Virginia Research Day 2022

Medical Resident Research Case Reports

02 Late Onset Acromegaly Presenting With Insulin Resistant Diabetes Mellitus

Nam Phan; Andres Tabares; Autumn Jordan Corresponding Author: andy1512005@gmail.com

LewisGale Hospital-Montgomery

Introduction: Acromegaly is a rare acquired disease that usually affects adults between the ages of 30 and 40 but due to the insidious nature of the disease, diagnosis is often delayed years after its onset. Acromegaly results in the persistent hypersecretion of growth hormone (GH) leading to hepatic secretion of insulin-like growth factor-1 (IGF- 1) which ultimately leads to insulin resistant diabetes mellitus. The hypersecretion of GH leads to lipolysis and impaired glucose uptake in adipose tissue leading to features of reduced body fat in the setting of insulin resistant diabetes. These features can clinically mask the diagnosis of diabetes which is clinically relevant as this negatively impacts patient care as diabetes increases the risk of cardiovascular morbidity and mortality. The goal of our case study is to illustrate the presenting complaints of insulin resistant diabetes as a clinical marker for late onset acromegaly.

Case Presentation: We present the case of a 51-year-old male who initially presents for evaluation and management of type 2 diabetes which has been uncontrolled for the past 10 years with an HA1c of 10.5 while on four different hypoglycemic agents. On initial presentation, patient presented as a well- built male with an active lifestyle and history of body building. The decision was made to check IGF-1 levels as the patient had clinically significant features of large hands and feet as well as crowned teeth which in the past was attributed to history of GH injections during his body building career. Further workup revealed elevated IGF-1 levels and negative GH suppression test following oral glucose load suggesting the presence of acromegaly. Subsequent MRI imaging revealed a 3 mm focus of relative decreased enhancement in the pituitary suspicious for a microadenoma. Patient was evaluated by neurosurgery and

underwent successful transsphenoidal resection of the pituitary microadenoma. Following resection of patient’s microadenoma, his HA1c drastically improved to 6.5 with noted improvement in quality of life. Conclusion: In conclusion, this highlights insulin resistant diabetes as an important marker for initial diagnosis of acromegaly. Early and prompt transsphenoidal surgical resection remains the first-line of treatment which leads to near resolution of glucose metabolism abnormalities and as a result can reduce a patient’s dependence on hypoglycemic medications which ultimately reduces unwanted side effects of these medications. Drastic improvement in patient’s hyperglycemia can also result in reduction in long-term complications of uncontrolled diabetes including cardiovascular events, neuropathy and chronic kidney disease.

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