Association of the common genetic variant upstream of INSIG2 gene with obesity related phenotypes in Chinese children and adolescents

Associations between genetic variants of HSD17B13 and fasting plasma glucose in Chinese children

BACKGROUND AND AIMS

Genetic variants in 17-β hydroxysteroid dehydrogenase 13 (HSD17B13) were demonstrated to protect against NAFLD, which is highly related with insulin resistance and dyslipidemia. However, the effects of NAFLD associated HSD17B13 variants on circulating glucose and lipids have not been adequately investigated in children. This study aimed to investigate associations between single nucleotide polymorphisms (SNPs) of HSD17B13 and NAFLD or its related phenotypes, such as blood glucose and serum lipids in Chinese children.

METHODS AND RESULTS

We studied 1027 Chinese Han children aged 7-18 years old, which included 162 NAFLD children and 865 controls without NAFLD. Three SNPs (rs13112695, rs7692397, rs6834314) in HSD17B13 were genotyped. The multivariable logistic and linear regression models were applied to detect the associations between three SNPs and NAFLD or its related phenotypes [alanine transaminase (ALT), fasting plasma glucose (FPG) and serum lipids]. The effect allele A of rs7692397 was negatively associated with FPG [β (SE) = -0.088 (0.027) mmol/L, P = 0.001], whereas the effect allele G of rs6834314 was positively associated with FPG (β (SE) = 0.060 (0.019) mmol/L, P = 0.002). After Bonferroni correction, the significant associations still remained (both P < 0.0024). No significant associations were found for NAFLD or serum lipids.

CONCLUSION

The study firstly revealed the association between two HSD17B13 variants and FPG in Chinese children, providing evidence for HSD17B13 variants and abnormal glucose metabolism.

Comparison of MAFLD and NAFLD Characteristics in Children

Background & aims: An international panel proposed a diagnostic framework for metabolic-associated fatty liver disease (MAFLD) in children. The aim was to compare the clinical features of MAFLD and nonalcoholic fatty liver disease (NAFLD) in children. Methods: The characteristic differences between NAFLD and MAFLD in children were compared with the National Health and Nutrition Examination Survey (NHANES) 2017–2018 in the U.S. and the Comprehensive Prevention Project for Overweight and Obese Adolescents (CPOOA) study in China. Results: In NHANES 2017–2018, regardless of which criteria were implemented, participants with hepatic steatosis were more likely to have higher BMI z-scores, a higher prevalence of hypertension or higher metabolic indices and higher non-invasive liver fibrosis scores (all p < 0.05). The cases diagnosed by those two definitions had a similarity of over 75%. More obese children were diagnosed with MAFLD than NAFLD (p < 0.001). However, approximately 19% of children with NAFLD present with normal weight and fasting glucose levels and cannot be diagnosed with MAFLD. The CPOOA study excluded viral infected liver disease and certain kinds of congenital causes of liver steatosis patients, resulting in children with NAFLD being identical with MAFLD children. Conclusions: Most clinical features were similar between children with MAFLD and children with NAFLD, and more than 75% of children with NAFLD can also be diagnosed with MAFLD. However, approximately 19% of children with NAFLD cannot be categorized as MAFLD. Therefore, to gain greater benefits from renaming NAFLD to MAFLD in pediatrics, the prevalence of different causes of hepatic steatosis in children needs to be understood.

Associations of genetic variants of lysophosphatidylcholine metabolic enzymes with levels of serum lipids

OBJECTIVE

Metabolic disturbance of lysophosphatidylcholine (LPC) is related with dyslipidemia. Therefore, eight single-nucleotide polymorphisms (SNPs) were selected from LPC metabolic enzymes to study their associations with obesity and serum levels of lipids.

METHODS

A total of 3305 children were recruited from four independent studies. Eight SNPs of LPC metabolic enzymes were selected and genotyped with the matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). The multivariable linear regression model was applied to detect the associations of eight SNPs with obesity-related phenotypes and levels of lipids in each study. Meta-analyses were used to combine the results of four studies.

RESULTS

Only SNP rs4420638 of APOC-1 gene was associated with serum lipids even after Bonferroni correction. The rs4420638 was positively associated with TC (β = 0.15, P = 8.59 × 10^-9) and low-density-lipoprotein-cholesterol (LDL-C, β = 0.16, P = 9.98 × 10^-14) individually.

CONCLUSION

The study firstly revealed the association between APOC-1/rs4420638 and levels of serum lipids in Chinese children, providing evidence for susceptible gene variants of dyslipidemia.

Fine Mapping of the MAP2K5 Region Identified rs7175517 as a Causal Variant Related to BMI in China and the United Kingdom Populations

Background: Genome-wide association studies (GWASs) have consistently identified MAP2K5 as an obesity susceptibility gene. To deepen our understanding of the potential causal genetic variants of this region, a fine-mapping study of MAP2K5 was conducted.

