Reversible Acute Kidney Injury and Rhabdomyolysis Due to Severe Autoimmune Hypothyroidism in an Adolescent Using Creatine Supplements.

Profound hypothyroidism is a rare but reversible etiology of acute renal failure (ARF) associated with rhabdomyolysis, and it occurs mainly in children or adolescents. We describe a 16-year-old previously healthy male who presented with progressive fatigability, hypersomnia, myalgia, cold intolerance, and dark-colored urine, along with raised serum creatinine levels, in the context of extreme dieting, dehydration, and creatine intake. Laboratory examination showed severe autoimmune hypothyroidism with a thyroid-stimulating hormone (TSH) level of >100 μIU/mL, significantly low free T4 and T3 concentrations, positive results for anti-thyroid peroxidase and anti-thyroglobulin antibodies, and elevated creatine kinase indicative of rhabdomyolysis in the setting of concurrent acute kidney injury (AKI). The patient was treated with intravenous hydration, levothyroxine replacement, and vitamin D supplementation and instructed not to use creatine. His clinical and biochemical condition improved rapidly, accompanied by gradual recovery of the renal function and disappearance of the musculature symptoms. Outpatient endocrine follow-up revealed ongoing recovery. Our case presents the role of hypothyroidism in such unexplained AKI with raised creatine kinase, especially in adolescents using performance-enhancing supplements and involved in restrictive dietary practices.