Dietary Insulin Load and Cancer Recurrence and Survival in Patients With Stage III Colon Cancer: Findings From CALGB 89803 (Alliance)

Post-diagnosis dietary factors, supplement use and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

The role of diet in colorectal cancer prognosis is not well understood and specific lifestyle recommendations are lacking. We searched for randomised controlled trials (RCTs) and longitudinal observational studies on post-diagnosis dietary factors, supplement use and colorectal cancer survival outcomes in PubMed and Embase from inception until 28th February 2022. Random-effects dose-response meta-analyses were conducted when at least three studies had sufficient information. The evidence was interpreted and graded by the CUP Global independent Expert Committee on Cancer Survivorship and Expert Panel. Five RCTs and 35 observational studies were included (30,242 cases, over 8700 all-cause and 2100 colorectal cancer deaths, 3700 progression, recurrence, or disease-free events). Meta-analyses, including 3-10 observational studies each, were conducted for: whole grains, nuts/peanuts, red and processed meat, dairy products, sugary drinks, artificially sweetened beverages, coffee, alcohol, dietary glycaemic load/index, insulin load/index, marine omega-3 polyunsaturated fatty acids, supplemental calcium, circulating 25-hydroxyvitamin D (25[OH]D) and all-cause mortality; for alcohol, supplemental calcium, circulating 25(OH)D and colorectal cancer-specific mortality; and for circulating 25(OH)D and recurrence/disease-free survival. The overall evidence was graded as 'limited'. The inverse associations between healthy dietary and/or lifestyle patterns (including diets that comprised plant-based foods), whole grains, total, caffeinated, or decaffeinated coffee and all-cause mortality and the positive associations between unhealthy dietary patterns, sugary drinks and all-cause mortality provided 'limited-suggestive' evidence. All other exposure-outcome associations provided 'limited-no conclusion' evidence. Additional, well-conducted cohort studies and carefully designed RCTs are needed to develop specific lifestyle recommendations for colorectal cancer survivors.

Long-term nutrition in patients candidate to neoadjuvant and adjuvant treatments

To improve outcomes, to decrease the rate of local recurrence and development of distant metastases neoadjuvant and adjuvant therapies are employed in cancer patients in forms of radiation, chemo-, endocrine-, targeted-, and immunotherapy or their combination. Nutrition therapy plays important role in all phases of the cancer journey. From neoadjuvant therapy to prehabilitation, early postoperative nutrition, and long-term nutrition care during the adjuvant phase and survivorship determines the survival and quality of life of cancer patients. During the neoadjuvant phase patients may be in poor nutritional condition which can be aggravated by the applied oncological treatment. Beside this apparent threat this period also gives an excellent opportunity to maintain or even improve the nutritional status of the patients by nutrition therapy. After surgery the burdening effects of the operation may jeopardize the execution of adjuvant therapy. After early postoperative feeding a long-term nutrition strategy should be developed for cancer patients in order to avoid nutritional deterioration during the usually lengthy postoperative therapy. In this narrative review we discuss how preoperative nutritional status and medical nutrition therapy influence the results of surgery and after the operation what is the available evidence about nutritional status and outcome and the potentials to influence them by nutrition therapy.

Adherence to the Paleolithic diet and Paleolithic-like lifestyle reduce the risk of colorectal cancer in the United States: a prospective cohort study

BACKGROUND

The plant-based paleolithic diet (PD) and the paleolithic-like lifestyle (PLL) may reduce the risk of chronic diseases, including colorectal adenomas. These dietary and lifestyle approaches are proposed to exert their effects through mechanisms such as reducing inflammation, oxidative stress, and insulin levels. However, whether PD and PLL is associated with the risk of colorectal cancer (CRC) has not been determined.

METHODS

A cohort of 74,721 individuals who participated in the PLCO study were included in this analysis. Adherence to the PD and PLL was assessed using PD and PLL scores, where higher scores indicated greater adherence. Multivariable Cox models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of CRC and its subsites (proximal colon cancer and distal CRC). Subgroup analyses were conducted to identify potential effect modifiers.

