptin and adiponectin) and pro-inflammatory cytokines (tumor necrosis factor alpha and resistin). Studies in vitro and in animal models have observed that obesity status presents a chronic low-grade inflammation as the consequence of the immune cells infiltrating the adipose tissue as well as adipocytes. This inflammatory signature is often related to the presence of cardiovascular diseases, including atherosclerosis and thrombosis. These links are less clear in humans, where the role of adipokines as prognostic marker and/or player in cardiovascular diseases is not as clear as that observed in experimental models. Moreover, plasma adipokine levels might reflect a condition of adipokine-resistance in which adipokine redundancy occurs. The investigation of the cardio-metabolic phenotype of carriers of single nucleotide polymorphisms affecting the levels or function of a specific adipokine might help determine their relevance in humans. Thus, the aim of the present review is to critically discuss the available data, identify the current gaps and provide key concepts that will help clinicians translate the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

TOX and ADIPOQ Gene Polymorphisms Are Associated with Antipsychotic-Induced Weight Gain in Han Chinese

To find the genetic markers related to the antipsychotic-induced weight gain (AIWG), we analyzed associations among candidate gene single-nucleotide polymorphisms (SNPs) and quantitative traits of weight changes and lipid profiles in a Chinese Han population. A total of 339 schizophrenic patients, including 86 first-episode patients (FEPs), meeting the entry criteria were collected. All patients received atypical antipsychotic drug monotherapy and hospitalization and were followed for 12 weeks. Forty-three SNPs in 23 candidate genes were calculated for quantitative genetic association with AIWG, performed by PLINK. The TOX gene SNP rs11777927 (P = 0.009) and the ADIPOQ gene SNP rs182052 (P = 0.019) were associated with AIWG (in body mass index, BMI). In addition, the BDNF SNP rs6265 (P = 0.002), BDAF SNP rs11030104 SNP (P = 0.001), and ADIPOQ SNPs rs822396 (P = 0.003) were significantly associated with the change of waist-to-hip ratio (WHR) induced by atypical antipsychotics. These results were still significant after age and gender adjustments. These findings provide preliminary evidence supporting the role of TOX, ADIPOQ and BDNF in weight and WHR gain induced by atypical antipsychotics.

Adiponectin gene variants and abdominal obesity in an Iranian population

INTRODUCTION

Waist-to-height ratio (WHtR) can be effective for the diagnosis of abdominal obesity and the risk of type 2 diabetes. The role of genetic factors in the development of obesity has been broadly recognized. Adiponectin's level is inversely correlated with body fat percentage and is reduced in obesity and type 2 diabetes. The aim of this study is to investigate the association between WHtR and adiponectin gene polymorphisms in Iranian population.

METHODS

This study was conducted on 610 subjects from two Iranian populations. Anthropometric characteristics were measured by routine methods. Blood samples were collected in tubes (3-5 mL) containing EDTA and were stored at 20 °C. After DNA extraction, genotyping was performed using PCR-RFLP technique.

RESULTS

There were statistically significant differences in genotype frequencies of -11391 G/A in centrally obese (WHtR >0.5) and noncentrally obese (WHtR ≤0.5) subjects (P value <0.044). In the former, the frequencies of GG and GA + AA genotypes were 89.4 and 10.6 %, respectively, while the frequencies of GG and GA + AA genotypes were 95.9 and 4.1 %, respectively, in noncentrally obese subjects.

CONCLUSIONS

The frequency of GG genotype was significantly increased in subjects with WHtR >0.5 compared to the other group. After adjustment for diabetes, abdominal obesity was significantly associated with the -11391 G/A polymorphism.

The association between leptin receptor gene polymorphisms and type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Several case-control studies have demonstrated a relationship between leptin receptor (LEPR) gene polymorphism and type 2 diabetes mellitus (T2DM) risk, though the results have not always been consistent among diverse populations. This meta-analysis was designed to assess a more accurate association between LEPR polymorphism and T2DM.

METHODS

Eight electronic databases were consulted and researchers searched for Chinese and English peer-reviewed articles, published between 2000 and 2015, that referred to the association between LEPR polymorphism and T2DM. Pooled odds ratios (OR) with a 95% confidence interval (CI) were calculated in allele contrast, recessive, dominant and additive genetic models to assess this association.

