A Linear Dose-Response Relationship between Fasting Plasma Glucose and Colorectal Cancer Risk: Systematic Review and Meta-analysis

Global burden of colorectal cancer attributable to metabolic risks from 1990 to 2021, with projections of mortality to 2035

BACKGROUND

The global burden of colorectal cancer (CRC) attributable to metabolic risk factors is increasing. It is crucial to analyze the global epidemiological patterns of CRC attributable to metabolic risk factors and predict future trends.

METHODS

Detailed data on CRC mortality and disability-adjusted life years (DALYs) attributable to metabolic risk factors were extracted for this study using data from the Global Burden of Diseases (GBD) 2021 study to assess the burden of CRC from 1990 to 2021 by global, regional, national, and sociodemographic index (SDI) regions and quantify the time trend using the estimated annual percentage change (EAPC). Bayesian age-period-cohort (BAPC) models projected the global mortality from 2022 to 2035.

RESULTS

The global number of CRC deaths due to metabolic risk factors increased from 70,916 in 1990 to 172,993 in 2021, a 2.4-fold increase. CRC mortality and DALYs attributable to high body mass index (BMI) and fasting plasma glucose (FPG) increased significantly at the global level from 1990 to 2021. In 2021, the GBD regions with the highest CRC age-standardized mortality rate (ASMR) due to high BMI and high FPG were in Central Europe. The ASMR of CRC attributable to high BMI and high FPG among males is expected to increase from 2022 to 2035.

CONCLUSION

CRC mortality and DALYs attributable to metabolic factors are increasing. Reducing the burden of CRC due to high BMI and FPG levels is critically needed.

Global disease burden of breast cancer attributable to high fasting plasma glucose: a comprehensive analysis from the global burden of disease study

Background

High fasting plasma glucose (HFPG) has been identified as one of the risk factors associated with the development of breast cancer. The worldwide distribution of breast cancer attributable to HFPG was not comprehensively investigated.

Methods

We utilized the data from the Global Burden of Disease Study 2021 to explore HFPG-related breast cancer deaths, disability adjusted life years (DALYs) and corresponding age-standardized rates (ASRs). The average annual percentage change (AAPC) and the estimated annual percentage change (EAPC) were employed to evaluate the temporal trend.

Results

The global effect of HFPG resulted in nearly 30,570 breast cancer deaths and 819,550 DALYs in 2021, representing an age-standardized deaths rate (ASMR) of 0.66 (95% UI -0.19-1.57) and an age-standardized DALYs rate (ASDR) of 18.05 (95% UI -5.31-42.71). In the regions with low, low-middle, and middle SDI, the ASRs of HFPG-related breast cancer increased significantly over time. The highest ASMR and ASDR were observed in several countries, such as Palau, American Samoa, Cook Islands, Marshall Islands, and United Arab Emirates. There was a positive correlation between ASRs and Socio-Demographic Index (SDI) in countries where SDI was below 0.75. The escalation in death and DALYs was primarily driven by epidemiological change and population growth in low, low-middle, middle SDI regions.

Conclusions

Substantial disparities exist across diverse regions in breast cancer burden attributed to HFPG. It is urgent to regulate glycemic levels, improve healthcare infrastructures, and provide cost-effective care in less developed and developing countries that endure a disproportionately heavier health burden.

Associations between blood glucose and early- and late-onset colorectal cancer: evidence from two prospective cohorts and Mendelian randomization analyses

Background

The incidence of early-onset colorectal cancer (EOCRC), which exhibits differential clinical, pathological, and molecular features compared to late-onset CRC (LOCRC), is rising globally. The potential differential effects of blood glucose on EOCRC compared to LOCRC have not been investigated.

Methods

This study analyzed 374,568 participants from the UK Biobank cohort and 172,809 participants from the Kailuan cohort. The linear associations between blood glucose and EOCRC/LOCRC were estimated using Cox regression models. Restricted cubic spline (RCS) analysis and non-linear Mendelian randomization (MR) analysis using a 70-SNPs genetic instrument for fasting glucose were used to explore the potential non-linear associations.

Results

Participants in the highest quintile of blood glucose had higher overall CRC risk compared to the lowest quintile (HR = 1.10 in the UK Biobank cohort, 95% CI: 1.01-1.21, P-trend = 0.012; HR = 1.23 in the Kailuan cohort, 95% CI: 1.01-1.51, P-trend = 0.036). Elevated glucose (>7.0 mmol/L) was more strongly associated with increased risk of EOCRC (HR = 1.61, 95% CI: 1.07-2.44) than with LOCRC (HR = 1.14, 95% CI: 1.02-1.27) in the UK Biobank cohort (P-heterogeneity = 0.014). Elevated glucose (>7.0 mmol/L) was associated with increased risk of LOCRC (HR = 1.25, 95% CI: 1.04-1.65) in the Kailuan cohort as well. There was no evidence for non-linear associations between blood glucose and risks of EOCRC/LOCRC.

Conclusions

This study showed a positive association between blood glucose and CRC risk in a dose-response manner, particularly for EOCRC, suggesting that tighter glucose control should be a priority for younger age groups.

Association between glucose levels and all-cause mortality in cancer survivors: findings from NHANES 1999-2018

BACKGROUND

Hyperglycemia is a rapidly increasing risk factor for cancer mortality worldwide. However, the dose‒response relationship between glucose levels and all-cause mortality in cancer survivors is still uncertain.

METHODS

We enrolled 4,491 cancer survivors (weighted population 19,465,739) from the 1999-2019 National Health and Nutrition Examination Survey (NHANES). Cancer survivors were defined based on the question of whether they had ever been diagnosed with cancer by a doctor or a health professional. Hemoglobin A1c (HbA1c) was selected in this study as a stable marker of glucose level. Mortality was ascertained by linkage to National Death Index records until December 31, 2019. Cox proportional hazard, Kaplan‒Meier survival curves and Restricted cubic spline regression models were used to evaluate the associations between HbA1c and all-cause mortality risk in cancer survivors.

RESULTS

In NHANES, after adjusting for confounders, HbA1c had an independent nonlinear association with increased all-cause mortality in cancer survivors (nonlinear P value < 0.05). The threshold value for HbA1c was 5.4%, and the HRs (95% CI) below and above the threshold value were 0.917 (0.856,0.983) and 1.026 (1.010,1.043), respectively. Similar associations were found between fasting glucose and all-cause mortality in cancer survivors, and the threshold value was 5.7 mmol/L.

CONCLUSIONS

HbA1c was nonlinearly associated with all-cause mortality in cancer survivors, and the critical value of HbA1c in decreased mortality was 5.4%, suggesting optimal glucose management in cancer survivors may be a key to preventing premature death in cancer survivors.