Methods and Results: SNPs rs7175517 (G > A) and rs4776970 (T > A) were identified as the leading SNPs associated with BMI in both Chinese and the United Kingdom populations. Second, colocalization of GWAS and expression quantitative trait loci (eQTL) analyses and bioinformatic analyses indicated that rs7175517 is the functionally leading variant in the MAP2K5 gene region. Dual-luciferase assays indicated that the G allele of rs7175517 reduced the mRNA expression of MAP2K5 in HEK293T cells. The possible mechanism was that the G allele interacted with more RNA repressors from nuclei extracts, which was evidenced by electrophoretic mobility shift assays (EMSAs). Furthermore, the pathway enrichment analyses of the products from DNA pull-down and protein mass spectrometry demonstrated that the G allele of rs7175517 might interact with RNA catabolic or splicing transcription factors, which consequentially increased adiposity deposition.

Conclusion: SNP rs7175517 of the MAP2K5 gene was the putative causal variant associated with BMI. More precisely designed in vitro or animal experiments are warranted to further delineate the function of MAP2K5 in adipogenesis.

TM6SF2 rs58542926 is related to hepatic steatosis, fibrosis and serum lipids both in adults and children: A meta-analysis

BACKGROUND AND AIMS

Findings about the associations between transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 and nonalcoholic fatty liver disease have not been consistently replicated, particularly in steatosis and fibrosis. The present study aimed to investigate the associations between the rs58542926T allele and the spectrum of NAFLD and its related metabolic phenotypes.

METHODS

Systematic literature research was performed to analyse the associations between rs58542926 and the spectrum of NAFLD and its related metabolic phenotypes. A random effects meta-analysis with a dominant genetic model was applied.

RESULTS

Data from 123,800 individuals across 44 studies were included in the current meta-analysis.rs58542926 T allele was associated with an increased risk of NAFLD in both adults (OR=1.62; 95% CI: 1.40, 1.86) and children (OR=2.87; 95% CI: 1.85, 4.46). Children had a stronger association with NAFLD (P=0.01). rs58542926 T allele was also positively associated with steatosis progression (mean difference=0.22; 95% CI: 0.05, 0.39) and fibrosis stage (OR=1.50; 95% CI: 1.20, 1.88) in adults. The TM6SF2 rs58542926 T allele was positively associated with ALT in both adults and children (both P<0.01) and only with higher AST in adults (P<0.01). The rs58542926 T allele was negatively associated with serum total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TGs) in both adults and children (all P<0.01).The serum level of TG was much lower in adults than in children (P<0.01).

CONCLUSION

TM6SF2 rs58542926 is involved in the entire spectrum of NAFLD and its related metabolic phenotype, and differences in serum lipid levels were observed between adults and children.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021288163.

The CC Genotype of Insulin-Induced Gene 2 rs7566605 Is a Protective Factor of Hypercholesteremia Susceptible to Mild Cognitive Impairment, Especially to the Executive Function of Patients with Type 2 Diabetes Mellitus

Methods

233 T2DM patients with MCI or without MCI were recruited. Baseline data and genotype frequency were compared between MCI and non-MCI groups. Demographic parameters and neuropsychological tests results were analyzed among patients with different genotypes. Further correlation and regression analysis were conducted to find the association between cognition and cholesterol.

Results

Despite no significant statistical difference was detected, we observed higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) in patients with MCI than those without MCI. In addition, we observed higher TC and LDL levels in patients with GG or GC genotypes than those with CC genotype (P < 0.001, P = 0.004, or P < 0.001, P = 0.002). Interestingly, increased MoCA and decreased TMTB scores were found in patients with CC genotype, compared to those with GG or CG genotype (P = 0.009, P = 0.024, or P = 0.005, P = 0.109). Moreover, partial correlation (P = 0.030 and P = 0.004, respectively) and multiple linear regression (P = 0.030 and P = 0.005, respectively) showed that TC and LDL levels are associated with the TMTB score, indicating the executive function.

Conclusions

CC genotype of INSIG-2 rs7566605 may be a protective factor of hypercholesteremia susceptible to MCI, especially to the executive function of T2DM. This trial is registered with ChiCTROCC15006060.

Genetic variants in the FAM3C gene are associated with lipid traits in Chinese children

BACKGROUND

Previous studies have related FAM3C gene with childhood bone health, and the regulation of lipid metabolism in hepatocytes. The present case-control study aimed to analyze the association of FAM3C genetic variants with overweight/obesity and lipid traits among Chinese children.

METHODS

Two genetic variants (rs7776725 and rs7793554) within the FAM3C gene were genotyped in 3305 Chinese children aged 6-18 years.

RESULTS

In the whole study population, the T-allele of rs7776725 and A-allele of rs7793554 within the FAM3C gene were associated with 40.2% (95% CI: 11.6-76.1%; P = 0.004) and 29.1% (6.9-56.0%; P = 0.008) increased risk of dyslipidemia, higher triglyceride (P = 0.014 and P = 0.001) and lower HDL-C (P = 0.015 and P = 0.003). In addition, we found that rs7776725 interacted with sex on dyslipidemia (P_{for interaction} = 0.004), and sex-stratified analyses showed that it was significantly associated with dyslipidemia only in girls (P = 8.78 × 10^-5). The variant also showed nominally significant interactions with sex on total cholesterol and LDL-C (P_{for interaction} = 0.012 and 0.008).

