The tetrad BMI, leptin, leptin/adiponectin (L/A) ratio and CA 15-3 are reliable biomarkers of breast cancer

Increases in BMI contribute to worsening inflammatory biomarkers related to breast cancer risk in women: a longitudinal study

BACKGROUND

Inflammatory adipokines and cytokines play a pivotal role in linking obesity and breast cancer (BC) risk in women. We investigated the longitudinal associations between BMI change and trajectories of inflammatory biomarkers related to BC risk.

METHODS

A longitudinal study was conducted among 442 Chinese women with 3-year repeated measures from 2019 to 2021. Plasma circulating inflammatory biomarkers related to BC risk, including adiponectin (ADP), resistin (RETN), soluble leptin receptor (sOB-R), insulin-like growth factor-binding protein-3 (IGFBP-3), and C-reactive protein (CRP), were examined annually. Linear mixed-effect models (LMM) were applied to investigate associations of time-varying BMI with trajectories of biomarkers. We additionally examined the modification effect of baseline BMI groups, menopausal status, and metabolic syndrome.

RESULTS

BMI was associated with increased levels of RETN, CRP, sOB-R, and decreased levels of ADP at baseline. An increasing BMI rate was significantly associated with an average 3-year increase in RETN (β = 0.019, 95% CI 0.004 to 0.034) and sOB-R (β = 0.022, 95% CI 0.009 to 0.035), as well as a decrease in ADP (β =  - 0.006, 95% CI  - 0.012 to 0.001). These associations persisted across different baseline BMI groups. An increasing BMI rate was significantly associated with an average 3-year increase in CRP levels among normal weight (β = 0.045, 95% CI 0.001 to 0.088) and overweight (β = 0.060, 95% CI 0.014 to 0.107) women. As BMI increased over time, a more remarkable decrease in ADP was observed among women with metabolic syndrome (β =  - 0.016, 95% CI - 0.029 to - 0.004) than those without metabolic syndrome at baseline.

CONCLUSIONS

A higher increase rate of BMI was associated with poorer trajectories of inflammatory biomarkers related to BC risk. Recommendations for BMI reduction may benefit BC prevention in women, particularly for those with metabolic syndrome.

[Association of Body Mass Index and Weight Gain With Obesity-Related Breast Cancer Risk Biomarkers in Adult Chinese Women]

Objective

To investigate the associatiojn of body mass index (BMI) at different stages of life and weight gain in adulthood with obesity-related breast cancer risk biomarkers and to provide evidence for formulating policies concerning the prevention and control of breast cancer.

Methods

A cross-sectional study was designed based on the follow-up cohort of southwest China community-based breast cancer screening of women. Using sequential sampling, eligible participants were enrolled from the cohort as the subjects of the study. Information on the basic risk factors was collected and the height, weight, and plasma biomarker levels were measured. Multiple linear regression model was applied to analyze the associations of early adulthood BMI (defined as the BMI of the participant at age 20), adulthood BMI (defined as the BMI measured at the time of enrollment), and weight gain in adulthood with the biomarkers. The concentrations of the biomarkers were incorporated in the model after log transformation.

Results

The average age of the 442 participants was 49 (45, 54) years old, the average early adulthood BMI and adulthood BMI were 21.47 (19.56, 23.11) and 24.10 (22.59, 25.97) kg/m 2, respectively, and the average weight gain in adulthood was 6.60 (2.00, 11.00) kg. Adulthood BMI was negatively associated with adiponectin level ( β=-0.026, 95% CI: -0.045--0.008, P=0.006), and positively associated with C-reactive protein level ( β=0.095, 95% CI: 0.054-0.137, P<0.001) and leptin receptor level ( β=0.090, 95% CI: 0.063-0.117, P<0.001). No association was found between adulthood BMI and resistin levels or between adulthood BMI and insulin-like growth factor-binding protein-3 levels. BMI in early adulthood was found to be negatively associated with only insulin-like growth factor-binding protein-3 levels ( β=-0.039, 95% CI: -0.068--0.010, P=0.009). Further analysis of adulthood weight gain after the age of 20 revealed that average annual weight gain in adulthood was negatively associated with adiponectin levels and positively associated with 4 other biomarkers. Furthermore, compared with those of women whose weight remained stable, the adiponectin level of women whose weight gain in adulthood exceeded 5.00 kg was much lower ( β=-0.185, 95% CI: -0.320--0.049, P=0.008), while their insulin-like growth factor-binding protein-3 ( β=0.389, 95% CI: 0.183-0.594, P<0.001) and leptin receptor ( β=0.245, 95% CI: 0.048-0.442, P=0.015) levels were higher.

