Clinical usefulness of glycosylated hemoglobin as a predictor of adenomatous polyps in the colorectum of middle-aged males

Glycosylated Hemoglobin as an Age-Specific Predictor and Risk Marker of Colorectal Adenomas in Non-Diabetic Adults

BACKGROUND

Diabetes is a risk factor for colorectal neoplasms. The association between the level of glycosylated hemoglobin (HbA1c) and the risk of colorectal adenomas (CRAs) in non-diabetic adults needs to be investigated.

METHODS

A cross-sectional study was performed on non-diabetic adults with normal HbA1c level who underwent colonoscopy between January 2010 and December 2016 during health check-ups in our hospital in China. The association between HbA1c level and CRAs was assessed by multiple logistic regression models stratified by age group (<40, ≥40 and <50, and ≥50 years old). The age group-specified thresholds for HbA1c on elevated risk of CRAs were estimated using the piecewise logistic regression.

RESULTS

Among the 2,764 subjects, 445 (16.1%) had CRA. The prevalence of CRA varied across the three age groups. A higher HbA1c level was found to be significantly associated with increased CRA risk in the 40-50 years group (odds ratio [OR]=1.70, 95% confidence interval [CI] 1.04-2.78, p=0.035) after adjusting for other related factors, while this association was borderline significant among the 50 years and older group (OR=1.57, 95% CI 0.97-2.54, p=0.067). Based on the piecewise logistic regression analysis results, the thresholds for HbA1c on elevated risk of CRA were 5.44% for the 40-50 years group and 4.81% for the 50 years and older group, respectively.

CONCLUSIONS

Higher levels of HbA1c, even within the normal range, were associated with elevated CRA risk among non-diabetic adults. The threshold effects of HbA1c on the risk of CRA varied across different age groups, and early screening colonoscopy might be needed for individuals in their 40s and with HbA1c levels ≥5.44%.

Association between Hemoglobin Levels and Colorectal Polyps in Asymptomatic Chinese Adults

Methods

A cross-sectional analysis was performed among 1633 asymptomatic adults who underwent colonoscopy examinations during routine health check-ups at the First Affiliated Hospital, College of Medicine, Zhejiang University, between 2015 and 2018.

Results

A total of 449 (27.50%) participants were diagnosed with colorectal polyps, and those with colorectal polyps had significantly higher hemoglobin levels than did those without colorectal polyps. Hemoglobin levels were positively associated with the prevalence of colorectal polyps, with rates of 16.43%, 26.20%, 32.17%, and 35.87% among participants with hemoglobin levels in the first, second, third, and fourth quartiles, respectively (P for trend < 0.001). Stepwise multiple regression analysis showed that elevated hemoglobin levels independently increased the risk of colorectal polyps (odd ratio = 1.017; 95% confidence interval: 1.008–1.026).

Conclusion

Elevated hemoglobin levels were significantly and independently associated with the prevalence and risk of colorectal polyps in asymptomatic adults.

Measurement of biological age may help to assess the risk of colorectal adenoma in screening colonoscopy

AIM

To investigate the clinical utility of biological age (BA) measurement in screening colonoscopy for the detection of colorectal adenomas in the average-risk population.

METHODS

A consecutive series of asymptomatic subjects aged ≥ 30 years who underwent colonoscopy in routine check-ups were enrolled. Colorectal adenoma was classified according to size, number, and location. BAs were calculated using the MEDIAGE^TM Biological Age Measurement System.

RESULTS

A total of 2696 subjects were investigated (1876 men and 820 women). The mean chronological age (CA) was 46.0 years and the mean BA was 44.7 years. Metabolic syndrome (MS) was diagnosed in 218 subjects (8.1%). The prevalence of overall colorectal adenoma was 23.1% (622/2,696). When the subjects were divided into four groups based on BA (≤ 39 years; 40-49 years; 50-59 years; ≥ 60 years), the prevalence of colorectal adenoma was increased as BA increased (P < 0.001). Colorectal adenoma located in the proximal colon was more prevalent in the BA-dominant group (BA-CA ≥ 5 years) than the CA-dominant group (CA-BA ≥ 5 years) (P = 0.034). When the subjects were categorized into four groups according to MS and age gap between BA and CA, the incidence of colorectal adenoma increased with MS and BA-dominance (P < 0.05).

CONCLUSION

Measurement of BA may help to assess the risk of colorectal adenoma in screening colonoscopy.