Metabolomic landscape of overall and common cancers in the UK Biobank: A prospective cohort study

Information about the NMR metabolomics landscape of overall, and common cancers is still limited. Based on a cohort of 83,290 participants from the UK Biobank, we used multivariate Cox regression to assess the associations between each of the 168 metabolites with the risks of overall cancer and 20 specific types of cancer. Then, we applied LASSO to identify important metabolites for overall cancer risk and obtained their associations using multivariate cox regression. We further conducted mediation analysis to evaluate the mediated role of metabolites in the effects of traditional factors on overall cancer risk. Finally, we included the 13 identified metabolites as predictors in prediction models, and compared the accuracies of our traditional models. We found that there were commonalities among the metabolic profiles of overall and specific types of cancer: the top 20 frequently identified metabolites for 20 specific types of cancer were all associated with overall cancer; most of the specific types of cancer had common identified metabolites. Meanwhile, the associations between the same metabolite with different types of cancer can vary based on the site of origin. We identified 13 metabolic biomarkers associated with overall cancer, and found that they mediated the effects of traditional factors. The accuracies of prediction models improved when we added 13 identified metabolites in models. This study is helpful to understand the metabolic mechanisms of overall and a wide range of cancers, and our results also indicate that NMR metabolites are potential biomarkers in cancer diagnosis and prevention.

Metabolic Alteration Bridging the Prediabetic State and Colorectal Cancer

Prediabetes and colorectal cancer (CRC) represent compelling health burdens responsible for high mortality and morbidity rates, sharing several modifiable risk factors. It has been hypothesized that metabolic abnormalities linking prediabetes and CRC are hyperglycemia, hyperinsulinemia, and adipokines imbalance. The chronic stimulation related to these metabolic signatures can favor CRC onset and development, as well as negatively influence CRC prognosis. To date, the growing burden of prediabetes and CRC has generated a global interest in defining their epidemiological and molecular relationships. Therefore, a deeper knowledge of the metabolic impairment determinants is compelling to identify the pathological mechanisms promoting the onset of prediabetes and CRC. In this scenario, this review aims to provide a comprehensive overview on the metabolic alterations of prediabetes and CRC as well as an overview of recent preventive and therapeutic approaches for both diseases, focusing on the role of the metabolic state as a pivotal contributor to consider for the development of future preventive and therapeutic strategies.

Cancer risk according to fasting blood glucose trajectories: a population-based cohort study

INTRODUCTION

Diabetes mellitus is known to increase the risk of cancer. Fasting blood glucose (FBG) levels can be changed over time. However, the association between FBG trajectory and cancer risk has been insufficiently studied. This research aims to examine the relationship between FBG trajectories and cancer risk in the Korean population.

RESEARCH DESIGN AND METHODS

We analyzed data from the National Health Insurance Service-National Health Screening Cohort collected between 2002 and 2015. Group-based trajectory modeling was performed on 256,271 Koreans aged 40-79 years who had participated in health examinations at least three times from 2002 to 2007. After excluding patients with cancer history before 2008, we constructed a cancer-free cohort. The Cox proportional hazards model was applied to examine the association between FBG trajectories and cancer incidence by cancer type, after adjustments for covariates. Cancer case was defined as a person who was an outpatient thrice or was hospitalized once or more with a cancer diagnosis code within the first year of the claim.

RESULTS

During the follow-up time (2008-2015), 18,991 cancer cases were identified. Four glucose trajectories were found: low-stable (mean of FBG at each wave <100 mg/dL), elevated-stable (113-124 mg/dL), elevated-high (104-166 mg/dL), and high-stable (>177 mg/dL). The high-stable group had a higher risk of multiple myeloma, liver cancer and gastrointestinal cancer than the low-stable group, with HR 4.09 (95% CI 1.40 to 11.95), HR 1.68 (95% CI 1.25 to 2.26) and HR 1.27 (95% CI 1.11 to 1.45), respectively. In elevated-stable trajectory, the risk increased for all cancer (HR 1.08, 95% CI 1.02 to 1.16) and stomach cancer (HR 1.24, 95% CI 1.07 to 1.43). Significant associations were also found in the elevated-high group with oral (HR 2.13, 95% CI 1.01 to 4.47), liver (HR 1.50, 95% CI 1.08 to 2.08) and pancreatic cancer (HR 1.99, 95% CI 1.20 to 3.30).

CONCLUSIONS

Our study highlights that the uncontrolled high glucose level for many years may increase the risk of cancer.

Lifetime occupational and recreational physical activity and risk of lymphoma subtypes. Results from the European Epilymph case-control study

Physical activity is known to convey protection against several cancers. However, results on the risk of lymphoma overall and its subtypes have been inconsistent. The aim of this study was to investigate occupational and recreational physical activity in relation to risk of lymphoma subtypes adjusting for established occupational risk factors. We applied standardized tools to assess energy expenditure at work and in recreational physical activities to the questionnaire information on lifetime work and exercise history in 1117 lymphoma cases, including Hodgkin lymphoma, and B-cell (including chronic lymphocytic leukemia, and multiple myeloma) and T-cell non-Hodgkin's lymphoma (NHL) subtypes, and 1207 controls who took part in the multicentre European EpiLymph case-control study. We calculated the risk of lymphoma (all subtypes), B-cell NHL and its most represented subtypes, and Hodgkin's lymphoma (all subtypes) associated with weekly average Metabolic Equivalent of Task (MET-hours/week) and cumulative MET-hours of lifetime recreational, occupational, and total physical activity, with unconditional logistic regression and polytomous regression analysis adjusting by age, centre, sex, education, body mass index, history of farm work and solvent use. We observed an inverse association of occupational, and total physical activity with risk of lymphoma (all subtypes), and B-cell non-Hodgkin's lymphoma among women, and an upward trend in risk of Hodgkin's lymphoma with recreational and total physical activity among men, for which we cannot exclude chance or bias. Our results suggest no effect of overall physical activity on risk of lymphoma and its subtypes.

Epigenetic changes underlie the association between diabetes mellitus and oral diseases

Patients with diabetes mellitus (DM) suffer from oral complications related to oral infections, periodontal diseases, and endodontic lesions. Emerging evidence has revealed the contribution of the epigenetic process as the underlying mechanism of DM complications. DNA methylation, histone modifications, and non-coding RNAs are epigenetic regulators that directly affect gene expression. The present review elaborated on the role of epigenetic dysregulation in the etiology of diabetes-related periodontal and endodontic diseases. The narrative review study was prepared using databases such as PubMed, Google Scholar, Science Direct, and Scopus. The formation of glycation products as a result of hyperglycemic condition increases oxidative stress, and elevates chronic inflammatory mediators that could in turn adversely change the cellular environment and alter the epigenetic status. This process contributes to the alteration of regulatory genes expression, leading to the development of diabetes-induced bone complications and impaired odontogenic capacity of pulp. Indeed, epigenetic mechanisms mediate the interaction between gene expression and DM cellular environment. Further investigations on epigenetic factors involved in DM oral complications may provide novel therapeutic targets.

