Homeostasis model assessment to detect insulin resistance and identify patients at high risk of breast cancer development: National Cancer Institute of Naples experience

Mediation effects of metabolites and sex hormones on the relationship between body mass index and breast cancer: Mendelian randomization analysis and mediation analysis

Background

Observational investigations have indicated a notable correlation between body mass index (BMI) and breast cancer (BC). Nevertheless, the precise biological pathways driving this correlation remain ambiguous. Consequently, we utilized Mendelian randomization (MR) techniques to explore the causative link between BMI and genetic predisposition to BC, as well as the potential intermediary influences.

Methods

Utilizing extensive cohorts sourced from publicly accessible genome-wide association studies (GWAS) datasets of European populations, we conducted Mendelian randomization (MR) analysis. The primary method employed was the Inverse Variance Weighted (IVW) model. We evaluated both heterogeneity and horizontal pleiotropy. Our MR analysis unveiled several metabolites and sex hormones as mediators in the association between BMI and BC.

Results

The IVW model indicated significant negative causal correlations between BMI and BC, ER+BC, and ER-BC. Thirty-five metabolites, thirty-three metabolites and sex hormones, and fifteen metabolites respectively mediated the causal effects of BMI on BC, ER+BC, and ER-BC. Furthermore, our study found that BMI influences BC risk through different mediating factors; BMI increases ER+BC risk through the pathway of sex hormones (biologically available testosterone) and decreases the causal relationship of BC risk through multiple metabolite pathways.

Conclusion

This study discovered that BMI increases ER+BC risk through the pathway of sex hormones (biologically available testosterone), and decreases BC risk through multiple metabolite pathways causally. These discoveries could offer insights into the development of preventive strategies and interventions for BC, while further investigations should delve into alternative feasible biological pathways.

Dietary-Based Diabetes Risk Score and breast cancer: a prospective evaluation in the SUN project

An association between type 2 diabetes (T2D) and breast cancer risk has been reported. This association can be potentially explained by alteration of the insulin/IGF system. Therefore, we aimed to prospectively investigate whether a previously reported Dietary-Based Diabetes Risk Score (DDS) inversely associated with T2D was also associated with breast cancer risk in the SUN ("Seguimiento Universidad de Navarra") cohort. We followed up 10,810 women (mean age = 35 years, SD = 11 years) for an average of 12.5 years during which 147 new cases of invasive breast cancer were diagnosed. A validated 136-item FFQ was administered at baseline and after 10 years of follow-up. The DDS (range: 11 to 55 points) positively weighted vegetables, fruit, whole cereals, nuts, coffee, low-fat dairy, fiber, PUFA; while it negatively weighted red meat, processed meats, and sugar-sweetened beverages. The DDS was categorized into tertiles. Self-reported medically diagnosed breast cancer cases were confirmed through medical records. We found a significant inverse association between the intermediate tertile of the DDS score and overall breast cancer risk (Hazard ratio, HRT2 vs. T1= 0.55; 95% CI: 0.36-0.82) and premenopausal breast cancer risk (HRT2= 0.26; 95% CI: 0.13-0.53), but not for the highest tertile. This association was stronger among women with a BMI < 25 kg/m2 (pinteraction: 0.029). In conclusion, moderate adherence to the DDS score was associated with a lower risk of breast cancer, especially among premenopausal women and women with a lower BMI. These findings underscore the importance of antidiabetic diet in reducing the risk of breast cancer.

Association between triglyceride glucose index and breast cancer in 142,184 Chinese adults: findings from the REACTION study

Background

The triglyceride glucose (TyG) index has been associated with an increased risk in breast cancer. However, this association remains unclear among the Chinese population. This study aimed to investigate whether the TyG index is associated with the risk of prevalent breast cancer in Chinese women.

Methods

This cross-sectional study included 142,184 women from the REACTION (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal) Study, which recruited adults aged 40 years or older from 25 centers across mainland China between 2011 and 2012. The TyG index was calculated according to the formula: Ln (fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). Multivariable-adjusted logistic regression models were used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs) regarding the associations between the TyG index and breast cancer.

Results

Multivariable-adjusted logistic regression analysis showed that compared with the lowest quartile of the TyG index, the highest quartile of the TyG index was significantly associated with an increased risk of prevalent breast cancer, with an OR (95% CI) of 1.61 (1.19-2.17). In the stratified analysis, the association of each 1 SD increase in the TyG index with risk of prevalent breast cancer was more dominant in individuals with menarche at age 13-17, those who were postmenopausal, those with a history of breastfeeding, and those who had two to four children, with the ORs (95% CIs) of 1.35 (1.09-1.68), 1.27 (1.05-1.54), 1.26 (1.05-1.52), and 1.32 (1.08-1.62), respectively. Moreover, among those without discernible insulin resistance (homeostatic model assessment-insulin resistance [HOMA-IR] ≥2.5), hyperglycemia and dyslipidemia, each 1 SD increase in the TyG index was associated with a 1.36-fold increase in breast cancer risk, with an OR (95% CI) of 2.36 (1.44-3.87).

Conclusion

The TyG index is significantly associated with the prevalent breast cancer risk among middle-aged and elderly Chinese women.

Association of preoperative serum adipokines, insulin, and sex steroid hormones with breast cancer risk in the Indian women

BACKGROUND

Obesity-related factors such as adipokines, insulin, insulin-like growth factors, and sex steroid hormones have been reported to be involved in breast carcinogenesis. Studies across the world suggest an important, but still controversial, role of obesity in breast cancer risk. This study aims to evaluate the association of obesity-related factors such as adipokines, insulin, insulin resistance, and sex steroid hormones with breast cancer risk in the Indian population.