RESULTS

During a mean follow-up of 9.2 years, a total of 694 CRC cases were identified. Participants in the highest compared with the lowest quartiles of PD score had a lower risk of CRC (Q4 vs Q1: HR 0.76, 95% CI 0.61-0.95, P_trend = 0.009) and proximal colon cancer (Q4 vs Q1: HR 0.73, 95% CI 0.55-0.97, P_trend = 0.02). A stronger inverse association was observed for PLL score with the risk of CRC (Q4 vs Q1: HR 0.64, 95% CI 0.51-0.81, P_trend < 0.001), proximal colon (Q4 vs Q1: HR 0.62, 95% CI 0.46-0.83, P_trend = 0.001) and distal CRC (Q4 vs Q1: HR 0.69, 95% CI 0.48-0.98, P_trend = 0.03). Subgroup analyses revealed the inverse association of PD score with the risk of CRC was more pronounced in participants with BMI < 30 (Q4 vs Q1: HR 0.68, 95% CI 0.53-0.87) than in those with BMI ≥ 30 (Q4 vs Q1: HR 1.07, 95% CI 0.68-1.67) (P_interaction = 0.02).

CONCLUSIONS

Our findings suggest that adhering to the PD and PLL could be a new option to reduce CRC risk.

Carbohydrate quality indices and colorectal cancer risk: a case-control study

BACKGROUND

Colorectal cancer (CRC) is the fourth and third most common cancer in Iran and the world, respectively. Carbohydrates can lead to the proliferation of cancer cells, including CRC. The current study aimed to investigate the association between glycemic load (GL), insulin load (IL), glycemic index (GI), insulin index (II), low-carbohydrate diet score (LCDS), and carbohydrate quality index (CQI) with CRC odds.

METHODS

The present case-control study was performed on 71 CRC cases and 142 controls in the Hospital Cancer Organization and three general hospitals in Tehran, Iran. We calculated the dietary GI, GL, IL, II, CQI, and LCDS by a validated food frequency questionnaire.

RESULTS

The results indicated that people who were in the highest tertile of the GI had higher odds of CRC compared to the lower tertile (in the adjusted model: odds ratio (OR) = 3.89; 95% confidence interval (CI): 1.71-8.84). On the contrary, people who were in the highest tertile of the CQI and LCDS had significantly lower odds of CRC compared to the lower tertile (in the adjusted model: tertile (T) ₂-OR = 0.24; 95% CI: 0.11-0.53 and T₃-OR = 0.15; 95% CI: 0.06-0.39 for CQI and T₂-OR = 0.33; 95% CI: 0.13-0.79 and T₃-OR = 0.28; 95% CI: 0.10-0.82 for LCDS). Also, IL was positively associated with the odds of CRC after adjusting for confounding factors (T₂-OR = 2.46; CI: 1.08-5.61 and T₃- OR = 2.80; 95% CI: 1.07-7.31). Regarding the GL, only individuals who were in the second tertile had significantly higher odds of CRC compared to the first tertile (OR = 2.42; CI: 1.07-5.47).

CONCLUSION

According to the findings, it is recommended to use a diet with high-quality carbohydrates and low GI and GL to minimize the odds of developing CRC. People should also be encouraged to have a balanced carbohydrate intake.

Lifestyle interventions after colorectal cancer surgery using a mobile digital device: A study protocol for a randomized controlled trial

BACKGROUND

In treating colorectal cancer, surgical techniques and adjuvant treatments have advanced over the past century, but relatively less attention has been given to improve health-related quality of life (HRQOL). Recent studies report a significant association between cancer recurrence and patient lifestyle after surgery, hence emphasizing the need to assist patients to reduce this risk through appropriate lifestyle choices. The proposed study will evaluate the effects of digital interventions on lifestyle after surgery for colorectal cancer using mobile applications.

METHODS

A randomized controlled trial design was proposed. A total of 320 patients diagnosed with colorectal cancer aged between 20 and 70 years were to be enrolled and randomized in equal numbers into 4 groups (3 groups assigned to different mobile applications and a control group). Surveys that evaluate HRQOL, physical measurements, and metabolic parameters (fasting glucose, hemoglobin A1C, triglyceride, high-density lipoprotein cholesterol), and fat/muscle mass measurements by abdominal computed tomography (CT), will be conducted prior to surgery and every 6 months post-surgery for 18 months. Statistical analysis will be used to compare the outcomes between groups.

