NAMPT gene rs2058539 variant is a risk factor for nonalcoholic fatty liver disease.

OBJECTIVE: Nonalcoholic fatty liver disease is a chronic liver disease and a growing global epidemic. The aim of this study was to investigate the association between a visfatin gene (NAMPT) variant and nonalcoholic fatty liver disease, owing to the connection between this disease and insulin resistance, obesity, inflammation, and oxidative stress, and the role of visfatin in these metabolic disorders. METHODS: In the present case-control study, we enrolled 312 genetically unrelated individuals, including 154 patients with biopsy-proven nonalcoholic fatty liver disease and 158 controls. The rs2058539 polymorphism of NAMPT gene was genotyped using the PCR-RFLP method. RESULTS: Genotype and allele distributions of NAMPT gene rs2058539 polymorphism conformed to the Hardy-Weinberg equilibrium both in the case and control groups (p>0.05). The distribution of NAMPT rs2058539 genotypes and alleles differed significantly between the cases with nonalcoholic fatty liver disease and controls. The "CC" genotype of the NAMPT rs2058539 compared with "AA" genotype was associated with a 2.5-fold increased risk of nonalcoholic fatty liver disease after adjustment for confounding factors [p=0.034; odds ratio (OR)=2.52, 95% confidence interval (CI)=1.36-4.37]. Moreover, the NAMPT rs2058539 "C" allele was significantly overrepresented in the nonalcoholic fatty liver disease patients than controls (p=0.022; OR=1.77, 95%CI=1.14-2.31). CONCLUSION: Our findings indicated for the first time that the NAMPT rs2058539 "CC" genotype is a marker of increased nonalcoholic fatty liver disease susceptibility; however, it needs to be supported by further investigations in other populations.

The rs1862513 promoter variant of resistin gene influences susceptibility to nonalcoholic fatty liver disease.

OBJECTIVES: Nonalcoholic fatty liver disease is the term used for a range of conditions in which fat builds up in the liver and exceeds 5% of hepatocytes without inordinate alcohol intake or other causes of lipid accumulation. Regarding the fact that insulin resistance and obesity play key roles in the pathogenesis of nonalcoholic fatty liver disease, as well as the connection between resistin and these metabolic diseases, the association between nonalcoholic fatty liver disease and a resistin gene (RETN) polymorphism was examined. METHODS: In this genetic case-control association study, 150 biopsy-proven nonalcoholic fatty liver disease patients and 154 controls were enrolled and genotyped for the RETN rs1862513 (-420C>G) gene polymorphism using PCR-RFLP method. RESULTS: The -420C>G genotype frequency distributions in both groups were consistent with Hardy-Weinberg equilibrium (HWE; p>0.05). The carriers of the RETN -420C>G "CC" genotype compared with the "GG" genotype occurred less frequently in the cases with nonalcoholic fatty liver disease than in the controls, and the difference remained significant even after adjustment for confounding factors (p=0.030; OR=0.47, 95%CI=0.36-0.93). Interestingly, the RETN -420C>G "C" allele was also associated with a decreased risk for nonalcoholic fatty liver disease too (p=0.042; OR=0.72, 95%CI=0.53-0.95). CONCLUSION: We found for the first time an association between biopsy-proven nonalcoholic fatty liver disease and RETN -420C>G promoter polymorphism. The carriers of the RETN -420C>G "CC" genotype had a 53% decreased risk for nonalcoholic fatty liver disease. Our findings, however, need to be corroborated by further studies.

