GDF-15 Is Associated with Cancer Incidence in Patients with Type 2 Diabetes

Growth differentiation factor-15 may be a novel biomarker in pancreatic cancer: A review

Pancreatic cancer is a highly malignant and invasive gastrointestinal tumor that is often diagnosed at an advanced stage with a poor prognosis and high mortality. Currently, carbohydrate antigen199(CA199) is the only biomarker approved by the FDA for the diagnosis of pancreatic cancer, but it has great limitations. Growth differentiation factor-15 (GDF-15) is expected to be a novel biomarker for the diagnosis, efficacy prediction, and prognosis assessment of pancreatic cancer patients. In this paper, we searched the keywords GDF-15, macrophage inhibitory cytokine-1 (MIC-1), CA199, pancreatic cancer, and tumor markers in PubMed and Web of Science, searched related articles, and read and analyzed the retrieved papers. Finally, we systematically described the characteristics, mechanism of action, and clinical value of GDF-15, aiming to provide help for the detection and treatment of pancreatic cancer.

Relationship Between Plasma Growth Differentiation Factor 15 Levels and Complications of Type 2 Diabetes Mellitus: A Cross-sectional Study

OBJECTIVE

Our aim in this study was to identify the associations between growth differentiation factor 15 (GDF15) and type 2 diabetes mellitus (T2DM) complications in a community-based population in China.

METHODS

Based on a cross-sectional study registered in the National Basic Public Health Service for disease management of Changshu in China, a total of 1,689 T2DM patients were enrolled and tested further for plasma GDF15 levels. Macrovascular (cardiovascular disease and diabetic foot) and microvascular (diabetic kidney disease [DKD], diabetic retinopathy, and neuropathy) complications were evaluated. Logistic regression models were conducted to identify the associations of GDF15 with the risk of diabetes complications, and linear regression models were used to assess relationships between GDF15 and other clinical features.

RESULTS

Overall, 459 of the 1,689 T2DM patients (27.18%) had complications. GDF15 levels were significantly higher in patients with any type of complication compared with their counterparts. With each standard deviation increase of base 10 logarithms of GDF15 (lg-GDF15), the risk of overall complications increased by 1.17-fold (95% confidence interval [CI], 1.03 to 1.32). In contrast to macrovascular complications, associations of GDF15 with microvascular complications appeared to be stronger (adjusted odds ratio [OR], 1.24; 95% CI, 1.08 to 1.43), especially for DKD (adjusted OR, 1.51; 95% CI, 1.19 to 1.93). Subgroup analyses showed that the strength of association between GDF15 and complications varied by distinct age and T2DM duration subgroups. Patients with 2 or more types of complications had higher levels of GDF15 than those with fewer types of complications. Also, linear relationships were identified between GDF15 and several liver and kidney function indices.

CONCLUSION

Higher GDF15 levels were associated with T2DM complications, especially DKD. GDF15 may serve as a biomarker for monitoring the deterioration of T2DM.

Major Adverse Cardiovascular Events and Mortality Prediction by Circulating GDF-15 in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

Background: Growth differentiation factor 15 (GDF-15) is a homeostatic cytokine that regulates neural and cardio-metabolic functions, and its release is increased in response to stress, injury, and inflammation. In patients with coronary artery disease and heart failure (HF), three separate meta-analyses have found that elevated circulating GDF-15 was predictive of major adverse cardiovascular events (MACE), but none has evaluated its effects on incident MACE including HF and mortality hazard in type 2 diabetes. Methods: MEDLINE, EMBASE, and Scopus databases were queried. Articles that met the predefined eligibility criteria, including prospective studies that reported adjusted hazard ratios (aHRs), were selected according to the Cochrane Handbook and PRISMA guidelines. Study endpoints were (1) MACE including HF, and (2) all-cause mortality. Different GDF-15 concentration measurements were harmonized using a validated mathematical approach to express log2-transformed values in per standard deviation (SD). Study heterogeneity (I2), quality, and bias were assessed. Results: 19354 patients in 8 prospective studies were included. In 7 studies that reported 4247 MACE among 19200 participants, the incident rate was 22.1% during a median follow-up of 5.6 years. It was found that four of eight studies included HF decompensation or hospitalization as a component of MACE. In 5 studies that reported all-cause mortality, 1893 of 13223 patients died, at an incidence rate of 15.1% over 5.0 years. Of note, each 1 SD increase of log2[GDF-15] was associated with aHRs of 1.12 (1.09−1.15, I2 = 5%, p < 0.000001) and 1.27 (1.11−1.46, I2 = 86%, p = 0.00062) and for MACE and all-cause mortality, respectively. Conclusion: Elevated circulating level of GDF-15 was robustly predictive of MACE in patients with T2D but its prognostic significance in the prediction of mortality requires further studies.