MATERIALS AND METHODS

Anthropometric and biochemical measurements were taken in 60 newly diagnosed and histologically confirmed breast cancer patients and 50 healthy controls. Preoperative serum levels of adiponectin, leptin, insulin, estrogen, and testosterone were measured using ELISA (enzyme-linked immunosorbent assay). The data were analyzed and compared.

RESULTS

The mean serum total cholesterol (T.CHOL) and leptin levels were significantly higher ( P = 0.047), whereas testosterone levels were significantly lower in patients than in controls. Waist circumference (WC) and leptin levels showed a significant positive association with breast cancer risk. Association of serum leptin levels with breast cancer risk persisted after adjusting for age, body mass index (BMI), and WC parameters (odds ratio [ OR ] = 1.042, P = 0.03). Leptin levels positively correlated with WC and triglycerides (TG), whereas insulin and insulin resistance positively correlated with BMI, WC, TG, and T.CHOL ( P < 0.05). Among the tumor characteristics, serum adiponectin showed a positive correlation with lymph node involvement, whereas serum estradiol levels were positively correlated with ER (estrogen receptor) and PR (progesterone receptor) status.

CONCLUSION

Together, our study supports the association of obesity (WC) with breast cancer risk and also suggests the potential role of leptin as a biomarker for breast cancer risk, independent of obesity.

Association between metabolic syndrome, insulin resistance, and IGF-1 in breast cancer survivors of DIANA-5 study

PURPOSE

Circulating insulin-like growth factor-1 (IGF-1) is positively associated with the risk of BC recurrence, and is more frequently dysregulated in older people, especially in those with metabolic syndrome (MetS) and obesity. This study aimed to analyze the association between IGF-1 levels and indices of MetS and insulin resistance in BC survivors.

METHODS

Baseline data of 563 BC survivors enrolled in the DIet and ANdrogen-5 (DIANA-5; NCT05019989) study were analyzed.

RESULTS

Lower circulating IGF-1 levels in subjects with MetS than in those without MetS were found. After stratification of the patients according to the diagnosis of MetS, we highlighted that the insulin was the main predictor of elevated IGF-1 levels only in subjects without MetS. Moreover, we found an interaction between high-density lipoprotein cholesterol (HDL-C), glycemia, and IGF-1 levels, showing a positive correlation between HDL-C and IGF-1, especially in subjects with higher values of glycemia and without a diagnosis of MetS.

CONCLUSIONS

While IGF-1 levels appear to be much more impaired in subjects diagnosed with MetS, in non-MetS subjects, IGF-1 levels may respond better to metabolic parameters and lifestyle changes. Further studies are needed to analyze the role of physical activity and/or dietary intervention in modulating IGF-1 concentrations in BC survivors.

IMPLICATIONS FOR CANCER SURVIVORS

These results could have important clinical implications for planning customized strategies aimed at modulating IGF-1 levels in BC survivors. In fact, while the IGF-1 system seems to be much more compromised in subjects with a diagnosis of MetS, in noMetS subjects, IGF-1 levels could better respond to lifestyle changes.

Insulin resistance and the development of breast cancer in premenopausal women: the Kangbuk Samsung Health Study

PURPOSE

Research on the role of insulin resistance (IR) in breast cancer risk in premenopausal women is scarce. We aimed to investigate the relationship between IR and the development of breast cancer in premenopausal women.

METHODS

We analyzed the prospective association of IR and incident breast cancer in premenopausal women without breast cancer at baseline using a subsample of the Kangbuk Samsung Health Study.

RESULTS

Among 134,488 Korean premenopausal women, 696 women developed incident breast cancers during a median follow-up of 4.34 years. After adjustment for dense breast and other potential confounders, HR (95% CI) for incident breast cancer comparing HOMA-IR quintiles 2, 3, 4, and 5 to the first quintile was 0.91 (0.71-1.17), 0.89 (0.69-1.15), 0.75 (0.57-0.98), and 0.87 (0.65-1.16), respectively (P for trend = 0.117), while HR (95% CI) comparing insulin quintiles 2, 3, 4, and 5 to the first quintile was 1.02 (0.80-1.30), 0.90 (0.69-1.16), 0.72 (0.54-0.96), and 0.96 (0.72-1.28), respectively (P for trend = 0.151). This pattern did not significantly differ by obesity. These results were attenuated and no longer significant in time-dependent analyses where updated status of insulin and other covariates over time were treated as time-varying covariates.

CONCLUSION

Our findings do not support the positive relationship of IR with the development of breast cancer in premenopausal women, unlike in postmenopausal women. Thus, the role of IR as a risk factor for breast cancer may differ by menopausal status.

Insulin/IGF-1 Signaling Is Downregulated in Barrett's Esophagus Patients Undergoing a Moderate Calorie and Protein Restriction Program: A Randomized 2-Year Trial

Obesity and associated insulin resistance (Ins-R) have been identified as important risk factors for esophageal adenocarcinoma development. Elevated calories and protein consumption are also associated with Ins-R and glucose intolerance. We investigated the effect of a 24-month moderate calorie and protein restriction program on overweight or obese patients affected by Barrett’s esophagus (BE), as no similar dietary approach has been attempted to date in this disease context. Anthropometric parameters, levels of serum analytes related to obesity and Ins-R, and the esophageal insulin/IGF-1 signaling pathway were analyzed. This study is registered with ClinicalTrials.gov, number NCT03813381. Insulin, C-peptide, IGF-1, IGF-binding protein 3 (IGFBP3), adipokines, and esophageal expression of the main proteins involved in insulin/IGF-1 signal transduction were quantified using Luminex-XMAP^® technology in 46 patients who followed the restriction program (IA) and in 54 controls (CA). Body mass index and waist circumference significantly decreased in 76.1% of IA and 35.2% of CA. IGF-1 levels were reduced in 71.7% of IA and 51.8% of CA. The simultaneous reduction of glycaemia, IGF-1, the IGF-1/IGFBP3 ratio, and the improvement in weight loss-dependent insulin sensitivity, were associated with the downregulation of the insulin/IGF-1 signal on BE tissue. The proposed intervention program was an effective approach to counteract obesity-associated cancer risk factors. The improvement in metabolic condition resulted in a downregulation of the ERK-mediated mitogenic signal in 43.5% of patients, probably affecting the molecular mechanism driving adenocarcinoma development in BE lesions.

