# The Hidden Hazard of Hypothyroidism: Statin-Associated Rhabdomyolysis With Life-Threatening Complications

## TL;DR

A 76-year-old man with undiagnosed hypothyroidism developed severe muscle breakdown and kidney failure after starting a statin, highlighting the risk of combining these conditions.

## Contribution

This case highlights the previously underappreciated risk of statin-induced rhabdomyolysis in patients with untreated hypothyroidism.

## Key findings

- A patient with undiagnosed hypothyroidism developed severe rhabdomyolysis and acute kidney injury after starting atorvastatin.
- Aggressive treatment improved the patient's condition, but he required hemodialysis and rehabilitation.
- The case emphasizes the importance of screening for thyroid dysfunction in patients on statins to prevent life-threatening complications.

## Abstract

Statins are among the most widely prescribed medications for reducing cardiovascular morbidity and mortality. While generally well tolerated, they carry a rare but potentially fatal risk of rhabdomyolysis - a condition marked by massive skeletal muscle breakdown, electrolyte abnormalities, and acute kidney injury (AKI). We report the case of a 76-year-old man who developed profound rhabdomyolysis, severe transaminitis, and dialysis, requiring AKI shortly after initiating atorvastatin. His initial symptoms included excruciating bilateral lower extremity pain and progressive weakness, ultimately rendering him unable to walk. Laboratory evaluation revealed a creatine kinase level exceeding 25,000 U/L, marked elevations in aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and a creatinine of 9.6 mg/dL. Despite prompt initiation of aggressive intravenous hydration, bladder decompression, and supportive care, the patient remained anuric and progressed to volume overload, necessitating initiation of hemodialysis.

Further evaluation revealed profoundly uncontrolled hypothyroidism, with a thyroid-stimulating hormone (TSH) of 121.7 µIU/mL and a free T4 level of less than 0.4 ng/dL, despite reported use of levothyroxine. MRI of the thigh showed diffuse muscular edema without myonecrosis, and an autoimmune myositis panel was negative. Atorvastatin was promptly discontinued, and thyroid hormone therapy was intensified. Over the next several days, his biochemical parameters slowly improved, and he was ultimately discharged to acute rehabilitation with plans for outpatient dialysis and endocrine follow-up.

This case underscores the synergistic danger of statin therapy in the presence of untreated or undertreated hypothyroidism. Routine screening for thyroid dysfunction, particularly in elderly patients or those with known thyroid disease, may help prevent catastrophic complications such as rhabdomyolysis and irreversible renal injury.