GDF-15, a future therapeutic target of glucolipid metabolic disorders and cardiovascular disease

Growth and differentiation factor 15 (GDF-15) was discovered as a member of the transforming growth factor β (TGF-β) superfamily and the serum level of GDF-15 was significantly correlated with glucolipid metabolic disorders (GLMD) and cardiovascular diseases. In 2017, a novel identified receptor of GDF-15-glial-derived neurotrophic factor receptor alpha-like (GFRAL) was found to regulate energy homeostasis (such as obesity, diabetes and non-alcoholic fatty liver disease (NAFLD)). The function of GDF-15/GFRAL in suppressing appetite, enhancing glucose/lipid metabolism and vascular remodeling has been gradually revealed. These effects make it a potential therapeutic target for GLMD and vascular diseases. In this narrative review, we included and reviewed 121 articles by screening 524 articles from literature database. We primarily focused on the function of GDF-15 and its role in GLMD/cardiovascular diseases and discuss its potential clinical application.

Ageing-related markers and risks of cancer and cardiovascular disease: a prospective study in the EPIC-Heidelberg cohort

Biological age is an important risk factor for chronic diseases. We examined the associations between five markers of unhealthy ageing; Growth Differentiation Factor-15 (GDF-15), N-terminal pro-brain natriuretic peptide (NT-proBNP), glycated hemoglobin A1c (HbA1C), C-Reactive Protein (CRP) and cystatin-C; with risks of cancer and cardiovascular disease (CVD). We used a case-cohort design embedded in the EPIC-Heidelberg cohort, including a subcohort of 3792 participants along with 4867 incident cases of cancer and CVD. Hazard ratios (HRs) were computed and the strongest associations were used to build weighted multi-marker combinations, and their associations with cancer and CVD risks were tested. After adjusting for common confounders, we observed direct associations of GDF-15 with lung cancer risk, NT-proBNP with breast, prostate and colorectal cancers, HbA1C with lung, colorectal, and breast cancer risks, and CRP with lung and colorectal cancer risks. An inverse association was observed for GDF-15 and prostate cancer risk. We also found direct associations of all 5 markers with myocardial infarction (MI) risk, and of GDF-15, NT-proBNP, CRP and cystatin-C with stroke risk. A combination of the independently-associated markers showed a moderately strong association with the risks of cancer and CVD (HR_Q4-Q1 ranged from 1.78[1.36, 2.34] for breast cancer, when combining NT-proBNP and HbA1C, to 2.87[2.15, 3.83] for MI when combining NT-proBNP, HbA1C, CRP and cystatin-C). This analysis suggests that combinations of biomarkers related to unhealthy ageing show strong associations with cancer risk, and corroborates published evidence on CVD risk. If confirmed in other studies, using these biomarkers could be useful for the identification of individuals at higher risk of age-related diseases.

Association Between Circulating GDF-15 and Cardio-Renal Outcomes and Effect of Canagliflozin: Results From the CANVAS Trial

Background

Studies have suggested that sodium glucose co‐transporter 2 inhibitors exert anti‐inflammatory effects. We examined the association of baseline growth differentiation factor‐15 (GDF‐15), a marker of inflammation and cellular injury, with cardiovascular events, hospitalization for heart failure (HF), and kidney outcomes in patients with type 2 diabetes in the CANVAS (Canagliflozin Cardiovascular Assessment Study) and determined the effect of the sodium glucose co‐transporter 2 inhibitor canagliflozin on circulating GDF‐15.

Methods and Results

The CANVAS trial randomized 4330 people with type 2 diabetes at high cardiovascular risk to canagliflozin or placebo. The association between baseline GDF‐15 and cardiovascular (non‐fatal myocardial infarction, non‐fatal stroke, cardiovascular death), HF, and kidney (40% estimated glomerular filtration rate decline, end‐stage kidney disease, renal death) outcomes was assessed using multivariable adjusted Cox regression models. During median follow‐up of 6.1 years (N=3549 participants with available samples), 555 cardiovascular, 129 HF, and 137 kidney outcomes occurred. Each doubling in baseline GDF‐15 was significantly associated with a higher risk of cardiovascular (hazard ratio [HR], 1.2; 95% CI, 1.0‒1.3), HF (HR, 1.5; 95% CI, 1.2‒2.0) and kidney (HR, 1.5; 95% CI, 1.2‒2.0) outcomes. Baseline GDF‐15 did not modify canagliflozin’s effect on cardiovascular, HF, and kidney outcomes. Canaglifozin treatment modestly lowered GDF‐15 compared with placebo; however, GDF‐15 did not mediate the protective effect of canagliflozin on cardiovascular, HF, or kidney outcomes.