Global, regional, and national time trends in cancer mortality attributable to high fasting plasma glucose: an age-period cohort analysis

BACKGROUND

High fasting plasma glucose (HFPG) is the fastest-growing risk factor for cancer deaths worldwide. We reported the cancer mortality attributable to HFPG at global, regional, and national levels over the past three decades and associations with age, period, and birth cohort.

METHODS

Data for this study were retrieved from the Global Burden of Disease Study 2019, and we used age-period-cohort modelling to estimate age, cohort and period effects, as well as net drift (overall annual percentage change) and local drift (annual percentage change in each age group).

RESULTS

Over the past 30 years, the global age-standardized mortality rate (ASMR) attributable to HFPG has increased by 27.8%. The ASMR in 2019 was highest in the male population in high sociodemographic index (SDI) areas (8.70; 95% CI, 2.23-18.04). The net drift for mortality was highest in the female population in low SDI areas (2.33; 95% CI, 2.12-2.55). Unfavourable period and cohort effects were found across all SDI quintiles. Cancer subtypes such as "trachea, bronchus, and lung cancers", "colon and rectal cancers", "breast cancer" and "pancreatic cancer" exhibited similar trends.

CONCLUSIONS

The cancer mortality attributable to HFPG has surged during the past three decades. Unfavourable age-period-cohort effects on mortality were observed across all SDI quintiles, and the cancer mortality attributable to HFPG is expected to continue to increase rapidly in the future, particularly in lower SDI locations. This is a grim global public health issue that requires immediate attention.

Anti-tumor effects of anti-programmed cell death-1 antibody treatment are attenuated in streptozotocin-induced diabetic mice

Hyperglycemia impairs immune response; however, it remains unknown whether the anti-tumor effects of anti-programmed cell death-1 antibody (PD-1-Ab) treatment are changed in hyperglycemic conditions. We analyzed the effect of PD-1-Ab on tumor growth in streptozotocin-induced diabetic mice (STZ-mice) subcutaneously inoculated with MC38 (a colon carcinoma cell line). Furthermore, we assessed the expression of chemokines by polymerase chain reaction (PCR) array in tumor-draining lymph nodes (dLNs) of these mice and MC38 cells cultured in different glucose concentrations. The suppressive effect of PD-1-Ab on tumor growth was attenuated. This was accompanied by fewer tumor-infiltrating CD8⁺ T cells, and STZ-mice had fewer tumor-infiltrating CD11c⁺ dendritic cells (DCs) than normoglycemic mice. mRNA expression levels of CXCL9, a chemokine recruiting CD8⁺ T cells, were lower in dLNs of STZ-mice than in normoglycemic mice after PD-1-Ab treatment, and its protein was expressed in DCs. In MC38 cells cultured with 25 mM glucose, mRNA expression of CCL7, a chemokine recruiting DCs, was decreased compared to cells cultured with 5 mM glucose. These results suggest that the STZ-induced hyperglycemia impairs the effect of PD-1-Ab treatment on MC38 tumor growth, and is accompanied by reduced infiltration of DCs and CD8⁺ T cells and decreased expression of CCL7 and CXCL9.

The global burden of colorectal cancer attributable to high plasma glucose in 204 countries and territories, 1990-2019: an analysis of the Global Burden of Disease Study

OBJECTIVES

This study aimed to estimate the burden of colorectal cancer (CRC) attributable to high plasma glucose from 1990 to 2019.

STUDY DESIGN AND METHODS

Data on the disease burden were retrieved from the Global Burden of Disease online database. Estimated average percentage change (EAPC) was used to quantify the age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life years (DALYs) rate (ASDR) of high plasma glucose-related CRC trends by sex and location between 1990 and 2019.

RESULTS

Globally, the death number and DALYs of CRC attributable to high plasma glucose remained a steady increase at global level from 1990 to 2019, and similar trends have been reported in age-standardized rate. The country with the largest number of death cases and DALYs of high plasma glucose-related CRC in 2019 was China, followed by the United States of America and India. Nearly three-quarters of total countries experienced an increase in the ASMR and ASDR, and the greatest increase of ASMR and ASDR was found in Uzbekistan (EAPC = 5.32) and Equatorial Guinea (EAPC = 4.65), respectively. A negative correlation was found between sociodemographic indices and the EAPC of ASMR and ASDR (r_ASMR = -0.259, p < 0.001; r_ASDR = -0.282, p < 0.001).

CONCLUSIONS

A significant increase in mortality and DALYs of CRC attributable to high plasma glucose was observed in global and most countries, especially in the developing countries. Public health policies and targeted programs are needed to reduce the burden of disease.

The prognostic role of fasting plasma glucose levels on survival in advanced colorectal cancer patients with type II diabetes mellitus: a retrospective cohort study

Background

Previous studies have shown that type II diabetes mellitus (T2DM) has a significant effect on the occurrence and development of colorectal cancer (CRC). The associations between fasting plasma glucose (FPG) and overall survival (OS) of CRC patients with T2DM are still controversial. The present study sought to examine the association between FPG control and OS in advanced CRC patients with T2DM.

Methods

The data of advanced CRC patients with T2DM who were admitted to Harbin Medical University Cancer Hospital from May 2010 to May 2019 were retrospectively collected and examined. Record patient clinical data including age, sex, blood pressure, body mass index (BMI), primary tumor site, T stage, N stage, histological grade, number of metastatic sites, primary tumor surgery, etc. The baseline FPG which was measured before the first-line treatment and the FPG measured before each admission treatment during advanced chemotherapy were collected. OS was determined as the end point of the study. All the patients were followed-up for at least 3 years. The Kaplan-Meier log-rank method and the Cox proportional hazards regression analyses were used for the analysis of OS and hazard factors.

Results

A total of 210 patients met the inclusion criteria for the study, who had a median age of 66.5 years; 94 patients had baseline FPG levels ≤7 mmol/L, and 116 patients had baseline FPG levels >7 mmol/L. Compared to the baseline FPG >7 mmol/L group, the OS of patients in the baseline FPG ≤7 mmol/L group was not significantly prolonged (P=0.88). There were 52 patients in the FPG-A group and 61 in the FPG-B group. Similarly, there was no significant difference in OS between the FPG-A and FPG-B groups (P=0.96). The N0 stage subgroup analysis showed that glycemic control ≤7 mmol/L resulted in longer OS.

Conclusions

The results of the present study showed that FPG levels may not affect the survival of advanced CRC patients with T2DM. However, this needs multicenter prospective studies to confirm.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Effect of diabetes mellitus comorbidity on outcomes in stages II and III colorectal cancer

AIM

The effects of diabetes mellitus (DM) on the outcomes of colorectal cancer (CRC) are controversial. This retrospective study evaluated the effects of DM on American Joint Committee on Cancer (AJCC, 7th) Stages II and III CRC patients who received curative surgery.

