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.