Association of ADIPOQ polymorphisms with obesity risk: A meta-analysis

Single nucleotide polymorphisms (SNPs) that are associated with obesity and type 2 diabetes among Asians: a systematic review and meta-analysis

Single nucleotide polymorphisms (SNPs) could increase the susceptibility of individuals to develop obesity and type 2 diabetes (T2DM). Obesity and T2DM are closely related pathophysiologically, thus similar SNPs could mediate both these diseases, but this is rarely reported. Furthermore, limited studies have been performed to summarize SNP data in the Asian population compared to the Western population. In this study, we aimed to summarize SNPs that are associated with the development of obesity and T2DM among Asian populations. We searched six literature databases and Review Manager (RevMan) was used for meta-analysis. The pooled odds ratios (ORs) and 95% CIs were calculated with a random effects model for the heterogeneity among studies. The pooled analysis showed that rs9939609 (FTO gene) and rs17782313 and rs571312 (MC4R gene) are associated with obesity with an odd ratio (OR) of 1.37, 1.36 and 1.29 respectively. For T2DM, five SNPs, rs7903146 and rs12255372 (TCF7L2 gene), rs13266634 and rs11558471 (SLC30A8 gene) and rs2283228 (KCNQ1 gene) have also shown strong associations with T2DM at OR of 1.64, 1.61, 1.22, 1.29 and 1.60 respectively. This data could be used to develop a gene screening panel for assessing obesity and T2DM susceptibility.

ADIPOQ-rs2241766 polymorphism is associated with changes in cholesterol levels of Mexican adolescents

BACKGROUND

The ADIPOQ gene encodes a fat-derived protein hormone with a preponderant role in the homeostasis of glucose and fatty acids. However, previous association studies between ADIPOQ genetic variants and metabolic disorders have shown controversial results. In this study, we evaluated the effect of the ADIPOQ-rs2241766 polymorphism on diverse biochemical parameters (i.e., insulin resistance, atherogenic index, overweight and obesity) in an adolescent population from Mexico.

METHODS

A cross-sectional study with convenience sampling was carried out in 356 adolescents from Northern Mexico. They were classified by sex and BMI-z score. The biochemical parameters were measured from blood samples using conventional methods. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

In low and normal weight groups, GG carriers had a significantly higher cholesterol level (P ≤ 0.05) than TG and TT carriers. However, there was no association between ADIPOQ-rs2241766 polymorphism and atherogenic index, overweight, or obesity.

CONCLUSIONS

Our findings suggest that the cholesterol levels are under the influence of the ADIPOQ-rs2241766 polymorphism in Mexican adolescents and may explain how ADIPOQ variants increase the risk of developing metabolic disorders. Nevertheless, further studies are required to rule out the influence of other genetic and non-genetic factors.

Risk variants of obesity associated genes demonstrate BMI raising effect in a large cohort

Obesity is highly polygenic disease where several genetic variants have been reportedly associated with obesity in different ethnicities of the world. In the current study, we identified the obesity risk or protective association and BMI raising effect of the minor allele of adiponectin, C1Q and collagen domain containing (ADIPOQ), cholesteryl ester transfer protein (CEPT), FTO alpha-ketoglutarate dependent dioxygenase (FTO), leptin (LEP), and leptin receptor (LEPR) genes in a large cohort stratified into four BMI-based body weight categories i.e., normal weight, lean, over-weight, and obese. Based on selected candidate genetic markers, the genotyping of all study subjects was performed by PCR assays, and genotypes and allele frequencies were calculated. The minor allele frequencies (MAFs) of all genetic markers were computed for total and BMI-based body weight categories and compared with MAFs of global and South Asian (SAS) populations. Genetic associations of variants with obesity risk were calculated and BMI raising effect per copy of the minor allele were estimated. The genetic variants with higher MAFs in obese BMI group were; rs2241766 (G = 0.43), rs17817449 (G = 0.54), rs9939609 (A = 0.51), rs1421085 (C = 0.53), rs1558902 (A = 0.63), and rs1137101 (G = 0.64) respectively. All these variants were significantly associated with obesity (OR = 1.03–4.42) and showed a high BMI raising effect (β = 0.239–0.31 Kg/m²) per copy of the risk allele. In contrast, the MAFs of three variants were higher in lean-normal BMI groups; rs3764261 A = 0.38, rs9941349 T = 0.43, and rs7799039 G = 0.40–0.43). These variants showed obesity protective associations (OR = 0.68–0.76), and a BMI lowering effect per copy of the protective allele (β = -0.103–0.155 Kg/m²). The rs3764261 variant also showed significant and positive association with lean body mass (OR = 2.38, CI = 1.30–4.34). Overall, we report six genetic variants of ADIPOQ, FTO and LEPR genes as obesity-risk markers and a CETP gene variant as lean mass/obesity protective marker in studied Pakistani cohort.

