S5610 A Graves’ Concern? Thyrotoxicosis Presenting as GI and Liver Abnormalities

Introduction: Untreated thyrotoxicosis (TTX) commonly presents with distinctive symptoms such as weight loss, diaphoresis, palpitations, tremors, and even goiter. Gastrointestinal (GI) manifestations, including vomiting and signs of liver dysfunction, are rarely the primary presenting features. While the mechanism is not fully understood, a subset of patients can show signs of hepatocellular and cholestatic liver injury. Gastroenterologists should be aware of atypical GI manifestations of hyperthyroidism when considering a differential diagnosis. Here, we describe an unusual presentation of TTX leading to the diagnosis of Graves’ disease (GD). Case Description/Methods: A healthy 27-year-old woman presented to the ED with 2 days of vomiting and watery diarrhea. She had presented to urgent care one month earlier with similar symptoms and was treated conservatively as her symptoms resolved. She denied fever or abdominal pain, but endorsed extreme nausea and a 30-pound weight loss over the past few months. Her family history was significant for GD in her mother. Her vitals were stable except for sinus tachycardia. Her physical exam revealed no significant abnormalities. Labs were notable for aspartate aminotransferase (AST) 496, alanine aminotransferase (ALT) 379, total bilirubin 0.5, and alkaline phosphatase (ALP) 75. Hepatitis and Lyme serologies, mononucleosis assays, AMA, ANA, ASMA, ceruloplasmin, LKM, and IgG were within normal limits. The patient has the Pi MS genotype, which is unlikely clinically significant given her normal A1AT level. The GI consultant recommended a thyroid panel, which revealed a TSH <0.008, Free T4 >5.0, and total T3 662. Anti-TPO was 14.8. These findings were consistent with a diagnosis of TTX secondary to GD. The patient was treated with methimazole, hydrocortisone, and propranolol and monitored for one week in the hospital. At her follow-up visit 2 weeks later, the diarrhea, nausea, and vomiting had resolved, and her transaminases had normalized with ALT 40 and AST 22. Discussion: Our patient presented primarily with GI complaints of vomiting, nausea, and diarrhea, and labs were consistent with hepatocellular liver injury. A recent meta-analysis revealed that 60% of patients with untreated GD may have at least one abnormal liver blood test. The most common abnormalities involve alkaline phosphatase (44%) and ALT (33%). As in this case, most patients' liver tests normalize once the hyperthyroidism is treated. This case highlights the need for gastroenterologists to consider a broad differential for common and nonspecific GI complaints.