AKumagai SpontaneousHypoglycemia析课件.ppt

Non-Islet Cell Tumor Hypoglycemia Really Weird Causes of Fasting Hypoglycemia Non-Islet Cell Tumor Hypoglycemia Large mesenchymal tumors ( 2 kg in size) - leiomyosarcomas, mesotheliomas, fibrosarcoma. Hepatocellular carcinoma (“hepatoma”), but NOT metastatic disease to the liver. Adrenal cortical tumors. Carcinoid (bronchus, ileum, pancreas). Adenocarcinoma of the lung, stomach or colon. Hematologic malignancies - “pseudohypoglycemia” Remember these two Non-Islet Cell Tumor Hypoglycemia:Proposed Pathological Mechanisms BRAIN Tumor produces “Big” IGF-2 (~12 kDa) IGF-2 feedback on pituitary decreases GH Decreased GH decreases synthesis of IGFBP3 Decreased IGFBP increases free “Big IGF-2”, which binds to the insulin receptor A. Kumagai Anti-Insulin Receptor Antibody Syndrome Really Truly Weird Causes of Fasting Hypoglycemia Autoimmune Hypoglycemic Syndromes Anti-Insulin Receptor Antibodies (anti-IR Ab) First described in individuals with extreme insulin resistance; however, may be seen in association with type 1 diabetes. Characterized by extreme HYPERglycemia (BG 500) alternating with severe, refractory HYPOglycemia (BG’s 20), depending on the anti-IR Ab titer. Extremely rare: less than 100 cases in the literature Typically causes FASTING hypoglycemia A. Kumagai Spontaneous Hypoglycemia POSTPRANDIAL HYPOGLYCEMIA Postgastrectomy Hypoglycemia “Reactive” Hypoglycemia Postgastrectomy Hypoglycemia Shortened stomach (e.g., post-Billroth II procedure) Rapid transit of carbohydrate through shortened stomach Rapid transit through shortened stomach causes release of insulin secretogogue from GI track. Different than the postgastrectomy “dumping syndrome.” A. Kumagai Spontaneous Hypoglycemia While you are sitting around attempting to digest Thanksgiving dinner, your favorite aunt Ursula, a hulk-like 49-year-old construction worker and crane operator, wipes grease off of her slightly hairy chin and says, “Yo…my doc says that I should lose some weight, but if I don’t e