Association of ADIPOQ-rs2241766 and FTO-rs9939609 genetic variants with body mass index trajectory in women of reproductive age over 6 years of follow-up: the PREDI study

BACKGROUND

Interindividual variations in body mass index (BMI) can be partially explained by genetic differences. We aimed to examine the association of the ADIPOQ-rs2241766, LEP-rs7799039 and FTO-rs9939609 genetic variants with BMI trajectory in women of reproductive age over 6 years of follow-up.

METHODS

This was a prospective study that used data from 435 women of the PREDI Study conducted in Brazil. Socioeconomic, biological and anthropometric data were collected at four time points: 2012 (baseline) in the maternity hospital, and 2013-14, 2016-17 and 2018 (1^st, 2^nd and 3^rd follow-ups) at the participant's home. Genotyping was performed by PCR-RFLP. Linear mixed-effect and Poisson regression models were used to address the association of ADIPOQ, LEP and FTO genotypes with BMI and overweight/obesity status.

RESULTS

Women carrying the risk allele (TA or AA) of the FTO-rs9939609 genetic variant had a 1.16 kg/m² higher BMI over the follow-up period than those carrying the wild-type genotype (TT), even when adjusted for potential confounders (95% CI: 0.23-2.10, p = 0.015). The risk of obesity associated with the FTO-TA or AA genotype decreased over the years, demonstrating an influence of time on its trajectory (IRR = 0.99, 95% CI: 0.98-0.99, p = 0.016). There was no variation in BMI trajectories for the ADIPOQ-rs2241766, LEP-rs7799039 or FTO-rs9939609 genetic variant.

CONCLUSIONS

The results of this study suggest that monitoring women of reproductive age with ADIPOQ-rs2241766 TG/GG or FTO-rs9939609 TA/AA genotypes may be an important strategy to reduce maternal excess body weight and, consequently, the long-term public health burden of obesity.

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.

Dietary patterns interact with the variations of 18q21.23 rs17782313 locus on regulation of hypothalamic-pituitary axis hormones and cardio-metabolic risk factors in obesity

BACKGROUND

Evidence shows the role of polymorphisms in rs17782313 MC4R gene with increased risk of obesity in Asians adult. In the current report, we investigated the interaction between rs17782313 MC4R gene and major dietary patterns on α-melanocyte stimulating hormone (α-MSH), Agouti-related peptide (AgRP), serum lipids and blood pressure among obese individuals.

METHODS

This cross-sectional study was performed in 288 obese adults between 20 and 50 years of age. Anthropometric measurements and biochemical assays were conducted with standard methods. To evaluate appetite, the Visual Analogue Scale (VAS) was used. Dietary patterns were obtained by principal component analysis (PCA). Genotyping of rs17782313 was assessed by restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Three major dietary patterns were extracted: Prudent Dietary Pattern (PDP), Legume Dietary Pattern (LDP) and Mixed Dietary Pattern (MDP). Higher PDP score was associated with reduced SBP and insulin concentration while highest MDP score was associated with lower TG concentration (P < 0.05). Significant interactions were observed between higher adherence to PDP and rs17782313 CC genotype on increased SBP (P_Interaction = 0.04), serum insulin (P_Interaction = 0.05) and AgRP (P_Interaction = 0.03) and also between higher adherence to MDP and CC genotype of rs17782313 on reduced serum TG (P = 0.03).