RESULTS

Four repeatedly reviewed polymorphisms, taken from 22 studies on Arg109Lys, Asn656Lys, Gln223Arg and Pro1019Pro with 31,260 controls and 25,560 cases, were included in the meta-analysis model. The meta-result demonstrated that only the Pro1019Pro polymorphism was substantially associated with T2DM risk-G vs. A: OR with 95% CI 0.58 (0.43-0.79), Z=3.51, p=0.0005; GG vs. AG+AA: 0.57 (0.42-0.77), Z=3.66, p=0.0002; GG+AG vs. AA: 0.55 (0.37-0.81), Z=3.01, p=0.003; GG vs. AA: 0.51 (0.37-0.69), Z=4.24, p<0.001.

CONCLUSIONS

Our meta-analysis suggested a significant association between the LEPR Pro1019Pro polymorphism and T2DM risk. Thus, targeted healthcare should be strengthened with regard to this gene carrier in order to prevent T2DM.

Adipokines in psoriasis: An important link between skin inflammation and metabolic alterations

Psoriasis is a chronic inflammatory skin disease most common in Europe, North America, and Australia. The etiology and pathomechanisms underlying the evolution and persistence of the skin alterations are increasingly being understood and have led to the development of effective anti-psoriatic therapies. Apart from the skin manifestations, psoriasis is associated with the metabolic syndrome (MetS), known to increase the risk of type 2 diabetes mellitus and cardiovascular disorders. Research of the last years demonstrated a dysregulated adipokine balance as an important link between inflammation, MetS, and consequential disorders. This article describes selected adipokines and their potential role in both metabolic comorbidity and skin inflammation in psoriasis.

Adipokine Gene Single-Nucleotide Polymorphisms in Portuguese Obese Adolescents: Associations with Plasma Concentrations of Adiponectin, Resistin, IL-6, IL-1β, and TNF-α

BACKGROUND

The genetic contribution to obesity and to circulating adipokine levels has not been completely clarified. We aimed to evaluate adipokine genes' single-nucleotide polymorphism (SNP) prevalence and its association with circulating adipokine levels and risk factors for cardiovascular disease in an obese Portuguese pediatric population.

METHODS

Two hundred forty-eight obese adolescents (mean age 13.4 years old; 47.2% females) participated in a cohort study. We screened 12 SNPs by direct sequencing in five adipokine genes: adiponectin (ADIPOQ: rs16861194, rs17300539, rs266729, rs2241766, rs1501299), interleukin-1β (IL-1β; rs1143627), IL-6 (IL-6; rs1800795), tumor necrosis factor-α (TNF-α; rs1800629), and resistin (RETN; rs1862513, rs3219177, rs3745367, rs3745368). Biochemical analysis included determination of circulating adipokines, C-reactive protein (CRP) levels, lipid profile, and markers of insulin resistance.

RESULTS

Compared to males, females presented higher circulating levels of insulin, adiponectin, IL-6, resistin, and leptin concentrations, but lower TNF-α levels. No statistically significant differences were found for genotype or allelic distributions between genders. In the whole sample population, adiponectin levels were influenced by ADIPOQ rs17300539 (c.-1138G>A; lower in subjects with GG genotype). When only males were considered, IL-1β, IL-6, and TNF-α levels were associated with ADIPOQ rs1501299 (c.214 + 62G>T; higher in GG subjects). TNF-α concentrations were modulated by TNF-α rs1800629 (c.-488G>A; lower in GG males), RETN rs1862513 (c.-216C>G; higher in CC subjects), and RETN rs3219177 (c.118 + 39C>T; higher in CC subjects). Leptin levels were influenced by IL-1β rs1143627 (c.-118C>T) presenting TT individuals' lower levels.

CONCLUSIONS

Our data demonstrate that in pediatric obese patients, some adipokine gene SNPs have an association with circulating adipokine levels and lipid profile.

Effects of adiponectin polymorphisms on the risk of advanced age-related macular degeneration

OBJECTIVE

To determine the relationships between variants in adiponectin gene (ADIPOQ) with advanced forms of age-related macular degeneration (AMD) susceptibility.

METHODS

A total of 189 advanced AMD patients and 168 controls were recruited. Seven tagging single-nucleotide polymorphisms in ADIPOQ were genotyped by the SNaPshot method.