DISCUSSION

Results from this study could provide evidence that easily accessible mobile applications can influence patient lifestyles. Results showing minimal effects of such applications could also be constructive for improving healthcare-related applications.

Insulin and cancer: a tangled web

For a century, since the pioneering work of Otto Warburg, the interwoven relationship between metabolism and cancer has been appreciated. More recently, with obesity rates rising in the U.S. and worldwide, epidemiologic evidence has supported a link between obesity and cancer. A substantial body of work seeks to mechanistically unpack the association between obesity, altered metabolism, and cancer. Without question, these relationships are multifactorial and cannot be distilled to a single obesity- and metabolism-altering hormone, substrate, or factor. However, it is important to understand the hormone-specific associations between metabolism and cancer. Here, we review the links between obesity, metabolic dysregulation, insulin, and cancer, with an emphasis on current investigational metabolic adjuncts to standard-of-care cancer treatment.

Cancer and its predictors in Chinese adults with newly diagnosed diabetes and impaired glucose tolerance (IGT): a 30-year follow-up of the Da Qing IGT and Diabetes Study

Background

We aimed to explore if hyperglycaemia and hyperinsulinemia in the diabetes and prediabetes population were associated with increased risk of cancer occurence.

Methods

Overall, 1700 participants with different glycaemic statuses were screened from the 110,660 residents of Da-Qing, China, in 1985. They were followed up to 30 years to access cancer outcomes.

Results

Cancer was identified in 15.2% (259/1700) of the participants. The incidence of cancer in the normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and diabetes groups was 6.06, 6.77, and 7.18 per 1000 person-years, respectively (P = 0.02). In the Fine-Gray model with all cause death as competing risk, compared with the NGT controls, both IGT and diabetes groups demonstrated significantly higher risk of cancer (for the IGT group, adjusted hazard ratio (aHR) = 1.77, 95% CI 1.38–2.27, P < 0.0001; for the diabetes, aHR = 3.34, 95% CI 2.64–4.22, P < 0.0001). Among the IGT participants, progress to diabetes (aHR = 2.28, 95%CI 1.24–4.20, P = 0.008) and insulin-area under the curve at baseline (for 1 SD increase, aHR = 1.39, P = 0.02) were also associated with the risk of cancer after adjustment of covariables.

Conclusions

Hyperglycaemia in patients with diabetes, hyperinsulinemia, and progression to diabetes in people with IGT is significantly associated with the long-term increased risk of cancer occurrence.

The association of dietary insulin load and index with the risk of cancer and cancer mortality: a systematic review and meta-analysis

Purpose

Insulin levels play an important role in cancer development. However, the link between an insulinogenic diet and cancer is still unclear. Therefore, we performed a systematic review with meta-analysis to investigate the association between dietary insulin index (II) and load (IL) with cancer risk and mortality.

Methods

A comprehensive search between electronic databases (Web of Science, PubMed/Medline, Scopus, and Google Scholar) was conducted to identify relevant studies up to January 2022. The relative risks (RR) and Odds ratios (OR) were extracted from eligible studies, and meta-analysis was performed to calculate the pooled effect size.

Result

12 papers including 14 studies (10 cohorts and 4 case-control) were included for the meta-analysis. Among them, 10 studies reported effect size for the risk of cancer, and 4 studies reported effect size for cancer mortality. We observed no significant association between II and IL with cancer overall (RR_II: 1.03, 95%CI: 0.91-1.17, RR_IL: 1.16, 95%CI: 0.94-1.42) and in cohort studies, however, in case-control studies was related with higher odds of cancer (OR_II: 2.30, 95%CI: 1.21-4.38, OR_IL: 2.57, 95%CI: 1.64-4.02). Higher II and IL scores were associated with the increased risk of total (RR_II: 1.29, 95%CI: 1.02-1.63) and (RR_IL: 1.39, 95%CI: 1.06-1.83) and colorectal cancer mortality (RR_II: 1.29, 95%CI: 1.13-1.48) and (RR_IL: 1.37, 95%CI: 1.18-1.60).