Iterative principal component analysis method for improvised classification of breast cancer disease using blood sample analysis

Breast cancer is the most common cancer in women occurring worldwide. Some of the procedures used to diagnose breast cancer are mammogram, breast ultrasound, biopsy, breast magnetic resonance imaging, and blood tests such as complete blood count. Detecting breast cancer at an early stage plays an important role in diagnostic and curative procedures. This paper aims to develop a predictive model for detecting the breast cancer using blood samples data containing age, body mass index (BMI), glucose, insulin, homeostasis model assessment (HOMA), leptin, adiponectin, resistin, and chemokine monocyte chemoattractant protein 1 (MCP-1).The two main challenges encountered in this process are identification of biomarkers and the precision of disease prediction accuracy. The proposed methodology employs principal component analysis in a peculiar approach followed by random forest tree prediction model to discriminate between healthy and breast cancer patients. This approach extracts high communalities, a linear combination of input attributes in a systematic procedure as principal axis elements. The iteratively extracted principal axis elements combined with minimum number of input attributes are able to predict the disease with higher accuracy of classification with increased sensitivity and specificity score. The results proved that the proposed approach generates a higher predictor performance than the previous reported results by opting relevant extracted principal axis elements and attributes that commend the classifier with increased performance measures.

Association of vitamin D deficiency and insulin resistance with breast cancer in premenopausal Algerian women: A cross-sectional study

BACKGROUND

Low 25(OH)D levels are mainly related to breast cancer (BC) risk in postmenopausal women, while the impact of insulin resistance (IR) on BC prognosis is controversial.

OBJECTIVE

Considering the high prevalence of BC in younger Algerian women, this cross-sectional study analyzed whether vitamin D status and IR are biomarkers for breast tumor status in premenopausal women.

METHODS

In 96 women (mean age, 40.96±0.65years) newly diagnosed with BC, tumor status was determined immunohistochemically, classified by molecular subtype, then correlated with body-mass index, total plasma 25(OH)D, insulin and glucose levels and HOMA-IR, using chi², Student t, Spearman and ANOVA tests and multivariate logistic regression.

RESULTS

66 of the 98 patients (68.75%) showed vitamin D deficiency (9.74ng/mL). Overweight and obese patients with HOMA-IR >2.5, positive for HER2 and with high Ki-67 index had the most severe vitamin D deficiency. There was a significant association between vitamin D deficiency, high Ki-67 index (OR, 14.55; 95% CI, 3.43-82.59; p=0.00078) and IR (OR, 4.99; 95% CI, 1.27-24.47; p=0.03), and between IR and HER2-positivity (OR, 3.23; 95% CI, 1.05-10.56; p=0.04).

CONCLUSIONS

Vitamin D deficiency and IR are potential biomarkers for poorer prognosis in BC patients, independently of and/or synergically with high Ki-67 index and HER2-positivity in premenopausal overweight or obese women. The potential relationship of vitamin D receptor gene expression with breast cancer survival in Algerian patients will be investigated in a large cohort.

Insulin resistance and breast cancer incidence and mortality in postmenopausal women in the Women's Health Initiative

BACKGROUND

Insulin resistance is associated with higher all-cause and cancer-specific mortality in postmenopausal women. However, to the authors' knowledge, information regarding insulin resistance and breast cancer mortality risk is limited. Therefore, the authors examined associations between insulin resistance and breast cancer incidence and mortality in a subsample of Women's Health Initiative participants.

METHODS

A total of 22,837 postmenopausal women with fasting baseline glucose and insulin levels were followed for incident breast cancer and breast cancer mortality. Breast cancers were verified by medical record review and serial National Death Index linkage-enhanced mortality findings. Insulin resistance was estimated using the homeostatic model assessment of insulin resistance (HOMA-IR). Multivariable Cox proportional hazards models were used to compute hazard ratios (HRs) with 95% confidence intervals (95% CIs) for quartile comparisons. Outcomes included breast cancer incidence, deaths from breast cancer, and deaths after breast cancer (breast cancer followed by death from any cause).

RESULTS

During a median of 19.8 years of follow-up of 1328 breast cancer cases, there were 512 deaths reported, 151 of which were from breast cancer. Breast cancer incidence was higher in women in the highest HOMA-IR quartile (HR, 1.34; 95% CI, 1.12-1.61 [P for trend = .003]). Although HOMA-IR was not found to be associated with risk of death from breast cancer (HR, 1.04; 95% CI, 0.60-1.79), women in the highest versus those in the lowest HOMA-IR quartile were at a higher risk of death after breast cancer (HR, 1.78; 95% CI, 1.32-2.39 [P for trend <.001]).

CONCLUSIONS

Higher levels of insulin resistance in postmenopausal women are associated with higher breast cancer incidence and higher all-cause mortality after breast cancer.

The Metabolic Syndrome Is a Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

The metabolic syndrome (MetS) has been associated with the pathogenesis and prognosis of various malignant tumors. In this systematic review and meta-analysis, we explored the relationship between MetS and breast cancer (BC).