METHODS

We reviewed the records of CRC patients who were treated from January 2008 to December 2014 and identified the presence of DM and hypertension prior to CRC diagnosis. Cox proportional hazards analyses were used for prognostic factor determination, and survival was analyzed using the Kaplan-Meier method with the log-rank test.

RESULTS

Total of 1066 consecutive eligible patients with stage II/III CRC were enrolled. There were 326 (30.6%) patients diagnosed with DM, and 311 (29.2%) CRC patients had recurrence. Patients with DM did not have a higher recurrence risk (p = 0.183) but had higher mortality (adjusted hazard ratio [aHR] = 1.381; 95% conference interval [CI], 1.069-1.782). In addition, HbA1c (≥7 vs. <7) was not associated with recurrence (p = 0.365). Patients with DM had more hypertension than patients without DM (69.1% vs. 37.6%, p < 0.001). A lower recurrence risk was noted in patients with hypertension (p = 0.002), but the overall survival (OS) did not reach statistical significance (aHR = 0.910; 95% CI, 0.707-1.169).

CONCLUSION

In our study, DM was a poor prognostic factor for survival in curative CRC patients. More studies are required to elucidate the effects that DM and other metabolic disorders, such as hypertension, have on the prognosis of patients with CRC.

Global, Regional and National Burden of Cancers Attributable to High Fasting Plasma Glucose in 204 Countries and Territories, 1990-2019

Background

To report the burden of cancers attributable to high fasting plasma glucose (HFPG) by sex, age, location, cancer type and Socio-demographic Index (SDI) over the period 1990 to 2019 for 204 countries and territories.

Methods

Using the Comparative Risk Assessment approach of Global Burden of Disease (GBD) study 2019, the burden of cancers attributable to HFPG was reported in 1990 and 2019.

Results

Globally, in 2019 there were an estimated 419.3 thousand cancer deaths (95% UI: 115.7 to 848.5) and 8.6 million cancer DALYs (2.4 to 17.6) attributable to HFPG. By sex, 4.6 (1.1 to 9.9) and 4.0 (1.1 to 8.4) million global cancer DALYs were attributable to HFPG in men and women, respectively. The global age-standardized death and DALY rates of cancers attributable to HFPG (per 100,000) have increased by 27.8% (20.5 to 38.7%) and 24.5% (16.4 to 35.6%), respectively, since 1990. High-income North America (9.5 [2.7 to 18.8]) and Eastern Sub-Saharan Africa (2.0 [0.5 to 4.2]) had the highest and lowest regional age-standardized death rates, respectively, for cancers attributable to HFPG. In 2019, the global number of attributable cancer DALYs were highest in 65-69 age group. Moreover, there was an overall positive association between SDI and the regional age-standardized DALY rate for HFPG-attributable cancers.

Conclusions

HFPG was associated with more burden in 2019. Preventive programs for diabetes and screening of individuals with diabetes for cancers, especially in older males living in developed countries, are required to arrest the large increases in HFPG-attributable cancers.

Association of Visit-to-Visit Variability in Fasting Plasma Glucose with Digestive Cancer Risk

BACKGROUND AND AIMS

The aim of this study is to investigate the association between visit-to-visit variability in fasting plasma glucose (FPG) and the risk of digestive cancers among individuals with and without diabetes.

METHODS

Using data from Kailuan cohort, a prospective population-based study, individuals who had at least two measurements of FPG between 2006 and 2012 without prior cancer were included in this study. Four indexes of variability were used, including standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average successive variability (ARV). Cox regression was used to evaluate the relationship between the quartiles of FPG variability and digestive cancers.

RESULTS

A total of 98,161 individuals were studied. Over a mean follow-up of 9.32 ± 0.81 years, 1103 individuals developed incident digestive cancer (1.21 per 1000 person-years). Compared to the individuals in the lowest quartile, those in the highest quartile of FPG variability by SD had 38.7% higher risk of developing overall digestive cancers after adjusting for the significant confounders (hazard ratio, 1.387; 95% confidence interval, 1.160-1.659; P = 0.0003). Higher FPG variability was associated with significantly higher risks of colorectal cancer (fully adjusted HR 1.432, 95% CI [1.073-1.912], P = 0.015) and pancreatic cancer (fully adjusted HR 2.105, 95% CI [1.024-4.329], P = 0.043), but not liver cancer (fully adjusted HR 1.427, 95% CI [0.973-2.092], P = 0.069) or esophageal and gastric cancer (fully adjusted HR 1.139, 95% CI [0.776-1.670], P = 0.506). Subgroup analyses showed that individuals who were younger (<65 years), male, and those without diabetes experienced a predominantly higher risk of developing digestive cancers. Similar results were observed when using CV, VIM, and ARV.

CONCLUSIONS

FPG variability was significantly associated with increasing risk of digestive cancers, especially for pancreatic and colorectal cancer. Our study suggested a potential role of FPG variability in risk stratification of digestive cancers. Approaches that reduce FPG variability may lower the risks of incident digestive cancers among the general population. This trial is registered with ChiCTR-TNRC-11001489.

Energy Costs of Household and Eldercare Activities in Young to Middle-Aged Chinese Adults

BACKGROUND

The 2011 Compendium of Physical Activities provides metabolic equivalent (MET) values for household and eldercare activities (physical activities [PAs]). METs are from published studies, estimated if values are not published, or combined with other PAs with different METs in a single entry. Some PAs are missing from the Compendium. This study measures the energy costs for 15 household and eldercare PAs with estimated METs, PAs in combined entries, and new PAs.

METHODS

Participants were 30 adults (14 males and 16 females), ages 22-58 years (33.7 [11.2] y). PAs were measured in a laboratory for 8 minutes with a 4-minute rest between PAs. A portable indirect calorimeter measured oxygen uptake (in milliliters per kilogram per minute). Standard METs were computed as activity VO2/3.5 mL·kg-1·min-1.

RESULTS

Cooking, meal tasks, laundry, light cleaning, and watering plants ranged from 1.8 to 2.3 METs. Sweeping, walking, and carrying groceries and boxes on the ground and stairs ranged from 3.0 to 5.5 METs. Eldercare ranged from 1.8 to 3.0 METs. Measured METs differed from estimated values by ±0.3 to 2.2 METs. Most measured METs were lower than estimated METs.

CONCLUSION

Updating estimated METs with measured values and separating PAs from combined entries increases the accuracy of household and eldercare PAs presented in the Compendium.

Importance of ideal cardiovascular health metrics in the risk of colorectal cancer among people aged 50 years or older: a UK Biobank cohort study

OBJECTIVE

To explore the correlation between the ideal cardiovascular health metrics (ICVHMs) and the incidence of colorectal cancer (CRC) among people aged 50 years or older.

