Fasting glucose and risk of colorectal cancer in the Korean Multi-center Cancer Cohort

<div><p>Previous cohort studies have demonstrated a positive association between diabetes mellitus (DM) and colorectal cancer (CRC). However, there are few comparisons between DM groups categorized by fasting glucose level. This study examined associations between diabetes as defined by fasting glucose level and self-reported history of DM and CRC risk among Korean adults. Data from the Korean Multi-center Cancer Cohort between 1993 and 2005 were analyzed. The study population comprised 14,570 participants aged 20 years or older. Participants were followed until December 31, 2012 (median follow-up: 11.9 years). Among participants with high fasting glucose (≥126mg/dL), the risk of developing CRC was significantly higher (HR: 1.51 [1.02–2.25]) than among participants with low fasting glucose (<126mg/dL). Risk was not significantly higher among participants with self-reported history of DM (HR: 1.34 [0.78–2.31]). When both fasting glucose and history of DM were considered together, the risk of CRC among participants with both high fasting glucose and history of DM was 54% (HR: 1.54 [0.97–2.43]), and the risk of CRC among participants with high fasting glucose and no history of DM was 50% (HR: 1.50 [0.73–3.05]). When the first 5 years of follow-up were excluded, among participants with high fasting glucose, the risk of developing CRC was significantly higher (HR: 1.61 [1.02–2.56]) than among participants with low fasting glucose. Risk of CRC was also significantly higher among participants with high fasting glucose and no history of DM (HR: 1.69 [1.01–2.84]). High fasting glucose and self-reported history of DM were associated with increased risk of CRC in this Korean population.</p></div

Hazard ratios (HRs) and 95% confidence intervals (CIs) for colorectal cancer according to fasting glucose level and history of diabetes mellitus (DM) after excluding the first 5 years of follow-up in the Korean Multi-center Cancer Cohort, 1993–2005.

<p>Hazard ratios (HRs) and 95% confidence intervals (CIs) for colorectal cancer according to fasting glucose level and history of diabetes mellitus (DM) after excluding the first 5 years of follow-up in the Korean Multi-center Cancer Cohort, 1993–2005.</p

Diabetes mellitus and risk of colorectal cancer

The Korean Multi-center Cancer Cohort is a population-based prospective cohort study designed to investigate the relationship between exposures to environmental factors, lifestyle factors, and the risk of cancer in Korea. A total of 20,636 participants (8,235 men and 12,401 women) were recruited from six geographic areas of Korea from 1993 to 2005. For these analyses, we excluded participants who had no information on age at cohort recruitment (1,182 men and 1,792 women), whose FSG level information was incomplete or who had no information about history of diabetes mellitus (1,007 men and 1,575 women), who were aged 20 years or younger (156 men and 334 women), who had a prior diagnosis of colorectal cancer (6 men and 13 women), or who were censored within one month from the baseline survey (1 man). After these exclusions, 14,570 participants (5,883 men and 8,687 women) were included in the final analysis. Data were created using SAS software version 9.4 (SAS Institute Inc., Cary, North Carolina, United States)

Hazard ratios (HRs) and 95% confidence intervals (CIs) for colorectal cancer according to fasting glucose level and history of diabetes mellitus (DM) in the Korean Multi-center Cancer Cohort, 1993–2005.

<p>Hazard ratios (HRs) and 95% confidence intervals (CIs) for colorectal cancer according to fasting glucose level and history of diabetes mellitus (DM) in the Korean Multi-center Cancer Cohort, 1993–2005.</p

General characteristics of the study participants according to history of diabetes mellitus (DM) and fasting glucose levels, Korean Multi-center Cancer Cohort, 1993–2005.

<p>General characteristics of the study participants according to history of diabetes mellitus (DM) and fasting glucose levels, Korean Multi-center Cancer Cohort, 1993–2005.</p

Additional file 1: Table S1. of Body mass index at age 18–20 and later risk of spontaneous abortion in the Health Examinees Study (HEXA)

Stratification analyses by gestational diabetes (GDM) for the likelihood for total and recurrent spontaneous abortion (SA) of body mass index (BMI) at 18–20 years old in the Health Examinee Study (HEXA), 2004–2012. (DOC 33 kb

Details of studies on type 2 diabetes for thyroid cancer risk.

<p>NIH-AARP (National Institutes of Health-American Association of Retired Persons) study; USRT (United States Radiologic Technologists) study; PLCO (Prostate, lung, colorectal and Ovarian Cancer Screening Trial) study.</p>a<p>Study quality was judged based on the Newcastle-Ottawa Scale (range, 1–9 stars).</p>b<p>Standardized incidence ratio (SIR) per 1,000,000 within reference population.</p>c<p>Prostate, lung, colorectal and Ovarian Cancer Screening Trial (PLCO) data.</p>d<p>Participants who were classified into the highest quintile (quintile 5) were regarded as diabetic patients (including level for impaired fasting glucose metabolism).</p>e<p>Participants with Impaired Fasting Glucose (IFG, 100≤FBS or OGTT<125) or Impaired Glucose Tolerance (IGT, 140≤OGTT≤199) by 2009 ADA criteria.</p>f<p>Controls were benign thyroid diseases.</p

Additional file 2: Table S2. of Body mass index at age 18–20 and later risk of spontaneous abortion in the Health Examinees Study (HEXA)

Stratification analyses by gestational hypertension (GHT) for the likelihood for total and recurrent spontaneous abortion (SA) of body mass index (BMI) at 18–20 years old in the Health Examinee Study (HEXA), 2004–2012. (DOC 33 kb

Meta-analysis of the association between diabetes mellitus and thyroid cancer in women: (a) all studies and (b) high quality studies.

<p>Meta-analysis of the association between diabetes mellitus and thyroid cancer in women: (a) all studies and (b) high quality studies.</p

Literature search algorithm.

<p>Literature search algorithm.</p