{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T14:51:03Z","timestamp":1783003863326,"version":"3.54.5"},"reference-count":61,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,11]],"date-time":"2024-09-11T00:00:00Z","timestamp":1726012800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Medical University of Silesia","award":["KNW-1-075\/N\/4\/0"],"award-info":[{"award-number":["KNW-1-075\/N\/4\/0"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Neuroendocrine tumors (NETs) are a heterogeneous group of tumors that are characteristically different from other malignancies. The difference is not only in the prognosis, which is usually more favorable in such patients, but also in the high clinical progression of the disease, where NET patients do not experience the cachexia typical of other malignancies. The purposes of this study were to evaluate the ghrelin and leptin levels in a group of patients diagnosed with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and bronchopulmonary neuroendocrine tumors (BP-NETs) and to analyze the relationship between the body mass index (BMI), cachexia and selected NET markers. The study group comprised 52 patients with GEP-NETs and BP-NETs, while the controls comprised 67 healthy volunteers. The ghrelin and leptin concentrations were determined in both groups. The concentrations of chromogranin A, serotonin, 5-hydroxyindoleacetic acid (5-HIAA), total cholesterol, triglycerides and glucose were determined in the study group. Characteristics of the study group and of the controls were defined by age, sex and BMI, and the effects of these factors on the ghrelin and leptin concentrations were assessed. The data obtained were subject to statistical analysis. The study cohort showed higher levels of ghrelin as compared to the controls (142.31 \u00b1 26.00 vs. 121.49 \u00b1 35.45, p = 0.016), and no statistical difference in the levels of leptin (11.15 \u00b1 9.6 vs. 12.94 \u00b1 20.30, p = 0.439) were observed. Significantly lower levels of leptin were found in patients with the small intestine primary location, as compared to individuals with primary locations in the lungs and the pancreas (4.9 \u00b1 6.49 vs. 16.97 \u00b1 15.76, p = 0.045, and 4.9 \u00b1 6.49 vs. 12.89 \u00b1 8.56, p = 0.016, respectively). A positive correlation was observed between the leptin levels and the BMIs in both the study group (rS = 0.33, p = 0.016) and the controls (rS = 0.41, p = 0.001). The study group showed a negative correlation between the leptin levels and 5-HIAA (rS = \u22120.32, p = 0.026) and a negative correlation between the leptin levels and Ki-67 (rS = \u22120.33, p = 0.018). The control group showed negative correlations between the ghrelin and the volunteer age (rS = \u22120.41, p = 0.008), the leptin and the volunteer age (rS = \u22120.44, p &lt; 0.001), the leptin and total cholesterol (rS = \u22120.24, p &lt; 0.049) as well as the leptin and triglycerides (rS = \u22120.33, p &lt; 0.006). The current study emphasized the importance of the markers\u2019 determination, where ghrelin appears as a valuable diagnostic biomarker in NETs, probably responsible for maintaining a normal BMI, despite the progression of the disease.<\/jats:p>","DOI":"10.3390\/ijms25189820","type":"journal-article","created":{"date-parts":[[2024,9,11]],"date-time":"2024-09-11T05:45:12Z","timestamp":1726033512000},"page":"9820","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Adipokines in Neuroendocrine Tumors: An Evaluation of the Serum Levels of Ghrelin and Leptin"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7987-7344","authenticated-orcid":false,"given":"Janusz","family":"Strzelczyk","sequence":"first","affiliation":[{"name":"Department of Endocrinology and Neuroendocrine Tumors, Department of Pathophysiology and Endocrinology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-514 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5765-8258","authenticated-orcid":false,"given":"Agnes","family":"Bocian-Jastrz\u0119bska","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Neuroendocrine Tumors, Department of Pathophysiology and Endocrinology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-514 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3686-5685","authenticated-orcid":false,"given":"Joanna Katarzyna","family":"Strzelczyk","sequence":"additional","affiliation":[{"name":"Department of Medical and Molecular