Conclusion

Higher dietary II and IL were not associated with cancer risk in overall and cohort studies, whereas related with a higher risk of cancer in case-control studies. We observed a significant positive relation of II and IL with cancer mortality, especially CRC mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01013-3.

The Association between Dietary Insulin Index and Load with Gastric Cancer in Afghanistan

BACKGROUND

Insulin has a critical role in the pathogenesis of several cancers. We are aware of no study that examined the association between dietary insulin index (DII) and dietary insulin load (DIL) and gastric cancer.

OBJECTIVE

This study aimed to investigate the relationship between dietary insulin index and DIL and odds of gastric cancer in Afghanistan.

METHODS

In this hospital-based case-control study, we recruited 90 patients with newly-diagnosed gastric cancer and 180 healthy controls in Kabul, Afghanistan. Cases were chosen based on convenience-sampling method from the patients with pathologically confirmed gastric cancer aged between 20 and 75 years that had been referred to Jamhuriat Hospital, Kabul, Afghanistan. We applied a pre-tested food frequency questionnaire for dietary assessment of study participants. DIL and DII were calculated based on earlier publications. Multivariable logistic regression models were applied to examine the association between DII and DIL and gastric cancer.

RESULTS

Mean BMI of study participants was 23.55 ± 3.06 kg/m², of them 73% were males. After adjustment for potential confounders, participants in the top tertile of DII had 3.96 times greater odds for gastric cancer compared with those in the first tertile (95% CI: 1.23, 12.69; P-trend = 0.03). After adjustment for potential confounders, people in the highest tertile of DIL were 3.41 times more likely to have gastric cancer compared with those in the lowest tertile (95% CI: 1.28, 9.09; P-trend = 0.01). These associations remained significant even after further controlling for BMI, family history of cancer, H. pylori infection and salt intake.

CONCLUSION

A significant positive association was seen between dietary insulin index and insulin load and odds of gastric cancer in Afghan adults. Prospective cohort studies are required to confirm our findings.

Dietary insulin index and load with risk of breast cancer in a case-control study

OBJECTIVE

Circulating insulin levels have been positively associated with risk of breast cancer (BrCa); however, it remains unclear whether a diet inducing an elevated insulin response influences Breast risk.

METHODS

In this study, 250 newly diagnosed breast cancer patients and 250 hospitalised controls were recruited using convenience sampling. The dietary insulin index (DII) was calculated by dividing the dietary insulin load by the total energy intake.

RESULTS

Compared with those in the lowest tertiles of DII and dietary insulin load (DIL), subjects in the highest tertile were more likely to be overweight, have a family history of breast and other types of cancer and a history of benign breast diseases. After controlling for multiple potential confounders, a significantly increased BrCa odds was observed in the highest tertiles of DII and DIL score compared with the lowest tertiles (odds ratio (OR): 1.46; 95% CI: 0.67-3.19, P = .006) and (OR: 1.87; 95% CI: 0.92-3.80, P = .038), respectively.

CONCLUSIONS

Our findings suggest that a diet that induces an elevated postprandial insulin response, indicated by higher DII and DIL scores, may increase the odds of BrCa, especially among women.

Targeting Adipokines in Obesity-Related Tumors

Obesity, a global epidemic, is an independent risk factor for the occurrence and development of a variety of tumors, such as breast cancer, pancreatic cancer, ovarian cancer and colorectal cancer. Adipocytes are important endocrine cells in the tumor microenvironment of obesity-related tumors, which can secrete a variety of adipokines (such as leptin, adiponectin, estrogen, resistin, MIF and MCP-1, etc.), among which leptin, adiponectin and estrogen are the most in-depth and valuable ones. These adipokines are closely related to tumorigenesis and the progression of tumors. In recent years, more and more studies have shown that under chronic inflammatory conditions such as obesity, adipocytes secrete more adipokines to promote the tumorigenesis and development of tumors. However, it is worth noting that although adiponectin is also secreted by adipocytes, it has an anti-tumor effect, and can cross-talk with other adipokines (such as leptin and estrogen) and insulin to play an anti-tumor effect together. In addition, obesity is the main cause of insulin resistance, which can lead to the increase of the expression levels of insulin and insulin-like growth factor (IGF). As important regulators of blood glucose and lipid metabolism, insulin and IGF also play an important role in the progress of obesity related tumors. In view of the important role of adipokines secreted by adipocytes and insulin/IGF in tumors, this article not only elaborates leptin, adiponectin and estrogen secreted by adipocytes and their mechanism of action in the development of obesity- related tumors, but also introduces the relationship between insulin/IGF, a regulator of lipid metabolism, and obesity related tumors. At the same time, it briefly describes the cancer-promoting mechanism of resistin, MIF and MCP-1 in obesity-related tumors, and finally summarizes the specific treatment opinions and measures for various adipokines and insulin/insulin-like growth factors in recent years.