RESULTS

Alleles or genotypes of rs822396 distributed significantly differently in advanced AMD patients and controls. The minor allele G at rs822396 was associated with an increased risk of advanced AMD in a dominant model. Furthermore, haplotype analysis revealed that haplotypes AGGACCT and TGACCCC were significantly increased the advanced AMD susceptibility, whereas haplotypes AGAACGC, TGAACGT and TGACAGC had protective effects.

CONCLUSION

ADIPOQ genetic variant rs822396 might affect an individual's susceptibility to AMD, making it efficient genetic biomarkers for early detection of AMD.

Genetics of Common Antipsychotic-Induced Adverse Effects

The effectiveness of antipsychotic drugs is limited due to accompanying adverse effects which can pose considerable health risks and lead to patient noncompliance. Pharmacogenetics (PGx) offers a means to identify genetic biomarkers that can predict individual susceptibility to antipsychotic-induced adverse effects (AAEs), thereby improving clinical outcomes. We reviewed the literature on the PGx of common AAEs from 2010 to 2015, placing emphasis on findings that have been independently replicated and which have additionally been listed to be of interest by PGx expert panels. Gene-drug associations meeting these criteria primarily pertain to metabolic dysregulation, extrapyramidal symptoms (EPS), and tardive dyskinesia (TD). Regarding metabolic dysregulation, results have reaffirmed HTR2C as a strong candidate with potential clinical utility, while MC4R and OGFR1 gene loci have emerged as new and promising biomarkers for the prediction of weight gain. As for EPS and TD, additional evidence has accumulated in support of an association with CYP2D6 metabolizer status. Furthermore, HSPG2 and DPP6 have been identified as candidate genes with the potential to predict differential susceptibility to TD. Overall, considerable progress has been made within the field of psychiatric PGx, with inroads toward the development of clinical tools that can mitigate AAEs. Going forward, studies placing a greater emphasis on multilocus effects will need to be conducted.

Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels

Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health.

ADIPOQ -11377C>G Polymorphism Increases the Risk of Adipokine Abnormalities and Child Obesity Regardless of Dietary Intake

OBJECTIVE

The aim of the present study was to verify whether selected functional single nucleotide polymorphisms in LEP, LEPR, and ADIPOQ loci are associated with the development of obesity and serum levels of the respective adipokines in prepubertal white children with obesity.

METHODS

Frequencies of -2548G>A LEP (rs7799039), Q223R (rs1137101) and K656N (rs8129183) LEPR, and -11377C>G (rs266729) and -11426A>G (rs16861194) ADIPOQ polymorphisms were analyzed by restriction fragment length polymorphism in 101 obese (standard deviation score [SDS]-body mass index [BMI] >2) and 67 normal-weight (SDS-BMI <- 1 + 1 >) children. Serum adipokine concentrations were measured using the enzyme-linked immunosorbent assay method.

RESULTS

The GC/GG genotypes of -11377C>G ADIPOQ polymorphism were associated with a higher risk of obesity (P = 0.022, odds ratio 2.08 [95% confidence interval 1.11-3.90]). Individuals carrying the GG genotype had a higher leptin/total adiponectin ratio by 25% than CC homozygotes (P trend = 0.05). In the multivariate linear regression model, we found differences among particular genotypes of this polymorphism in concentrations of high molecular weight (HMW) adiponectin (P trend = 0.043) and HMW/total adiponectin ratio (P trend = 0.048), with the lowest values in GG homozygotes. Positive correlations between SDS-BMI and dietary reference intake percentage were observed in individuals homozygous for allele C (r = 0.403, P = 0.01) and CG heterozygotes (r = 0.428, P = 0.004). No significant correlations between both parameters were found in the GG homozygotes.

CONCLUSIONS

Among the analyzed polymorphisms, only -11377C>G ADIPOQ single nucleotide polymorphism was associated with obesity during the prepubertal period. Adipokine abnormalities coexisting with the lack of relations between SDS-BMI and dietary intake may predict a higher risk of future obesity-related disorders in obese children carrying the GG genotype than in those with other genotypes.