Biology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 41-808 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monika","family":"W\u00f3jcik-Giertuga","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Neuroendocrine Tumors, Department of Pathophysiology and Endocrinology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-514 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2620-3880","authenticated-orcid":false,"given":"Krzysztof","family":"Biernacki","sequence":"additional","affiliation":[{"name":"Department of Medical and Molecular Biology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 41-808 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5577-800X","authenticated-orcid":false,"given":"Dariusz","family":"Kajdaniuk","sequence":"additional","affiliation":[{"name":"Department of Pathophysiology and Endocrinology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 41-808 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3755-1722","authenticated-orcid":false,"given":"Beata","family":"Kos-Kud\u0142a","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Neuroendocrine Tumors, Department of Pathophysiology and Endocrinology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 40-514 Katowice, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"387","DOI":"10.5603\/EP.a2022.0049","article-title":"Update of the Diagnostic and Therapeutic Guidelines for Gastro-Entero-Pancreatic Neuroendocrine Neoplasms (Recommended by the Polish Network of Neuroendocrine Tumours)","volume":"73","author":"Foltyn","year":"2022","journal-title":"Endokrynol. Pol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"844","DOI":"10.1016\/j.annonc.2020.03.304","article-title":"Gastroenteropancreatic Neuroendocrine Neoplasms: ESMO Clinical Practice Guidelines for Diagnosis, Treatment and Follow-Up","volume":"31","author":"Pavel","year":"2020","journal-title":"Ann. Oncol."},{"key":"ref_3","unstructured":"(2024, July 22). WHO Classifications of Tumours Online. Available online: https:\/\/tumourclassification.iarc.who.int\/welcome\/."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Herrera-Mart\u00ednez, Y., Teomiro, C.A., Idougourram, S.L., Puertas, M.J.M., Continente, A.C., Blanch, R.S., Casta\u00f1o, J.P., Moreno, M.\u00c1.G., Gahete, M.D., and Luque, R.M. (2022). Sarcopenia and Ghrelin System in the Clinical Outcome and Prognosis of Gastroenteropancreatic Neuroendocrine Neoplasms. Cancers, 14.","DOI":"10.3390\/cancers14010111"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1038\/45230","article-title":"Ghrelin Is a Growth-Hormone-Releasing Acylated Peptide from Stomach","volume":"402","author":"Kojima","year":"1999","journal-title":"Nature"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.3892\/ol.2020.11662","article-title":"Inflammatory Cytokines, Appetite\u2014Regulating Hormones, and Energy Metabolism in Patients with Gastrointestinal Cancer","volume":"20","author":"Shinsyu","year":"2020","journal-title":"Oncol. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1530\/EJE-12-0456","article-title":"Mechanisms in endocrinology: Ghrelin: The Differences between Acyl- and Des-Acyl Ghrelin","volume":"167","author":"Delhanty","year":"2012","journal-title":"Eur. J. Endocrinol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e12772","DOI":"10.1111\/jne.12772","article-title":"Ghrelin: What\u2019s the Function?","volume":"31","author":"Andrews","year":"2019","journal-title":"J. Neuroendocrinol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5604\/17322693.931085","article-title":"Rola Greliny w Organizmie (The Role of Ghrelin in the Organism)","volume":"65","author":"Kemona","year":"2011","journal-title":"Postep. Hig. Med. Dosw."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4727","DOI":"10.1172\/JCI91578","article-title":"The Long Road to Leptin","volume":"126","author":"Friedman","year":"2016","journal-title":"J. Clin. Investig."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"146","DOI":"10.1016\/j.metabol.2014.07.014","article-title":"Leptin Treatment: Facts and Expectations","volume":"64","author":"Mastronardi","year":"2015","journal-title":"Metab. Clin. Exp."