DESIGN

Prospective cohort study.

SETTING

The UK Biobank, a prospective cohort of middle-aged participants recruited between 2006 and 2010.

PARTICIPANTS

The study included 342 226 participants from the UK Biobank aged 50 years or older without prevalent cancer.

EXPOSURE

The ICVHMs consist of four behavioural factors (abstinence from smoking, ideal body mass index (BMI), physical activity at goal and consumption of healthy diet) and three cardiometabolic factors (untreated total cholesterol <200 mg/dL, untreated blood pressure <120/80 mm Hg and untreated fasting plasma glucose <100 mg/dL).

MAIN OUTCOMES

The outcome was ascertained by linkage to cancer and death registries using the International Classification of Diseases, Tenth codes C18-C20.

RESULTS

During a median follow-up time of 8.72 years, 3060 CRC cases were identified. Compared with the reference (participants with ICVHMs ≤2), the multivariable-adjusted HRs for subgroups with 3, 4, 5 and ≥6 ICVHM factors were 0.98 (95% CI 0.85 to 1.12), 0.90 (95% CI 0.77 to 1.02), 0.85 (95% CI 0.71 to 0.98) and 0.69 (95% CI 0.48 to 0.90), respectively. Among the seven ICVHM factors, lower BMI, healthier diet and ideal fasting plasma glucose were significantly associated with lower risk of CRC (HR: 0.86, 95% CI 0.78 to 0.95; HR: 0.92, 95% CI 0.84 to 0.99; HR: 0.90, 95% CI 0.80 to 0.99).

CONCLUSIONS

Adherence to the ICVHMs was associated with a lower risk of CRC among people aged 50 years or older. Among the seven ICVHM factors, BMI, diet and fasting plasma glucose played a more critical role in the prevention of CRC. These findings imply that adherence to ICVHMs should be encouraged to reduce the burden of cardiovascular disease as well as CRC.

The interaction between glycemic index, glycemic load, and the genetic variant ADIPOQ T45G (rs2241766) in the risk of colorectal cancer: a case-control study in a Korean population

PURPOSE

The glycemic index (GI), glycemic load (GL), and adiponectin level contribute to glycemic response and insulin sensitivity in the body. Studies have shown that tumor development is related to glycemic disorders; however, the results are contradictory. We aimed to investigate the association of GI and GL with colorectal cancer (CRC) risk in a Korean population and their possible interactions with the genetic variant ADIPOQ T45G.

METHODS AND RESULTS

A case-control study including 2096 participants with 695 CRC cases was conducted. The results showed that diets with high GI or GL were significantly associated with an increased risk of CRC [odds ratio (OR) = 5.44, 95% confidence interval (CI) 3.85-7.68; OR = 4.43, 95% CI 3.18-6.15, respectively; all p-trends < 0.001]. Moreover, even with a low-GI and low-GL diet, G/G genotype carriers may have 2.93-fold and 3.77-fold higher risk of rectal cancer compared to carriers of other genotypes (T/T + T/G), (OR = 2.93, 95% CI 1.01-8.59, p-interaction = 0.011 for GI; OR = 3.77, 95% CI 1.46-9.77, p-interaction = 0.025 for GL).

CONCLUSIONS

Overall, our study suggests positive associations of GI and GL with CRC risk. Moreover, the associations of GI and GL with rectal cancer risk could be modified by ADIPOQ T45G in a Korean population. Further studies with larger sample sizes are needed to confirm our findings.

Fasting Plasma Glucose and Incident Colorectal Cancer: Analysis of a Nationwide Epidemiological Database

CONTEXT

Although diabetes mellitus (DM) was reported to be associated with incident colorectal cancer (CRC), the detailed association between fasting plasma glucose (FPG) and incident CRC has not been fully understood.

OBJECTIVE

We assessed whether hyperglycemia is associated with a higher risk for CRC.

DESIGN

Analyses were conducted using the JMDC Claims Database [n = 1 441 311; median age (interquartile range), 46 (40-54) years; 56.6% men). None of the participants were taking antidiabetic medication or had a history of CRC, colorectal polyps, or inflammatory bowel disease. Participants were categorized as normal FPG (FPG level < 100 mg/dL; 1 125 647 individuals), normal-high FPG (FPG level = 100-109 mg/dL; 210 365 individuals), impaired fasting glucose (IFG; FPG level = 110-125 mg/dL; 74 836 individuals), and DM (FPG level ≥ 126 mg/dL; 30 463 individuals).

RESULTS

Over a mean follow-up of 1137 ± 824 days, 5566 CRC events occurred. After multivariable adjustment, the hazard ratios for CRC events were 1.10 (95% CI 1.03-1.18) for normal-high FPG, 1.24 (95% CI 1.13-1.37) for IFG, and 1.36 (95% CI 1.19-1.55) for DM vs normal FPG. We confirmed this association in sensitivity analyses excluding those with a follow-up of< 365 days and obese participants.

CONCLUSION

The risk of CRC increased with elevated FPG category. FPG measurements would help to identify people at high-risk for future CRC.

Pathophysiological Characteristics Linking Type 2 Diabetes Mellitus and Colorectal Neoplasia

A substantial body of literature has provided evidence that type 2 diabetes mellitus (T2DM) and colorectal neoplasia share several common factors. Both diseases are among the leading causes of death worldwide and have an increasing incidence. In addition to usual risk factors such as sedentary lifestyle, obesity, and family history, common pathophysiological mechanisms involved in the development of these diseases have been identified. These include changes in glucose metabolism associated with adipose tissue dysfunction including insulin resistance resulting to hyperinsulinemia and chronic hyperglycemia. In addition to altered glucose metabolism, abdominal obesity has been associated with accented carcinogenesis with chronic subclinical inflammation. An increasing number of studies have recently described the role of the gut microbiota in metabolic diseases including T2DM and the development of colorectal cancer (CRC). Due to the interconnectedness of different pathophysiological processes, it is not entirely clear which factor is crucial in the development of carcinogenesis in patients with T2DM. The aim of this work is to review the current knowledge on the pathophysiological mechanisms of colorectal neoplasia development in individuals with T2DM. Here, we review the potential pathophysiological processes involved in the onset and progression of colorectal neoplasia in patients with T2DM. Uncovering common pathophysiological characteristics is essential for understanding the nature of these diseases and may lead to effective treatment and prevention.