Sequence analysis of three canine adipokine genes revealed an association between TNF polymorphisms and obesity in Labrador dogs

Obesity is an emerging health problem in purebred dogs. Due to their crucial role in energy homeostasis control, genes encoding adipokines are considered candidate genes, and their variants may be associated with predisposition to obesity. Searching for polymorphism was carried out in three adipokine genes (TNF, RETN and IL6). The study was performed on 260 dogs, including lean (n = 109), overweight (n = 88) and obese (n = 63) dogs. The largest cohort was represented by Labrador Retrievers (n = 136). Altogether, 24 novel polymorphisms were identified: 12 in TNF (including one missense SNP), eight in RETN (including one missense SNP) and four in IL6. Distributions of five common SNPs (two in TNF, two in RETN and one in IL6) were further analyzed with regard to body condition score. Two SNPs in the non-coding parts of TNF (c.-40A>C and c.233+14G>A) were associated with obesity in Labrador dogs. The obtained results showed that the studied adipokine genes are highly polymorphic and two polymorphisms in the TNF gene may be considered as markers predisposing Labrador dogs to obesity.

Understanding Academic Clinicians' Decision Making for the Treatment of Childhood Obesity

BACKGROUND

Although most clinicians agree that obesity is a major problem, treatment rates remain low. We conducted this discrete choice experiment (DCE) to understand academic clinicians' decisions in treating childhood obesity.

METHODS

A total of 198 academic pediatric surgeons, pediatricians, family physicians, and allied health professionals were recruited from 15 teaching hospitals across Canada to participate in this DCE. Participants completed 15 tasks choosing between three obesity treatment scenarios to identify the scenario in which they would most likely treat pediatric obesity.

RESULTS

Latent class analysis revealed two classes with early intervention and late intervention preferences. Participants in the early intervention group (30%) were sensitive to variations in patient and family support. They would likely intervene if patients were obese, with normal lipid levels, were prediabetic, had high blood pressure, and when obesity was lifestyle associated. Late intervention clinicians (70%) were more likely to intervene if patients were morbidly obese, had abnormal lipid levels, required insulin for diabetes, had very high blood pressure, or when obesity impacted the patient's mental health. Simulations predicted that increasing colleague support for intervention, providing expert consultation, and mobilizing multidisciplinary support would increase the likelihood of treating pediatric obesity earlier from 16.1% to 81.5%.

CONCLUSIONS

This DCE was implemented to understand the factors clinicians use in making decisions. Most academic clinicians choose to intervene late in the clinical course when more-severe obesity-related morbidities are present. Increased support from colleagues, expert consultation, and multidisciplinary support are likely to lead to earlier treatment of obesity among academic clinicians caring for children.

Common variants in LEPR, IL6, AMD1, and NAMPT do not associate with risk of juvenile and childhood obesity in Danes: a case-control study

Background

Childhood obesity is a highly heritable disorder, for which the underlying genetic architecture is largely unknown. Four common variants involved in inflammatory-adipokine triggering (IL6 rs2069845, LEPR rs1137100, NAMPT rs3801266, and AMD1 rs2796749) have recently been associated with obesity and related traits in Indian children. The current study aimed to examine the effect of these variants on risk of childhood/juvenile onset obesity and on obesity-related quantitative traits in two Danish cohorts.

Methods

Genotype information was obtained for 1461 young Caucasian men from the Genetics of Overweight Young Adults (GOYA) study (overweight/obese: 739 and normal weight: 722) and the Danish Childhood Obesity Biobank (TDCOB; overweight/obese: 1022 and normal weight: 650).

Overweight/obesity was defined as having a body mass index (BMI) ≥25 kg/m²; among children and youths, this cut-off was defined using age and sex-specific cut-offs corresponding to an adult body mass index ≥25 kg/m². Risk of obesity was assessed using a logistic regression model whereas obesity-related quantitative measures were analyzed using a general linear model (based on z-scores) stratifying on the case status and adjusting for age and gender. Meta-analyses were performed using the fixed effects model.

Results

No statistically significant association with childhood/juvenile obesity was found for any of the four gene variants among the individual or combined analyses (rs2069845 OR: 0.94 CI: 0.85–1.04; rs1137100 OR: 1.01 CI: 0.90–1.14; rs3801266: 0.96 CI: 0.84–1.10; rs2796749 OR: 1.02 CI: 0.90–1.15; p > 0.05). However, among normal weight children and juvenile men, the LEPR rs1137100 A-allele significantly associated with lower BMI (β = −0.12, p = 0.0026).

Conclusions

The IL6, LEPR, NAMPT, and AMD1 gene variants previously found to associate among Indian children did not associate with risk of obesity or obesity-related quantitative measures among Caucasian children and juvenile men from Denmark.