CONCLUSIONS

The findings of the current study showed that being on CC genotype of rs17782313 polymorphism made obese individuals more prone to have higher SBP, insulin and AgRP even in highest adherence to PDP. However, adherence to MDP could attenuate the risky effects of being on CC genotype of rs17782313 by reducing serum TG concentrations.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Leptin gene polymorphism (rs 7799039;G2548A) is associated with changes in lipid profile during a partial meal-replacement hypocaloric diet

BACKGROUND

Some studies have demonstrated a positive association of the rs7799039 genetic variant of the LEP gene with energy intake and metabolic parameters. The present study aimed to analyse the effects of the rs7799039 genetic variant of the LEP gene on metabolic parameters after weight loss secondary to a partial meal-replacement (pMR) hypocaloric diet.

METHODS

We conducted a non-randomised, single-treatment study in 122 obese subjects with body mass index (BMI) > 35 kg m^-2 . The subjects were treated with two intakes of a normocaloric hyperproteic formula during 12 weeks. Anthropometric parameters and biochemical profile were measured at basal time and after 12 weeks. The variant genetic variant (rs7799039) of the LEP gene was assessed by a real-time polymerase chain reaction.

RESULTS

We recruited 122 subjects [26 GG (21.3%), 59 GA (29.5%) and 37 AA (30.3%)]. The mean (SD) age of the all group was 59.4 (6.3) years (range 45-63 years) and the mean (SD) BMI was 39.3 (2.8) kg m^-2 (range 36.2-45.1 kg m^-2 ). After the pMR hypocaloric diet, body weight, BMI, fat mass, waist circumference, fasting insulin, homeostasis model assessment for insulin resistance and blood pressure decreased in both genotypes. All of these improvements were similar in both genotypes. Moreover, after dietary intervention, only subjects without an A allele showed a significant improvement in triglycerides (GG versus GA + AA) [mean (SD) -15.3 (6.4) mg dL^-1 versus -3.7 (4.3) mg dL^-1 : P = 0.02], total cholesterol [-25.0 (5.3) mg dL^-1 versus -8.1 (3.5) mg dL^-1 : P = 0.02] and low-density lipoprotein-cholesterol [-20.7 (4.2) mg dL^-1 versus -5.4 (2.3) mg dL^-1 : P = 0.01].

CONCLUSIONS

Subjects with an A allele of the rs7799039 variant in the LEPR gene showed a significant improvement in low-density lipoprotein-cholesterol and triglycerides levels after weight loss secondary to a pMR hypocaloric diet.

Contribution of ADIPOQ Variants to the Genetic Susceptibility of Recurrent Pregnancy Loss

Adiponectin is a hormone implicated in regulating energy, lipid, and glucose metabolism and is encoded by the ADIPOQ gene. ADIPOQ variants can regulate the circulating levels of adiponectin. Irregular adiponectin concentrations have been associated with numerous reproductive diseases including recurrent pregnancy loss (RPL). The main objective of this study was to determine whether the 14 selected polymorphisms of the ADIPOQ gene are linked with RPL. The retrospective case-control study comprised a total of 332 women with RPL, adjusted as more than three consecutive abortions of unknown etiology, and 286 healthy controls. They were genotyped for the ADIPOQ variants using allele exclusion method on real-time PCR. Significantly higher rs1501299 minor allele frequencies (MAF) and lower rs2241767 and rs2241766 MAF were seen among RPL women, thereby assigning disease susceptibility and protective aspect to the mentioned variants, respectively. Different associations of ADIPOQ genotypes with RPL were noticed according to the genetic model exploited: rs1501299 and rs2241767 were significantly linked with RPL under the three models, while rs17366568 and rs2241766 were associated with RPL under codominant and dominant models, and rs7649121 was related to RPL under the dominant and recessive models. rs4632532 was linked according to the recessive model only. Based on LD pattern, 2-haplotype blocks were specified. Reduced frequency of AGG and GAGG and increased frequency of TAAG were noted in cases, compared with controls, hence indicating these haplotypes as RPL-protective and RPL-susceptible, respectively. These results support a significant role of ADIPOQ as an RPL candidate locus.