METHODS

Relevant studies were systematically searched on Ovid MEDLINE, Embase, Cochrane database, and PubMed up to September 16, 2019, using "breast cancer" and "metabolic syndrome" as keywords. Eligible studies with clear definition of MetS, available data, and relationships between MetS and BC were evaluated using a risk ratio (RR) and its 95% confidence interval (CI).

RESULTS

Twenty-five studies, including 13 cohort studies and 12 case-control studies, met the inclusion criteria, which assessed a total of 392,583 female participants and 19,628 BC patients. The results revealed a statistically significant increase by 52% of the risk of BC in adult females with MetS (RR = 1.49, 95% CI = 1.31-1.70, p < 0.0001). Postmenopausal MetS patients may have a twofold risk to suffer BC (RR = 2.01, 95% CI = 1.55-2.60, p < 0.001). The risk of BC increased markedly with the number of MetS components: RR = 1.00 for 1 component (p = 0.976), RR = 1.40 for 2 components (p = 0.121), and RR = 1.98 for >3 components (p < 0.001). The risk factors associated with BC were obesity, hypertension, and diabetes (RR = 1.33, 1.19, and 1.30 respectively, all p < 0.001).

CONCLUSIONS

Our study demonstrated that MetS is highly related with BC. In postmenopausal patients with ≥2 MetS components or a combination of obesity, hypertension, and diabetes, routine BC screening could help to detect BC at an early stage.

Higher Insulin Resistance and Adiposity in Postmenopausal Women With Breast Cancer Treated With Aromatase Inhibitors

CONTEXT

Aromatase deficiency causes obesity and insulin resistance in aromatase knockout mice and humans with rare mutations of the aromatase gene (CYP19). Aromatase inhibitors are a commonly prescribed therapy for postmenopausal breast cancer.

OBJECTIVE

We hypothesized that aromatase inhibitors induce obesity and insulin resistance when used in treatment of breast cancer.

DESIGN

Case-control study.

SETTING

University teaching hospital.

PARTICIPANTS

Patients with postmenopausal breast cancer (n = 20) treated with aromatase inhibitors and 20 age-matched control subjects.

MAIN OUTCOME MEASURES

The primary outcome measure was insulin sensitivity index - Matsuda, derived from a 75-g oral glucose tolerance test. Body composition was assessed by dual energy x-ray absorptiometry and biopsy specimens of subcutaneous adipose tissue obtained for assessment of mRNA transcript levels. Data are reported as mean ± SEM (patients receiving inhibitors vs control group, respectively).

RESULTS

Aromatase inhibitor therapy was associated with significantly lower insulin sensitivity (5.15 ± 0.45 vs 6.80 ± 0.64; P = 0.041), higher peak insulin concentration after oral glucose tolerance test (693.4 ± 78.6 vs 527.6 ± 85.5 pmol/L; P = 0.035), greater percentage of body fat (38.4% ± 1.0% vs 34.6% ± 1.3%; P = 0.026), and higher plasma leptin concentration (23.5 ± 2.8 vs 15.5 ± 2.3 ng/mL; P = 0.035).

CONCLUSION

Women who received aromatase inhibitors for postmenopausal breast cancer had greater percentage body fat and insulin resistance compared with control subjects with no history of breast cancer.

Resistance training reduces inflammation and fatigue and improves physical function in older breast cancer survivors

OBJECTIVE

Resistance training (RT) reduces fatigue and improves physical function and quality of life (QOL) in breast cancer survivors (BCS). This may be related to reductions in systemic and tissue-specific inflammation. This pilot study examines the hypothesis that RT induces changes in systemic and tissue-specific inflammation that contribute to improvements in physical and behavioral function in postmenopausal BCS.

METHODS

Eleven BCS (60 ± 2 years old, body mass index 30 ± 1 kg/m, mean ± SEM) underwent assessments of fatigue (Piper Fatigue Scale), physical function, QOL (SF-36), glucose and lipid metabolism, and systemic, skeletal muscle, and adipose tissue inflammation (n = 9) before and after 16 weeks of moderate-intensity whole-body RT.

RESULTS

Muscle strength improved by 25% to 30% (P < 0.01), QOL by 10% (P = 0.04), chair stand time by 15% (P = 0.01), 6-minute walk distance by 4% (P = 0.03), and fatigue decreased by 58% (P < 0.01), fasting insulin by 18% (P = 0.04), and diastolic and systolic blood pressure by approximately 5% (P = 0.04) after RT. BCS with the worst fatigue and QOL demonstrated the greatest improvements (absolute change vs baseline: fatigue: r = -0.95, P < 0.01; QOL: r = -0.82, P < 0.01). RT was associated with an approximately 25% to 35% relative reduction in plasma and adipose tissue protein levels of proinflammatory interleukin (IL)-6sR, serum amyloid A, and tumor necrosis factor-α, and 75% relative increase in muscle pro-proliferative, angiogenic IL-8 protein content by 75% (all P < 0.05). BCS with the highest baseline proinflammatory cytokine levels had the greatest absolute reductions, and the change in muscle IL-8 correlated directly with improvements in leg press strength (r = 0.53, P = 0.04).

CONCLUSIONS

These preliminary results suggest that a progressive RT program effectively lowers plasma and tissue-specific inflammation, and that these changes are associated with reductions in fatigue and improved physical and behavioral function in postmenopausal BCS.

When Diet and Exercise Aren't Enough: The Added Benefits of Connection, Community, and Psychosocial Support in Navigating Breast Cancer Treatment

Breast cancer is the most common cancer diagnosis in women, and many lifestyle factors have been linked to an elevated risk for development of the disease. This case provides an example of how breast cancer can occur even in people who engage in healthy lifestyle behaviors, yet underscores the importance of exercise, healthy dietary patterns, and addressing psychological distress in supporting women through their treatment and beyond.