},{"key":"ref_12","first-page":"309","article-title":"Rola Leptyny W Patogenezie Nowotwor\u00f3w Zwi\u0105zanych Z Oty\u0142o\u015bci\u0105","volume":"42","author":"Nowak","year":"2015","journal-title":"Post\u0119py Biol. Kom\u00f3rki"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.cytogfr.2017.11.002","article-title":"The Potential Role of Leptin in Tumor Invasion and Metastasis","volume":"38","author":"Ray","year":"2017","journal-title":"Cytokine Growth Factor Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"640","DOI":"10.4236\/jct.2013.42080","article-title":"The Role of Leptin in Cancer Pathogenesis","volume":"4","author":"Tourkantonis","year":"2013","journal-title":"J. Cancer Ther."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1385138","DOI":"10.1155\/2020\/1385138","article-title":"Physiological Effect of Ghrelin on Body Systems","volume":"2020","author":"Akalu","year":"2020","journal-title":"Int. J. Endocrinol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1300","DOI":"10.1210\/jcem.87.3.8279","article-title":"Expression of Ghrelin and of the GH Secretagogue Receptor by Pancreatic Islet Cells and Related Endocrine Tumors","volume":"87","author":"Volante","year":"2002","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_17","first-page":"51","article-title":"Biochimica et Biophysica Acta Ghrelin and Cancer Progression","volume":"1868","author":"Lin","year":"2017","journal-title":"BBA-Rev. Cancer"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e209","DOI":"10.1038\/ctg.2016.64","article-title":"Prognostic Significance of Preoperative and Postoperative Plasma Levels of Ghrelin in Gastric Cancer: 3-Year Survival Study","volume":"8","author":"Abdirad","year":"2017","journal-title":"Clin. Transl. Gastroenterol."},{"key":"ref_19","first-page":"881","article-title":"The Expression of the Growth Hormone Secretagogue Receptor Ligand Ghrelin in Normal and Abnormal Human Pituitary and Other Neuroendocrine Tumors","volume":"86","author":"Korbonits","year":"2001","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Gr\u00f6nberg, M., Nilsson, C., Markholm, I., Hedenfalk, I., Blomqvist, C., Holmberg, L., Janson, E.T., and Fj\u00e4llskog, M. (2018). Ghrelin Expression Is Associated with a Favorable Outcome in Male Breast Cancer. Sci. Rep., 8.","DOI":"10.1038\/s41598-018-31783-x"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhu, C., Liu, Y., Kang, W., Zhang, Z., Zeng, Z., and Liu, D. (2020). Exploration of the Role of Serum Ghrelin in the Diagnosis and Treatment of Digestive Tract Malignancies. J. Int. Med. Res., 48.","DOI":"10.1177\/0300060520920441"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5052","DOI":"10.1210\/jcem.86.10.7918","article-title":"Ghrelin-Producing Endocrine Tumors of the Stomach and Intestine","volume":"86","author":"Papotti","year":"2001","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1159\/000345366","article-title":"Ghrelin and Obestatin in Human Neuroendocrine Tumors: Expression and Effect on Obestatin Levels after Food Intake","volume":"97","author":"Tsolakis","year":"2013","journal-title":"Neuroendocrinology"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"19619","DOI":"10.18632\/oncotarget.4316","article-title":"In1-Ghrelin, a Splice Variant of Ghrelin Gene, Is Associated with the Evolution and Aggressiveness of Human Neuroendocrine Tumors: Evidence from Clinical, Cellular and Molecular Parameters","volume":"6","author":"Luque","year":"2015","journal-title":"Oncotarget"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e196","DOI":"10.1038\/s41424-018-0058-8","article-title":"Ghrelin-O-Acyltransferase (GOAT) Enzyme as a Novel Potential Biomarker in Gastroenteropancreatic Neuroendocrine Tumors","volume":"9","author":"Gahete","year":"2018","journal-title":"Clin. Transl. Gastroenterol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.lungcan.2017.05.006","article-title":"The Components of Somatostatin and Ghrelin Systems Are Altered in Neuroendocrine Lung Carcinoids and Associated to Clinical-Histological Features","volume":"109","author":"Gahete","year":"2017","journal-title":"Lung Cancer"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"663","DOI":"10.3892\/mmr.2021.12302","article-title":"Ghrelin and Its Role in Gastrointestinal Tract Tumors (Review)","volume":"24","author":"Spiridon","year":"2021","journal-title":"Mol. Med. Rep."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1530\/EC-16-0021","article-title":"Plasma Acylated and Plasma Unacylated Ghrelin: Useful New Biomarkers in Patients with Neuroendocrine Tumors?","volume":"5","author":"Huisman","year":"2016","journal-title":"Endocr. Connect."