CONCLUSION

We found that FAM3C genetic variants were associated with dyslipidemia and lipid traits among Chinese children. In addition, we found significant gene-by-sex interactions. Our findings provided evidence supporting the role of FAM3C gene in regulating lipid metabolism in humans.

IMPACT

FAM3C genetic variants were associated with dyslipidemia and lipid traits among Chinese children. In addition, we found significant gene-by-sex interactions. FAM3C/rs7776725 was associated with dyslipidemia and lipid traits only in girls. Our findings provided evidence supporting the role of FAM3C gene in regulating lipid metabolism in humans.

Causal associations of body mass index and waist-to-hip ratio with cardiometabolic traits among Chinese children: A Mendelian randomization study

BACKGROUND AND AIMS

Body mass index (BMI) and waist-to-hip ratio (WHR) have been reported to be causally associated with cardiometabolic diseases in adults in European populations. However, this causality was less explored in East Asian populations and in children. Our study aimed to explore and compare the causal associations of general obesity (measured by BMI) and central obesity (measured by WHR) with cardiometabolic traits.

METHODS AND RESULTS

We performed a Mendelian randomization (MR) analysis in 2030 unrelated children from two independent case-control studies in Beijing, China. BMI-associated single nucleotide polymorphisms (SNPs) and WHR-SNPs identified by previous genome-wide association studies were used as genetic instruments to examine the casual associations of BMI and WHR with cardiometabolic traits, including glycemic traits, blood lipids, and blood pressure. Each 1-SD increase in BMI and WHR were significantly associated with 0.111 mmol/L and 0.110 mmol/L increase in log-transformed fasting insulin (FINS), 0.049 and 0.060 increase in log-transformed HOMA-β, 0.112 and 0.108 increase in log-transformed HOMA-IR, 0.009 mmol/L and 0.015 mmol/L increase in log-transformed triglyceride, and 15.527 mmHg and 7.277 mmHg increase in systolic blood pressure, respectively (all P < 0.05). The receiver operating characteristic curves showed that WHR had a stronger effect on FINS, HOMA-β, HOMA-IR, and triglyceride than BMI (all P < 0.05).

CONCLUSIONS

Using the MR method, we found that the genetic predisposition to higher BMI or WHR was associated with altered cardiometabolic traits in Chinese children. When compared with general obesity, central obesity might have stronger effects on glycemic traits and blood lipids among children.

Interaction between lifestyle behaviors and genetic polymorphism in SCAP gene on blood pressure among Chinese children

BACKGROUNDS

Previous studies had revealed that sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) rs12487736 polymorphism was associated with blood pressure (BP), but whether rs12487736 could interact with lifestyle behaviors on BP is unknown.

METHODS

A case-control study with 1092 Chinese children was conducted.

RESULTS

We found an interaction between rs12487736 and high calorie foods intake (fried chips/cakes/cookies) on systolic blood pressure (SBP) (P_interaction = 0.027), and rs12487736 was associated with SBP in the subgroup having high calorie foods at least once in the last week (b = 2.19, P = 0.025), but not in the subgroup not having high calorie foods. Also, interaction between protein intake (meat/fish/soy beans/egg) and rs12487736 on diastolic BP (DBP) was identified (P_interaction = 0.049); rs12487736 was associated with DBP in the subgroup consuming protein (meat/fish/soy beans/egg) <twice/day (b = 3.38, P = 0.014), but not in the subgroup ≥twice/day. There is combined effect between rs12487736 and physical activity on DBP. In the subgroup who were inactive (physical activity <1 h/day), rs12487736 was significantly associated with DBP (b = 3.27, P = 0.046), but not in the active group (physical activity ≥1 h/day). Similar combined effect between rs12487736 and soft drink was found.

CONCLUSIONS

Interactions or combined effects between SCAP and lifestyle behaviors on BP support the importance of promoting a healthy lifestyle in the children genetically predisposed to higher BP.

Physical activity attenuates the association between the IRS1 genotype and childhood obesity in Chinese children

BACKGROUND AND AIMS

The insulin receptor substrate 1 (IRS1) rs2943650 was found to be associated with obesity in adults, but the association has not been evaluated in children. The present study aimed to examine whether IRS1 rs2943650 was associated with obesity in Chinese children and investigate the interaction between rs2943650 and physical activity.

METHODS AND RESULTS

IRS1 rs2943650 was genotyped in 3303 Chinese children aged 6-18 years recruited from four independent studies. Logistic regression and linear regression were performed to examine associations. Meta-analyses were conducted to pool the results of the four independent studies. The C-allele carriers of rs2943650 showed a 29% higher risk of obesity than noncarriers (OR (95% CI) = 1.29 (1.05, 1.58), P = 0.02) and a 0.41 kg/m² increase in BMI (β (95% CI) = 0.41 (0.05, 0.78) kg/m², P = 0.02). We also observed significant interactions between rs2943650 and physical activity/sedentary behaviors on obesity (P_{forinteraction}<0.05). Compared with the physically active children (physical activity ≥1 h/d and sedentary behaviors <2 h/d), the risk allele (C) of rs2943650 was significantly associated with a 241% increased risk of obesity among inactive children who participated in physical activity <1 h/d and sedentary behaviors ≥2 h/d (OR (95% CI) = 3.41 (1.45, 8.01), P = 0.005).