Insulin promotes HER2 signaling activation during Barrett's Esophagus carcinogenesis

BACKGROUND

Insulin-resistance and hyperinsulinemia could have a role in the growing incidence of esophageal adenocarcinoma (EAC) and its pre-cancerous lesion Barrett's Esophagus (BE). HER2 activation has also a pivotal role in EAC carcinogenesis but no data correlate these two phenomena in this disease context.

AIMS

To investigate the role of hyperinsulinemia in BE-dysplasia-adenocarcinoma sequence and the possible relationship between insulin-mediated and HER2 signaling in EAC development.

METHODS

Serum insulin, C-peptide, IGF1, glucagon, IL-6, TNF-alpha, leptin, adiponectin and Insulin-Resistance-index were analyzed in 19 patients with gastro-esophageal reflux disease, 51 with BE, 24 with dysplastic-BE and 14 with EAC. Insulin/IGF1/HER2 pathways were analyzed in esophageal biopsies using Luminex^® Technology. Insulin effect was also evaluated in EAC-derived OE19 cells. Data were analyzed by Fisher's exact test, Kruskal-Wallis test, Mann-Whitney U-test, Cuzick's test and Spearman correlation coefficient calculation.

RESULTS

Insulin-Resistance-index, insulin and C-peptide levels increased along with disease progression (p=0.019, p=0.002, p<0.0001, respectively) and correlated with HER2 expression and with downstream mediators phospho-Akt and phospho-mTOR in esophageal tissue. In vitro, insulin was also able to induce cell proliferation through HER2 activation.

CONCLUSIONS

Our data pinpoint a possible role of hyperinsulinemia in the Barrett's Esophagus metaplasia-dysplasia-adenocarcinoma sequence through HER2 activation in esophageal epithelial cells.

Relationship Between Glucocorticoids and Insulin Resistance in Healthy Individuals

Background

The aim of this study was to determine the correlation between glucocorticoids (GCs) and insulin resistance (IR) in healthy individuals by conducting a systematic meta-analysis.

Material/Methods

A systematic literature review was conducted using 9 electronic databases. Only case-control studies investigating fasting plasma glucose (FPG) and IR were enrolled based on strictly established selection criteria. Statistical analyses were performed by Stata software, version 12.0 (Stata Corporation, College Station, Texas, USA).

Results

Among 496 initially retrieved articles, only 6 papers published in English were eventually included in this meta-analysis. A total of 201 healthy individuals (105 in GC group and 96 in control group) were included in the 6 studies. In 4 of these 6 studies, dexamethasone was used, and in the other 2 studies prednisolone was given. This meta-analysis revealed that the FPG, fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) levels in the GC group were all significantly higher than that in the control group (FPG: SMD=2.65, 95%CI=1.42~3.88, P<0.001; FINS: SMD=2.48, 95%CI=1.01~3.95, P=0.001; HOMA-IR: SMD=38.30, 95%CI=24.38~52.22, P<0.001).

Conclusions

In conclusion, our present study revealed that therapies using GCs might result in elevated FPG, FINS, and HOMA-IR, and thereby contribute to IR in healthy individuals.

Optimal cut-off values for the homeostasis model assessment of insulin resistance (HOMA-IR) and pre-diabetes screening: Developments in research and prospects for the future

Diabetes mellitus (DM) appears to be increasing rapidly, threatening to reduce life expectancy for humans around the globe. The International Diabetes Federation (IDF) has estimated that there will be 642 million people living with the disease by 2040 and half as many again who will be not diagnosed. This means that pre-DM screening is a critical issue. Insulin resistance (IR) has emerged as a major pathophysiological factor in the development and progression of DM since it is evident in susceptible individuals at the early stages of DM, and particularly type 2 DM (T2DM). Therefore, assessment of IR via the homeostasis model assessment of IR (HOMA-IR) is a key index for the primary prevention of DM and is thus found in guidelines for screening of high-risk groups. However, the cut-off values of HOMA-IR differ for different races, ages, genders, diseases, complications, etc. due to the complexity of IR. This hampers the determination of specific cut-off values of HOMA-IR in different places and in different situations. China has not published an official index to gauge IR for primary prevention of T2DM in the diabetic and non-diabetic population except for children and adolescents ages 6-12 years. Hence, this article summarizes developments in research on IR, HOMA-IR, and pre-DM screening in order to provide a reference for optimal cut-off values of HOMA-IR for the diagnosis of DM in the Chinese population.

Maternal Dietary Patterns are Associated with Lower Levels of Cardiometabolic Markers during Pregnancy

BACKGROUND

Elevated levels of cardiometabolic markers are characteristic of normal pregnancy, however, insulin resistance and increased glucose, triglyceride, and cholesterol levels can adversely influence maternal and child health. Diet is a modifiable behaviour that could have significant impact on maternal cardiometabolic levels during pregnancy. We investigated the association between dietary patterns and cardiometabolic markers (glucose, insulin, insulin resistance (HOMA-IR), triglycerides, and cholesterol) during pregnancy.

METHODS

Data from the Pregnancy, Infection, and Nutrition prospective cohort study (2000-05) was used (n = 513). Diet was assessed using a food frequency questionnaire. Dietary patterns were derived using latent class analysis (LCA) and the Dietary Approaches to Stop Hypertension (DASH) diet. Linear regression was used to examine the dietary patterns-cardiometabolic markers association during pregnancy.