Interaction between Metabolic Genetic Risk Score and Dietary Fatty Acid Intake on Central Obesity in a Ghanaian Population

Obesity is a multifactorial condition arising from the interaction between genetic and lifestyle factors. We aimed to assess the impact of lifestyle and genetic factors on obesity-related traits in 302 healthy Ghanaian adults. Dietary intake and physical activity were assessed using a 3 day repeated 24 h dietary recall and global physical activity questionnaire, respectively. Twelve single nucleotide polymorphisms (SNPs) were used to construct 4-SNP, 8-SNP and 12-SNP genetic risk scores (GRSs). The 4-SNP GRS showed significant interactions with dietary fat intakes on waist circumference (WC) (Total fat, P_interaction = 0.01; saturated fatty acids (SFA), P_interaction = 0.02; polyunsaturated fatty acids (PUFA), P_interaction = 0.01 and monounsaturated fatty acids (MUFA), P_interaction = 0.01). Among individuals with higher intakes of total fat (>47 g/d), SFA (>14 g/d), PUFA (>16 g/d) and MUFA (>16 g/d), individuals with ≥3 risk alleles had a significantly higher WC compared to those with <3 risk alleles. This is the first study of its kind in this population, suggesting that a higher consumption of dietary fatty acid may have the potential to increase the genetic susceptibility of becoming centrally obese. These results support the general dietary recommendations to decrease the intakes of total fat and SFA, to reduce the risk of obesity, particularly in individuals with a higher genetic predisposition to central obesity.

Genomic and Genetic Approaches to Deciphering Acute Respiratory Distress Syndrome Risk and Mortality

Significance: Acute respiratory distress syndrome (ARDS) is a severe, highly heterogeneous critical illness with staggering mortality that is influenced by environmental factors, such as mechanical ventilation, and genetic factors. Significant unmet needs in ARDS are addressing the paucity of validated predictive biomarkers for ARDS risk and susceptibility that hamper the conduct of successful clinical trials in ARDS and the complete absence of novel disease-modifying therapeutic strategies. Recent Advances: The current ARDS definition relies on clinical characteristics that fail to capture the diversity of disease pathology, severity, and mortality risk. We undertook a comprehensive survey of the available ARDS literature to identify genes and genetic variants (candidate gene and limited genome-wide association study approaches) implicated in susceptibility to developing ARDS in hopes of uncovering novel biomarkers for ARDS risk and mortality and potentially novel therapeutic targets in ARDS. We further attempted to address the well-known health disparities that exist in susceptibility to and mortality from ARDS. Critical Issues: Bioinformatic analyses identified 201 ARDS candidate genes with pathway analysis indicating a strong predominance in key evolutionarily conserved inflammatory pathways, including reactive oxygen species, innate immunity-related inflammation, and endothelial vascular signaling pathways. Future Directions: Future studies employing a system biology approach that combines clinical characteristics, genomics, transcriptomics, and proteomics may allow for a better definition of biologically relevant pathways and genotype-phenotype connections and result in improved strategies for the sub-phenotyping of diverse ARDS patients via molecular signatures. These efforts should facilitate the potential for successful clinical trials in ARDS and yield a better fundamental understanding of ARDS pathobiology.

Genetic polymorphisms associated with obesity and non-alcoholic fatty liver disease in Asian Indian adolescents