CONCLUSIONS

We found that IRS1 rs2943650 was significantly associated with BMI and risk of childhood obesity. Additionally, we also found significant interaction between IRS1 rs2943650 polymorphism and physical activity/sedentary behaviors on childhood obesity. Our study would provide novel insights into the function of the IRS1 gene and the implementation of effective intervention strategies of childhood obesity.

Waist-hip ratio related genetic loci are associated with risk of impaired fasting glucose in Chinese children: a case control study

Background

The meta-analyses of genome-wide association studies identified several waist-hip ratio (WHR) related loci in individuals of European ancestry. Since the pattern of fat distribution and the relationship between fat distribution and glucose metabolism disturbance in Chinese are different from those in Europeans, the present study aimed to explore the individual and cumulative effects of WHR-related loci on glycemic phenotypes in Chinese children.

Methods

A total of 2030 children were recruited from two independent studies. Eleven single nucleotide polymorphisms (SNPs) were selected and genotyped using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Logistic regression and linear regression model were used to examine the association of 11 SNPs and genetic risk score (GRS) with impaired fasting glucose (IFG) and fasting plasma glucose (FPG), respectively.

Results

Three SNPs (rs6795735, rs984222 and rs1011731) were nominally associated with IFG (all P < 0.05). Each WHR-increasing (C) allele of rs6795735 (ADAMTS9) was associated with a 40.1% increased risk of IFG (OR = 1.401, 95% CI = 1.131–1.735, P = 0.002), which remained significant after Bonferroni correction. We observed no association of both weighted and unweighted GRS with FPG and IFG (all P > 0.05).

Conclusions

We identified individual effects of rs6795735 (ADAMTS9), rs984222 (TBX15-WARS2), and rs1011731 (DNM3-PIGC) on glycemic phenotypes in Chinese children for the first time. The study suggests that genetic predisposition to central obesity is associated with impaired fasting glucose, providing more evidence for the pathogenesis of diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0270-2) contains supplementary material, which is available to authorized users.

Interaction between obesity and the Hypoxia Inducible Factor 3 Alpha Subunit rs3826795 polymorphism in relation with plasma alanine aminotransferase

BACKGROUND

Hypoxia Inducible Factor 3 Alpha Subunit (HIF3A) DNA has been demonstrated to be associated with obesity in the methylation level, and it also has a Body Mass Index (BMI)-independent association with plasma alanine aminotransferase (ALT). However, the relation among obesity, plasma ALT, HIF3A polymorphism and methylation remains unclear. This study aims to identify the association between HIF3A polymorphism and plasma ALT, and further to determine whether the effect of HIF3A polymorphism on ALT could be modified by obesity or mediated by DNA methylation.

METHODS

The HIF3A rs3826795 polymorphism was genotyped in a case-control study including 2030 Chinese children aged 7-18 years (705 obese cases and 1325 non-obese controls). Furthermore, the HIF3A DNA methylation of the peripheral blood was measured in 110 severely obese children and 110 age- and gender- matched normal-weight controls.

RESULTS

There was no overall association between the HIF3A rs3826795 polymorphism and ALT. A significant interaction between obesity and rs3826795 in relation with ALT was found (P _inter = 0.042), with rs3826795 G-allele number elevating ALT significantly only in obese children (β' = 0.075, P = 0.037), but not in non-obese children (β' = -0.009, P = 0.741). Additionally, a mediation effect of HIF3A methylation was found in the association between the HIF3A rs3826795 polymorphism and ALT among obese children (β' = 0.242, P = 0.014).

CONCLUSION

This is the first study to report the interaction between obesity and HIF3A gene in relation with ALT, and also to reveal a mediation effect among the HIF3A polymorphism, methylation and ALT. This study provides new evidence to the function of HIF3A gene, which would be helpful for future risk assessment and personalized treatment of liver diseases.