Conclusion

Weight gain in adulthood is strongly associated with the changes in obesity-related breast cancer risk biomarkers. Women should maintain a stable weight throughout adulthood and it is preferred that their weight gain should not exceed 5.00 kg.

Effectiveness of a Global Multidisciplinary Supportive and Educational Intervention in Thermal Resort on Anthropometric and Biological Parameters, and the Disease-Free Survival after Breast Cancer Treatment Completion (PACThe)

A growing knowledge highlights the strong benefit of regular physical activity in the management of breast cancer patients, but few studies have considered biological parameters in their outcomes. In the prospective randomised trial after breast cancer treatment completion “PACThe,” we determined the effects of physical activity and nutritional intervention on the biological and anthropometric status of patients after one year of follow-up, and clarified the link between biomarkers at allocation and disease-free survival. 113 patients from the population of the “PACThe” study (n = 251) were analysed for biological parameters. Patients were randomized after chemotherapy in two arms: the intervention “SPA” receiving a 2-week session of physical training, dietary education, and physiotherapy (n = 57), and the control “CTR” (n = 56). Diet questionnaire, anthropometric measures, and blood parameters were determined at allocation and one year later. Survival and recurrence were checked over 7 years. Data were considered as a function of BMI, i.e., ≤25 for normal, 25–30 for overweight, and >30 for obese patients. At allocation, the large standard deviation for nutrient-intake values reflected an unbalanced diet for some patients in the three groups. At one-year follow-up, we noticed an increase in glucose (p < 10⁻⁶), insulin (p < 10⁻⁷), and adiponectin (p < 0.022) plasma levels for both intervention arms, which were more accentuated for the >30 groups. Using the Cox model, we demonstrated that the highest testosterone plasma values were linked to an increase of the recurrence risk (HR [CI–95%] = 5.06 [1.66–15.41]; p=0.004). One-year after a global multidisciplinary supportive and educational intervention, we found few anthropometric and biological changes, mainly related to the patient's initial BMI. We highlighted the importance of plasma testosterone in the evaluation of patient's recurrence risk. Future studies would help better understand the mechanisms by which such multidisciplinary interventions could interact with breast cancer recurrence and define the most effective modalities.

A Computational Statistics Approach to Evaluate Blood Biomarkers for Breast Cancer Risk Stratification

Breast cancer is the second leading cause of cancer mortality among women. Mammography and tumor biopsy followed by histopathological analysis are the current methods to diagnose breast cancer. Mammography does not detect all breast tumor subtypes, especially those that arise in younger women or women with dense breast tissue, and are more aggressive. There is an urgent need to find circulating prognostic molecules and liquid biopsy methods for breast cancer diagnosis and reducing the mortality rate. In this study, we systematically evaluated metabolites and proteins in blood to develop a pipeline to identify potential circulating biomarkers for breast cancer risk. Our aim is to identify a group of molecules to be used in the design of portable and low-cost biomarker detection devices. We obtained plasma samples from women who are cancer free (healthy) and women who were cancer free at the time of blood collection but developed breast cancer later (susceptible). We extracted potential prognostic biomarkers for breast cancer risk from plasma metabolomics and proteomics data using statistical and discriminative power analyses. We pre-processed the data to ensure the quality of subsequent analyses, and used two main feature selection methods to determine the importance of each molecule. After further feature elimination based on pairwise dependencies, we measured the performance of logistic regression classifier on the remaining molecules and compared their biological relevance. We identified six signatures that predicted breast cancer risk with different specificity and selectivity. The best performing signature had 13 factors. We validated the difference in level of one of the biomarkers, SCF/KITLG, in plasma from healthy and susceptible individuals. These biomarkers will be used to develop low-cost liquid biopsy methods toward early identification of breast cancer risk and hence decreased mortality. Our findings provide the knowledge basis needed to proceed in this direction.