Background The objective of this study was to investigate the association of polymorphisms in four genes, tumor necrosis factor-α (TNFA), patatin-like phospholipase domain containing 3 (PNPLA3), adiponectin (ADIPOQ) and apolipoprotein C3 (APOC3), with obesity and non-alcoholic fatty liver disease (NAFLD) in Asian Indian adolescents. Methods In this case-control study, 218 Asian Indian adolescents with overweight/obesity and 86 lean healthy adults without fatty liver were enrolled. Hepatic steatosis was assessed and graded by ultrasonography (USG). Serum insulin, lipids, alanine aminotransferase (ALT), aspartate aminotransferase (AST), TNF-α, adiponectin and apolipoprotein C3 were measured and genotyping was done. Frequencies of variant and wild genotypes in all adolescents and in the subgroups without steatosis, with grade 1 steatosis and with grade 2 or 3 steatosis were compared to those in the controls. The frequencies were also compared in the overweight adolescents with grade 2 or 3 steatosis and without steatosis. Results Variant genotypes of polymorphisms -863 C > A and -1031 T > C of the TNFA gene, 455 T > C of the APOC3 gene and the wild type of +276 G > T of the ADIPOQ gene were associated with obesity with odds ratios (OR, 95% confidence interval [CI]) of 2.5 (1.5-4.4), 2.5 (1.5-4.2), 2.0 (1.1-3.6) and 2.5 (1.4-5.0), respectively. Polymorphisms 455 T > C of APOC3 and rs738409 C > G of PNPLA3 were associated with NAFLD. Fasting insulin and triglycerides (TG) were higher in the adolescents with homozygous variant polymorphisms -1031 T > C of TNFA and 455 T > C of APOC3 genes, respectively. Conclusions Several polymorphisms were noted to have a significant association with obesity and NAFLD in Asian Indian adolescents.

Associations of ADIPOQ and LEP Gene Variants with Energy Intake: A Systematic Review

This systematic review aims to evaluate the association of adiponectin (ADIPOQ) and leptin (LEP) gene variants with energy intake. Cross-sectional, cohort, and case–control studies that reported an association of leptin and/or adiponectin gene variants with energy intake were included in this review. Human studies without any age restrictions were considered eligible. Detailed individual search strategies were developed for each of the following bibliographic databases: Cochrane, Latin American and Caribbean Center on Health Sciences Information (LILACS), PubMed/MEDLINE, Scopus, and Web of Science. Risk of bias assessment was adapted from the Downs and Black scale and was used to evaluate the methodology of the included studies. Seven studies with a pooled population of 2343 subjects were included. The LEP and ADIPOQ gene variants studied were LEP-rs2167270 (k = 1), LEP-rs7799039 (k = 5), ADIPOQ-rs2241766 (k = 2), ADIPOQ-rs17300539 (k = 1), and ADIPOQ marker D3S1262 (k = 1). Two of the seven studies reviewed demonstrated a positive association between the LEP-rs7799039 polymorphism and energy intake. Two other studies—one involving a marker of the ADIPOQ gene and one examining the ADIPOQ-rs17300539 polymorphism—also reported associations with energy intake. More research is needed to further elucidate the contributions of genetic variants to energy metabolism.

Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links

Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.

ADIPOQ polymorphisms are associated with changes in obesity-related traits in response to aerobic training programme in women

Among genetic variants of the ADIPOQ gene +276 G>T (rs1501299) and –11377 G>C (rs266729) are the most frequently investigated polymorphisms which were described in the context of genetic conditioning for a predisposition to obesity. However, the information of polymorphisms’ potential modifying effect on obesity-related traits achieved through training procedures are still unknown. DNA was extracted from buccal cells donated by the 201 participants and genotyping was carried out using real-time PCR. The genotype distribution was examined in a group of women measured for chosen traits before and after the completion of a 12-week training programme. Our results suggest that the ADIPOQ genotypes analyzed individually or in combination can modulate training-induced body mass measurements changes: after the training programme, carriers of rs1501299 T allele and rs266729 C allele were characterized by a greater reduction in fat mass percentage (FM), fat mass, and body mass. Moreover, the ADIPOQ polymorphisms were associated with changes in lipid profile in response to training. Additionally, we showed three main effects of genotypes for the FM, LDL-C (rs266729), and TBW (rs1501299). Our study indicate that the both polymorphisms are associated with changes in obesity-related traits in response to 12-week aerobic training programme in Caucasian women. From this evidence, it could be concluded that rs1501299 G and rs266728 G variants may be considered as disadvantageous factor in the context of training-induced effects on body mass traits.

Association of MTTP gene variants with pediatric NAFLD: A candidate-gene-based analysis of single nucleotide variations in obese children

Objective

We used targeted next-generation sequencing to investigate whether genetic variants of lipid metabolism-related genes are associated with increased susceptibility to nonalcoholic fatty liver disease (NAFLD) in obese children.