Physical Activity and Sedentary Behaviors Modify the Association between Melanocortin 4 Receptor Gene Variant and Obesity in Chinese Children and Adolescents

Effects of MC4R variants in previous Chinese population studies were inconsistent. Gene-environment interactions might influence the effect of MC4R variants on obesity, which was still unclear. We performed the study to clarify the association of variants near MC4R gene with obesity-related phenotypes and gene-environment interactions in Chinese children and adolescents. Two common variants (rs12970134 and rs17782313) near MC4R were genotyped in 2179 children and adolescents aged 7-18 years in Beijing of China. Associations between the variants and obesity-related phenotypes together with gene-environment interactions were analyzed. The A-alleles of rs12970134 were nominally associated with risk of overweight/obesity (Odds Ratios (OR) = 1.21, 95%CI: 1.03-1.44, P = 0.025) and BMI (β = 0.33 kg/m2, 95%CI: 0.02-0.63, P = 0.025), respectively. The rs12970134 was also associated with HDL-C (β = -0.03mmol/L per A-allele, 95%CI: -0.05, -0.01, P = 0.013) independent of BMI. In the further analysis, we found the significant interaction of rs12970134 and physical activity/sedentary behaviors on BMI (Pinteraction = 0.043). The rs12970134 was found to be associated with BMI only in children with physical activity<1h/d and sedentary behaviors ≥2h/d (BMI: β = 1.27 kg/m2, 95%CI: 0.10-2.45, P = 0.034). The association was not detected in their counterparts with physical activity≥1h/d or sedentary behaviors <2h/d. We identified the effect of MC4R rs12970134 on overweight/obesity and BMI, and we also found physical activity and sedentary behaviors modified the association between the rs12970134 and BMI in Chinese children and adolescents.

Association Study of Three Gene Polymorphisms Recently Identified by a Genome-Wide Association Study with Obesity-Related Phenotypes in Chinese Children

OBJECTIVE

This study aimed to examine associations of three single-nucleotide polymorphisms (SNPs) with obesity-related phenotypes in Chinese children. These SNPs were identified by a recent genome-wide association (GWA) study among European children. Given that varied genetic backgrounds across different ethnicity may result in different association, it is necessary to study these associations in a different ethnic population.

METHODS

A total of 3,922 children, including 2,191 normal-weight, 873 overweight and 858 obese children, from three independent studies were included in the study. Logistic and linear regressions were performed, and meta-analyses were conducted to assess the associations between the SNPs and obesity-related phenotypes.

RESULTS

The pooled odds ratios of the A-allele of rs564343 in PACS1 for obesity and severe obesity were 1.180 (p = 0.03) and 1.312 (p = 0.004), respectively. We also found that rs564343 was nominally associated with BMI, BMI standard deviation score (BMI-SDS), waist circumference, and waist-to-height ratio (p < 0.05).

CONCLUSIONS

We showed for the first time that the rs564343 in PACS1 was associated with risk of severe obesity in a non-European population. This SNP was also found to be associated with common obesity and various obesity-related phenotypes in Chinese children, which had not been reported in the original study. The results demonstrated the value of conducting genetic researches in populations with different ethnicity.

Physical activity and sedentary behavior can modulate the effect of the PNPLA3 variant on childhood NAFLD: a case-control study in a Chinese population

Background

The patatin like phospholipase containing domain 3 gene (PNPLA3) rs738409 C > G polymorphism, one of the most important gene polymorphisms involved in hepatic steatosis, has been reported to interact with different nutrients and dietary patterns on Non-Alcoholic Fatty Liver Disease (NAFLD), but no studies have focused on its interaction with physical activity or sedentary behavior. Therefore, this study aims at determining whether physical activity or sedentary behavior could modulate the effect of the PNPLA3 variant on childhood NAFLD.

Methods

A case-control study was conducted including 1027 Chinese children aged 7–18 years old (162 children with NAFLD and 865 children without). The anthropometric measurements, liver ultrasound examination, questionnaires and genotyping of the PNPLA3 rs738409 polymorphism were performed.

Results

Stratified analyses showed that the proportions of NAFLD increased with the G-allele number only in children who did not have enough physical activity (physical activity < 1 h/d) (OR 3.05, 95% CI 1.82–5.12, P < 0.001), and in children with a sedentary lifestyle (sedentary behavior ≥ 2 h/d) (OR 3.41, 95% CI 1.88–6.18, P < 0.001). Significant interactions on childhood NAFLD were found between the G-allele number in the PNPLA3 rs738409 polymorphism and behaviors, including physical activity (P = 0.001), sedentary behavior (P = 0.010) and the combination of physical activity and sedentary behavior (P < 0.001).

Conclusion

This is the first study to report the interaction between the PNPLA3 rs738409 polymorphism and physical activity or sedentary behavior on NAFLD, providing new clues on the function of the PNPLA3 gene, which will also be useful for future risk assessment and personalized treatment of NAFLD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0352-9) contains supplementary material, which is available to authorized users.

Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment

Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options.

Association of common variants identified by recent genome-wide association studies with obesity in Chinese children: a case-control study

Background

Large-scale genome-wide association studies have identified multiple genetic variants that are associated with elevated body mass index (BMI) or the risk of obesity in Caucasian or Asian populations. We examined whether these variants are individually associated with obesity in Chinese children, and also assessed their cumulative effects and predictive value for obesity risk in Chinese children.

Methods

We genotyped 40 single nucleotide polymorphisms (SNPs) and conducted association analyses for 32/40 SNPs with an estimated minor allele frequency >1 % in 2 030 unrelated Chinese children, including 607 normal-weight, 718 overweight, and 705 obese individuals from two cross-sectional study groups. Logistic regression and linear regression under the additive model were used to examine associations, and the area under the receiver operating characteristic curve (AUC_ROC) was reported as prediction summary.