Personalized nutrition for colorectal cancer

The substantial burden of colorectal cancer and its increasing trend in young adults highlight the importance of dietary and lifestyle modifications for improved cancer prevention and survivorship. In this chapter, we review the cutting-edge evidence for the interplay between diet/lifestyle and the gut microbiota in the incidence and prognosis of colorectal cancer. We focus on factors for which there are data supporting their importance for the gut microbiota and colorectal cancer, including excess body weight, fiber, red and processed meat, and coffee. We discuss the potential precision nutrition approaches for modifying and exploiting the gut microbiota for improved cancer prevention and survivorship.

Dietary Intake in Association with All-Cause Mortality and Colorectal Cancer Mortality among Colorectal Cancer Survivors: A Systematic Review and Meta-Analysis of Prospective Studies

Simple Summary

Given that an extensive range of dietary factors has not been investigated among colorectal cancer (CRC) survivors to date, we carried out a systematic review and meta-analysis to determine the effects of both prediagnostic and postdiagnostic dietary intake on all-cause mortality and CRC-specific mortality among CRC survivors. In total, 45 studies were included in the final analysis of 35 food items, 8 macronutrients, 27 micronutrients, 2 dietary patterns, and 13 dietary indexes in association with all-cause mortality and CRC-specific mortality. We found that an unhealthy dietary pattern increased the risks of both all-cause mortality and CRC-specific mortality. The role of prediagnostic and postdiagnostic intake such as macronutrients and fatty acids could be different in the risk of all-cause mortality. Overall, comprehensive evidence for the effect of substantial numbers of prediagnostic and postdiagnostic dietary items on mortality outcomes is reported in this study.

Abstract

We carried out a systematic review and meta-analysis to determine the effects of both prediagnostic and postdiagnostic dietary intake on all-cause mortality and CRC-specific mortality among CRC survivors. An extensive search of PubMed and Embase was conducted to identify eligible studies. We applied a random-effects model to estimate the pooled relative risks (RRs)/hazard ratios (HRs) and their 95% confidence intervals (CIs). As a result, a total of 45 studies were included in the final analysis. Pooled effect sizes from at least three study populations showed that whole grains and calcium were inversely associated with all-cause mortality, with RRs/HRs (95% CIs) of 0.83 (0.69–0.99) and 0.84 (0.73–0.97), respectively. In contrast, a positive association between an unhealthy dietary pattern and both all-cause mortality (RR/HR = 1.47, 95% CI = 1.05–2.05) and CRC-specific mortality (RR/HR = 1.52, 95% CI = 1.13–2.06) was observed among CRC survivors. In the subgroup analysis by CRC diagnosis, prediagnostic and postdiagnostic dietary intake such as carbohydrates, proteins, lipids, and fiber were observed to have different effects on all-cause mortality. Overall, an unhealthy dietary pattern increased the risks of both all-cause mortality and CRC-specific mortality. The role of prediagnostic and postdiagnostic intake of dietary elements such as macronutrients and fatty acids could be different in the risk of all-cause mortality.

Association of Coffee Intake With Survival in Patients With Advanced or Metastatic Colorectal Cancer

Importance

Several compounds found in coffee possess antioxidant, anti-inflammatory, and insulin-sensitizing effects, which may contribute to anticancer activity. Epidemiological studies have identified associations between increased coffee consumption and decreased recurrence and mortality of colorectal cancer. The association between coffee consumption and survival in patients with advanced or metastatic colorectal cancer is unknown.

