Adiposity factors are not related to the presence of colorectal adenomas

The role of BMI, serum lipid profile molecules and their derivative indexes in colorectal polyps

Objectives

To investigate the role of body mass index (BMI), serum lipid profile molecules and their derivative indexes in colorectal polyps.

Methods

A total of 352 individuals who underwent colonoscopy at our center were included in this retrospective analysis. Of these, 247 patients without evident abnormalities (control group), while 105 patients diagnosed with colorectal polyps (patient group). Serum lipid profile molecules and their derivative indexes were then compared between the two groups.

Results

The patient group exhibited significantly higher levels of total cholesterol (TC) and apolipoprotein B (ApoB) compared to the control group (p<0.05). In males, the patient group displayed elevated levels of ApoB and ApoB/ApoA1 ratio compared to the control group (p<0.05). Additionally, the triglycerides (TG) and TG/high-density lipoprotein-cholesterol (HDL-C) ratios were significantly higher in the multiple polyps group than in the single polyp group (p<0.05). Furthermore, the HDL-C and HDL-C/ApoA1 ratio levels were higher in the adenomatous polyp group when compared to the non-adenomatous polyp group (p<0.05). Multiple logistic regression analysis indicated that total cholesterol (TC), TG, low-density lipoprotein-cholesterol (LDL-C), TC/HDL-C ratio, TG/HDL-C ratio and LDL-C/HDL-C ratio were risk factors for the occurrence of colorectal polyps (p<0.05). ROC curve analyses revealed that TC, ApoB, and ApoB/ApoA1 ratio were associated with colorectal polyps. No significant difference in BMI between the two groups (p>0.05).

Conclusions

The incidence and progression of colorectal polyps are linked to serum lipid molecules and their derivative indexes. Dyslipidemia may increase the risk of colorectal polyps, potentially leading to colorectal cancer (CRC).

El papel del IMC, las moléculas del perfil lipídico sérico y sus índices derivados en los pólipos colorrectales

Objetivos

Investigar el papel del IMC, las moléculas del perfil lipídico en suero y los cocientes lipoproteicos en los pólipos colorrectales.

Métodos

En un análisis retrospectivo, se incluyó a 352 sujetos sometidos a una colonoscopia en nuestro centro, de los cuales 247 no mostraron ninguna alteración evidente (grupo control), mientras que 105 recibieron un diagnóstico de uno o múltiples pólipos (grupo de pacientes). Se compararon las moléculas del perfil lipídico sérico y los cocientes lipoproteicos de los dos grupos.

Resultados

El grupo de pacientes mostró niveles significativamente mayores de colesterol total (CT) y apolipoproteína B (ApoB) que el grupo de control (p<0,05). Entre los hombres, el grupo de pacientes mostró niveles de ApoB y una relación ApoB/ApoA1 superiores a los del grupo de control (p<0,05). Así mismo, los niveles de triglicéridos (TG) y la relación TG/C-HDL (colesterol de lipoproteínas de alta densidad) fueron significativamente más elevados en el grupo de pólipos múltiples que en el de un solo pólipo (p<0,05). Además, los niveles de C-HDL y la relación C-HDL/ApoA1 fueron más altos en el grupo con pólipos adenomatosos que en el de no adenomatosos (p<0,05). El análisis de regresión logística múltiple identificó al CT, TG, LDL-C y a los cocientes CT/C-HDL, TG/C-HDL y C-LDL/C-HDL como factores de riesgo para el desarrollo de pólipos colorrectales (p<0,05). Los análisis de la curva ROC revelaron una asociación entre el CT, la ApoB, y la relación ApoB/ApoA1 y los pólipos colorrectales. Por otro lado, no se observaron diferencias estadísticamente significativas en el IMC entre los dos grupos (p>0,05).

Conclusiones

La incidencia y evolución de los pólipos colorrectales están relacionados con las moléculas del perfil lipídico en suero y los cocientes lipoproteicos de las mismas. La dislipidemia podría incrementar el riesgo de desarrollar pólipos colorrectales, pudiendo derivar posteriormente en el desarrollo de cáncer colorrectal (CRC).

Systemic adiponectin levels in colorectal cancer and adenoma: a systematic review and meta-analysis

BACKGROUND

Obesity is a well-established risk factor in the development of colorectal cancer; however, the mechanism mediating this relationship is not well understood. The adipokine, adiponectin, has an inverse relationship with obesity. Experimental studies have shown adiponectin to have dichotomous inflammatory and tumorigenic roles. Its role in the development of colorectal cancer, including the potential effect of its increase following bariatric surgery, is not yet clear. There are conflicting results from studies evaluating this relationship. This study sought to provide a systematic review and meta-analysis to examine the association between systemic adiponectin levels in patients with colorectal cancer and adenoma.

METHODS

An electronic literature search was performed using PubMed, EMBASE, Web of Science as well as gray literature. Articles were screened for inclusion criteria and assessed for quality using the Newcastle-Ottawa Scale. Pooled mean differences were calculated using a random effects model. Subgroup and meta-regression analyses were performed to identify potential sources of heterogeneity.

RESULTS

Thirty-two observational studies comparing systemic adiponectin in colorectal cancer vs healthy controls were included. Colorectal cancer cases had lower systemic adiponectin levels (overall pooled mean difference = -1.05 μg/ml [95% CI: -1.99; -0.12] p = 0.03); however, significant heterogeneity was present (I2 = 95% p < 0.01). Subgroup and meta- regression analyses results could not identify a source of the significant heterogeneity across the studies.

