Two Cases of Acute Musclar Syndrome during Clofibrate Treatment of Non-Insulin-Dependent Diabetes Mellitus

Abstract

Acute muscular syndrome with transient muscular symptoms and elevation of serum levels of CPK, LDH, GOT and GPT occurred in two 58-year-old female patients with non-insulin-dependent diabetes mellitus when clofibrate was used for glucose intolerance, because of its effect on insulin receptors or the post-receptor mechanism.
Case 1, complicated with chronic renal failure, complained of bilateral calf myalgia 6 days after the initial clofibrate administration at a dose of 1.5 g daily. Then serum levels of enzymes originating from the muscles increased abruptly and the fasting plasma glucose level was elevated from 188 to 506 mg/dl. However, these symptoms disappeared quickly after 2 days and the increased enzyme levels returned to the normal range within 10 days after the cessation of clofibrate treatment. A muscle biopsy disclosed scattered atrophic muscle cells. Finally, combined therapy of insulin and low-dose (500 mg) clofibrate enabled a stable daily profile of glucose levels and improvement of hyperlipidemia without re-elevation of enzyme levels.
Case 2, who was under continuous subcutaneous insulin injection, had the same syndrome induced by clofibrate. In spite of continued clofibrate administration, the symptoms and abnormal enzme levels resolved completely and good control of glucose metabolism was achieved without insulin injections.