Objective

To evaluate the association of coffee consumption with disease progression and death in patients with advanced or metastatic colorectal cancer.

Design, Setting, and Participants

This prospective observational cohort study included 1171 patients with previously untreated locally advanced or metastatic colorectal cancer who were enrolled in Cancer and Leukemia Group B (Alliance)/SWOG 80405, a completed phase 3 clinical trial comparing the addition of cetuximab and/or bevacizumab to standard chemotherapy. Patients reported dietary intake using a semiquantitative food frequency questionnaire at the time of enrollment. Data were collected from October 27, 2005, to January 18, 2018, and analyzed from May 1 to August 31, 2018.

Exposures

Consumption of total, decaffeinated, and caffeinated coffee measured in cups per day.

Main Outcomes and Measures

Overall survival (OS) and progression-free survival (PFS).

Results

Among the 1171 patients included in the analysis (694 men [59%]; median age, 59 [interquartile range, 51-67] years). The median follow-up time among living patients was 5.4 years (10th percentile, 1.3 years; IQR, 3.2-6.3 years). A total of 1092 patients (93%) had died or had disease progression. Increased consumption of coffee was associated with decreased risk of cancer progression (hazard ratio [HR] for 1-cup/d increment, 0.95; 95% CI, 0.91-1.00; P = .04 for trend) and death (HR for 1-cup/d increment, 0.93; 95% CI, 0.89-0.98; P = .004 for trend). Participants who consumed 2 to 3 cups of coffee per day had a multivariable HR for OS of 0.82 (95% CI, 0.67-1.00) and for PFS of 0.82 (95% CI, 0.68-0.99), compared with those who did not drink coffee. Participants who consumed at least 4 cups of coffee per day had a multivariable HR for OS of 0.64 (95% CI, 0.46-0.87) and for PFS of 0.78 (95% CI, 0.59-1.05). Significant associations were noted for both caffeinated and decaffeinated coffee.

Conclusions and Relevance

Coffee consumption may be associated with reduced risk of disease progression and death in patients with advanced or metastatic colorectal cancer. Further research is warranted to elucidate underlying biological mechanisms.

Post-diagnosis dietary insulinemic potential and survival outcomes among colorectal cancer patients

Background

The empirical dietary index for hyperinsulinemia (EDIH) score is a validated food-based dietary score that assesses the ability of whole-food diets to predict plasma c-peptide concentrations. Although the EDIH has been extensively applied and found to be predictive of risk of developing major chronic diseases, its influence on cancer survival has not been evaluated. We applied the EDIH score in a large cohort of colorectal cancer patients to assess the insulinemic potential of their dietary patterns after diagnosis and determine its influence on survival outcomes.

Methods

We calculated EDIH scores to assess the insulinemic potential of post-diagnosis dietary patterns and examined survival outcomes in a sample of 1718 stage I-III colorectal cancer patients in the Nurses’ Health Study and Health Professionals Follow-up Study cohorts. Multivariable-adjusted Cox regression was applied to compute hazard ratios (HR) and 95% confidence intervals (CI) for colorectal cancer-specific mortality and all-cause mortality. We also examined the influence of change in diet from pre- to post-diagnosis period, on mortality.

Results

During a median follow-up of 9.9 years, there were 1008 deaths, which included 272 colorectal cancer-specific deaths (27%). In the multivariable-adjusted analyses, colorectal cancer patients in the highest compared to lowest EDIH quintile, had a 66% greater risk of dying from colorectal cancer: HR, 1.66; 95% CI, 1.03, 2.69; and a 24% greater risk of all-cause death: HR, 1.24; 95%CI, 0.97, 1.58. Compared to patients who consumed low insulinemic diets from pre- to post-diagnosis period, patients who persistently consumed hyperinsulinemic diets were at higher risk of colorectal cancer death (HR,1.51; 95%CI, 0.98, 2.32) and all-cause death (HR, 1.31; 95%CI, 1.04, 2.64).