RESULTS

Three dietary patterns evolved from the LCA characterised by high intakes of: (1) hamburgers, hot dogs, bacon, French fries, fried chicken, white bread, and soft drinks; (2) some vegetables, fruit juice, refined grains, mixed dishes, processed meat, and empty calorie foods; and (3) fruits, vegetables, whole grains, low-fat dairy, breakfast bars, and water. After adjustment for potential confounders including prepregnancy body mass index, a diet consistent with Latent Class 3 was negatively associated with maternal insulin (μU/mL: β = -0.12; 95% CI -0.23, -0.01) and HOMA-IR (β = -0.13; 95% CI -0.25, -0.00). Additionally, DASH scores within Tertile 3 (higher dietary quality) were also negatively associated with maternal triglycerides (mg/dL).

CONCLUSIONS

The study findings suggest an association between maternal dietary patterns and several cardiometabolic markers during pregnancy.

Body weight and risk of molecular breast cancer subtypes among postmenopausal Mediterranean women

Breast cancer (BC) is the most common malignant tumor in women, obesity is associated with increased BC incidence and mortality and high levels of circulating insulin may negatively impact on cancer incidence. In the present study, we investigated whether the strength of several anthropometric and metabolic parameters varies between BC molecular subtypes. Eligible cases were 991 non-metastatic BC patients recruited between January 2009 and December 2013. Anthropometric, clinical and immunohistochemical features were measured. Multivariate logistic regression models were built to assess HER2 positive BC risk, comparing (a) triple positive (TP) with luminal A, luminal B and triple negative (TN) and (b) HER2-enriched group with luminal A, luminal B and TN. We stratified patients in pre- and post-menopause: significant differences emerged for luminal A in relation to age: they were more likely to be older compared to other groups. Among postmenopausal patients, the adjusted multivariate analysis showed that high BMI and high waist circumference were inversely correlated to TP subtype when compared to luminal B (OR=0.48 and OR=0.49, respectively). Conversely, HOMA-IR was a risk factor for TP when compared to luminal A and TN (OR=2.47 and OR=3.15, respectively). Our findings suggest a potential role of higher abdominal fat in the development of specific BC molecular subtypes in postmenopausal women. Moreover, they support a potential role of insulin resistance in the development of HER2 positive BC, although this role appears to be stronger when hormone receptors are co-expressed, suggesting a difference in the etiology of these two BC subtypes.

The molecular mechanisms between metabolic syndrome and breast cancer

Metabolic syndrome, which is extremely common in developed and some developing countries, is a clustering of at least three of five of the following medical conditions: abdominal obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides, and low high-density lipoprotein levels. It has been proved that there is a strong association between metabolic syndrome and breast cancer. Metabolic syndrome could increase the risk of breast cancer and influence the prognosis of the breast cancer patients. Some characteristic of metabolic syndrome such as obesity and lack of physical exercise are all risk factors for developing breast cancer. The metabolic syndrome mainly include obesity, type 2 diabetes, hypercholesterolemia and nonalcoholic fatty liver disease, and each of them impacts the risk of breast cancer and the prognosis of the breast cancer patients in different ways. In this Review, we focus on recently uncovered aspects of the immunological and molecular mechanisms that are responsible for the development of this highly prevalent and serious disease. These studies bring new insight into the complex associations between metabolic syndrome and breast cancer and have led to the development of novel therapeutic strategies that might enable a personalized approach in the management of this disease.

Association of diabetes and cancer mortality in American Indians: the Strong Heart Study

PURPOSE

The metabolic abnormalities that accompany diabetes mellitus are associated with an increased risk of many cancers. These associations, however, have not been well studied in American Indian populations, which experience a high prevalence of diabetes. The Strong Heart Study is a population-based, prospective cohort study with extensive characterization of diabetes status.

METHODS

Among a total cohort of 4,419 participants who were followed for up to 20 years, 430 cancer deaths were identified.

RESULTS

After adjusting for sex, age, education, smoking status, drinking status, and body mass index, participants with diabetes at baseline showed an increased risk of gastric (HR 4.09; 95% CI 1.42-11.79), hepatocellular (HR 2.94; 95% CI 1.17-7.40), and prostate cancer mortality (HR 3.10; 95% CI 1.22-7.94). Further adjustment for arsenic exposure showed a significantly increased risk of all-cause cancer mortality with diabetes (HR 1.27; 95% CI 1.03-1.58). Insulin resistance among participants without diabetes at baseline was associated with hepatocellular cancer mortality (HR 4.70; 95% CI 1.55-14.26).

CONCLUSIONS

Diabetes mellitus, and/or insulin resistance among those without diabetes, is a risk factor for gastric, hepatocellular, and prostate cancer in these American Indian communities, although relatively small sample size suggests cautious interpretation. Additional research is needed to evaluate the role of diabetes and obesity on cancer incidence in American Indian communities as well as the importance of diabetes prevention and control in reducing the burden of cancer incidence and mortality in the study population.

Metabolic syndrome, insulin resistance, and mammographic density in pre- and postmenopausal women

Little is known about the association of metabolic syndrome (MetS) or insulin resistance (IR) with mammographic density, a strong risk factor for breast cancer. The goal of this study was to evaluate these associations in pre- and postmenopausal women. A cross-sectional study was performed in 73,974 adult women who underwent a comprehensive health screening examination that included a mammogram between 2011 and 2013 (mean age 42.6 years). MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III. IR was assessed with the homeostasis model assessment-insulin resistance (HOMA-IR). Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for dense breast were estimated using logistic regression models after adjustment for potential confounders. In premenopausal women, MetS and all its components except waist circumference were associated with dense breast. After adjustment for potential confounders, the OR (95% CI) for dense breast in women with MetS compared with those without MetS was 1.22 (1.06-1.39). In postmenopausal women, however, there was positive but non-significant association between MetS and dense breast. In both pre- and postmenopausal women, high blood glucose and IR were positively associated with dense breast. The OR (95% CI) for dense breast between the highest and lowest quartiles of HOMA-IR was 1.29 (1.20-1.39) for premenopausal women and 1.44 (1.05-1.97) for postmenopausal women. In a large sample of Korean women, MetS and IR were associated with mammographic dense breast, demonstrating that IR, a potentially modifiable risk factor, may increase breast cancer risk, possibly through high mammographic density.