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3117","DOI":"10.1210\/jc.2002-021842","article-title":"Circulating Ghrelin Levels in Patients with Pancreatic and Gastrointestinal Neuroendocrine Tumors: Identification of One Pancreatic Ghrelinoma","volume":"88","author":"Corbetta","year":"2003","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2340","DOI":"10.1016\/j.peptides.2011.10.006","article-title":"Ghrelin in Neuroendocrine Tumors","volume":"32","author":"Vu","year":"2011","journal-title":"Peptides"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3739","DOI":"10.1210\/jc.2003-032118","article-title":"Malignant Gastric Ghrelinoma with Hyperghrelinemia","volume":"89","author":"Tsolakis","year":"2004","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_32","first-page":"E34","article-title":"Transition of a Pancreatic Neuroendocrine Tumor from Ghrelinoma to Insulinoma: A Case Report","volume":"6","author":"Chauhan","year":"2015","journal-title":"J. Gastrointest. Oncol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1007\/s12031-007-0004-9","article-title":"Elevated Serum Ghrelin Exerts an Orexigenic Effect That May Maintain Body Mass Index in Patients with Metastatic Neuroendocrine Tumors","volume":"33","author":"Wang","year":"2007","journal-title":"J. Mol. Neurosci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"5597","DOI":"10.2147\/CMAR.S261585","article-title":"Cancer Cachexia: Definition, Staging, and Emerging Treatments","volume":"12","author":"Ni","year":"2020","journal-title":"Cancer Manag. Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"966","DOI":"10.1002\/cncr.21690","article-title":"In Breast and Colon Cancer Patients","volume":"106","author":"Wolf","year":"2006","journal-title":"Cancer"},{"key":"ref_36","first-page":"CD012229","article-title":"Ghrelin for the Management of Cachexia Associated with Cancer","volume":"2018","author":"Khatib","year":"2018","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2832","DOI":"10.1210\/jc.2003-031768","article-title":"Ghrelin Increases Energy Intake in Cancer Patients with Impaired Appetite: Acute, Randomized, Placebo-Controlled Trial","volume":"89","author":"Neary","year":"2004","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1530\/EJE-09-0073","article-title":"Major Hyperghrelinemia in Advanced Well-Differentiated Neuroendocrine Carcinomas: Report of Three Cases","volume":"161","author":"Walter","year":"2009","journal-title":"Eur. J. Endocrinol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1111\/j.1365-2265.2006.02695.x","article-title":"Co-Expression of Ghrelin and Its Receptor in Pancreatic Endocrine Tumours","volume":"66","author":"Ekeblad","year":"2007","journal-title":"Clin. Endocrinol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1210\/jc.2013-3158","article-title":"Age-Dependent Decline in Acyl-Ghrelin Concentrations and Reduced Association of Acyl-Ghrelin and Growth Hormone in Healthy Older Adults","volume":"99","author":"Nass","year":"2014","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1097\/00019616-199607000-00020","article-title":"Serum Immunoreactive-Leptin Concentrations in Normal-Weight and Obese Humans","volume":"6","author":"Considine","year":"1996","journal-title":"Endocrinol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"88","DOI":"10.12775\/QS.2023.09.01.012","article-title":"Influence of Excessive Body Weight on Cancer Development and Prognosis","volume":"9","author":"Bielak","year":"2023","journal-title":"Qual. Sport"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"80","DOI":"10.12775\/JEHS.2023.24.01.008","article-title":"Is Breast Cancer a Civilization Disease? Common Components of Type 2 Diabetes and Breast Cancer","volume":"24","author":"Wijas","year":"2023","journal-title":"J. Educ. Health Sport"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"63","DOI":"10.5114\/wo.2019.85877","article-title":"The Influence of Leptin on the Process of Carcinogenesis","volume":"23","author":"Modzelewska","year":"2019","journal-title":"Wspolczesna Onkol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1210\/endrev\/bnad015","article-title":"Update on Adipose Tissue and Cancer","volume":"44","author":"Brown","year":"2023","journal-title":"Endocr. Rev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1016\/j.fct.2017.05.058","article-title":"Leptin Induces CREB-Dependent Aromatase Activation through COX-2 Expression in Breast Cancer Cells","volume":"106","author":"Gyun","year":"2017","journal-title":"Food