Results

We identified obesity association for 6 SNPs near SEC16B, RBJ, CDKAL1, TFAP2B, MAP2K5 and FTO (odds ratios (ORs) ranged from 1.19 to 1.41, nominal two-sided P-values < 0.05). Association (Bonferroni corrected) of rs543874 near SEC16B and rs2241423 near MAP2K5 had presumably stronger effects on obesity in Chinese children than in Caucasian populations. Their risk alleles were also associated with BMI standard deviation score (BMI-SDS) variability. We demonstrated the cumulative effects of the 32 SNPs on obesity risk (per risk allele: OR = 1.06, 95 % CI: 1.03-1.11, P = 4.84 × 10^-4) and BMI-SDS (β = 0.04, 95 % CI: 0.02-0.06, P = 3.69 × 10^-7). The difference in AUC_ROC for a model with covariates (age, age square, sex and study group) and the model including covariates and all 32 SNPs was 2.8 % (P = 0.0002).

Conclusion

While six SNPs were individually associated with obesity in Chinese children, the 32 common variants identified by recent GWA studies had cumulative effects and resulted in a limited increase in the AUC_ROC predictive value for childhood obesity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0268-4) contains supplementary material, which is available to authorized users.

HIF3A DNA Methylation Is Associated with Childhood Obesity and ALT

Gene polymorphisms associated so far with body mass index (BMI) can explain only 1.18–1.45% of observed variation in BMI. Recent studies suggest that epigenetic modifications, especially DNA methylation, could contribute to explain part of the missing heritability, and two epigenetic genome-wide analysis studies (EWAS) have reported that Hypoxia Inducible Factor 3 Alpha Subunit (HIF3A) methylation was associated with BMI or BMI change. We therefore assessed whether the HIF3A methylation is associated with obesity and other obesity-related phenotypes in Chinese children. The subjects included 110 severe obese cases aged 7–17y and 110 normal-weight controls matched by age and gender for measurement of blood DNA methylation levels at the HIF3A gene locus using the Sequenom’s MassARRAY system. We observed significantly higher methylation levels in obese children than in controls at positions 46801642 and 46801699 in HIF3A gene (P<0.05), and found positive associations between methylation and alanine aminotransferase (ALT) levels adjusted by gender, age and BMI at the position 46801699 (r = 0.226, P = 0.007). These results suggest that HIF3A DNA methylation is associated with childhood obesity, and has a BMI-independent association with ALT. The results provide evidence for identifying epigenetic factors of elivated ALT and may be useful for risk assessment and personalized medicine of liver diseases such as non-alcoholic fatty liver disease (NAFLD).

GWAS-Identified Common Variants With Nonalcoholic Fatty Liver Disease in Chinese Children

OBJECTIVES

Three genome-wide association studies were previously done for nonalcoholic fatty liver disease (NAFLD) among individuals of Western countries and identified several genetic variants associated with NAFLD. The study aimed to identify whether 7 GWAS-identified common variants (GCKR rs780094, PDGFA rs343064, FDFT1 rs2645424, COL13A1 rs1227756, EHBP1L1 rs6591182, NCAN rs2228603, and PNPLA3 rs738409) were associated with NAFLD in Chinese children.

METHODS

This case-control study recruited 1027 Chinese children of age 7 to 18 years, including 162 children with NAFLD and 865 children without NAFLD. Anthropometric measurements, alanine transaminase (ALT) detection, liver ultrasound examination, and genotyping of 7 variants were performed.

RESULTS

The G-allele of PNPLA3 rs738409 was associated with NAFLD (odds ratio [OR] 1.55, 95% confidence interval 1.13-2.11, P = 0.006) and moderate-to-severe steatosis (OR 3.77, 95% confidence interval 1.78-7.98, P = 0.001) adjusted for age, sex, and BMI standard deviation score. In addition, we found each G-allele of rs738409 increased ALT level by 1.09 IU/L (P = 0.011). Subjects carrying 10 or more risk alleles of 7 variants had an OR of 4.76 (P = 0.025) for NAFLD compared with subjects carrying 3 or fewer risk alleles.

CONCLUSIONS

The PNPLA3 rs738409 G-allele was associated with NAFLD and ALT level in Chinese children. It had stronger association with moderate-to-severe steatosis. Children carrying 10 or more risk alleles of 7 variants were susceptible for NAFLD.

Association of INSIG2 polymorphism with overweight and LDL in children

Background

Dyslipidemia and overweight are common issues in children. Identifying genetic markers of risk could lead to targeted interventions. A polymorphism of SNP rs7566605 near insulin-induced gene 2 (INSIG2) has been identified as a strong candidate gene for obesity, through its feedback control of lipid synthesis.

Objective

To identify polymorphisms in INSIG2 which are associated with overweight (BMI ≥ 85% for age) and dyslipidemia in children. Hypothesis: The C allele of rs7566605 would be significantly associated with BMI and LDL.