Conclusions

In patients with type 2 diabetes at high cardiovascular risk, higher GDF‐15 levels were associated with a higher risk of cardiovascular, HF, and kidney outcomes. Canagliflozin modestly lowered GDF‐15, but GDF‐15 reduction did not mediate the protective effect of canagliflozin.

Advances in Biomarkers for Detecting Early Cancer Treatment-Related Cardiac Dysfunction

With the gradual prolongation of the overall survival of cancer patients, the cardiovascular toxicity associated with oncology drug therapy and radiotherapy has attracted increasing attention. At present, the main methods to identify early cancer treatment-related cardiac dysfunction (CTRCD) include imaging examination and blood biomarkers. In this review, we will summarize the research progress of subclinical CTRCD-related blood biomarkers in detail. At present, common tumor therapies that cause CTRCD include: (1) Chemotherapy—The CTRCD induced by chemotherapy drugs represented by anthracycline showed a dose-dependent characteristic and most of the myocardial damage is irreversible. (2) Targeted therapy—Cardiovascular injury caused by molecular-targeted therapy drugs such as trastuzumab can be partially or completely alleviated via timely intervention. (3) Immunotherapy—Patients developed severe left ventricular dysfunction who received immune checkpoint inhibitors have been reported. (4) Radiotherapy—CTRCD induced by radiotherapy has been shown to be significantly associated with cardiac radiation dose and radiation volume. Numerous reports have shown that elevated troponin and B-type natriuretic peptide after cancer treatment are significantly associated with heart failure and asymptomatic left ventricular dysfunction. In recent years, a few emerging subclinical CTRCD potential biomarkers have attracted attention. C-reactive protein and ST2 have been shown to be associated with CTRCD after chemotherapy and radiation. Galectin-3, myeloperoxidas, placental growth factor, growth differentiation factor 15 and microRNAs have potential value in predicting CTRCD. In this review, we will summarize CTRCD caused by various tumor therapies from the perspective of cardio-oncology, and focus on the latest research progress of subclinical CTRCD biomarkers.

Dynamics of growth differentiation factor 15 in acute heart failure

Aims

Risk stratification in acute heart failure (HF) patients can help to decide therapies and time for discharge. The potential of growth differentiation factor 15 (GDF‐15) in HF has been previously shown. We aimed to study the importance of GDF‐15‐level variations in acute HF patients.

Methods and results

We retrospectively evaluated a cohort of patients hospitalized due to acute HF. GDF‐15 was measured both at admission and on the discharge day. Patients were followed‐up during a 3 year period. The endpoint under analysis was all‐cause mortality. GDF‐15 variation is equal to [(admission GDF‐15 − discharge GDF‐15)∕admission GDF‐15] × 100. Variation was categorized in levels of increase or decrease of GDF‐15. Patients were cross‐classified according to admission and discharge GDF‐15 cut‐off points. A Cox regression analysis was used to assess the prognostic impact of GDF‐15 variation and the impact of both admission and discharge GDF‐15 according to the cross‐classification. We studied a group of 249 patients with high co‐morbidity burden. Eighty‐one patients died at 1 year and 147 within 3 years. There was a modest decrease in GDF‐15 during hospitalization from a median value of 4087 to 3671 ng/mL (P = 0.02). No association existed between GDF‐15 variation and mortality. In multivariate analysis, patients with admission GDF‐15 ≥ 3500 ng/mL and discharge GDF‐15 ≥ 3000 ng/mL had a significantly higher 1 year death risk when compared with the remaining—hazard ratio = 2.59 (95% confidence interval: 1.41–4.76)—and a 3 year 1.76 (95% confidence interval: 1.08–2.87) higher death risk compared with those with both values below the cut‐off.

Conclusions

Growth differentiation factor 15 decreased during an acute HF hospitalization, but its variation had no prognostic implications. The knowledge of both admission and discharge GDF‐15 added meaningful information to patients' risk stratification.

Associations of GDF-15 and GDF-15/adiponectin ratio with odds of type 2 diabetes in the Chinese population

PURPOSE

We elucidate the effect of Growth differentiation factor-15(GDF-15)/adiponectin ratio in improving the assessment value for odds of type 2 diabetes.

METHODS

Cross-sectional design. A total of 405 participants (135 patients with newly diagnosed type 2 diabetes, 135 age- and sex-matched participants with prediabetes, and 135 healthy controls) were collected from Guangzhou and Dongguan, China. The serum GDF-15 and adiponectin levels were measured by ELISA and latex-enhanced immunoturbidimetry. Logistic regression analysis and restricted cubic splines were used to evaluate the associations between diabetes and the indicators.