Fasting blood glucose was linearly associated with colorectal cancer risk in the population without self-reported diabetes mellitus history

Fasting plasma glucose level was linearly associated with colorectal cancer (CRC) risk. However, the dose-response relationship between fasting blood glucose (FBG) and CRC risk was still uncertain.A total of 11,632 patients without self-reported diabetes mellitus and colorectal polyps' history were identified in the Korean Multicenter Cancer Cohort (1993-2005). The nonlinear relationship was estimated through a restricted cubic spline regression, and a two-piece-wise Cox proportional hazards model was further performed to calculate the threshold effect. Multiple imputation was used to control the bias from missing data.Overall, 1.1% (n = 132) of participants were diagnosed with CRC in the follow-up duration. With a median follow-up duration of 12.0 years, participants with FBG ≥126 mg/dL were associated with higher CRC risk (adjusted hazard ratio [HR], 1.67; 95% confidence interval [CI]: 1.01, 2.76). Landmark analyses limited to long-term survivors demonstrated increased CRC risk with FBG ≥ 126 mg/dL in all subsets (≥3years: HR,1.93 (95% CI: 1.13-3.29); ≥5years: HR, 2.04 (95% CI: 1.-3.63); ≥10years: HR, 2.50 (95% CI: 1.19-5.25)). With FBG smoothly increasing before, the latter increased dramatically after the turning point (P for nonlinearity = 0.283). When FBG was increasing per mmol/L, HR was 1.07(95% CI: 0.90, 1.29) for FBG < 126 mg/dL and 1.27 (95% CI: 1.06, 1.53) for FBG ≥ 126 mg/dL. Besides, HR was 1.09 (95% CI: 1.02, 1.16) for the CRC risk.In the population without self-reported diabetes mellitus and colorectal polyps' history. FBG was linearly associated with CRC risk, especially for FBG over 126 mg/dL.

Longitudinal changes in fasting plasma glucose are associated with risk of cancer mortality: A Chinese cohort study

BACKGROUND

Numerous studies have suggested that fasting plasma glucose (FPG) was associated with the risk of mortality. However, relationship on longitudinal changes of FPG with the risk of mortality remained inconsistent.

METHODS

We examined the association of FPG at baseline and its longitudinal changes with risk of mortality based on a cohort study in Yinzhou, China, during 2010-2018. Cox regression models and competing risk models were separately used to examine the association of FPG levels and long-term fluctuation with risk of total and cause-specific mortality.

RESULTS

Subjects who had an impaired fasting glucose or diabetes suffered a higher risk of total mortality than subjects who had a normal fasting glucose (HRs and 95% CIs: 1.17 [1.01-1.35], 1.30 [1.10-1.53], respectively). The HR for total mortality was 1.54 (95% CI: 1.29-1.84) and for cancer mortality was 1.41 (95% CI: 1.04-1.92) in the highest quartile of coefficient of variation of FPG. Trajectory analysis indicated that subjects with a significantly changed FPG suffered a higher risk of total mortality.

CONCLUSION

According to this cohort study, we found that long-term fluctuation of FPG was significantly associated with the risk of total and cancer mortality. Our findings suggest that long-term fluctuation of FPG could be used as an efficient indicator for predicting the subsequent risk of mortality.

Narrative review of the influence of diabetes mellitus and hyperglycemia on colorectal cancer risk and oncological outcomes

Diabetes mellitus (DM) and hyperglycemia have been shown to have significant effects on the incidence, chemoresistance, and prognosis of colorectal cancer (CRC), as well as the outcomes of localized and metastatic CRC. Inflammation and endocrine effects may act as central mechanisms of DM and cancer and stimulate the insulin-like growth factor 1-phosphoinositide 3-kinase-Akt-mammalian target of rapamycin (IGF-1-PI3K-AKT-mTOR) pathway. Dysregulation of the AMP-activated protein kinase (AMPK) pathway leads to metabolic imbalance and indicates cancer risk. The use of metformin for chemoprevention has been shown to reduce CRC and adenoma incidence through the upregulation of AMPK, which causes cell cycle arrest in the Gap 1-S (G1-S) phase and inhibits the mTOR pathway, even potentially reversing the epithelial-mesenchymal transition. However, evidence of the effects of metformin remain controversial in cancer prognosis. Several genes, such as transcription factor 7-like 2(TCF7L2), tumor protein P53 inducible nuclear protein 1(TP53INP1), gremlin 1 (GREM1), and potassium voltage-gated channel subfamily Q member 1(KCNQ1), are pleiotropically related to DM as well as cancer risk and prognosis. Epigenetic modification of members of the Let-7 family such as miR-497, miR-486, and miR-223 is strongly associated with impaired glucose tolerance and CRC risk. Herein we review the pathophysiological and epidemiological evidence as well as potential underlying molecular mechanisms by which DM and hyperglycemia affect CRC risk. We also suggest potential roles of glucose modulation in CRC therapy and propose an agenda for future research and clinical practice.

Waist circumference, body mass index, and colorectal cancer risk according to diabetes status: A Korean nationwide population-based cohort study

BACKGROUND AND AIM

We investigated the relationship of BMI and waist circumference with the risk of colorectal cancer (CRC) using a population-based cohort database and to explore the relationship of CRC with diabetes status.

METHODS

Retrospective data (age >20 years) on anthropometric variables, blood parameters of fasting sugar, lipid levels, and blood pressure were collected from the National Health Insurance Corporation database between 2009 and 2012. Cox regression models were used to estimate hazard ratio (HR) and corresponding 95% confidence intervals (95% CI).

RESULTS

Of the 23 121 360 people studied, 120 579 were diagnosed with CRC after a median follow-up period of 5.4 years. Both waist circumference and body mass index were positively associated with increased risk of CRC, regardless of age or sex. After mutual adjustment, only waist circumference was significantly associated with increased risk of CRC (HR = 1.275, 95% CI: 1.205-1.349). When the risk of CRC was compared according to diabetes status among people with the same waist circumference range, risk of CRC was higher for those with worse diabetes status.

CONCLUSION

When waist circumference and body mass index were mutually adjusted, only waist circumference was associated with CRC risk. In addition, the risk of CRC is gradually higher in those with worsening diabetes, even if their waist circumferences are within the same range.