Design/Methods

We genotyped 15 SNPs in/near INSIG2 in 1,058 healthy children (53% non-Hispanic white (NHW), 37% overweight) participating in a school based study. Genotype was compared with BMI and lipid markers, adjusting for age, gender, and puberty.

Results

We found a significant association between the SNP rs12464355 and LDL in NHW children, p < 0.001. The G allele is protective (lower LDL). A different SNP was associated with overweight in NHW: rs17047757. SNP rs7566605 was not associated with overweight or lipid levels.

Conclusions

We identified novel genetic associations between INSIG2 and both overweight and LDL in NHW children. Polymorphisms in INSIG2 may be important in the development of obesity through its effects on lipid regulation.

Gender-Specific Effect of -102G>A Polymorphism in Insulin Induced Gene 2 on Obesity in Chinese Children

Background. Insulin induced gene 2 (INSIG2) encodes a protein that has a biological effect on regulation of adipocyte metabolism and body weight. This study aimed to investigate the association of INSIG2 gene -102G>A polymorphism with obesity related phenotypes in Chinese children and test gender-specific effects. Methods. The 2,030 independent individuals aged from 7 to 18 years, including 705 obese cases and 1,325 nonobese controls, were recruited from local schools. We measured the obesity-related phenotypes and detected the serum lipids. We genotype -102G>A polymorphism by using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results. In all individuals, we found that the GG/GA genotype of INSIG2 -102G>A polymorphism was associated with risk of severe obesity (OR = 1.62, 95% CI: 1.11-2.36, and P = 0.012) under the dominant model. The association with severe obesity existed only in boys (OR = 1.91, 95% CI: 1.15-3.17, P = 0.012). The GG/GA genotype of -102G>A polymorphism was also associated with higher waist circumference (β = 2.61 cm, P = 0.031) in boys. No similar association was found in girls. The polymorphism was not associated with other obesity-related phenotypes, neither in all individuals nor in gender-specific population. Conclusions. This study identified a gender-specific effect of INSIG2 -102G>A polymorphism on risk of severe obesity and waist circumference in Chinese boys.

Association study of childhood obesity with eight genetic variants recently identified by genome-wide association studies

BACKGROUND

Being overweight or obese is becoming increasingly common in low- and middle-income countries. The present study aimed to examine association of eight genetic variants with obesity and to estimate the cumulative effects of these variants in Chinese children.

METHODS

We conducted the case-control study in a total of 2,030 subjects. Genotyping of seven novel variants was performed with matrix-assisted laser desorption ionization time of flight mass spectrometry, while rs9939609 was genotyped with tetra-primer amplification refractory mutation system analysis.

RESULTS

The association of two fat mass and obesity-associated gene (FTO) single-nucleotide polymorphisms (SNPs; rs9939609 and rs62048402) with body mass index (BMI) or obesity reached nominal significance at P < 0.05. We found a cumulative effect of five SNPs on the risk of overweight and obesity (odds ratio (OR) = 1.197, 95% confidence interval (CI) = 1.068-1.342, P = 0.002). Subjects carrying 9 or more effect alleles had a 127% increased risk of overweight and obesity (OR = 2.270, 95% CI = 1.403-3.671, P = 0.001) compared with subjects who carry 6 or fewer effect alleles.

CONCLUSION

We confirmed two FTO SNPs (rs62048402 and rs9939609) had nominal significant effects on BMI or obesity. We identified the cumulative effect of five SNPs on risk of overweight and obesity. The results provided evidence for identifying genetic factors related to childhood obesity.

The gene-gene interaction of INSIG-SCAP-SREBP pathway on the risk of obesity in Chinese children

Background. Childhood obesity has become a global public health problem in recent years. This study aimed to explore the association of genetic variants in INSIG-SCAP-SREBP pathway with obesity in Chinese children. Methods. A case-control study was conducted, including 705 obese cases and 1,325 nonobese controls. We genotyped 15 single nucleotide polymorphisms (SNPs) of five genes in INSIG-SCAP-SREBP pathway, including insulin induced gene 1 (INSIG1), insulin induced gene 2 (INSIG2), SREBP cleavage-activating protein gene (SCAP), sterol regulatory element binding protein gene 1 (SREBP1), and sterol regulatory element binding protein gene 2 (SREBP2). We used generalized multifactor dimensionality reduction (GMDR) and logistic regression to investigate gene-gene interactions. Results. Single polymorphism analyses showed that SCAP rs12487736 and rs12490383 were nominally associated with obesity. We identified a 3-locus interaction on obesity in GMDR analyses (P = 0.001), involving 3 genetic variants of INSIG2, SCAP, and SREBP2. The individuals in high-risk group of the 3-locus combinations had a 79.9% increased risk of obesity compared with those in low-risk group (OR = 1.799, 95% CI: 1.475–2.193, P = 6.61 × 10⁻⁹). Conclusion. We identified interaction of three genes in INSIG-SCAP-SREBP pathway on risk of obesity, revealing that these genes affect obesity more likely through a complex interaction pattern than single gene effect.