Leptin/adiponectin ratio correlates with hepatic steatosis but not arterial stiffness in nonalcoholic fatty liver disease in Japanese population

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is a leading cause of mortality in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the relationship of leptin-to-adiponectin (L/A) ratio with hepatic steatosis and arterial stiffness in NAFLD.

METHODS

The subjects were 871 Japanese adults who participated in a health survey. Dietary intake, body composition, lipid profile, serum interleukin-6 (IL-6), leptin, and adiponectin were analyzed. NAFLD was defined as fatty liver on ultrasonography in the absence of other causes of steatosis. Arterial stiffness was evaluated by the brachial-ankle pulse wave velocity (baPWV).

RESULTS

The subjects with NAFLD had a greater body mass index (BMI) and body fat percentage (BFP); a higher intake of daily energy (kcal) and carbohydrates; and a higher prevalence of hypertension, diabetes, and hyperlipidemia. The subjects with NAFLD had higher serum leptin and lower serum adiponectin concentrations and a higher L/A ratio than subjects without NAFLD. The L/A ratio increased with increasing severity of steatosis. The L/A ratio showed positive correlations with BMI and BFP, and a negative correlation with age. Women had higher L/A ratio and BFP levels than men regardless of the presence or absence of NAFLD. There was a weak positive correlation between baPWV and severity of steatosis. BaPWV was strongly correlated with age, while no relation was found between baPWV and L/A ratio. IL-6 level was correlated with baPVW and age, while the correlation between Il and 6 level and L/A ratio was very weak. The L/A ratio was correlated with triglycerides and the ratio of total cholesterol to high-density lipoprotein-cholesterol.

CONCLUSION

L/A ratio and arterial stiffness were associated with the severity of steatosis, whereas there was no correlation between L/A ratio and arterial stiffness in NAFLD. These findings suggest that not only leptin and adiponectin but also other factors might be involved in the pathogenesis for atherosclerosis in NAFLD.

The weight of obesity in breast cancer progression and metastasis: Clinical and molecular perspectives

The escalating epidemic of overweight and obesity is currently recognized as one of the most significant health and economic concern worldwide. At the present time, over 1.9 billion adults and more than 600 million people can be, respectively, classified as overweight or obese, and numbers will continue to increase in the coming decades. This alarming scenario implies important clinical implications since excessive adiposity can progressively cause and/or exacerbate a wide spectrum of co-morbidities, including type 2 diabetes mellitus, hypertension, cardiovascular disease, and even certain types of cancer, including breast cancer. Indeed, pathological remodelling of white adipose tissue and increased levels of fat-specific cytokines (mainly leptin), as a consequence of the obesity condition, have been associated with several hallmarks of breast cancer, such as sustained proliferative signaling, cellular energetics, inflammation, angiogenesis, activating invasion and metastasis. Different preclinical and clinical data have provided evidence indicating that obesity may worsen the incidence, the severity, and the mortality of breast cancer. In the present review, we will discuss the epidemiological connection between obesity and breast cancer progression and metastasis and we will highlight the candidate players involved in this dangerous relationship. Since the major cause of death from cancer is due to widespread metastases, understanding these complex mechanisms will provide insights for establishing new therapeutic interventions to prevent/blunt the effects of obesity and thwart breast tumor progression and metastatic growth.

The Effect of the Leptin and Leptin Receptor Expression on the Efficacy of Neoadjuvant Chemotherapy in Breast Cancer

Background

The purpose of the present study was to evaluate the effect of leptin and leptin receptor (LEPR) expression on the efficacy of neoadjuvant chemotherapy in breast cancer.

Material/Methods

There were 325 breast cancer patients with complete data enrolled in this study. Patients were categorized into 3 groups: pathological complete response group, non-pathological complete response group, and progressive disease group. Immunohistochemistry was performed to determine leptin and its receptor LEPR expression levels that were compared among the 3 groups.

Results

Compared with the non-pathological complete response group, patients in the pathological complete response group had increased leptin and LEPR expression, although the difference was not statistically significant (P=0.194, P=0.110). In addition, the expression of leptin and LEPR in the pathological complete response group was also higher than that in the progressive disease group, and the difference of LEPR expression was statistically significant (P=0.008) while the leptin expression was not (P=0.065). There were more HER2+ breast cancer patients in the pathological complete response group categorized into strong positive, and positive expression of leptin and LEPR compared with the progressive disease group (P<0.05). There were significant differences of leptin and LEPR expression among breast cancer patients under different molecular subtypes HER2+, HR+, and triple negative, in which the triple negative patients had the highest expression of leptin and LEPR. In addition, patients in the progressive disease group had high and low expression of leptin and LEPR: 13.25% versus 11.32% and 13.1% versus 10.42% respectively.