Chem. Toxicol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"75","DOI":"10.3892\/mco.2016.1087","article-title":"Increased Serum Leptin Level in Overweight Patients with Colon Carcinoma: A Cross-Sectional and Prospective Study","volume":"6","author":"Wang","year":"2017","journal-title":"Mol. Clin. Oncol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.bbrc.2015.01.118","article-title":"Intestinal Epithelial Cells Promote Secretion of Leptin and Adiponectin in Adipocytes","volume":"458","author":"Ishihara","year":"2015","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1369\/jhc.2008.950782","article-title":"Leptin and the Obesity Receptor (OB-R) in the Small Intestine and Colon: A Colocalization Study","volume":"56","author":"Hansen","year":"2008","journal-title":"J. Histochem. Cytochem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1053\/jpsu.2002.30805","article-title":"Leptin: A New Growth Factor for the Small Intestine","volume":"37","author":"Alavi","year":"2002","journal-title":"J. Pediatr. Surg."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1006\/jsre.2001.6153","article-title":"Novel Effect of Leptin on Small Intestine Adaptation","volume":"97","author":"Pearson","year":"2001","journal-title":"J. Surg. Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.jss.2004.10.005","article-title":"Altered Intestinal Motility in Leptin-Deficient Obese Mice","volume":"124","author":"Kiely","year":"2005","journal-title":"J. Surg. Res."},{"key":"ref_53","first-page":"30","article-title":"Impaired Intestinal Cell Proliferation and Cell Death in Leptin-Deficient Obese Mice","volume":"29","author":"Kiely","year":"2005","journal-title":"J. Parenter. Enter. Nutr."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Bocian-Jastrz\u0119bska, A., Malczewska-Herman, A., Rosiek, V., and Kos-Kud\u0142a, B. (2023). Assessment of the Role of Leptin and Adiponectinas Biomarkers in Pancreatic Neuroendocrine Neoplasms. Cancers, 15.","DOI":"10.3390\/cancers15133517"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1207\/S15327914NC4402_06","article-title":"Circulating Concentrations of \u201cFree\u201d Leptin in Relation to Fat Mass and Appetite in Gastrointestinal Cancer Patients","volume":"44","author":"Wallace","year":"2009","journal-title":"Nutr. Cancer"},{"key":"ref_56","unstructured":"Lambris, J.D. (2017). Advances in Experimental Medicine and Biology: Sex and Gender Factors Affecting Metabolic Homeostasis, Diabetes and Obesity, Springer."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Rosiek, V., Bocian-Jastrz\u0119bska, A., and Kos-Kud\u0142a, B. (2023). Selected Serum Biomarkers (Leptin, Chromogranin A, CA19-9, CEA) in Patients with Pancreatic Neuroendocrine Neoplasm and Associations with Metabolic Syndrome. Cancers, 15.","DOI":"10.3390\/cancers15082348"},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Santos, A.P., Santos, A.C., Castro, C., Raposo, L., Pereira, S.S., Torres, I., Henrique, R., Cardoso, H., and Monteiro, M.P. (2018). Visceral Obesity and Metabolic Syndrome Are Associated with Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors. Cancers, 10.","DOI":"10.3390\/cancers10090293"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"922","DOI":"10.1177\/0148607114538059","article-title":"Relationship Between Triglyceride Tolerance, Body Mass Index, and Fat Depots in Hospitalized Patients Receiving Parenteral Nutrition","volume":"39","author":"Frazee","year":"2015","journal-title":"J. Parenter. Enter. Nutr."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1007\/s40618-023-02213-1","article-title":"Gender-related differences in patients with carcinoid syndrome: New insights from an Italian multicenter cohort study","volume":"47","author":"Ruggeri","year":"2024","journal-title":"J. Endocrinol. Investig."},{"key":"ref_61","unstructured":"R Core Team (2024, February 20). R: A Language and Environment for Statistical Computing. Available online: https:\/\/www.r-project.org\/."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/18\/9820\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:53:41Z","timestamp":1760111621000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/25\/18\/9820"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,11]]},"references-count":61,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["ijms25189820"],"URL":"https:\/\/doi.org\/10.3390\/ijms25189820","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,11]]}}}