Insulin-like growth factor binding protein 3 promoter variant (rs2854744) is associated with nonalcoholic fatty liver disease

ABSTRACT Objective: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and a growing global epidemic. In NAFLD, liver fat surpasses 5% of hepatocytes without the secondary causes of lipid accumulation or excessive alcohol consumption. Given the link between NAFLD and insulin resistance, the possible association between the rs2854744 (−202 G>T) promoter polymorphism of insulin-like growth factor binding protein 3 (IGFBP3) gene and NAFLD was investigated in this study. Materials and methods: In this genetic case-control association study, the IGFBP3 rs2854744 genotypes of 315 unrelated individuals, including 156 patients with biopsy-proven NAFLD and 159 controls, were determined using polymerase chain reaction/restriction fragment length polymorphism analyses. Results: The "GT+TT" genotype of the IGFBP3 rs2854744 polymorphism, compared with the "GG" genotype, was associated with a 2.7-fold increased risk of NAFLD after adjustment for confounding factors (P = 0.009; odds ratio [OR] = 2.71; 95% confidence interval [CI] = 1.19-3.18). Additionally, the IGFBP3 rs2854744 "T" allele, in comparison with the "G" allele, was significantly overrepresented in NAFLD patients than the controls (P = 0.008; OR = 1.85; 95%CI = 1.23-2.94). Conclusion: Our findings first indicated that the IGFBP3 rs2854744 "GT+TT" genotype is a marker of increased NAFLD susceptibility; however, it needs to be supported by further investigations in other populations.

The rs1862513 promoter variant of resistin gene influences susceptibility to nonalcoholic fatty liver disease

SUMMARY OBJECTIVES: Nonalcoholic fatty liver disease is the term used for a range of conditions in which fat builds up in the liver and exceeds 5% of hepatocytes without inordinate alcohol intake or other causes of lipid accumulation. Regarding the fact that insulin resistance and obesity play key roles in the pathogenesis of nonalcoholic fatty liver disease, as well as the connection between resistin and these metabolic diseases, the association between nonalcoholic fatty liver disease and a resistin gene (RETN) polymorphism was examined. METHODS: In this genetic case-control association study, 150 biopsy-proven nonalcoholic fatty liver disease patients and 154 controls were enrolled and genotyped for the RETN rs1862513 (-420C>G) gene polymorphism using PCR-RFLP method. RESULTS: The −420C>G genotype frequency distributions in both groups were consistent with Hardy-Weinberg equilibrium (HWE; p>0.05). The carriers of the RETN −420C>G "CC" genotype compared with the "GG" genotype occurred less frequently in the cases with nonalcoholic fatty liver disease than in the controls, and the difference remained significant even after adjustment for confounding factors (p=0.030; OR=0.47, 95%CI=0.36-0.93). Interestingly, the RETN −420C>G "C" allele was also associated with a decreased risk for nonalcoholic fatty liver disease too (p=0.042; OR=0.72, 95%CI=0.53-0.95). CONCLUSION: We found for the first time an association between biopsy-proven nonalcoholic fatty liver disease and RETN −420C>G promoter polymorphism. The carriers of the RETN −420C>G "CC" genotype had a 53% decreased risk for nonalcoholic fatty liver disease. Our findings, however, need to be corroborated by further studies.

NAMPT gene rs2058539 variant is a risk factor for nonalcoholic fatty liver disease

SUMMARY OBJECTIVE: Nonalcoholic fatty liver disease is a chronic liver disease and a growing global epidemic. The aim of this study was to investigate the association between a visfatin gene (NAMPT) variant and nonalcoholic fatty liver disease, owing to the connection between this disease and insulin resistance, obesity, inflammation, and oxidative stress, and the role of visfatin in these metabolic disorders. METHODS: In the present case-control study, we enrolled 312 genetically unrelated individuals, including 154 patients with biopsy-proven nonalcoholic fatty liver disease and 158 controls. The rs2058539 polymorphism of NAMPT gene was genotyped using the PCR-RFLP method. RESULTS: Genotype and allele distributions of NAMPT gene rs2058539 polymorphism conformed to the Hardy-Weinberg equilibrium both in the case and control groups (p>0.05). The distribution of NAMPT rs2058539 genotypes and alleles differed significantly between the cases with nonalcoholic fatty liver disease and controls. The "CC" genotype of the NAMPT rs2058539 compared with "AA" genotype was associated with a 2.5-fold increased risk of nonalcoholic fatty liver disease after adjustment for confounding factors [p=0.034; odds ratio (OR)=2.52, 95% confidence interval (CI)=1.36-4.37]. Moreover, the NAMPT rs2058539 "C" allele was significantly overrepresented in the nonalcoholic fatty liver disease patients than controls (p=0.022; OR=1.77, 95%CI=1.14-2.31). CONCLUSION: Our findings indicated for the first time that the NAMPT rs2058539 "CC" genotype is a marker of increased nonalcoholic fatty liver disease susceptibility; however, it needs to be supported by further investigations in other populations.