Conclusions

Overexpression of leptin and LEPR improved the therapeutic efficacy of neoadjuvant chemotherapy for patients with breast cancer, especially for those with HER2+ subtype. Overexpression of leptin and LEPR was distinct among the different molecular subtypes of breast cancer, suggesting a certain predictive value for breast cancer prognosis.

Association of serum leptin with breast cancer: A meta-analysis

BACKGROUND

Accumulating evidence has demonstrated that leptin is associated to the tumorigenesis and progression of breast cancer (BC). However, these studies remain inconsistent. Thus, a meta-analysis was conducted to investigate the role of leptin in the patients with BC.

METHOD

A systematic search in PubMed, Embase, ISI Web of Science, and Chinese National Knowledge Infrastructure (CNKI) databases was conducted up to September 1, 2017. The standardized mean difference (SMD) with 95% confidence interval (CI) was applied to pool the effect size. A funnel plot and Egger test were used to evaluate publication bias.

RESULTS

Finally, 43 eligible studies were included in the current meta-analysis. Overall, serum leptin levels in BC cases were significantly higher compared with the controls (SMD = 0.61, P <.0001). When subgroup analyses were restricted to ethnicity and menstrual status, higher serum leptin concentration was also detected in patients with BC. Moreover, BC cases with body mass index (BMI) >25 indicated significantly higher serum leptin levels (SMD = 1.48, P = .034). Furthermore, the BC cases with lymph node metastases showed significantly higher serum leptin concentration (SMD = 0.53, P = .015).

CONCLUSION

The present meta-analysis suggests that the serum leptin may profiles as a pivotal role in the pathogenesis and metastasis of BC. In addition, leptin will provide useful information for a therapeutic target to treat BC.

Association of serum adiponectin with breast cancer: A meta-analysis of 27 case-control studies

BACKGROUND

Emerging published studies have indicated that adiponectin is involved in tumorigenesis of breast cancer. However, the results of available studies were inconsistent. The aim of this updated meta-analysis was to assess the association of adiponectin with breast cancer.

MATERIALS AND METHODS

PubMed, EMBASE, Wanfang databases, and the China National Knowledge Infrastructure (CNKI) were systematically searched from inception to June 2018. The mean difference (MD) with 95% confidence interval (CI) were estimated and pooled to investigate the effect sizes.

RESULTS

Twenty-seven eligible articles that met the study criteria were included in the current meta-analysis. Overall, there was an evident inverse association between serum adiponectin levels and breast cancer (MD = -0.29, 95%CI = (-0.38, -0.21), P < .001). Asian subgroup showed a significant negative association between serum adiponectin concentrations and breast cancer in subgroup analysis by ethnicity (MD = -2.19, 95%CI = (-3.45, -0.94), P < .001). However, no statistical significance was found in Caucasian subgroup (MD = -0.65, 95%CI = (-1.47, 0.17), P = 0.12). Additionally, a further subgroup analysis of Asian stratified by menopausal status showed higher concentrations of adiponectin in healthy control group, whether they were premenopausal (MD = -0.85, 95%CI = (-1.50, -0.19), P = .01) or postmenopausal (MD = -2.17, 95%CI = (-4.17, -0.18), P = .03). No significant difference was observed concerning the association between serum adiponectin and breast cancer metastasis (MD = -1.56, 95%CI = (-4.90, 1.78), P = .36).

CONCLUSION

The current meta-analysis suggests that the serum adiponectin may be inversely associated with breast cancer. Decreased serum adiponectin levels in premenopausal women may also be inversely associated with breast cancer risk other than postmenopausal status. In addition, low serum adiponectin levels in Asian women were more likely to be associated with breast cancer risk than Caucasian women.

Serum adiponectin in breast cancer: A meta-analysis

BACKGROUND

Accumulating data have found that adiponectin is involved in development of breast cancer (BC). However, these results were inconsistent.