Conclusion

Our findings suggest that a hyperinsulinemic dietary pattern after diagnosis of colorectal cancer is associated with poorer survival. Interventions with dietary patterns to reduce insulinemic activity and impact survivorship are warranted.

Insulinemic Potential of Lifestyle Is Inversely Associated with Leukocyte Mitochondrial DNA Copy Number in US White Adults

BACKGROUND

Poor lifestyles have been linked to insulin insensitivity/hyperinsulinemia, which may contribute to downstream changes such as inflammation and oxidative damage and the development of chronic diseases. As a biomarker of intracellular oxidative stress, leukocyte mitochondrial DNA copy number (mtDNA-CN) has been related to lifestyle factors including diet and weight. No epidemiologic study has examined the relation between combined insulinemic potential of lifestyle and mtDNA-CN.

OBJECTIVES

Our aim was to examine the association between Empirical Lifestyle Index for Hyperinsulinemia (ELIH) and leukocyte mtDNA-CN in US men and women.

METHODS

This cross-sectional analysis included 2835 white adults without cancers, diabetes, or cardiovascular disease at blood collection, including 2160 women from the Nurses' Health Study and 675 men from the Health Professionals Follow-Up Study. ELIH is an index based on plasma C-peptide that characterizes the insulinemic potential of lifestyle (diet, body weight, and physical activity). Relative mtDNA-CN in peripheral blood leukocytes was measured by qPCR-based assay.

RESULTS

We found a significant inverse association between ELIH and mtDNA-CN. In multivariable-adjusted linear models, absolute least squares means ± SDs of mtDNA-CN z score across ELIH quintiles in women were as follows: Q1: 0.14 ± 0.05; Q2: 0.04 ± 0.06; Q3: 0.008 ± 0.05; Q4: 0.01 ± 0.05; and Q5: -0.06 ± 0.05 (P-trend = 0.006). Means ± SDs in men were as follows: Q1: 0.25 ± 0.09; Q2: 0.23 ± 0.09; Q3: 0.07 ± 0.09; Q4: 0.02 ± 0.09; and Q5: -0.04 ± 0.09 (P-trend = 0.007). Means ± SDs in all participants were as follows: Q1: 0.16 ± 0.05; Q2: 0.07 ± 0.05; Q3: 0.01 ± 0.05; Q4: 0.01 ± 0.05; and Q5: -0.05 ± 0.05 (P-trend = 0.0004).

CONCLUSIONS

Hyperinsulinemic lifestyles (i.e., higher ELIH) were associated with lower leukocyte mtDNA-CN among subjects without major diseases, suggesting that the difference in lifestyle insulinemic potential may be related to excessive oxidative stress damage.

The Diet of Higher Insulinemic Potential Is Not Associated with Worse Survival in Patients with Stage III Colon Cancer (Alliance)

BACKGROUND

Hyperinsulinemia is considered to be important in the development of colon cancer, but few studies have investigated the associations of hyperinsulinemia with colon cancer survival via dietary scores.

METHODS

Empirical dietary index for hyperinsulinemia (EDIH) was derived to assess the insulinemic potential of daily diets reflecting the long-term insulin exposure, with higher (more positive) scores indicating higher insulinemic diets. We prospectively estimated the HRs and 95% confidence intervals (CI) to investigate the association of EDIH with disease-free, recurrence-free, and overall survival among patients with stage III colon cancer (1999-2009) enrolled in a randomized adjuvant chemotherapy trial (CALGB 89803).

RESULTS

Of 1,024 patients (median follow-up: 7.3 years), 311 died, 350 had recurrences, and 394 had events for disease-free survival. Compared with patients in the lowest quintile of EDIH, the corresponding HRs of patients in the highest quintile for disease-free survival events, cancer recurrence, and overall mortality were 0.80 (95% CI, 0.56-1.15), 0.76 (95% CI, 0.51-1.11), and 0.77 (95% CI, 0.52-1.14).

CONCLUSIONS

Higher EDIH was not associated with the risk of colon cancer recurrence or mortality in this population of patients with stage III colon cancer.

IMPACT

EDIH, as a measure of dietary insulinemic potential, may be associated with colon cancer risk but not survival in patients with late-stage colon cancer.