Insulin-like growth factor binding protein 3 promoter variant (rs2854744) is associated with nonalcoholic fatty liver disease.

Objective: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and a growing global epidemic. In NAFLD, liver fat surpasses 5% of hepatocytes without the secondary causes of lipid accumulation or excessive alcohol consumption. Given the link between NAFLD and insulin resistance, the possible association between the rs2854744 (-202 G>T) promoter polymorphism of insulin-like growth factor binding protein 3 (IGFBP3) gene and NAFLD was investigated in this study. Materials and methods: In this genetic case-control association study, the IGFBP3 rs2854744 genotypes of 315 unrelated individuals, including 156 patients with biopsy-proven NAFLD and 159 controls, were determined using polymerase chain reaction/restriction fragment length polymorphism analyses. Results: The "GT+TT" genotype of the IGFBP3 rs2854744 polymorphism, compared with the "GG" genotype, was associated with a 2.7-fold increased risk of NAFLD after adjustment for confounding factors (P = 0.009; odds ratio [OR] = 2.71; 95% confidence interval [CI] = 1.19-3.18). Additionally, the IGFBP3 rs2854744 "T" allele, in comparison with the "G" allele, was significantly overrepresented in NAFLD patients than the controls (P = 0.008; OR = 1.85; 95%CI = 1.23-2.94). Conclusion: Our findings first indicated that the IGFBP3 rs2854744 "GT+TT" genotype is a marker of increased NAFLD susceptibility; however, it needs to be supported by further investigations in other populations.

RESISTIN GENE POLYMORPHISM AND NONALCOHOLIC FATTY LIVER DISEASE RISK.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and one of the main global health issues in which liver fat surpasses 5% of hepatocytes without the secondary causes of lipid accumulation or excessive alcohol consumption. Owing to the link between NAFLD and insulin resistance (IR) and obesity and the role of resistin in theses metabolic disorders, we explored the possible association between resistin gene (RETN) variant and NAFLD. METHODS: A total of 308 unrelated subjects, including 152 patients with biopsy-proven NAFLD and 156 controls were enrolled and genotyped for the RETN gene rs3745367 variant using PCR-RFLP method. RESULTS: NAFLD patients had higher liver enzymes, systolic blood pressure (SBP), and diastolic blood pressure (DBP) than the controls (P<0.001). However, we observed no significant difference in genotype and allele frequencies between the cases with NAFLD and the controls for the RETN rs3745367 polymorphism either before or after adjustment for confounding factors including age, BMI, sex, smoking status, SBP, and DBP. CONCLUSION: To our knowledge, this study is the first one that investigated the association between RETN gene rs3745367 variant and biopsy-proven NAFLD. Our findings do not support a role for this gene polymorphism in NAFLD risk in Iranian population; nonetheless, they need to be further investigated in other populations.

Risco de polimorfismo genético resistina e doença hepática gordurosa não alcoólica / Resistin gene polymorphism and nonalcoholic fatty liver disease risk

ABSTRACT Background Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and one of the main global health issues in which liver fat surpasses 5% of hepatocytes without the secondary causes of lipid accumulation or excessive alcohol consumption. Owing to the link between NAFLD and insulin resistance (IR) and obesity and the role of resistin in theses metabolic disorders, we explored the possible association between resistin gene (RETN) variant and NAFLD. Methods A total of 308 unrelated subjects, including 152 patients with biopsy-proven NAFLD and 156 controls were enrolled and genotyped for the RETN gene rs3745367 variant using PCR-RFLP method. Results NAFLD patients had higher liver enzymes, systolic blood pressure (SBP), and diastolic blood pressure (DBP) than the controls (P<0.001). However, we observed no significant difference in genotype and allele frequencies between the cases with NAFLD and the controls for the RETN rs3745367 polymorphism either before or after adjustment for confounding factors including age, BMI, sex, smoking status, SBP, and DBP. Conclusion To our knowledge, this study is the first one that investigated the association between RETN gene rs3745367 variant and biopsy-proven NAFLD. Our findings do not support a role for this gene polymorphism in NAFLD risk in Iranian population; nonetheless, they need to be further investigated in other populations.