METHOD

A systematic search in PubMed, Embase, ISI Web of Science, and Chinese National Knowledge Infrastructure databases were conducted up to October 1, 2017. The standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size.

RESULTS

Finally, 31 eligible studies were included in this meta-analysis. The overall results indicated that serum adiponectin levels in BC cases were significantly lower than the controls (SMD = -0.33, P < 0.0001). As for the subgroup analysis of menstrual status, serum adiponectin levels were significantly lower in pre- and postmenopausal BC cases. Moreover, the subgroup analysis by ethnicity in pre- and postmenopausal group indicated an inverse association between adiponectin levels and BC risk in Asian population, but not in Caucasian population.

CONCLUSION

The present meta-analysis suggests that low serum adiponectin concentration may be associated with an increased BC risk in premenopausal and postmenopausal women, especially among Asians. Adiponectin may serve as a biomarker of BC risk and help to identify subjects at high risk for BC development.

Association between serum leptin levels and breast cancer risk: An updated systematic review and meta-analysis

BACKGROUND

Many studies have indicated that leptin is correlated with breast cancer occurrence and tumor behavior. However, this issue remains controversial. Therefore, we conducted an updated meta-analysis to investigate the role of leptin in breast cancer.

METHODS

We performed a systematic literature search and identified relevant papers up to 1 September 2017. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to evaluate effect sizes.

RESULTS

Thirty-five eligible studies were included in the current meta-analysis. Serum leptin levels were related to breast cancer risk as demonstrated by calculations of the overall SMD = 0.46 (95% CI = 0.31-0.60, I = 93.5%). A subgroup analysis of BMI identified an association between breast cancer and serum leptin levels in patients who are overweight and obese (overweight: SMD = 0.35, 95% CI = 0.13-0.57, I = 88.1%; obesity: SMD = 1.38, 95% CI = 0.64-2.12, I = 89.6%). Additionally, menopausal status subgroup analysis revealed a significant association in postmenopausal women (SMD = 0.26, 95% CI = 0.12-0.40, I = 77.9%). Furthermore, we identified a significant association between breast cancer and serum leptin levels in Chinese women (SMD = 0.61, 95% CI = 0.44-0.79, I = 40.6%).

CONCLUSION

The results of this meta-analysis suggested that leptin could be a potential biomarker for breast cancer risk in women, especially overweight/obese or postmenopausal women. Therefore, it may be useful for identifying subjects with a high risk for breast cancer who may benefit from preventive treatments.

Using Resistin, glucose, age and BMI to predict the presence of breast cancer

Background

The goal of this exploratory study was to develop and assess a prediction model which can potentially be used as a biomarker of breast cancer, based on anthropometric data and parameters which can be gathered in routine blood analysis.

Methods

For each of the 166 participants several clinical features were observed or measured, including age, BMI, Glucose, Insulin, HOMA, Leptin, Adiponectin, Resistin and MCP-1. Machine learning algorithms (logistic regression, random forests, support vector machines) were implemented taking in as predictors different numbers of variables. The resulting models were assessed with a Monte Carlo Cross-Validation approach to determine 95% confidence intervals for the sensitivity, specificity and AUC of the models.

Results

Support vector machines models using Glucose, Resistin, Age and BMI as predictors allowed predicting the presence of breast cancer in women with sensitivity ranging between 82 and 88% and specificity ranging between 85 and 90%. The 95% confidence interval for the AUC was [0.87, 0.91].

Conclusions

These findings provide promising evidence that models combining age, BMI and metabolic parameters may be a powerful tool for a cheap and effective biomarker of breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3877-1) contains supplementary material, which is available to authorized users.

Leptin and Adiponectin Modulate the Self-renewal of Normal Human Breast Epithelial Stem Cells

