KEY WORDS: Rhabdomyolysis, muscle damage, statin.

Exertional rhabdomyolysis is often seen following strenuous muscular exercise and is a response to intensive and severe exercise. It is associated with a damage to the muscle group predominantly involved in the activity (Clarkson, 2002; Hamer, 1997; Knochel, 1990; 1993; Line and Rust, 1995; Walsworth and Kessler, 2001). The causes of rhabdomyolysis are drug (Braseth et al., 2001; Sandhu et al., 2002) or alcohol abuse, use of statins (Thompson et al., 2003), intensive eccentric exercise (Clarkson and Sayers, 1999), crush trauma and high-intensity exercise in heat stress conditions.

Key clinical features are severe muscle pain, muscle swelling, muscle weakness and elevated creatine kinase (CK) level. CK>10.000 IU/L is accepted as diagnostic criterion of rhabdomyolysis. (Lemos, 2004)

Exertional rhabdomyolysis cases mostly involve individuals who were inexperienced exercisers, dehydrated and uneducated in fitness (Sandhu et al., 2002; Wirthwein et al., 2001). Two recently published case reports show that rhabdomyolysis can develop in individuals who are physically fit, exercise-trained and healthy, due to overexertion following exercise under the guidance of a trainer in a sports club (22y female and 37y male) (Springer and Clarkson, 2003). Exertional rhabdomyolysis localized to one muscle is not also a rare condition. Three cases have been previously reported, in which localized rhabdomyolysis developed in the biceps (Bolgiano, 1994), triceps (Goubier et al., 2002), and soleus (Watanabe et al., 2007) muscles. We present a case of rhabdomyolysis of the bilateral adductor muscles.

MK is a 63-yr-old male, height 1.81 m and weight 73 kg. He agreed to the use of his clinical data for this report. He applied to the sports medicine polyclinic with pain and swelling in the bilateral adductor muscle groups of the hip (predominantly in the right limb). He stated in his anamnesis that on Sunday (4 days ago) he was hiking in the mountains (30 km) for 6 hours, the weather was hot and they had a break for only 30 minutes and that the group of hikers took lesser liquid with them than usually was the case.

The same night he drank one bottle of red wine (70 cc, %12 alcohol). The next morning he realized a slight swelling in the bilateral adductor areas of the hip. He applied to our polyclinic on Thursday as the swelling and pain got more severe.

He did not pay attention to the color of his urine. He stated that he did not use any performance boosting substances (creatine, protein powder, steroids...) or any other medication. He had hypertriglycemia, an underlying chronic disease. He has been using simvastatin [Zocor ®) since 1991 for 18 years (20mg/day 1991-2002, 10 mg/day 2002-2007)]. Due to statin use MK underwent measurement for creatine kinase (CK) once in 6 months, the values of which were slightly above normal at approximately 300 IU/L. His CPK of 6 months before was 320 IU/L.

Aside from an active professional life he engaged regularly in sports activities. He was weightlifting regularly weekdays around noon in the fitness room of the hospital with his personal trainer for 8 months. His daily fitness activities consisted of the following sets: 5 min warm up cycling, 3×10 rowing, 3×10 chest press, 4×10 biceps curls, 4×10 triceps curls and several types of lower back/abdominal muscle exercises. MK was doing garden work in his backyard for 30 minutes during the last 5 years after work. He was hiking every Sunday for 2-3 hours (10 km) for the last 20 years. Clinical examination showed predominantly on the right side muscle swelling (no increase of heat on the affected area) and palpational pain of the bilateral adductor muscle groups and bilateral tibial edema. There was no echimosis and no sensory or motor deficit of the limbs. Distal pulsations were clear.

His serum CK level was 12218 IU/L. Myoglobin levels were not assessed. The blood chemistry results for the days after the exertion are shown in Table 1. Statin was ceased. Muscle US and Doppler tests were normal. MRI and T2- weighted images showed a hyperintense signal in the bilateral adductor muscle groups of the hip (especially in the adductor magnus) with swelling (Figure 1a). All adductor muscle groups of both thighs showed an extensive edema pattern that was more discerned in the bilateral medial cutaneous and subcutaneous fatty tissues of the right thigh. T1-weighted images showed no specific findings (Isointens in the T1 sequency, hyperintens in the T2 sequency) (Figure1b).

Since the urinary output of the patient was normal, he did not receive intravenous saline infusion. At least 3 lt/day of oral isotonic liquid and resting of the affected muscle group were prescribed. On day 6 post- exercise the musle swelling and on day 15 the myalgia subsided. On day 20 he restarted statin use (10 mg/day) and on day 30 post-exercise he returned to his usual sports activity level.

• Statin use can be one of the causes of the rhabdomyolysis following a strenuous eccentric exercise.
• Elevated CK levels and MRI imaging are important for the diagnosis.
• The treatment consists of complete rest and adequate hydration.