Methods

A cohort of 100 obese children aged 6 to 18 years were divided into NAFLD and non-NAFLD groups and subjected to hepatic ultrasound, anthropometric, and biochemical analyses. We evaluated the association of genetic variants with NAFLD susceptibility by investigating the single nucleotide polymorphisms in each of 36 lipid-metabolism-related genes. The panel genes were assembled for target region sequencing. Correlations between single nucleotide variations, biochemical markers, and clinical phenotypes were analyzed.

Results

97 variants in the 36 target genes per child were uncovered. Twenty-six variants in 16 genes were more prevalent in NAFLD subjects than in in-house controls. The mutation rate of MTTP rs2306986 and SLC6A2 rs3743788 was significantly higher in NAFLD subjects than in non-NAFLD subjects (OR: 3.879; P = 0.004; OR: 6.667, P = 0.005). Logistic regression analysis indicated the MTTP variant rs2306986 was an independent risk factor for NAFLD (OR: 23.468, P = 0.044).

Conclusions

The results of this study, examining a cohort of obese children, suggest that the genetic variation at MTTP rs2306986 was associated with higher susceptibility to NAFLD. This may contribute to the altered lipid metabolism by disruption of assembly and secretion of lipoprotein, leading to reducing fat export from the involved hepatocytes.

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.

Family-Based Association Study of rs17300539 and rs12495941 Polymorphism in Adiponectin Gene and Polycystic Ovary Syndrome in a Chinese Population

Backgriond

Polycystic ovary syndrome (PCOS) is a complex disease that has both genetic and environmental components. Adiponectin plays an important role in the regulation of insulin sensitivity and insulin resistance (IR) in PCOS. The aim of this study was to determine 2 single-nucleotide polymorphisms (SNPs) variants (rs12495941 and rs17300539) of the adiponectin gene (ADIPOQ) in polycystic ovary syndrome (PCOS) families.

Material/Methods

We recruited 197 PCOS probands, their biological parents, and 192 controls. Anthropometric variables, including hip circumference (HC) and waist circumference (WC), were measured in all subjects during their first visit to the outpatient department. Serum T, FBG, FINS, TC, TG, LDL, and HDL levels were measured. PCOS patients were divided into 2 groups based on BMI: group A (BMI <25 kg/m²) and group B (BMI ≥25 kg/m²). Parents of PCOS were accordingly categorized into group C and group D (fathers), and group E and group F (mothers). The associations among ADIPOQ rs12495941, rs17300539, and PCOS were analyzed using the transmission disequilibrium test (TDT).

Results

A significant association was found between SNP rs17300539 and PCOS in our Chinese population. The levels of TG and FINS and the genotype frequencies of rs17300539 are significantly different between overweight and lean PCOS. No significant association was detected for rs12495941.

Conclusions

TDT confirms that rs17300539 of ADIPOQ is strongly associated with the risk of PCOS in a Chinese Han population, but rs12495941 of ADIPOQ is not associated with the occurrence of PCOS.

Distinct Penetrance of Obesity-Associated Susceptibility Alleles in the Hungarian General and Roma Populations

AIMS

The aim of our study was to explore differences in genetic predisposition to obesity between the Hungarian general and Roma populations.

METHODS

A total of 1,152 samples from the Hungarian Roma population and 1,743 samples from the Hungarian general population were genotyped for 20 single nucleotide polymorphisms (SNPs) associated with the risk of obesity. Two types of multilocus genetic risk scores were constructed to estimate the combined effect of selected SNPs.

RESULTS

Risk allele frequencies differed significantly between the two populations for 11 SNPs, with no enrichment in any of the two study groups. Variants (rs1558902, rs1121980, rs9939609, and rs9941349) in the fat mass and obesity-associated (FTO) gene exhibited strong but ethnicity-independent association with obesity. Genetic risk scores showed stronger associations with obesity in the Roma population compared with the Hungarian general population; however, without significant gene-population interaction.

CONCLUSION

Differences in obesity prevalence between the Hungarian general and Hungarian Roma populations could not be explained by their distinct genetic susceptibility, rather by ethnicity-related environmental and behavioral factors. Nonetheless, particular gene-environment interactions might contribute to the distinct penetrance of the obesity-associated genetic factors in populations of different ethnic backgrounds.