RESUMO Contexto: A doença hepática gordurosa não alcoólica (DHGNA) é uma doença hepática crônica e um dos principais problemas de saúde global em que a gordura hepática ultrapassa 5% dos hepatócitos sem as causas secundárias de acúmulo lipídico ou consumo excessivo de álcool. Devido à ligação entre a DHGNA e resistência à insulina (IR) e obesidade e o papel da resistina em distúrbios metabólicos, exploramos a possível associação entre a variante do gene resistina (RETN) e a DHGNA. Metodos Foram selecionados 308 indivíduos não relacionados, incluindo 152 pacientes com DHGNA comprovada por biópsia e 156 controles para a variante do gene RETN rs3745367 usando o método PCR-RFLP. Resultados Pacientes com DHGNA apresentaram enzimas hepáticas mais elevadas, assim como pressão arterial sistólica e pressão arterial diastólica maiores do que os controles (P<0,001). No entanto, não se observou diferença significativa nas frequências genótipo e alelo entre os casos com DHGNA e os controles para o polimorfismo RETN rs3745367 antes ou depois do ajuste para fatores de confusão, incluindo idade, índice de massa corporal, sexo, estado de tabagismo, pressão arterial sistólica e pressão arterial diastólica. Conclusão Para nosso conhecimento, este estudo foi o primeiro que investigou a associação entre a variante do gene RETN rs3745367 e a DHGNA comprovada em biópsia. Nossas descobertas não suportam um papel para este polimorfismo genético no risco DHGNA na população iraniana; no entanto, eles precisam ser mais investigados em outras populações.

CIRCULATING GHRELIN LEVELS AND SUSCEPTIBILITY TO COLORECTAL CÂNCER.

BACKGROUND AND OBJECTIVE: Considering the association between colorectal cancer (CRC) and both insulin resistance and obesity, and the prominent role of ghrelin in these metabolic disorders, we explored whether plasma levels of ghrelin were associated with CRC. Moreover, in the patients with CRC the possible correlations between ghrelin and insulin, insulin resistance, and body mass index (BMI) as an indicator of obesity were examined. METHODS: A total of 170 subjects, including 82 cases with CRC and 88 controls were enrolled in this study. Plasma levels of ghrelin, insulin, and glucose were measured in all the subjects using ELISA and glucose oxidase methods. Furthermore, insulin resistance was assessed by calculating HOMA-IR index. RESULTS: The cases with CRC had decreased ghrelin levels (P<0.001) and a higher HOMA-IR index (P<0.001) than controls. Interestingly, when CRC patients were stratified based on tumor site, lower ghrelin levels and a higher HOMA-IR index were observed in the patients with either colon or rectal cancer vs. controls too. Additionally, there were an age and BMI-independent negative correlation between ghrelin levels and HOMA-IR (r=-0.365, P<0.05), and an age-independent negative correlation between ghrelin levels and BMI (r=-0.335, P<0.05) in the rectal subgroup. CONCLUSION: Our findings support a role for ghrelin in connection with insulin resistance and obesity in CRC susceptibility; however, it needs to be corroborated by further studies.

