Solvent-induced occupational myopathy.

Serum creatine kinase (CK) was significantly higher (p < 0.02) in 69 patients examined for occupational intoxication from solvents than in 96 non-exposed control subjects. A needle muscle biopsy was performed in nine patients randomly selected from the patients with elevated levels of serum CK. A higher activity of muscle lactate dehydrogenase (LDH) (p < 0.05) and a lower activity of muscle succinate dehydrogenase (SDH) (p < 0.01) was found in the patients when compared with 16 non-exposed control subjects. No histological abnormalities were observed using light microscopy. The elevated serum CK represented the serum CKM isoenzyme fraction. It is concluded that skeletal muscles should be added to the list of organs involved in intoxication from solvents and that serum CK should be analyzed in solvent-intoxicated patients as an indicator of myopathy.