Metabolic unhealthiness is an important predictor for the development of advanced colorectal neoplasia

Obesity is a well-known risk factor for colorectal neoplasia. Yet, the associations of both metabolic and obesity status with metachronous colorectal neoplasia remain unclear. We conducted a cohort study of 9,331 adults who underwent screening colonoscopy and surveillance colonoscopy. Participants were classified as metabolically healthy if they had no metabolic syndrome component. Participants were categorized into four groups according to body mass index and metabolic status: metabolically healthy non-obese (MHNO; n = 2,745), metabolically abnormal non-obese (MANO; n = 3,267), metabolically healthy obese (MHO; n = 707), and metabolically abnormal obese (MAO; n = 2,612). MAO individuals [n = 159 advanced colorectal neoplasia (AN) cases, 6.1%] and MANO individuals (n = 167 AN cases, 5.1%) had a higher incidence of AN compared with MHNO individuals (n = 79 AN cases, 2.9%). In a multivariable model, the risk of metachronous AN was higher in MANO (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.12–1.84) and MAO (HR 1.52, 95% CI 1.18–1.96) than in MHNO. In contrast, the risk of metachronous AN was not significantly elevated in MHO. In subgroup analyses, with or without adenoma at baseline, MAO was a risk group for metachronous AN, and MHO was not. Our findings suggest that metabolic unhealthiness is a significant predictor for metachronous AN.

Parameters of Glucose and Lipid Metabolism Affect the Occurrence of Colorectal Adenomas Detected by Surveillance Colonoscopies

PURPOSE

Limited data are available regarding the associations between parameters of glucose and lipid metabolism and the occurrence of metachronous adenomas. We investigated whether these parameters affect the occurrence of adenomas detected on surveillance colonoscopy.

MATERIALS AND METHODS

This longitudinal study was performed on 5289 subjects who underwent follow-up colonoscopy between 2012 and 2013 among 62171 asymptomatic subjects who underwent an initial colonoscopy for a health check-up between 2010 and 2011. The risk of adenoma occurrence was assessed using Cox proportional hazards modeling.

RESULTS

The mean interval between the initial and follow-up colonoscopy was 2.2±0.6 years. The occurrence of adenomas detected by the follow-up colonoscopy increased linearly with the increasing quartiles of fasting glucose, hemoglobin A1c (HbA1c), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides measured at the initial colonoscopy. These associations persisted after adjusting for confounding factors. The adjusted hazard ratios for adenoma occurrence comparing the fourth with the first quartiles of fasting glucose, HbA1c, insulin, HOMA-IR, and triglycerides were 1.50 [95% confidence interval (CI), 1.26-1.77; p(trend)<0.001], 1.22 (95% CI, 1.04-1.43; p(trend)=0.024), 1.22 (95% CI, 1.02-1.46; p(trend)=0.046), 1.36 (95% CI, 1.14-1.63; p(trend)=0.004), and 1.19 (95% CI, 0.99-1.42; p(trend)=0.041), respectively. In addition, increasing quartiles of low-density lipoprotein-cholesterol and apolipoprotein B were associated with an increasing occurrence of adenomas.

CONCLUSION

The levels of parameters of glucose and lipid metabolism were significantly associated with the occurrence of adenomas detected on surveillance colonoscopy. Improving the parameters of glucose and lipid metabolism through lifestyle changes or medications may be helpful in preventing metachronous adenomas.

Associations Between Parameters of Glucose and Lipid Metabolism and Risk of Colorectal Neoplasm

BACKGROUND

Diabetes and dyslipidemia have been linked to an increased risk of colorectal neoplasm (CRN). However, previous studies evaluating these associations have shown inconsistent results, and large-scale studies are few in number.

AIM

To investigate the associations between the parameters of glucose and lipid metabolism and the presence of CRN.

METHODS

A cross-sectional study was performed on 38,490 Korean adults aged ≥30 years undergoing their first colonoscopy as part of routine preventive health care between 2010 and 2011.

RESULTS

The prevalence of overall CRN increased with increasing levels of glucose, hemoglobin A1c (HbA1c), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (ApoB) and with decreasing level of apolipoprotein A1 (ApoA1). The adjusted prevalence ratios for overall CRN comparing the fourth with the first quartiles of fasting glucose, HbA1c, insulin, HOMA-IR, triglycerides, total cholesterol, LDL-C, ApoB, and ApoA-1 were 1.83 (95% CI 1.62-2.06), 1.17 (95% CI 1.03-1.33), 1.09 (95% CI 0.97-1.23), 1.22 (95% CI 1.08-1.37), 1.31 (95% CI 1.16-1.48), 1.19 (95 % CI 1.07-1.33), 1.38 (95% CI 1.23-1.54), 1.30 (95% CI 1.14-1.47), and 0.85 (95% CI 0.76-0.95), respectively. There was also a significant association between higher levels of glucose, LDL-C, and ApoB with a higher prevalence of advanced CRN. Moreover, the risk of CRN increased further in cases in which the parameters of glucose metabolism and lipid metabolism worsened simultaneously.