Níveis de grelina circulante e a suscetibilidade ao câncer colorretal / Circulating ghrelin levels and susceptibility to colorectal câncer

ABSTRACT BACKGROUND AND OBJECTIVE: Considering the association between colorectal cancer (CRC) and both insulin resistance and obesity, and the prominent role of ghrelin in these metabolic disorders, we explored whether plasma levels of ghrelin were associated with CRC. Moreover, in the patients with CRC the possible correlations between ghrelin and insulin, insulin resistance, and body mass index (BMI) as an indicator of obesity were examined. METHODS: A total of 170 subjects, including 82 cases with CRC and 88 controls were enrolled in this study. Plasma levels of ghrelin, insulin, and glucose were measured in all the subjects using ELISA and glucose oxidase methods. Furthermore, insulin resistance was assessed by calculating HOMA-IR index. RESULTS: The cases with CRC had decreased ghrelin levels (P<0.001) and a higher HOMA-IR index (P<0.001) than controls. Interestingly, when CRC patients were stratified based on tumor site, lower ghrelin levels and a higher HOMA-IR index were observed in the patients with either colon or rectal cancer vs. controls too. Additionally, there were an age and BMI-independent negative correlation between ghrelin levels and HOMA-IR (r=-0.365, P<0.05), and an age-independent negative correlation between ghrelin levels and BMI (r=-0.335, P<0.05) in the rectal subgroup. CONCLUSION: Our findings support a role for ghrelin in connection with insulin resistance and obesity in CRC susceptibility; however, it needs to be corroborated by further studies.

RESUMO CONTEXTO E OBJETIVO: Considerando a associação entre câncer colorretal (CCR), a resistência à insulina, à obesidade e o papel proeminente da grelina nessas doenças metabólicas, foi explorado se os níveis plasmáticos de grelina estavam associados ao CCR. Além disso, nos pacientes com CCR foram pesquisadas as possíveis correlações entre a grelina, insulina, resistência insulínica e índice de massa corporal (IMC) como indicadores de obesidade. MÉTODOS: Foram incluídos neste estudo 170 indivíduos, sendo 82 com CRC e 88 controles. Os níveis plasmáticos de grelina, insulina e glicose foram medidos em todos os sujeitos utilizando métodos ELISA e glicose oxidase. Além disso, a resistência à insulina foi avaliada pelo cálculo do índice HOMA-IR. RESULTADOS: Os pacientes com CRC apresentaram redução dos níveis de grelina (P<0,001) e maior índice HOMA-IR (P<0.001) do que os controles. Curiosamente, quando os pacientes com CRC foram estratificados com base no local do tumor, níveis mais baixos de grelina e maior índice de HOMA-IR foram observados nos indivíduos com câncer de cólon ou retal versus controles também. Além disso, houve uma correlação negativa entre idade e IMC independente entre os níveis de grelina e HOMA-IR (r=-0,365, P<0,05) e uma correlação negativa independente da idade entre os níveis de grelina e IMC (r=-0,335, P<0,05) no subgrupo retal. CONCLUSÃO: Nossos achados apoiam o papel da grelina em relação à resistência à insulina e à obesidade na suscetibilidade do CRC; no entanto, ela precisa ser corroborada por estudos posteriores.

INSULIN AND INSULIN RECEPTOR GENE POLYMORPHISMS AND SUSCEPTIBILITY TO NONALCOHOLIC FATTY LIVER DISEASE.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is an increasing global health concern defined by excessive hepatic fat content in the absence of excessive alcohol consumption. OBJECTIVE: Given the pivotal role of insulin resistance in NAFLD, we hypothesized that insulin (INS) and insulin receptor (INSR) gene polymorphisms may be associated with NAFLD risk. METHODS: A total of 312 subjects, including 153 cases with biopsy-proven NAFLD and 159 controls were enrolled in this case-control study. Four polymorphisms in INS (rs3842752, rs689) and INSR (rs1052371, rs1799817) genes were genotyped using PCR-RFLP method. RESULTS: The cases with NAFLD were older and had higher BMI, systolic blood pressure, diastolic blood pressure, as well as higher serum levels of aspartate aminotransferase, alanine aminotransferase, and gamma glutamyl transferase than the controls (P<0.001). The "TT" genotype of INSR rs1799817 compared with "CC" genotype occurred more frequently in the controls than the cases with NAFLD and the difference remained significant after adjustment for confounding factors (P=0.018; OR=0.10, 95%CI=0.02-0.76). However, no significant difference was found for INS rs3842752, INS rs689, and INSR rs1052371 gene polymorphisms between the cases with NAFLD and the controls either before or after adjustment for the confounders. CONCLUSION: These findings corroborate the hypothesis that genetic polymorphisms related to insulin resistance play a role in NAFLD susceptibility. Specifically, the INSR rs1799817 "TT" genotype had a protective effect for NAFLD. However, our results remain to be validated in other studies.