RESULTS

The low level of adiponectin and high GDF-15/adiponectin ratio were significantly associated with increased odds of type 2 diabetes, but not for GDF-15. Three clusters were identified based on the K-means clustering analysis. Compared to the lowest quartiles of adiponectin, the OR and 95% CI of the highest adiponectin with type 2 diabetes was 0.24 (0.07-0.74, p trend = 0.004) after adjusting for sex, age, BMI, and DBP only in cluster 1. After adjusting for confounding factors, subjects with the highest GDF-15/adiponectin ratio quartiles had 3.9 times (OR = 3.85, 95% CI = 0.76-24.25) and 3.8 times (OR = 3.80, 95% CI = 1.02-14.68) higher odds of type 2 diabetes in cluster 2 and cluster 3, respectively. The association between the GDF-15/adiponectin ratio and type 2 diabetes was attenuated, but still remarkable (OR = 3.18, 95% CI = 1.11-10.18), in cluster 1.

CONCLUSIONS

Higher GDF-15/adiponectin ratio is independently associated with increased odds of type 2 diabetes for all study populations, suggesting that the GDF-15/adiponectin ratio may be a better indicator of type 2 diabetes.

The GDF15-GFRAL Pathway in Health and Metabolic Disease: Friend or Foe?

GDF15 is a cell activation and stress response cytokine of the glial cell line-derived neurotrophic factor family within the TGF-β superfamily. It acts through a recently identified orphan member of the GFRα family called GFRAL and signals through the Ret coreceptor. Cell stress and disease lead to elevated GDF15 serum levels, causing anorexia, weight loss, and alterations to metabolism, largely by actions on regions of the hindbrain. These changes restore homeostasis and, in the case of obesity, cause a reduction in adiposity. In some diseases, such as advanced cancer, serum GDF15 levels can rise by as much as 10-100-fold, leading to an anorexia-cachexia syndrome, which is often fatal. This review discusses how GDF15 regulates appetite and metabolism, the role it plays in resistance to obesity, and how this impacts diseases such as diabetes, nonalcoholic fatty liver disease, and anorexia-cachexia syndrome. It also discusses potential therapeutic applications of targeting the GDF15-GFRAL pathway and lastly suggests some potential unifying hypotheses for its biological role.

Upregulated GDF-15 expression facilitates pancreatic ductal adenocarcinoma progression through orphan receptor GFRAL

Growth and differentiation factor 15 (GDF-15) has been studied as an important hallmark of cancer. However, the receptor of GDF-15 in pancreatic cancer cell remains unclear. Here, we investigated its biological effects in pancreatic ductal adenocarcinoma (PDAC). We found that aberrant GDF-15 expression positively correlated with poor survival of PDAC patients. GDF-15 protein enhanced tumor cell proliferation in two pancreatic cancer lines, AsPC-1 and BxPC-3. Knockdown GDF-15 attenuated its biological function in vitro and reduced PDAC cell tumorigenesis upon xenotransplantation into nude mice. Moreover, we identified that glial-derived neurotropic factor family receptor α-like (GFRAL) was upregulated in PDAC tissues and positively correlated with GDF-15 expression. High GFRAL expression was significantly associated with poor survival in PDAC patients. Furthermore, we identified that the biological effects of GDF-15 are mediated by its receptor GFRAL which is present in PDAC cells. After overexpression GFRAL in pancreatic cancer cells, the effect of GDF-15 was significantly enhanced. Overall, our findings demonstrated that the GDF-15 secreted by PDAC cells, binds to GFRAL, itself localized in PDAC cells, to promote cancer cell growth and metastasis through the GDF-15/GFRAL signaling pathway.

Growth Differentiation Factor 15 Provides Prognostic Information Superior to Established Cardiovascular and Inflammatory Biomarkers in Unselected Patients Hospitalized With COVID-19

Supplemental Digital Content is available in the text.

Background:

Growth differentiation factor 15 (GDF-15) is a strong prognostic marker in sepsis and cardiovascular disease (CVD). The prognostic value of GDF-15 in coronavirus disease 2019 (COVID-19) is unknown.

Methods:

Consecutive, hospitalized patients with laboratory-confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and symptoms of COVID-19 were enrolled in the prospective, observational COVID Mechanisms Study. Biobank samples were collected at baseline, day 3 and day 9. The primary end point was admission to the intensive care unit or death during hospitalization, and the prognostic performance of baseline and serial GDF-15 concentrations were compared with that of established infectious disease and cardiovascular biomarkers.