Lifestyle and Breast Cancer Incidence and Survival

Recently reported SEER data revealing an increase in the number of younger women who present with advanced breast cancer at diagnosis has led to much speculation regarding epidemiological factors that play a role in breast cancer risk and that may be modifiable by lifestyle. Molecular genomics has identified biological pathways that affect breast cancer prognosis and inform treatment decisions. Depending on menopausal status and breast cancer subtype, evidence is emerging that lifestyle could be implicated not only in the risk for breast cancer but also outcomes following breast cancer diagnosis. Several biologic mechanisms have been explored explaining the physiologic role of lifestyle and cancer risk and survival. In this report, we explore the interaction between lifestyle, breast cancer phenotype, and outcomes and review potential molecular mechanisms linking lifestyle to risk and prognosis in order to establish a platform for future exploration. The cost of breast cancer treatment and breast cancer morbidity and mortality during a woman’s productive years impose a psychosocial and socioeconomic burden on our nation. Efforts to ease that burden through lifestyle modification should be embraced and supported as we reevaluate and scrutinize the allocation of health care resources in our nation.

Metabolic syndrome-breast cancer link varies by intrinsic molecular subtype

BACKGROUND

Metabolic syndrome (MS) has been shown to increase the risk of breast cancer. Existing data suggest that the strength of metabolic syndrome-breast cancer link varies by intrinsic molecular subtype, but results from worldwide literature are controversial. Primary endpoint of the study was to assess whether MS is a predictor of specific breast cancer (BC) subtype. Secondary endpoint was to determine whether components of MS can individually increase the risk of specific breast cancer subtype.

METHODS

Anthropometric and metabolic variables were correlated to breast cancer specific subgroups, retrospectively. Statistical significance was considered when p ≤ 0.05 and 95% CI.

RESULTS

Data analysis suggests that MS per se represents a modifiable risk factor for BC in postmenopausal [OR 6.28 (95% CI 2.79-14.11) p < 0.00001]. MS per se prevalence is higher among Luminal breast cancers in postmenopausal [OR 1.37 (95% CI 1.07-2.80) p = 0.03]. Body Mass Index (BMI) alone is associated to Luminal A subtype breast cancer risk [OR 1.12 (95% CI 0.96-2.196 p = 0.2]. Waist Circumference > 88 cm has been shown to be specifically and statistically significant associated to HER-2+ breast cancer subtypes in postmenopausal [OR 2.72 (95% CI 1.69- 10.72) p = 0.01], whilst in Luminal B it was only marginally statistical associated [OR 2.21 (95% CI 0.77-2.60) p = 0.1]. Insulin resistance showed statistical significant association to HER-2+ and Luminal B tumors [OR 2.11 (95% CI 1.66-6.69) p = 0.05] and [OR 2.33 (95% CI 1.2-4.2) p = 0.006], respectively. Hence, it has emerged that BMI is weakly associated to Luminal A breast cancers in this case series, whereas visceral obesity and insulin resistance are likely to be linked to more aggressive breast cancer subtypes.

CONCLUSIONS

New molecular biomarkers unveiling metabolic syndrome related breast carcinogenesis need to be detected to further stratify breast cancer risk by subtypes.

Variability in HOMA-IR, lipoprotein profile and selected hormones in young active men

Resistance to insulin actions is contributing to many metabolic disturbances. Such factors as age, sex, nutrition, body fat, and physical activity determine body insulin resistance. Present study attempted to asses insulin resistance and its metabolic effects with respect to energy intake in young, lean, and active men. A total of 87 men aged 18-23 participated in the study. Plasma levels of glucose, insulin, lipoproteins, cortisol, and TSH were determined. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and calculated using homeostatic model. The median value of HOMA-IR (1.344) was used to divide subjects into two groups. Men did not differ in anthropometric parameters, daily physical activity, and plasma TSH and cortisol levels. However, in men with higher HOMA-IR significantly lower daily energy intake was observed concomitantly with higher TG, TC, and HDL-C concentrations in plasma versus their counterparts with lower HOMA-IR. Exclusively in subjects with higher HOMA-IR significant and positive correlation was noted between HOMA-IR and TC and LDL-C. We concluded that despite a normal body weight and physical activity, a subset of young men displayed unfavorable changes in insulin sensitivity and lipid profile, probably due to insufficient energy intake.

Evaluation of 25(OH) Vitamin D3 with Reference to Magnesium Status and Insulin Resistance in T2DM

INTRODUCTION

Calcium is a recognized second messenger implicated in insulin secretion. Vitamin D (1,25-dihydroxycholecalciferol, Calcitriol) plays a role in calcium metabolism. This explains the indirect role of Vitamin D in insulin secretion and insulin sensitivity. Hence, low Vitamin D levels are implicated in decreased insulin secretion and increased insulin resistance. In this study, we tried to find out the probable association of Vitamin D3, calcium and magnesium with reference to insulin resistance in type 2 diabetes mellitus (T2DM) cases. It is well documented that measurement of circulating 25-Hydroxycholecalciferol {25 (OH)Vitamin D3} is a marker of total Vitamin D status.

