MON-143 Diabetic Ketoacidosis Confounding Diagnosis of Acromegaly with Microadenoma

Abstract

Introduction: Acromegaly is a chronic endocrine disorder caused by excess secretion of GH. Due to the pulsatile nature of GH secretion, random GH levels do not necessarily correlate with the disease severity. Diagnosis of acromegaly is suggestive when IGF-1 levels are elevated. It can be further confirmed by demonstrating the failure of GH suppression with oral glucose tolerance test. Diabetes is a common complication of Acromegaly due to the GH hormone’s anti- insulin effect. However, the diagnosis of Acromegaly with co-existent uncontrolled DM may prove to be challenging. In the setting of uncontrolled DM, IGF-1 level may be normal, thus confounding the diagnosis of acromegaly. Case: Here we report a case of a newly diagnosed Acromegaly presenting with DKA as its initial manifestation with normal IGF-1 level and subsequently found to have microadenoma on imaging study. IGF-1 levels were confirmed to be elevated on subsequent visits after glucose optimization. Discussion: Manifestations of acromegaly present insidiously and evolve over many years, thus eluding a prompt diagnosis. The mean delay of acromegaly diagnosis from the onset of symptoms is approximately 9 years. Acromegaly is a disease process that has multiple negative consequences including impaired glucose tolerance, resistance and diabetes. Approximately 1% of patients with acromegaly present with DKA as its initial manifestation. Combination of lipotoxicity and glucose toxicity as a result of excess Growth Hormone may lead to a relatively insulin deficient state, predisposing to the development of DKA. IGF-1 levels can be altered by malnutrition, anorexia nervosa, liver cirrhosis, renal failure inflammatory diseases, malignant tumors and uncontrolled DM. Normal IGF-1 levels in the setting of DKA or uncontrolled diabetes can therefore erroneously lead a practitioner to exclude the diagnosis of acromegaly. Re-measuring IGF-1 levels after glucose control is imperative. Conclusion: Even though acromegaly with normal IGF-1 levels in the context of uncontrolled DM has been described in the literature, DKA and concomitant acromegaly is a rare presentation. According to literature review there are 22 reported cases where patients presented with DKA in combination with Acromegaly. Notably all cases were found to have pituitary macro-adenoma on MRI. We are reporting the case of Acromegaly presenting with DKA, microadenoma on MRI and normal IGF-1. Our case illustrates that normal IGF-1 levels in the setting of uncontrolled DM/DKA does not exclude acromegaly. As a result, the diagnosis of Acromegaly in the setting of DKA can be challenging. A clinician must be very vigilant and pursue further investigative workup if the clinical suspicion for acromegaly is high in patients presenting with DKA and normal IGF-1 levels.