CONCLUSIONS

Studies suggest a trend towards lower systemic adiponectin levels in colorectal cancer patients, but the heterogeneity observed showed current evidence is not sufficient to definitively draw any conclusions. These data, however, suggest rising adiponectin is unlikely to account for the reported observation of increased CRC following bariatric surgery. Further studies with prospective age, race, and BMI-matched cohorts, and standardized adiponectin measurements may provide a better understanding of this relationship.

Low circulating total adiponectin, especially its non-high-molecular weight fraction, represents a promising risk factor for colorectal cancer: a meta-analysis

Aim

The principal goal of this meta-analysis is to test the hypothesis that circulating total adiponectin or certain fractions may represent a promising biological candidate in modulating the risk of colorectal cancer.

Methods

The processes of paper identification, paper selection and data extraction were accomplished independently by two authors. Effect-size estimates were expressed as weighted mean difference (WMD) and 95% confidence interval (95% CI). A total of 31 papers including 48 qualified studies (7,554 patients with colorectal cancer and 9,798 controls) were meta-analyzed.

Results

Pooling all studies found that circulating total adiponectin was significantly lower in patients with colorectal cancer than in controls (WMD: −0.76 µg/mL, 95% CI: −1.20 to −0.32, p=0.001), with significant heterogeneity (I²: 94.2%) and low publication bias (Egger’s p=0.336). By adiponectin fractions, the difference in high-molecular weight (HMW) adiponectin was comparable between the two groups (WMD: −0.22 µg/mL, 95% CI: −0.70 to 0.25, p=0.350), while non-HMW adiponectin was significantly lower in patients with colorectal cancer than in controls (WMD: −0.27 µg/mL, 95% CI: −0.35 to −0.19, p<0.001), with marginal heterogeneity (I²: 52.3%). Subgroup analysis revealed that effect-size estimates were heterogeneous when grouping studies by cancer subtype, region, study design, matching status, gender and obesity. Further meta-regression analysis indicated that age and gender were significant potential sources of heterogeneity. The results showed the studied subgroups were not subject to publication bias (Egger’s p<0.1).

Conclusion

Our data collectively indicate that low circulating total adiponectin, especially its non-HMW fraction, represents a promising risk factor for colorectal cancer. Further studies are needed to explore underlying mechanisms.

Circulating levels of C-reactive protein, interleukin-6 and tumor necrosis factor-α and risk of colorectal adenomas: a meta-analysis

Results from publications on inflammatory markers of C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and risk of colorectal adenomas are not consistent. A meta-analysis was conducted to explore the above-mentioned associations. Relevant studies were identified by a search of Embase, Medline and PubMed through February 2016. A random effect model was adopted to combine study-specific odds ratio (OR) and 95% confidence interval (95% CI). Between-study heterogeneity and publications bias were assessed. Dose-response relationships were assessed by restricted cubic splines. Nineteen observational studies were included. For highest vs. lowest levels, results from this meta-analysis did not support an association between circulating levels of CRP [OR (95% CI): 1.15 (0.94-1.40)], IL-6 [1.17 (0.94-1.46)] and TNF-α [0.99 (0.75-1.31)] and risk of colorectal adenomas, respectively. The findings were supported by sensitivity analysis and subgroup analysis. In dose-response analysis, the risk of colorectal adenomas increased by 2% [1.02 (0.97-1.08)] for each 1 mg/L increment in circulation CRP levels, 9% [1.09 (0.91-1.31)] for each 1 ng/L increment in circulation IL-6 levels, and 6% [1.06 (0.93-1.21)] for each 1 pg/mL increment in circulation TNF-α levels. Moderate between-study heterogeneity was found. No evidence of publication bias was found. Circulation levels of CRP, IL-6 and TNF-α might be not useful biomarkers for identifying colorectal adenomas, respectively.

Changed adipocytokine concentrations in colorectal tumor patients and morbidly obese patients compared to healthy controls

BACKGROUND

Obesity has been associated with increased incidence of colorectal cancer. Adipose tissue dysfunction accompanied with alterations in the release of adipocytokines has been proposed to contribute to cancer pathogenesis and progression. The aim of this study was to analyze plasma concentrations of several adipose tissue expressed hormones in colorectal cancer patients (CRC) and morbidly obese (MO) patients and to compare these concentrations to clinicopathological parameters.

METHODS

Plasma concentrations of adiponectin, resistin, leptin, active plasminogen activator inhibitor (PAI)-1, monocyte chemotactic protein (MCP)-1, interleukin (IL)-1 alpha, and tumor necrosis factor (TNF)-alpha were determined in 67 patients operated on for CRC (31 rectal cancers, 36 colon cancers), 37 patients operated on for morbid obesity and 60 healthy blood donors (BD).

RESULTS

Compared to BD, leptin concentrations were lowered in CRC patients whereas those of MO patients were elevated. Adiponectin concentrations were only lowered in MO patients. Concentrations of MCP-1, PAI-1, and IL-1 alpha were elevated in both CRC and MO patients, while resistin and TNF-alpha were similarly expressed in MO and CRC patients compared to BD. Resistin concentrations positively correlated with tumor staging (p<0.002) and grading (p=0.015) of rectal tumor patients.

CONCLUSIONS

The results suggest that both MO and CRC have low-grade inflammation as part of their etiology.