Results:

Of the 123 patients enrolled, 35 (28%) reached the primary end point; these patients were older, more often had diabetes, and had lower oxygen saturations and higher National Early Warning Scores on baseline. Baseline GDF-15 concentrations were elevated (>95th percentile in age-stratified healthy individuals) in 97 (79%), and higher concentrations were associated with detectable SARS-CoV-2 viremia and hypoxemia (both P<0.001). Patients reaching the primary end point had higher concentrations of GDF-15 (median, 4225 [IQR, 3197–5972] pg/mL versus median, 2187 [IQR, 1344–3620] pg/mL, P<0.001). The area under the receiver operating curve was 0.78 (95% CI, 0.70–0.86). The association between GDF-15 and the primary end point persisted after adjusting for age, sex, race, body mass index, estimated glomerular filtration rate, previous myocardial infarction, heart failure, and atrial fibrillation (P<0.001) and was superior and incremental to interleukin-6, C-reactive protein, procalcitonin, ferritin, D-dimer, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide. Increase in GDF-15 from baseline to day 3 was also greater in patients reaching the primary end point (median, 1208 [IQR, 0–4305] pg/mL versus median, –86 [IQR, –322 to 491] pg/mL, P<0.001).

Conclusions:

GDF-15 is elevated in the majority of patients hospitalized with COVID-19, and higher concentrations are associated with SARS-CoV-2 viremia, hypoxemia, and worse outcome. The prognostic value of GDF-15 was additional and superior to established cardiovascular and inflammatory biomarkers.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04314232.

GDF-15 in solid vs non-solid treatment-naïve malignancies

AIM

GDF-15 is an established cardiovascular risk marker but is equally implicated in tumour biology. Elevated levels of GDF-15 have indeed been observed in distinct tumour entities. This study aimed to explore the relation of GDF-15 to other cardiac biomarkers and the general association of GDF-15 on prognosis in an unselected cohort of treatment-naïve cancer patients.

METHODS

We prospectively enrolled 555 consecutive patients at time of diagnosis of malignant disease prior receiving anticancer therapy. Plasma GDF-15 concentrations were determined alongside other cardiac and routine laboratory markers. All-cause mortality was defined as primary endpoint.

RESULTS

GDF-15 levels were 338 ng/L (IQR:205-534) for the total cohort, and values were comparable for different tumour entities except breast cancer. Metastatic disease was characterized by higher plasma GDF-15 [435 ng/L (IQR:279-614) vs 266 ng/L (IQR:175-427), P < .001]. GDF-15 correlated positively with inflammatory status reflected by CRP, SAA and IL-6 [r = .31, P < .001, r = .23, P < .001 and r = .14, P = .002] and cardiac biomarkers as NT-proBNP, hsTnT, MR-proADM and CT-proET-1 [r = .46; r = .46; r = .59 and r = .50; P < .001 for all]. GDF-15 was significantly associated with all-cause mortality after multivariate adjustment [adj.HR for ln(GDF-15) 1.78, 95%CI:1.47-2.16, P < .001]. There was a significant interaction between solid and haematological malignancies with loss of association of GDF-15 with outcome in myelodysplastic and myeloproliferative disease.

CONCLUSIONS

Elevated plasma GDF-15 is associated with progressing disease severity and poor prognosis in solid tumours of treatment-naïve cancer patients. GDF-15 increase is accompanied by worsening systemic inflammation and a subclinical functional impairment of different organs including the heart. GDF-15 represents a promising target for our pathophysiologic understanding in cardio-oncology linking conditions of both cardiac and neoplastic disease.

The impact of GDF-15, a biomarker for metformin, on the risk of coronary artery disease, breast and colorectal cancer, and type 2 diabetes and metabolic traits: a Mendelian randomisation study

AIMS/HYPOTHESIS

Growth differentiation factor 15 (GDF-15), a suggested biomarker for metformin use, may explain the potential cardioprotective and anti-cancer properties of metformin. We conducted a Mendelian randomisation study to examine the role of GDF-15 in risk of coronary artery disease (CAD) and breast and colorectal cancer. Secondary analyses included examination of the association of GDF-15 with type 2 diabetes, glycaemic traits, BP, lipids and BMI.

METHODS

We obtained SNPs strongly (p value <5 × 10^-8) predicting GDF-15 from a genome-wide association study (GWAS) (n = 5440) and applied them to genetic studies of CAD (CARDIoGRAMplusC4D 1000 Genomes-based GWAS [n = 184,305]), type 2 diabetes (DIAGRAM [DIAbetes Genetics Replication And Meta-analysis; n = 898,130]), glycaemic traits (MAGIC [the Meta-Analyses of Glucose and Insulin-related traits Consortium; HbA_1c: n = 123,665; fasting glucose: n = 46,186]), BP, breast cancer and colorectal cancer (UK Biobank [n ≤ 401,447]), lipids (GLGC [Global Lipids Genetic Consortium; n ≤ 92,820]) and adiposity (GIANT [Genetic Investigation of ANthropometric Traits Consortium; n = 681,275]). Causal estimates were obtained using inverse variance weighting, taking into account correlations between SNPs. Sensitivity analyses included focusing on the lead SNP (rs888663) and validation for CAD in the UK Biobank and for breast cancer in the Breast Cancer Association Consortium.