CONCLUSIONS

The levels of parameters of glucose and lipid metabolism are significantly associated with the prevalence of CRN. Altered glucose and lipid metabolism may contribute to the development of CRN.

Hyperinsulinemia, insulin resistance and colorectal adenomas: A meta-analysis

BACKGROUND

Insulin stimulates cell proliferation and inhibits apoptosis. While epidemiologic studies have investigated associations between markers of insulin resistance/hyperinsulinemia (i.e., circulating insulin, homeostasis model assessment-insulin resistance (HOMA-IR), C-peptide) and risk of colorectal adenoma (CRA), the effect size has not yet been quantified.

OBJECTIVE

We aimed to summarize the association between hyperinsulinemia/insulin resistance and risk of CRA, including whether the association is independent of adiposity.

MATERIALS AND METHODS

Pubmed and Embase were searched through April, 2015 to identify observational studies investigating the associations between insulin, C-peptide and HOMA-IR and CRA risk. Using the highest versus lowest category meta-analysis and dose-response meta-analysis based on a random-effects model, we estimated summary odds ratio (OR) and the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 27 studies (insulin: 16 studies including 14,007 cases; C-peptide: 11 studies including 8639 cases; HOMA-IR: 8 studies including 11,619 cases) were included in this meta-analysis. The summary ORs of CRA comparing the highest with the lowest quantile were 1.33 for insulin (95% CI=1.12-1.58, I(2)=73.9%, Pheterogeneity<0.001), 1.44 for C-peptide (95% CI=1.13-1.83, I(2)=63.5%, Pheterogeneity=0.003), and 1.33 for HOMA-IR (95% CI=1.10-1.60, I(2)=69.1%, Pheterogeneity=0.004). Upon stratification by ethnicity, higher levels of insulin and C-peptide were significantly associated with increased risk of CRA in non-Asian ethnicity (summary OR for insulin=1.67 [95% CI=1.28-2.17], I(2)=34.9%, Pheterogeneity=0.16; summary OR for C-peptide=1.59 [95% CI=1.22-2.08], I(2)=21.5%, Pheterogeneity=0.27) but not in Asians (summary OR for insulin=1.10 [95% CI=0.92-1.33], I(2)=76.6%, Pheterogeneity=0.001; summary OR for C-peptide=1.27 [95% CI=0.84-1.91], I(2)=72.6, Pheterogeneity=0.01). We observed evidence for the existence of publication bias for insulin (P=0.01 by Egger test) and HOMA-IR (P=0.05 by Egger test). The results were confirmed in linear dose-response meta-analysis. These significant positive associations generally persisted even after adjustment for adiposity, although the effect size was substantially attenuated.

CONCLUSIONS

Independent of adiposity, higher levels of insulin, C-peptide, and HOMA-IR were significantly associated with increased risk of CRA. The weaker associations and high heterogeneity in Asian studies warrant further research. These results indicate that insulin resistance and hyperinsulinemia may contribute in part to the association between obesity and CRA risk.

Glycated hemoglobin and all-cause and cause-specific mortality in Singaporean Chinese without diagnosed diabetes: the Singapore Chinese Health Study

OBJECTIVE

Glycated hemoglobin (HbA₁c) is a robust biomarker of the preceding 2 to 3 months average blood glucose level. The aim of this study was to examine the association between HbA₁c and mortality in a cohort of Southeast Asians.

RESEARCH DESIGN AND METHODS

Analysis of 7,388 men and women, mean age 62 years, from the Singapore Chinese Health Study who provided a blood sample at the follow-up I visit (1999-2004) and reported no history of diabetes, previous adverse cardiovascular events, or cancer. A total of 888 deaths were identified through 31 December 2011 via registry linkage. Participants represented a random study sample of potential control subjects for a nested case-control genome-wide association study of type 2 diabetes in the population. Hazard ratios (HRs) for all-cause and cause-specific mortality by six categories of HbA1c were estimated with Cox regression models.