Multiple mechanisms are likely to account for the link between obesity and increased risk of postmenopausal breast cancer. Two adipokines, leptin and adiponectin, are of particular interest due to their opposing biologic functions and associations with breast cancer risk. In the current study, we investigated the effects of leptin and adiponectin on normal breast epithelial stem cells. Levels of leptin in human adipose explant-derived conditioned media positively correlated with the size of the normal breast stem cell pool. In contrast, an inverse relationship was found for adiponectin. Moreover, a strong linear relationship was observed between the leptin/adiponectin ratio in adipose conditioned media and breast stem cell self-renewal. Consistent with these findings, exogenous leptin stimulated whereas adiponectin suppressed breast stem cell self-renewal. In addition to local in-breast effects, circulating factors, including leptin and adiponectin, may contribute to the link between obesity and breast cancer. Increased levels of leptin and reduced amounts of adiponectin were found in serum from obese compared with age-matched lean postmenopausal women. Interestingly, serum from obese women increased stem cell self-renewal by 30% compared with only 7% for lean control serum. Taken together, these data suggest a plausible explanation for the obesity-driven increase in postmenopausal breast cancer risk. Leptin and adiponectin may function as both endocrine and paracrine/juxtacrine factors to modulate the size of the normal stem cell pool. Interventions that disrupt this axis and thereby normalize breast stem cell self-renewal could reduce the risk of breast cancer.

Relationship between body mass index and incidence of breast cancer

OBJECTIVE

To investigate the relationship between body mass index (BMI) and the breast cancer incidence, so as to making contribution to breast cancer screening in high-risk groups, to adjustment from passive medical treatment to active treatment Methods: BMI status of 206 breast cancer patients and that of 210 healthy subjects at different ages were compared and analyzed.

RESULTS

The mean BMI was significantly higher in breast cancer patients than in healthy subjects 24.45±3.50 vs. 23.80±3.10 kg/m(2), t=-2.189, P=0.001. When stratified by age, BMI were significantly higher in ≥60 age for breast cancer than that of control group (Z=-3.408, P=0.001) and no significant difference in <60 years old .Logistic regression analysis showed that BMI was a risk factor of breast cancer (OR=1.886, 95% CI: 1.122-3.009).

CONCLUSION

BMI have a relationship with the occurrence of breast cancer, especially for ≥60 years old.

A dwarf mouse model with decreased GH/IGF-1 activity that does not experience life-span extension: potential impact of increased adiposity, leptin, and insulin with advancing age

Reduced growth hormone (GH) action is associated with extended longevity in many vertebrate species. GH receptor (GHR) null (GHR(-)(/-)) mice, which have a disruption in the GHR gene, are a well-studied example of mice that are insulin sensitive and long lived yet obese. However, unlike other mouse lines with reduced GH action, GH receptor antagonist (GHA) transgenic mice have reduced GH action yet exhibit a normal, not extended, life span. Understanding why GHA mice do not have extended life span though they share many physiological attributes with GHR(-)(/-) mice will help provide clues about how GH influences aging. For this study, we examined age- and sex-related changes in body composition, glucose homeostasis, circulating adipokines, and tissue weights in GHA mice and littermate controls. Compared with previous studies with GHR(-)(/-) mice, GHA mice had more significant increases in fat mass with advancing age. The increased obesity resulted in significant adipokine changes. Euglycemia was maintained in GHA mice; however, hyperinsulinemia developed in older male GHA mice. Overall, GHA mice experience a more substantial, generalized obesity accompanied by altered adipokine levels and glucose homeostasis than GHR(-)(/-) mice, which becomes more exaggerated with advancing age and which likely contributes to the lack of life-span extension in these mice.

Peripheral Pathways in the Food-Intake Control towards the Adipose-Intestinal Missing Link

In the physiological state a multitude of gut hormones are released into the circulation at the same time depending on the quality and quantity of the diet. These hormones interact with receptors at various points in the "gut-brain axis" to affect short-term and intermediate-term feelings of hunger and satiety. The combined effects of macronutrients on the predominant gut hormone secretion are still poorly understood. Besides, adipokines form an important part of an "adipoinsular axis" dysregulation which may contribute to β -cell failure and hence to type 2 diabetes mellitus (T2DM). Even more, gestational diabetes mellitus (GDM) and T2DM seem to share a genetic basis. In susceptible individuals, chronic exaggerated stimulation of the proximal gut with fat and carbohydrates may induce overproduction of an unknown factor that causes impairment of incretin production and/or action, leading to insufficient or untimely production of insulin, so that glucose intolerance develops. The bypass of the duodenum and jejunum might avoid a putative hormone overproduction in the proximal foregut in diabetic patients that might counteract the action of insulin, while the early presentation of undigested or incompletely digested food to the ileum may anticipate the production of hormones such as GLP1, further improving insulin action.