Case of asymptomatic rhabdomyolysis diagnosed at medical check-up

Abstract

AST (IU/L) 15e37 1066 723 39 ALT (IU/L) 3e41 314 339 115 ALP (IU/L) 50e136 65 TBI (mg/dL) 0.4e1.0 1.3 DBI (mg/dL) 0e0.3 0.2 BUN (mg/dL) 7e18 12 15 14 CRE (mg/dL) 0.8e1.3 1 1 1 TCH (mg/dL) 130e145 135 GGT (mg/dL) 15e85 16 Uric acid (mg/dL) 3.5e7.2 5.5 5.2 5.7 Potassium (mmol/L) 3.5e5.1 4.1 4.1 4 Occult blood <0.03 1.5 Urine protein (mg/dL) 10e20 20 Red blood cells count/HPF <3 0e2 Rhabdomyolysis is a potentially life-threatening syndrome. A serum creatine kinase (CK) level greater than five times the normal value is a criterion for diagnosis. Rhabdomyolysis with acute renal failure caused by statin-related myopathy is of most concern. However, exertional activity causing rhabdomyolysis, especially in untrained individuals or under extremely hot or humid conditions, is more commonly reported. The serum CK level begins to rise approximately 2e12 hours after the onset of muscle injury, peaks within 24e72 hours, and then declines at a relatively constant rate of 40% of the previous day's value. Rhabdomyolysis is treated by fluid administration and prevention of acute renal failure. A 50-year-old man came for his annual medical check-up. He maintained a healthy lifestyle, did not smoke or drink alcohol, and exercised regularly. He was not taking any medication, and had no history of hepatitis or known drug allergies. His father had hypertension, diabetes mellitus, and gastric cancer. Since his serum CK level was abnormally high (970 IU/L) at his last check up 1 year earlier at another hospital, he requested a serum CK test, although it is not a recommended screening item at our hospital. On examination, his body mass index was found to be 22.7 kg/ m2. His general physical examination showed no abnormalities or physical distress. The body temperature was 36.8 C, blood pressure 128/76 mmHg, pulse 86 beats per minute, and respiratory rate 16 breaths per minute. He was physically fit, without complaints of malaise or changes in appetite or weight. He reported mild muscle aching that might have been associated with jogging for 4e5 hours in the previous 48 hours.