RESULTS

Relative to participants with an HbA₁c of 5.4-5.6% (36-38 mmol/mol), participants with HbA₁c ≥6.5% (≥48 mmol/mol) had an increased risk of all-cause, cardiovascular, and cancer mortality during an average of 10.1 years of follow-up; HRs (95% CIs) were 1.96 (1.56-2.46), 2.63 (1.77-3.90), and 1.51 (1.04-2.18), respectively. No level of HbA1c was associated with increased risk of respiratory mortality. Levels <6.5% HbA₁c were not associated with mortality during follow-up. The results did not materially change after excluding observation of first 3 years post-blood draw.

CONCLUSIONS

HbA₁c levels consistent with undiagnosed type 2 diabetes (≥6.5%) are associated with an increased risk of all-cause and cause-specific mortality in Chinese men and women.

The relationship between different glycemic statuses and colon polyps in a Taiwanese population

BACKGROUND

While diabetes is considered as a risk factor for colorectal cancer, there are few studies that address the association between glycemic statuses and different colon polyps, ranging from non-neoplastic polyps to advanced adenomatous polyps.

METHODS

A total of 6,348 participants, consisting of 3,777 men and 2,571 women, with a mean age of 50.5 years, were included for final analysis after excluding subjects with a past history of colorectal cancer, colon polyps/polypectomy, familial adenomatous polyposis, and colorectomy, or missing data. Diabetes and pre-diabetes were defined using the 2011 American Diabetes Association criteria. Subjects were classified into four groups: polyp-free, non-neoplastic polyps, non-advanced and advanced adenomatous polyps.

RESULTS

There were significant differences in the prevalence of diabetes and pre-diabetes among groups with different kinds of colon polyps. In addition, significant differences were also noted in age, total cholesterol, body mass index, triglyceride, high density lipoprotein-cholesterol, fasting plasma glucose, and the prevalence of male gender, hypertension, obesity, current smoking and alcohol drinking among groups. In the multinomial logistic regression analyses, diabetes was related to both non-advanced and advanced adenomatous polyps, while pre-diabetes was only related to non-advanced adenomatous polyps. In addition, age ≥65 years and male gender were associated with both non-advanced and advanced adenomatous polyps, while hypertension and current smoking were independently related to advanced and non-advanced adenomatous polyps, respectively.

CONCLUSIONS

Diabetes, but not pre-diabetes, was associated with a higher risk of advanced adenomatous polyps. In addition, both diabetes and pre-diabetes were important correlates of non-advanced adenomatous polyps.

Association between markers of glucose metabolism and risk of colorectal adenoma

BACKGROUND & AIMS

Diabetes is a risk factor for colorectal cancer. We studied the association between markers of glucose metabolism and metabolic syndrome and the presence of colorectal adenomas in a large number of asymptomatic men and women attending a health screening program in South Korea. We also investigated whether these associations depend on adenoma location.

METHODS

In a cross-sectional study, we measured fasting levels of glucose, insulin, hemoglobin A1c, and C-peptide and calculated homeostatic model assessment (HOMA) values (used to quantify insulin resistance) for 19,361 asymptomatic South Korean subjects who underwent colonoscopy examinations from January 2006 to June 2009. Participants completed a standardized self-administered health questionnaire and a validated semiquantitative food frequency questionnaire. Blood samples were collected on the day of the colonoscopy; fasting blood samples were also collected. Robust Poisson regression was used to model the associations of glucose markers with the prevalence of any adenoma.

RESULTS

Using detailed multivariable-adjusted dose-response models, the prevalence ratios (aPR, 95% confidence interval [CI]) for any adenoma, comparing the 90th with the 10th percentile, were 1.08 (1.00-1.16; P = .04) for fasting glucose, 1.07 (0.99-1.15; P = .10) for insulin, 1.09 (1.02-1.18, P = .02) for HOMA, 1.09 (1.01-1.17; P = .02) for hemoglobin A1c, and 1.14 (1.05-1.24; P = .002) for C-peptide. The corresponding ratios for nonadvanced adenomas were 1.11 (0.99-1.25; P = .08), 1.10 (0.98-1.24; P = .12), 1.15 (1.02-1.29; P = .02), 1.14 (1.01-1.28; P = .03), and 1.20 (1.05-1.37; P = .007), respectively. The corresponding ratios for advanced adenomas were 1.32 (0.94-1.84; P = .11), 1.23 (0.87-1.75; P = .24), 1.30 (0.92-1.85; P = .14), 1.13 (0.79-1.61; P = .50), and 1.67 (1.15-2.42; P = .007), respectively. Metabolic syndrome was associated with the prevalence of any adenoma (aPR, 1.18; 95% CI, 1.13-1.24; P < .001), nonadvanced adenoma (aPR, 1.30; 95% CI, 1.20-1.40; P < .001), and advanced adenoma (aPR, 1.42; 95% CI, 1.14-1.78; P = .002). Associations were similar for adenomas located in the distal versus proximal colon.