Insulina e polimorfismos do gene do receptor de insulina e a suscetibilidade à doença hepática gordurosa não alcoólica / Insulin and insulin receptor gene polymorphisms and susceptibility to nonalcoholic fatty liver disease

ABSTRACT BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is an increasing global health concern defined by excessive hepatic fat content in the absence of excessive alcohol consumption. OBJECTIVE: Given the pivotal role of insulin resistance in NAFLD, we hypothesized that insulin (INS) and insulin receptor (INSR) gene polymorphisms may be associated with NAFLD risk. METHODS: A total of 312 subjects, including 153 cases with biopsy-proven NAFLD and 159 controls were enrolled in this case-control study. Four polymorphisms in INS (rs3842752, rs689) and INSR (rs1052371, rs1799817) genes were genotyped using PCR-RFLP method. RESULTS: The cases with NAFLD were older and had higher BMI, systolic blood pressure, diastolic blood pressure, as well as higher serum levels of aspartate aminotransferase, alanine aminotransferase, and gamma glutamyl transferase than the controls (P<0.001). The "TT" genotype of INSR rs1799817 compared with "CC" genotype occurred more frequently in the controls than the cases with NAFLD and the difference remained significant after adjustment for confounding factors (P=0.018; OR=0.10, 95%CI=0.02-0.76). However, no significant difference was found for INS rs3842752, INS rs689, and INSR rs1052371 gene polymorphisms between the cases with NAFLD and the controls either before or after adjustment for the confounders. CONCLUSION: These findings corroborate the hypothesis that genetic polymorphisms related to insulin resistance play a role in NAFLD susceptibility. Specifically, the INSR rs1799817 "TT" genotype had a protective effect for NAFLD. However, our results remain to be validated in other studies.

RESUMO CONTEXTO: A doença hepática gordurosa não alcoólica (NAFLD) é uma preocupação global crescente da saúde definida pelo excesso de teor de gordura hepática na ausência de consumo excessivo de álcool. OBJETIVO: Dado o papel crucial da resistência à insulina no NAFLD, criou-se a hipótese de que os polimorfismos genéticos da insulina (INS) e do receptor de insulina (INSR) podem estar associados ao risco de NAFLD. MÉTODOS: Um total de 312 indivíduos, incluindo 153 casos com NAFLD comprovado por biópsia e 159 controles foram inscritos neste estudo de caso-controle. Quatro polimorfismos em genes INS (rs3842752, rs689) e INSR (rs1052371, rs1799817) foram genotipados utilizando o método PCR-RFLP. RESULTADOS: Os casos com NAFLD foram mais idosos e apresentaram maior IMC, pressão arterial sistólica, pressão arterial diastólica, bem como níveis séricos mais elevados de aspartato aminotransferase, de alanina aminotransferase e de gama glutamil transpeptidase do que os controles (P<0,001). O genótipo "TT" de INSR rs1799817 em comparação com o genótipo "CC" ocorreu com mais frequência nos controles do que os casos com NAFLD e a diferença permaneceu significativa após ajuste para fatores de confusão (P=0,018; OR=0,10, IC95%=0,02-0,76). No entanto, não foi encontrada diferença significativa para INS rs3842752, INS rs689 e INSR rs1052371 polimorfismos genéticos entre os casos com NAFLD e os controles antes ou depois do ajuste para os fatores de confusão. CONCLUSÃO: Esses achados corroboram a hipótese de que os polimorfismos genéticos relacionados à resistência à insulina desempenham um papel na suscetibilidade do NAFLD. Especificamente, o genótipo INSR rs1799817 "TT" teve um efeito protetor para o NAFLD. No entanto, nossos resultados necessitam ser validados em outros estudos.