PPARG-LYPLAL1 Multi-Allelic Combination Associated with Obesity and Overweight in Mexican Adolescent Females

OBJECTIVE

We studied multi-loci variants to identify the contribution of six candidate genes (ADIPOQ, CDH13, LYPLAL1, MC4R, PPARG and PGC1A) in the development of obesity and overweight.

DESIGN

We genotyped 404 chromosomes with eleven SNPs in Mexican female adolescents, who were subdivided into two groups (obesity-overweight and normal-weight) using the World Health Organization parameters. Genomic (800 chromosomes) and ancestral (208 chromosomes) controls were included to reduce the population bias. Anthropometric measurements, biochemical parameters, and caloric intake were obtained only in the groups of Mexican female adolescents.

RESULTS

A positive genotype-phenotype association was found that involves the multi-allelic combination of three risk alleles (one in PPARG and two in LYPLAL1) with obesity and overweight (OR=3.1, P=.010). This combination also exhibited a significant association with waist circumference (P=.030) and triglycerides levels (P=.030). These associations were supported by a logistic regression analysis adjusted for several confounding variables.

CONCLUSIONS

Our data suggest the joint participation of PPARG-LYPLAL1 genes in metabolic disorders development. Hence, these genes could act as potential biomarkers in obesity and overweight. Our findings underscore the complexity of metabolic disorders and provide evidence about the importance of multi-loci analysis to study complex diseases.

Interactions with the MC4R rs17782313 variant, mental stress and energy intake and the risk of obesity in Genome Epidemiology Study

Background

The melanocortin-4 receptor (MC4R) regulates metabolism by modulating eating behavior and MC4R variants (rs17782313 and rs571312) are associated with obesity in Asians and Caucasians. However, the impact of their interactions with nutritional and lifestyle factors on obesity are poorly described. Therefore, we investigated the interaction of MC4R variants and dietary patterns on the risk of obesity in Korean middle-aged adults.

Methods

Data collected included, genetic variations, anthropometric and biochemical measurements, dietary and lifestyle habits, and food intake. Data were obtained from the 8830 adults aged 40–69 years in the Ansung and Ansan cohort of the Korean Genome Epidemiology Study.

Results

The MC4R rs18882313 minor allele had a higher frequency in the obese group (P < 0.01). MC4R genotypes were not associated with differences in daily energy and macronutrient intakes. However, the intakes of processed foods and fat (as percentages of energy) were significantly higher and intake of fruits were significantly lower in subjects with MC4R minor alleles (P < 0.05). Interestingly, there was a positive interaction between MC4R variants and mental stress levels that were associated with the risk of obesity after adjusting for age, gender, residence area, daily energy intake, smoking status and physical activity (interaction P = 0.0384). Only in subjects with high stress were MC4R minor alleles associated with higher BMIs after adjusting for confounders. The association was present without modulating energy and nutrient intake. In the group with energy intakes higher than estimated energy requirement (EER), subjects with MC4R minor alleles had higher BMIs than those with the major alleles (P < 0.001).

Conclusions

The interactions of mental stress and energy intakes with the MC4R minor allele genotype might be associated with increased risk of obesity in Korean adults. This research might identify subjects with a specific MC4R minor alleles as a human subset of people with a low metabolic tolerance for excessive energy intake, especially when under stress.

ADIPOQ single nucleotide polymorphism: Association with adiponectin and lipoproteins levels restricted to men

Adiponectin is an adipokine inversely correlated with obesity, which has beneficial effect on insulin resistance and lipid metabolism. Considering its potential as a therapeutic target in the metabolic disorder contexts, and in order to add knowledge in the area, our study evaluated the ADIPOQ 276G > T polymorphism effect on adiponectin levels, and on lipoproteins of clinical interest in a population sample composed of 211 healthy individuals. Significant effects were observed only among men: the carriers of heterozygous genotype (GT) showed high levels of adiponectin (p = 0.018), while the rare homozygous genotype (TT) gave its carriers a negative phenotype, represented by higher levels of low density lipoprotein cholesterol (LDL-C) (p = 0.004 and p = 0.005) and total cholesterol (TC) (p = 0.010 and p = 0.005) compared to carriers of other genotypes (GG and GT respectively), the independent effect of SNP on LDL-C and TC levels was confirmed by multiple regression analysis (p = 0.008 and p = 0.044). We found no evidence of correlation between circulating adiponectin levels and biochemical markers, which suggests, therefore, an SNP 276G > T independent effect on adiponectin levels and on lipoprotein metabolism in men enrolled in this study.