CONCLUSIONS

Increasing levels of glucose, HOMA values, levels of hemoglobin A1c and C-peptide, and metabolic syndrome are significantly associated with the prevalence of adenomas. Adenomas should be added to the list of consequences of altered glucose metabolism.

Pancreatic biomarkers: Could they be the answer?

Pancreatic ductal adenocarcinoma (PDA) is known for its poor prognosis. Most of the patients are diagnosed with advanced stages, when no curative treatment is available. Currently, despite extensive clinical research on PDA, the median overall survival remains short. Diagnosis delay and primary chemo-resistance due to its intrinsic biological nature may explain the challenges to improve our results. Our knowledge about the molecular biology of PDA has exponentially increased during the last decades and its use for the development of biomarkers could help to reach better results in the clinical setting. These biomarkers could be the clue for the improvement in PDA clinical research by earlier detection strategies with diagnostic biomarkers, and by an individualization of treatment approach with prognostic and predictive biomarkers. This review summarizes the current knowledge about the molecular biology of PDA and the status of the most important prognostic and predictive biomarkers.

Does cancer risk increase with HbA1c, independent of diabetes?

Background:

The risks for several cancer types are increased in people with diabetes. Hyperglycaemia, hyperinsulinaemia, inflammation and altered hormonal concentrations are common characteristics between the two diseases and can all be linked to hyperglycaemia.

Methods:

Here, we use glycated haemoglobin (HbA_1c) as a biomarker for chronic hyperglycaemia. We explore whether cancer risk increases with HbA_1c, independent of diabetes, and, therefore, if risk is already increased below the diabetic HbA_1c range, by analysing data from current studies linking HbA_1c to risk of several cancer types.

Results:

The data reveal that chronic hyperglycaemia correlates with increased cancer risk for a number of cancers, except prostate cancer. Evidence is also provided that risk is already increased in the pre-diabetic and normal ranges for several cancers.

Conclusions:

These results merit urgent investigation into the risks and advantages of updating recommendations for stricter glycaemic control in diabetic and non-diabetic subjects, as this could help reduce the risk of cancer incidence and mortality.

Prediabetes is associated with a high-risk colorectal adenoma

BACKGROUND

Type 2 diabetes mellitus is associated with an increased risk of colorectal neoplasia. However, association between prediabetes and colorectal adenoma has not been reported.

AIMS

The aim of this study was to evaluate the relationship between prediabetes and the presence of colorectal adenomas.

METHODS

Consecutive prediabetic subjects who underwent screening colonoscopy were enrolled at Kyung Hee University Hospital in Gangdong, Seoul, Korea, between June 2006 and May 2012. Non-prediabetic subjects were separately pooled from the database of the Center for Health Promotion between January 2012 and May 2012. Prediabetes was defined according to the recommendations of the American Diabetes Association. The prevalence of colorectal adenomas and their characteristics were compared between prediabetic and non-prediabetic groups.

RESULTS

The prevalence of colorectal adenoma was higher in prediabetic subjects than in non-prediabetic subjects (39.6 vs. 30.6 %, respectively, p = 0.019). Prediabetic subjects had more multiple and high-risk adenomas than the control group in non-matched analysis (p = 0.000, respectively). In age-matched analysis, the prevalence of multiple and high-risk adenomas were significantly higher in a prediabetic group than those in a control group (44.4 vs. 28.4 %, p = 0.034; 51.9 vs. 34.6 %, p = 0.026, respectively). Furthermore, prediabetes (odds ratio = 2.198; 95 % confidence interval = 1.042-4.637; p = 0.039) was found to be an independent risk factor for a high-risk adenoma by multivariate analysis.

CONCLUSIONS

The prevalence of multiple and high-risk colorectal adenomas is significantly higher in the prediabetic subjects than those in the control group. Furthermore, prediabetes was found to be an independent risk factor for a high-risk colorectal adenoma.