Distinct patterns of interleukin-12/23 and tumor necrosis factor α synthesis by activated macrophages are modulated by glucose and colon cancer metabolites

Chronic inflammation is a major risk factor for colitis-associated colorectal carcinoma (CRC). Macrophages play a key role in altering the tumor microenvironment by producing pro-inflammatory and anti-inflammatory cytokines. Our previous studies showed that glucose metabolism conferred death resistance for tumor progression and exerted anti-inflammatory effects in ischemic gut mucosa. However, the effect of glucose and cancer metabolites in modulating macrophage cytokine profiles remains poorly defined. We used an in vitro system to mimic intestinal microenvironment and to investigate the roles of glucose and cancer metabolites in the cross-talk between carcinoma cells and macrophages. Human monocyte-derived THP-1 macrophages were stimulated with bacterial lipopolysaccharide (LPS) in the presence of conditioned media (CM) collected from human CRC Caco-2 cells incubated in either glucose-free or glucose-containing media. Our results demonstrated that glucose modulated the macrophage cytokine production, including decreased LPS-induced pro-inflammatory cytokines (i.e., tumor necrosis factor [TNF]α and interleukin [IL]-6) and increased anti-inflammatory cytokine (i.e., IL-10), at resting state. Moreover, glucose-containing CM reduced the macrophage secretion of TNFα and IL-8 but elevated the IL-12 and IL-23 levels, showing an opposite pattern of distinct pro-inflammatory cytokines modulated by cancer glucose metabolites. In contrast, LPS-induced production of macrophage inflammatory protein-1 (a macrophage-derived chemoattractant for granulocytes) was not altered by glucose or CM, indicating that resident macrophages may play a more dominant role than infiltrating granulocytes for responding to cancer metabolites. In conclusion, glucose metabolites from CRC triggered distinct changes in the cytokine profiles in macrophages. The downregulation of death-inducing TNFα and upregulation of Th1/17-polarizing IL-12/IL-23 axis in macrophages caused by exposure to cancer-derived glucose metabolites may contribute to tumor progression.

The association between fasting blood glucose trajectory and cancer risk in Chinese population without diabetes

To examine the associations between fasting blood glucose (FBG) trajectories, the changes in FBG over time and the risk of cancer, particularly for gastrointestinal cancer, we enrolled 69,742 participants without diabetes from the Kailuan cohort. FBG trajectories (2006-2010) were modeled by group-based trajectory modeling, and five trajectories were identified: low-increasing (n = 6,275), moderate-stable (n = 44,120), moderate-increasing (n = 10,149), elevated-decreasing (n = 5,244) and elevated-stable (n = 3,954). A total of 1,364 cancer cases were accumulated between 2010 and 2015, including 472 gastrointestinal cancer cases. We used Cox proportional hazards regression models to evaluate the associations between FBG trajectory patterns and the risk of cancer. We further assessed the associations while carefully controlling for initial body mass index (BMI) in 2006 and for changes in BMI during 2006-2010. Relative to the moderate-stable group, we found a higher hazard ratio (HR) for overall cancer in the low-increasing group (HR = 1.26, 95% confidence interval (CI) 1.06-1.50); and for gastrointestinal cancer in the elevated-stable group (HR = 1.66, 95% CI 1.22-2.26). Moreover, among participants with an initial BMI ≥25 kg/m² , a positive association with the low-increasing group was observed for both overall cancer and gastrointestinal cancer (HR = 1.54, 95% CI 1.17-2.04; HR = 1.65, 95% CI 1.02-2.66; respectively); among participants with a stable BMI (4.40% loss-5.15% gain), a positive association with the elevated-stable group was observed both for overall cancer and gastrointestinal cancer (HR = 1.43, 95% CI 1.10-1.87; HR = 1.95, 95% CI 1.33-2.86; respectively). Our study observed that FBG trajectories were associated with cancer risk among participants without diabetes, and BMI may modify the associations.

Glucose Metabolites Exert Opposing Roles in Tumor Chemoresistance

Reprogrammed glucose metabolism and increased glycolysis have been implicated in tumor chemoresistance. The aim was to investigate the distinct roles of the glucose metabolites pyruvate and ATP in chemoresistance mechanisms, including cell death and proliferation. Our data showed higher glucose transporters in colorectal cancer (CRC) from non-responsive patients than those responsive to chemotherapy. Human CRC cell lines exposed to 5-fluorouracil (5-FU) displayed elevated cell viability and larger tumors in xenograft mouse models if cultured in high-glucose medium. Glucose conferred resistance to 5-FU-induced necroptosis via pyruvate scavenging of mitochondrial free radicals, whereas ATP replenishment had no effect on cell death. Glucose attenuated the 5-FU-induced G0/G1 shift but not the S phase arrest. Opposing effects were observed by glucose metabolites; ATP increased while pyruvate decreased the G0/G1 shift. Lastly, 5-FU-induced tumor spheroid destruction was prevented by glucose and pyruvate, but not by ATP. Our finding argues against ATP as the main effector for glucose-mediated chemoresistance and supports a key role of glycolytic pyruvate as an antioxidant for dual modes of action: necroptosis reduction and a cell cycle shift to a quiescent state.

Mediation of associations between adiposity and colorectal cancer risk by inflammatory and metabolic biomarkers

Inflammation and hyperinsulinemia may drive associations between adiposity and colorectal cancer (CRC) risk, but few studies have examined this hypothesis using mediation analysis. We used inverse odds ratio weighting and logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) for estimated total effects (OR^TE ) of body mass index, waist circumference, and adult weight gain on CRC risk, and estimated effects operating through seven inflammatory and metabolic biomarkers (natural indirect effect; OR^NIE ) or through paths independent of these biomarkers (natural direct effect; OR^NDE ) among 209 CRC cases and 382 matched controls nested within the Health Professionals Follow-up Study, a prospective cohort of male health professionals. A one-interquartile range (IQR) increase in body mass index (3.6 kg/m² ) was associated with an OR^TE of 1.40 (95% CI: 1.13, 1.73), which decomposed into an OR^NIE of 1.26 (95% CI: 0.97, 1.52) and an OR^NDE of 1.11 (0.87, 1.42), with possibly stronger mediation by these biomarkers for adult weight gain (IQR = 10.4 kg; OR^TE = 1.32 [95% CI: 1.06, 1.64]; OR^NIE = 1.47 [95% CI: 1.01, 1.81]; OR^NDE = 0.89 [95% CI: 0.72, 1.11]), but no mediation for waist circumference. Mediation appeared to be stronger for the metabolic biomarkers than the inflammatory biomarkers. Inflammatory and metabolic mechanisms may mediate associations between both body mass index and adult weight gain with CRC risk.

Metabolic syndrome is a risk factor for cancer mortality in the general Japanese population: the Jichi Medical School Cohort Study

BACKGROUND

Metabolic syndrome (MetS) and cancer are major public health problems worldwide. The relationship between MetS and cancer death is of great interest. We examined the predictive value of MetS for cancer mortality in Japan.

METHODS

Study participants included 4495 men and 7028 women aged 18-90 years who were registered between 1992 and 1995 as part of the Jichi Medical School Cohort Study. We used a definition of MetS modified for the Japanese population. The primary outcome was cancer mortality. Additionally, the relationship between MetS and cancer-type specific mortality was examined. Analyses were conducted with Cox's regression models adjusted for age, smoking status, alcohol drinking status, marital status, educational attainment, physical activity, occupational category, and menopausal status (only in women).