Association of adiponectin gene polymorphism with nonalcoholic fatty liver disease in Taiwanese patients with type 2 diabetes

Objective

Patients with type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) have a higher prevalence of cardiovascular diseases. In this study we investigated the frequency of single nucleotide polymorphisms (SNPs) of several candidate genes associated with NAFLD in Taiwanese patients with type 2 diabetes mellitus (DM) and NAFLD and in those with DM but without fatty liver disease.

Methods

We enrolled 350 patients with type 2 DM and NAFLD and 209 patients with DM but without NAFLD. Body mass index (BMI), % body fat (% BF), glycated hemoglobin (HbA1c), high molecular weight (HMW) isoform of adiponectin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels were measured. Thirteen SNPs in 5 genes (adiponectin, leptin, peroxisome proliferator-activated receptor alpha, adiponutrin/patatin-like phospholipase domain-containing protein 3 and peroxisome proliferator-activated receptor γ co-activator 1α ) were measured.

Results

Only adiponectin rs266729 polymorphism was associated with susceptibility to NAFLD (p = 0.001). Subgroup analysis revealed that the proportion of subjects with homozygous genotype GG was higher in patients with NAFLD (31%) than in controls (11%) and that the proportions of heterozygous CG and homozygous CC were higher in controls (37% and 52%, respectively) than in patients with NAFLD (33% and 36%, respectively). Patients with NAFLD carrying the GG genotype of rs266729 showed significantly lower serum HMW adiponectin levels than patients carrying the GC or CC genotype (3.75±0.37 vs. 3.99±0.66 vs. 4.79±0.58 μg/ml, p< 0.001). Body fat and serum HMW adiponectin levels were the strongest predictors of developing NAFLD (p < 0.001 and 0.004, respectively).

Conclusions

In patients with type 2 diabetes gene polymorphism of adiponectin rs266729 is associated with risk of NAFLD. G allele of rs266729 is associated with hypoadiponectinemia. Low serum adiponectin level may precipitate liver steatosis in patients with type 2 diabetes.

Association of adiponectin gene polymorphism with adiponectin levels and risk for insulin resistance syndrome

Background:

Adiponectin is an abundant adipose tissue–derived protein with anti-atherogenic, anti-inflammatory and antidiabetic properties. Plasma adiponectin levels are decreased in obesity, type 2 diabetes, and coronary artery disease and low adiponectin levels also predict insulin resistance (IR).

Methods:

Case-control study in which 642 male and female subjects were participated from the North Indian population. Lipid, insulin, leptin and adiponectin level were estimated using standard protocols by commercially available test kits. Single nucleotide polymorphisms +45T>G and +276G>T of the AMP1 (adiponectin) gene was genotyped by polymerase chain reaction restriction fragment length polymorphism method.

Results:

Levels of adiponectin, insulin, homeostasis model assessment-IR index (HOMA-IR index), systolic blood pressure and fat mass showed significant differences between male and female subjects. Serum adiponectin level showed highly significant association with both the +45 and the +276 genotypes. The common haplotype triglyceride (TG) showed a significantly lower adiponectin value than other haplotypes (P = 0.0001). A clear trend of decreasing adiponectin levels per copy of the common haplotype was observed. Nonobese insulin sensitive subjects showed a higher adiponectin value (P = 0.0006) than nonobese insulin resistant subjects. The values of blood pressure, adiponectin, insulin, HOMA-IR, total-cholesterol, and low-density lipoprotein-cholesterol significantly associated with TG haplotype.

Conclusions:

We observed the very strong association of the adiponectin 45-276 genotypes and haplotypes with adiponectin levels in healthy north Indian population and TG haplotypes also associated with metabolic parameters of the IR syndrome.