RESULTS

Using 5 SNPs, increased GDF-15 was associated with lower CAD (OR 0.93 per SD increase, 95% CI 0.87, 0.99) and breast cancer (OR 0.89 per SD increase, 95% CI 0.82, 0.96), with similar results from lead SNP analysis. However, the associations with CAD (OR 0.99 per SD increase, 95% CI 0.93, 1.04) and breast cancer (OR 0.97 per SD increase, 95% CI 0.94, 1.01) in the validation studies were not as apparent. GDF-15 was not associated with type 2 diabetes, glycaemic traits, CAD risk factors or colorectal cancer.

CONCLUSIONS/INTERPRETATION

There is no convincing evidence that GDF-15 reduces risk of CAD or breast or colorectal cancer. Whether the observed inverse association of metformin use with cancer risk is via other unexplored mechanistic pathways warrants further investigation.

Meta-Analysis of Microarray Expression Studies on Metformin in Cancer Cell Lines

Several studies have demonstrated that metformin (MTF) acts with variable efficiency as an anticancer agent. The pleiotropic anticancer effects of MTF on cancer cells have not been fully explored yet. By interrogating the Gene Expression Omnibus (GEO) for microarray expression data, we identified eight eligible submissions, representing five different studies, that employed various conditions including different cell lines, MTF concentrations, treatment durations, and cellular components. A compilation of the data sets of 13 different conditions contained 443 repeatedly up- and 387 repeatedly down-regulated genes; the majority of these 830 differentially expressed genes (DEGs) were associated with higher MTF concentrations and longer MTF treatment. The most frequently upregulated genes include DNA damage inducible transcript 4 (DDIT4), chromodomain helicase DNA binding protein 2 (CHD2), endoplasmic reticulum to nucleus signaling 1 (ERN1), and growth differentiation factor 15 (GDF15). The most commonly downregulated genes include arrestin domain containing 4 (ARRDC4), and thioredoxin interacting protein (TXNIP). The most significantly (p-value < 0.05, Fisher’s exact test) overrepresented protein class was entitled, nucleic acid binding. Cholesterol biosynthesis and other metabolic pathways were specifically affected by downregulated pathway molecules. In addition, cell cycle pathways were significantly related to the data set. Generated networks were significantly related to, e.g., carbohydrate and lipid metabolism, cancer, cell cycle, and DNA replication, recombination, and repair. A second compilation comprised genes that were at least under one condition up- and in at least another condition down-regulated. Herein, the most frequently deregulated genes include nuclear paraspeckle assembly transcript 1 (NEAT1) and insulin induced gene 1 (INSIG1). The most significantly overrepresented protein classes in this compilation were entitled, nucleic acid binding, ubiquitin-protein ligase, and mRNA processing factor. In conclusion, this study provides a comprehensive list of deregulated genes and biofunctions related to in vitro MTF application and individual responses to different conditions. Biofunctions affected by MTF include, e.g., cholesterol synthesis and other metabolic pathways, cell cycle, and DNA replication, recombination, and repair. These findings can assist in defining the conditions in which MTF exerts additive or synergistic effects in cancer treatment.

GDF15 reflects beta cell function in obese patients independently of the grade of impairment of glucose metabolism

BACKGROUND AND AIMS

Growth differentiation factor 15 (GDF15) is a strong predictor of cardiovascular morbidity and mortality found to be both marker and target of impaired glucose metabolism. GDF15 increases following glucose administration and is up-regulated in obesity and diabetes. We investigate here the relationship between GDF15 and beta cell function.

METHODS AND RESULTS

In this cross-sectional study we evaluated GDF15 concentrations in 160 obese subjects (BMI 35-63 kg/m², age 39.4 ± 18.6 years, m/f 38/122) who underwent a 75 g oral glucose tolerance test (OGTT). Based on the OGTT results, the cohort was divided into two groups: 1) normal fasting glucose and normal glucose tolerance (n = 80), 2) impaired fasting glucose, impaired glucose tolerance or type 2 diabetes (n = 80). The relationship of GDF15 to fasting and OGTT-based dynamic insulin sensitivity and insulin secretion parameters was evaluated. GDF15 was higher in the prediabetes and diabetes groups and correlated with HbA1c, glucose, insulin as well as baseline and dynamic indices of insulin sensitivity and estimated beta cell function. Multiple regression analysis revealed that age, waist-to-height ratio, glomerular filtration rate and prehepatic beta cell function, but not the grade of impairment of glucose metabolism, were independent predictors of GDF15. Subgroup analysis showed that of all parameters of glucose metabolism only C-peptide, fasting prehepatic beta cell function and insulinogenic index remained significantly related to GDF15 in both groups.