RESULTS

During a mean follow-up of 18.5 years, 473 men and 297 women died from cancer. MetS was positively associated with cancer mortality in women (hazard ratio [HR], 1.69; 95% confidence interval [CI] 1.21-2.36), but not in men (HR, 1.21; 95% CI 0.90-1.62). Additionally, MetS was associated with a high risk of colorectal (HR, 3.48; 95% CI 1.68-7.22) and breast (HR, 11.90; 95% CI 2.25-62.84) cancer deaths in women.

CONCLUSION

MetS was a significant predictor of cancer mortality in women.

Significance of prediabetes as a nosological entity

Prediabetes is a glucose metabolism disorder considered as a distinct nosological entity which strongly predicts the development of type 2 diabetes mellitus. This nosological entity itself is a serious condition indicating an increased risk of atherosclerotic and oncological complications. In patients with prediabetes, other components of metabolic syndrome are usually present, such as arterial hypertension, obesity or dyslipidaemia, further increasing an individual's risk of morbidity and mortality. Prediabetes is a long-developing disorder which offers enough time for early diagnosis and intervention; it may even be reversible. This review summarizes current knowledge on the definition, detection, epidemiology, cardiovascular and other consequences of prediabetes. It also gives suggestions for future research, along with recommendations for clinical practice.

Diabetes, plasma glucose and incidence of colorectal cancer in Chinese adults: a prospective study of 0.5 million people

Background

Diabetes is associated with higher risk of colorectal cancer (CRC). Uncertainty remains about the relevance of duration of diabetes and about the association of blood glucose with CRC risk among individuals without diabetes.

Methods

The prospective China Kadoorie Biobank recruited 512 713 participants in 2004–2008 from 10 diverse areas in China. After 10 years of follow-up, 3024 incident cases of CRC (1745 colon, 1716 rectal) were recorded among 510 136 participants without prior cancer at baseline. Cox regression was used to estimate adjusted HRs for CRC associated with diabetes (previously diagnosed or screen-detected) and, among those without previously diagnosed diabetes, with levels of random plasma glucose (RPG).

Results

Overall 5.8% of participants had diabetes at baseline. Individuals with diabetes had an adjusted HR of 1.18 (95% CI 1.04 to 1.33) for CRC, with similar risk for colon and rectal cancer (1.19 [1.01 to 1.39] vs 1.14 [0.96 to 1.35]). The HRs decreased with longer duration of diabetes (p for trend 0.03). Among those without previously diagnosed diabetes, RPG was positively associated with CRC, with adjusted HRs per 1 mmol/L higher baseline RPG of 1.04 (1.02 to 1.05) for CRC, again similar for colon and rectal cancer (1.03 [1.01to 1.05] and 1.04 [1.02 to 1.06], respectively). The associations of diabetes and RPG appeared stronger in men than in women, but the differences were non-significant (p for heterogeneity 0.3 and 0.2).

Discussion

Among Chinese adults, diabetes and higher blood glucose levels among those without known diabetes are associated with higher risk of CRC.

Expression of long-chain fatty acid receptor GPR40 is associated with cancer progression in colorectal cancer: A retrospective study

An increased risk of colorectal cancer (CRC) is associated with a western style diet, particularly hyperlipidemia. The expression of G-protein coupled receptor 40 (GPR40), a membrane-bound receptor for long-chain fatty acids (LCFAs), was examined in 36 cases of subserosal-invading CRC and compared with clinicopathological parameters as well as triglyceride (TG) and low-density lipoprotein (LDL) levels in the blood. All patients with CRC expressed GPR40, which was positively associated with blood TG levels (P<0.0001) but not with blood LDL levels. GPR40 expression was positively associated with nodal metastasis, distant metastasis (particularly to the liver), stage and poor prognosis. Patients with high GPR40 expression and high TG levels had comparatively worse survival outcomes compared with patients with low GPR40 expression and low TG levels. The results of the present study suggest that activation of GPR40 may be associated with the progression and prognosis of CRCs. High levels of GPR40 and/or concurrent high levels of GPR40 and TG may be a risk for CRC progression.

Myotubularin-related protein 7 inhibits insulin signaling in colorectal cancer

Phosphoinositide (PIP) phosphatases such as myotubularins (MTMs) inhibit growth factor receptor signaling. However, the function of myotubularin-related protein 7 (MTMR7) in cancer is unknown. We show that MTMR7 protein was down-regulated with increasing tumor grade (G), size (T) and stage (UICC) in patients with colorectal cancer (CRC) (n=1786). The presence of MTMR7 in the stroma correlated with poor prognosis, whereas MTMR7 expression in the tumor was not predictive for patients' survival. Insulin reduced MTMR7 protein levels in human CRC cell lines, and CRC patients with type 2 diabetes mellitus (T2DM) or loss of imprinting (LOI) of insulin-like growth factor 2 (IGF2) had an increased risk for MTMR7 loss. Mechanistically, MTMR7 lowered PIPs and inhibited insulin-mediated AKT-ERK1/2 signaling and proliferation in human CRC cell lines. MTMR7 provides a novel link between growth factor signaling and cancer, and may thus constitute a potential marker or drug target for human CRC.

Preoperative metabolic syndrome and prognosis after radical resection for colorectal cancer: The Fujian prospective investigation of cancer (FIESTA) study

This prospective study sought to investigate the prediction of preoperative metabolic syndrome and its components for the risk of colorectal cancer (CRC) mortality by analyzing a subset of data from the ongoing Fujian prospective investigation of cancer (FIESTA) study. In total, 1,318 CRC patients who received radical resection were consecutively enrolled between January 2000 and December 2008. The median follow-up time was 58.6 months, with 412 deaths from CRC. The CRC patients with metabolic syndrome had significantly shorter median survival time (MST) than those without (50.9 vs. 170.3 months, p < 0.001). Among four components of metabolic syndrome, hyperglycemia was the strongest predictor and its presence was associated with shorter MST than its absence (44.4 vs. 170.3 months, p < 0.001). Moreover, the complication of metabolic syndrome in CRC patients was associated with a 2.98-fold increased risk of CRC mortality (hazard ratio [HR] = 2.98, 95% confidence interval [CI]: 2.40-3.69, p < 0.001) after adjusting for confounding factors. The magnitude of this association was especially potentiated in CRC patients with tumor-node-metastasis stage I/II (HR = 3.94, 95% CI: 2.65-5.85, p < 0.001), invasion depth T1/T2 (HR = 5.41, 95% CI: 2.54-11.50, p < 0.001), regional lymph node metastasis N0 (HR = 4.06, 95% CI: 2.85-5.80, p < 0.001) and negative distant metastasis (HR = 3.23, 95% CI: 2.53-4.12, p < 0.001). Further survival tree analysis reinforced the prognostic capability of fasting blood glucose in CRC survival. Our findings convincingly demonstrated that preoperative metabolic syndrome, especially hyperglycemia, was a robust predictor for CRC mortality, and the protection was more obvious in patients with Stage I/II.