Diabetes and risk of cancer

Diabetes and cancer represent two complex, diverse, chronic, and potentially fatal diseases. Cancer is the second leading cause of death, while diabetes is the seventh leading cause of death with the latter still likely underreported. There is a growing body of evidence published in recent years that suggest substantial increase in cancer incidence in diabetic patients. The worldwide prevalence of diabetes was estimated to rise from 171 million in 2000 to 366 million in 2030. About 26.9% of all people over 65 have diabetes and 60% have cancer. Overall, 8–18% of cancer patients have diabetes. In the context of epidemiology, the burden of both diseases, small association between diabetes and cancer will be clinically relevant and should translate into significant consequences for future health care solutions. This paper summarizes most of the epidemiological association studies between diabetes and cancer including studies relating to the general all-site increase of malignancies in diabetes and elevated organ-specific cancer rate in diabetes as comorbidity. Additionally, we have discussed the possible pathophysiological mechanisms that likely may be involved in promoting carcinogenesis in diabetes and the potential of different antidiabetic therapies to influence cancer incidence.

Association of diabetes and HbA1c levels with gastrointestinal manifestations

OBJECTIVE

To determine the prevalence of gastrointestinal (GI) manifestations associated with diabetes mellitus (DM) in a Taiwanese population undergoing bidirectional endoscopies.

RESEARCH DESIGN AND METHODS

Subjects voluntarily undergoing upper endoscopy/colonoscopy as part of a medical examination at the National Taiwan University Hospital were recruited during 2009. Diagnosis of DM included past history of DM, fasting plasma glucose ≥ 126 mg/dL, or glycated hemoglobin (HbA(1c)) ≥ 6.5%. Comparisons were made between diabetic and nondiabetic subjects, subjects with lower and higher HbA(1c) levels, and diabetic subjects with and without complications, respectively, for their GI symptoms, noninvasive GI testing results, and endoscopic findings.

RESULTS

Among 7,770 study subjects, 722 (9.3%) were diagnosed with DM. The overall prevalence of GI symptoms was lower in DM subjects (30.3 vs. 35.4%, P = 0.006). In contrast, the prevalence of erosive esophagitis (34.3 vs. 28.6%, P = 0.002), Barrett's esophagus (0.6 vs. 0.1%, P = 0.001), peptic ulcer disease (14.8 vs. 8.5%, P < 0.001), gastric neoplasms (1.8 vs. 0.7%, P = 0.003), and colonic neoplasms (26.6 vs. 16.5%, P < 0.001) was higher in diabetic subjects. Diagnostic accuracy of immunochemical fecal occult blood test for colonic neoplasms was significantly decreased in DM (70.7 vs. 81.7%, P < 0.001). Higher HbA(1c) levels were associated with a decrease of GI symptoms and an increase of endoscopic abnormalities. Diabetic subjects with complications had a higher prevalence of colonic neoplasms (39.2 vs. 24.5%, P = 0.002) than those without.

CONCLUSIONS

DM and higher levels of HbA(1c) were associated with lower prevalence of GI symptoms but higher prevalence of endoscopic abnormalities.

Glycated hemoglobin A1c is superior to fasting plasma glucose as an independent risk factor for colorectal neoplasia

OBJECTIVE

To investigate which glycemic index is more strongly associated with colorectal neoplasia.

METHOD

This cross-sectional study enrolled 2,776 participants in a comprehensive health management program which included measurement of fasting plasma glucose and HbA1c, along with screening colonoscopy. Primary outcome was colorectal adenoma with or without dysplasia. Risk factors for colorectal neoplasia were determined by the multivariate regression analysis, which evaluated the interrelationship among different glycemic indices in a hierarchical way.

RESULTS

Colorectal neoplasms were found in 605 (21.79%) examinees, 68 (2.45%) of whom had high-risk tumors. Glycemic indices including diagnosis of diabetes mellitus, fasting plasma glucose, and HbA1c were all associated with colorectal tumors in the univariate analysis. However, HbA1c outperformed the other two markers as an independent risk factor (adjusted odds ratio, 1.22; 95% confidence interval, 1.10-1.36%) for colorectal neoplasia. Moreover, only HbA1c remained independently associated with colorectal tumor after patients with established diagnosis of diabetes (n = 132) were excluded. We also identified age, male gender, and smoking were independent risk factors for colorectal neoplasia.

CONCLUSION

HbA1c as compared with fasting plasma glucose is more strongly and independently associated with colorectal neoplasia. Further research is warranted to elucidate the value of HbA1c in stratifying risk of colorectal cancer.