CONCLUSION

We conclude that in patients with severe obesity, GDF15 strongly relates to beta cell function and should be further investigated as a potential therapeutic target and biomarker guiding treatment options.

Effects of plant and animal high protein diets on immune-inflammatory biomarkers: A 6-week intervention trial

BACKGROUND & AIMS

Pro-inflammatory biomarkers are well-established contributors to insulin resistance and represent valid targets for diabetes management and prevention. Yet, little is known whether nutrition could play a role in modulating various aspects of immune-inflammatory responses. Our aim is to assess the effect of isocaloric animal and plant protein dietary interventions on selected biomarkers representing various immune-inflammatory pathways.

METHODS

We enrolled 37 participants with type 2 diabetes (age 64 ± 6 years, body mass index 30.2 ± 3.6 kg/m², glycated hemoglobin 7.0 ± 0.6%) who underwent an either high-animal protein (AP) or high-plant protein (PP) diet (30 E% protein, 40 E% carbohydrates, 30 E% fat) for 6-weeks. Clinical examinations were performed at beginning and end of the study. Levels of pro-inflammatory adipokines [chemerin, progranulin], cytokines [tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), soluble urokinase-type plasminogen activator receptor (suPAR), transforming growth factor beta 1 (TGF-β1)], and proteins [calprotectin, lactoferrin and growth differentiation factor 15 (GDF-15)] were determined in blood serum using enzyme-linked immunosorbent assay.

RESULTS

Chemerin and progranulin concentrations decreased following AP and PP diets. TGF-β1 increased in AP and decreased in PP, whereas calprotectin increased in PP and decreased in AP. No statistically significant differences in the concentrations of IL-6, TNF-α, suPAR, lactoferrin and GDF-15 could be seen in either of the protein diet arms.

CONCLUSIONS

These results suggest that both AP and PP diets may effectively reduce the levels of the pro-inflammatory adipokines chemerin and progranulin. The effects on the additional immune-inflammatory biomarkers seem to be more complex.

CLINICAL TRIAL REGISTRY NUMBER

NCT02402985 (ww.clinicaltrials.gov).

Muscle wasting in the presence of disease, why is it so variable?

Skeletal muscle wasting is a common clinical feature of many chronic diseases and also occurs in response to single acute events. The accompanying loss of strength can lead to significant disability, increased care needs and have profound negative effects on quality of life. As muscle is the most abundant source of amino acids in the body, it appears to function as a buffer for fuel and substrates that can be used to repair damage elsewhere and to feed the immune system. In essence, the fundamentals of muscle wasting are simple: less muscle is made than is broken down. However, although well-described mechanisms modulate muscle protein turnover, significant individual differences in the amount of muscle lost in the presence of a given severity of disease complicate the understanding of underlying mechanisms and suggest that individuals have different sensitivities to signals for muscle loss. Furthermore, the rate at which muscle protein is turned over under normal conditions means that clinically significant muscle loss can occur with changes in the rate of protein synthesis and/or breakdown that are too small to be measurable. Consequently, the changes in expression of factors regulating muscle turnover required to cause a decline in muscle mass are small and, except in cases of rapid wasting, there is no consistent pattern of change in the expression of factors that regulate muscle mass. MicroRNAs are fine tuners of cell phenotype and are therefore ideally suited to cause the subtle changes in proteome required to tilt the balance between synthesis and degradation in a way that causes clinically significant wasting. Herein we present a model in which muscle loss as a consequence of disease in non-muscle tissue is modulated by a set of microRNAs, the muscle expression of which is associated with severity of disease in the non-muscle tissue. These microRNAs alter fundamental biological processes including the synthesis of ribosomes and mitochondria leading to reduced protein synthesis and increased protein breakdown, thereby freeing amino acids from the muscle. We argue that the variability in muscle loss observed in the human population arises from at least two sources. The first is from pre-existing or disease-induced variation in the expression of microRNAs controlling the sensitivity of muscle to the atrophic signal and the second is from the expression of microRNAs from imprinted loci (i.e. only expressed from the maternally or paternally inherited allele) and may control the rate of myonuclear recruitment. In the absence of disease, these factors do not correlate with muscle mass, since there is no challenge to the established balance. However, in the presence of such a challenge, these microRNAs determine the rate of decline for a given disease severity. Together these mechanisms provide novel insight into the loss of muscle mass and its variation in the human population. The involvement of imprinted loci also suggests that genes that regulate early development also contribute to the ability of individuals to resist muscle loss in response to disease.