Association of INSIG2 rs9308762 with ALT level independent of BMI

OBJECTIVES

An increasing number of people are at risk for developing nonalcoholic fatty liver disease (NAFLD). Because obesity is a risk factor for NAFLD, the common variants of obesity-susceptible genes may be associated with NAFLD. Our aim was to identify whether the obesity-susceptible gene variants (rs9939609, rs9930506, and rs4783819 in fat mass and obesity-associated gene (FTO); rs12970134 and rs17782313 in melanocortin-4 receptor gene (MC4R); and rs7566605, rs13428113, and rs9308762 in insulin-induced gene 2 [INSIG2]) were associated with NAFLD.

METHODS

The case-control study recruited 1027 Chinese children ages 7 to 18 years, including 162 children with NAFLD and 865 children without NAFLD. Anthropometric measurements, alanine transaminase (ALT) detection, liver ultrasound examination, and genotyping of 8 gene variants were performed.

RESULTS

The A-allele of FTO rs9939609 was associated with increased NAFLD risk (P = 0.029, odds ratio  1.43), but was not significant after being adjusted for body mass index (BMI) (P = 0.268). We also found an association between the 2 variants (rs12970134 in MC4R and rs9308762 in INSIG2) and ALT level. For rs12970134, each additional A-allele increased ALT level by 1.87 IU/L (P = 0.032). For rs9308762, the homozygotes of the C-allele had a higher ALT level than the T-allele carriers (β = 3.19, P = 0.007). After adjustment for BMI, the former association did not exist, whereas the latter reminded significant (P = 0.003).

CONCLUSIONS

The FTO rs9939609 A-allele increased risk of NAFLD and MC4R rs12970134 was associated with ALT level through an effect on BMI. The association between INSIG2 rs9308762 and ALT level was independent of BMI. The results provided evidence for identifying genetic factors of NAFLD and may be useful for risk assessment and personalized medicine of NAFLD.

INSIG2 variants, dietary patterns and metabolic risk in Samoa

BACKGROUND/OBJECTIVES

Association of insulin-induced gene 2 (INSIG2) variants with obesity has been confirmed in several but not all follow-up studies. Differences in environmental factors across populations may mask some genetic associations and therefore gene-environment interactions should be explored. We hypothesized that the association between dietary patterns and components of the metabolic syndrome could be modified by INSIG2 variants.

SUBJECTS/METHODS

We conducted a longitudinal study of adiposity and cardiovascular disease risk among 427 and 290 adults from Samoa and American Samoa (1990-1995). Principal component analysis on food items from a validated food frequency questionnaire was used to identify neotraditional and modern dietary patterns. We explored gene-dietary pattern interactions with the INSIG2 variants rs9308762 and rs7566605.

RESULTS

Results for American Samoans were mostly nonsignificant. In Samoa, the neotraditional dietary pattern was associated with lower triglycerides, body mass index (BMI), waist circumference, systolic and diastolic blood pressure and fasting glucose (all P-for-trend<0.05). The modern pattern was significantly associated with higher triglycerides, BMI, waist circumference and lower high-density lipoprotein-cholesterol (all P-for-trend<0.05). A significant interaction for triglycerides was found between the modern pattern and the rs9308762 polymorphism (P=0.04). Those from Samoa consuming the modern pattern have higher triglycerides if they are homozygous for the rs9308762 C allele.

CONCLUSIONS

The common INSIG2 variant rs9308762 was associated with poorer metabolic control and a greater sensitivity of trigylcerides to a modern dietary pattern. Environmental factors need to be taken into account when assessing genetic associations across and within populations.

Association of the rs10830963 polymorphism in MTNR1B with fasting glucose levels in Chinese children and adolescents

AIMS

We aimed to identify whether the risk G-allele was associated with fasting glucose level and other pre-diabetic and obesity-related phenotypes in Chinese children and adolescents.

METHODS

The rs10830963 polymorphism in MTNR1B was genotyped in 2,030 Chinese children and adolescents of two independent studies. Association with fasting glucose levels and risk of impaired fasting glucose (IFG) were initially tested. Subsequently we analyzed the association with fasting insulin, homeostasis model assessment for insulin resistance (HOMA-IR) and for beta cell function (HOMA-B), the quantitative insulin sensitivity check index (QUICK) and obesity-related phenotypes (BMI standard deviation score, waist circumference etc.).

RESULTS

The G-allele of rs10830963 was associated with increased fasting glucose level in Chinese children and adolescents (increase of 0.072 mmol/l per G-allele, 95% CI 0.034-0.111, p = 2.46 × 10(-4)). The G-allele was also associated with an increased risk of IFG (OR = 1.21, 95% CI 1.00-1.46, nominal p = 0.048). We found the glucose-raising G-allele was nominally associated with reduced HOMA-B. No association to other pre-diabetic or obesity-related phenotypes was detected.

CONCLUSIONS

The rs10830963 polymorphism in MTNR1B was associated with increased fasting glucose and risk of IFG in Chinese children and adolescents. The effect may result from reduced pancreatic beta cell function, but the mechanism awaits further studies.