METHODOLOGY

We measured 25(OH) Vitamin D3 levels in thirty T2DM subjects with thirty age and sex matched healthy controls. We estimated Vitamin D status, calcium and magnesium levels in the light of insulin resistance. Insulin resistance was measured by homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

Twenty five (OH) Vitamin-D3 level was significantly low among T2DM cases (12.29+2.32ng/ml) in comparison to healthy controls (19.55+0.50ng/ml) (p<0.01). The levels of calcium and magnesium were also significantly low in T2DM cases as compared to healthy controls (p<0.01). There was significant negative correlation between Vitamin D status and insulin levels, and insulin resistance (p<0.01).

IMPLICATION

A significant negative correlation between Vitamin D status and insulin levels suggest that the supplementation of Vitamin D has the potential to increase insulin sensitivity and lower the risk of developing type 2 diabetes mellitus.

Race differences in the relation of vitamins A, C, E, and β-carotene to metabolic and inflammatory biomarkers

Using archival data, we conducted a secondary analysis to examine race differences in the relation of serum vitamins A, C, E and β-carotene to insulin resistance (IR), fasting insulin and glucose, high sensitivity C-reactive protein (hs-CRP), and leukocyte count in 176 non-smoking, healthy, white, and African American (AA) adults aged 18 to 65 years (48% women, 33% AA). We hypothesized that micronutrient concentrations would be associated with early risk markers of cardiometabolic diseases in a race-dependent manner. Fasting blood samples were analyzed for micronutrients, insulin, glucose, hs-CRP, and leukocyte count. Insulin resistance was estimated using the homeostatic model assessment. After adjusting for age, body mass index, gender, educational level, use of vitamin supplements, alcohol intake, leisure time physical activity, menopausal status, and total cholesterol, we observed that β-carotene was significantly associated with insulin resistance and fasting insulin in a race-dependent manner. Among AA, lower β-carotene levels were associated with higher estimates of insulin resistance and fasting insulin; whereas, these same associations were not significant for whites. Race also significantly moderated the relation of vitamin C to leukocyte count, with lower vitamin C being associated with higher leukocyte count only in AA but not whites. For all subjects, lower β-carotene was associated with higher hs-CRP. In AA, but not whites, lower levels of β-carotene and vitamin C were significantly associated with early risk markers implicated in cardiometabolic conditions and cancer. Whether or not lower levels of micronutrients contribute uniquely to racial health disparities is a worthwhile aim for future research.

Mitochondrial dysfunction induces formation of lipid droplets as a generalized response to stress

Lipid droplet (LD) formation is a hallmark of cellular stress. Cells attempt to combat noxious stimuli by switching their metabolism from oxidative phosphorylation to glycolysis, sparing resources in LDs for generating cellular reducing power and for anabolic biosynthesis. Membrane phospholipids are also a source of LDs. To elucidate the formation of LDs, we exposed mice to hyperoxia, hypoxia, myocardial ischemia, and sepsis induced by cecal ligation and puncture (CLP). All the above-mentioned stressors enhanced the formation of LDs, as assessed by transmission electron microscopy, with severe mitochondrial swelling. Disruption of mitochondria by depleting mitochondrial DNA ( ρ 0 cells) significantly augmented the formation of LDs, causing transcriptional activation of fatty acid biosynthesis and metabolic reprogramming to glycolysis. Heme oxygenase (HO)-1 counteracts CLP-mediated septic shock in mouse models. In HO-1-deficient mice, LD formation was not observed upon CLP, but a concomitant decrease in "LD-decorating proteins" was observed, implying a link between LDs and cytoprotective activity. Collectively, LD biogenesis during stress can trigger adaptive LD formation, which is dependent on mitochondrial integrity and HO-1 activity; this may be a cellular survival strategy, apportioning energy-generating substrates to cellular defense.

Combination of inositol and alpha lipoic acid in metabolic syndrome-affected women: a randomized placebo-controlled trial

Background

Inositol has been reported to improve insulin sensitivity since it works as a second messenger achieving insulin-like effects on metabolic enzymes. The aim of this study was to evaluate the inositol and alpha lipoic acid combination effectiveness on metabolic syndrome features in postmenopausal women at risk of breast cancer.

Methods

A six-month prospective, randomized placebo-controlled trial was carried out on a total of 155 postmenopausal women affected by metabolic syndrome at risk of breast cancer, the INOSIDEX trial. All women were asked to follow a low-calorie diet and were assigned randomly to daily consumption of a combination of inositol and alpha lipoic acid (77 pts) or placebo (78 pts) for six months. Primary outcomes we wanted to achieve were both reduction of more than 20% of the HOMA-IR index and of triglycerides serum levels. Secondary outcomes expected were both the improvement of high-density lipoprotein cholesterol levels and the reduction of anthropometric features such as body mass index and waist-hip ratio.

Results

A significant HOMA-IR reduction of more than 20% was evidenced in 66.7% (P <0.0001) of patients, associated with a serum insulin level decrease in 89.3% (P <0.0000). A decrease in triglycerides was evidenced in 43.2% of patients consuming the supplement (P <0.0001). An increase in HDL cholesterol (48.6%) was found in the group consuming inositol with respect to the placebo group. A reduction in waist circumference and waist-hip ratio was found in the treated group with respect to the placebo group.

Conclusions

Inositol combined with alpha lipoic acid can be used as a dietary supplement in insulin-resistant patients in order to increase their insulin sensitiveness. Daily consumption of inositol combined with alpha lipoic acid has a significant bearing on metabolic syndrome. As metabolic syndrome is considered a modifiable risk factor of breast tumorigenesis, further studies are required to assess whether inositol combined with alpha lipoic acid can be administered as a dietary supplement in breast cancer primary prevention.

Trial registration

Current Controlled Trial ISRCTN74096908.