Additional Diagnostic Value of Growth Differentiation Factor-15 (GDF-15) to N-Terminal B-Type Natriuretic Peptide (NT-proBNP) in Patients with Different Stages of Heart Failure

BACKGROUND Growth differentiation factor-15 (GDF-15) is a promising biomarker of cardiac remodeling. The purpose of this study was to explore the diagnostic value of plasma GDF-15 levels in different stages of heart failure (HF) and to assess the relationship with ventricular remodeling. MATERIAL AND METHODS We enrolled 219 HF patients from the Department of Cardiology in Tianjin Union Medical Center as the HF group and 32 healthy subjects as the control group. Circulating GDF-15, NT-proBNP, procollagen I C-terminal propeptide (PICP), and N-terminal procollagen III propeptide (PIIINP) levels were measured using ELISA. Associations between GDF-15 and clinical indicators in cardiac remodeling were assessed using receiver operating characteristic (ROC) curves and Spearman correlation. All the patients were followed up for 1 year. RESULTS The level of plasma GDF-15 in HF patients was higher than in the control group (P<0.05) and increased with higher ACCF/AHA and NYHA classification (P<0.05). Patients with HFrEF had higher GDF-15 levels compared to patients with HFmrEF (P<0.05). GDF-15 and left ventricular mass index (LVMI) were significantly increased as early as the pre-clinical HF stage. Also, GDF-15 levels were positively correlated to LVMI (r=0.433, P<0.05), PICP (r=0.378, P<0.001) and PIIINP (r=0.382, P<0.001). ROC curves were constructed and GDF-15 plus NT-proBNP (AUC=0.905, 95%CI: 0.868-0.942, P<0.001) was superior to NT-proBNP (AUC=0.869, 95%CI: 0.825-0.913, P<0.001) in identifying HF. GDF-15 levels did not predict prognosis after a 1-year follow-up period. CONCLUSIONS GDF-15 combined with NT-proBNP significantly improves the accuracy of diagnosing HF. Plasma GDF-15 levels can indirectly reflect the degree of cardiac remodeling and fibrosis.

Elevated serum growth differentiation factor 15 levels are associated with thyroid nodules in type 2 diabetes aged over 60 years

In order to investigate whether serum growth differentiation factor 15 is associated with thyroid nodules in type 2 diabetes. We recruited 723 type 2 diabetic patients aged over 30 years who attended the clinic of Endocrinology of Xinhua Hospital from January 2013 to January 2015. Thyroid nodule was diagnosed by thyroid ultrasonographic examination. Serum growth differentiation factor 15, thyroid function, thyroid autoantibodies, thyroglobulin and other biochemical indicators were measured and compared between thyroid nodule positive and negative groups. We found that overall, serum growth differentiation factor 15 levels were significantly higher in subjects with thyroid nodules compared with nodule negative subjects (181.76±98.49 pg/ml vs. 162.32±83.63 pg/ml, p<0.05), and this was influenced by age. In the patients over 60 years, this difference became more significant (211.23±103.66 pg/ml vs. 177.38±85.51 pg/ml, p<0.01), but in patients under 60 years, there was no difference between the two groups. Multivariate logistic regression analysis showed that serum growth differentiation factor 15 levels were independently associated with thyroid nodule in diabetic patients over 60 years (P <0.001). After multiple adjustments, the odds ratios were substantially higher for thyroid nodule (odds ratio 2.63, 95% confidence interval 1.30-5.13, p<0.01) in the highest growth differentiation factor 15 quartile compared to those in the lowest quartile in patients over 60 years. In conclusion, serum growth differentiation factor 15 is increased significantly in subjects with thyroid nodules in type 2 diabetic patients aged over 60 years.

Cardiac biomarkers in diabetes mellitus: New dawn for risk stratification?

Type 2 diabetes mellitus (T2DM) remains a leading cause of cardiovascular (CV) events and diseases worldwide. The aim of the review is to summarize our knowledge regarding clinical implementation of the biomarker-based strategy of the CV risk assessment in T2DM patient population. There is large body of evidence regarding use of the cardiac biomarkers to risk stratification at higher CV risk individuals who belongs to general population and cohort with established CV disease. Although T2DM patients have higher incidence of macrovascular and microvascular CV complications than the general population, whether cardiac biomarkers would be effective to risk stratification of the T2DM is not fully understood. The role of natriuretic peptides, galectin-3, interleukins, growth differentiation factor-15, as well as biomarkers of endothelial dysfunction are widely discussed. In conclusion, future directions, which associate with discovering of novel biomarkers and their best combinations to provide additional predictive information beyond other traditional CV risk factors, are discussed.