Creatine Kinase Elevation,Lactacidemia, and Metabolic Myopathy in Adult Patients with Diabetes Mellitus

ObjectiveTo determine the frequency of elevated creatine kinase (CK) levels among patients with diabetes mellitus and to determine how often elevated CK is attributable to primary myopathy.MethodsIn this prospective study, we investigated how often CK, aspartate aminotransferase, alanine aminotransferase, and resting lactate were elevated among consecutive diabetic patients attending our clinic. Those with elevated CK values were offered a neurologic workup.ResultsNinety-nine patients with diabetes mellitus, aged 19 to 87 years, were assessed between May 2008 and April 2010. Seven patients had type 1 diabetes and 92 patients had type 2 diabetes. CK, aspartate aminotransferase, alanine aminotransferase, and resting lactate were elevated in 19 of 99, 25 of 99, 22 of 99, and 24 of 98 patients, respectively. Eleven of 19 patients with increased CK were self-injecting insulin. Ten of 24 patients with elevated serum lactate took metformin. Seven of 19 patients with elevated CK consented to neurologic workup. Two of the 7 had elevated resting lactate. In all 7 patients, the findings from neurologic investigation were indicative of a metabolic defect and further diagnostic evaluation was recommended.ConclusionsIn diabetic patients attending our clinic, elevated CK levels occur in one-fifth and lactacidemia occurs in one-quarter. Elevated CK levels are attributable to a primary metabolic myopathy in most cases. Elevated CK levels in the setting of diabetes mellitus require further neurologic evaluation. (Endocr Pract. 2012;18:387-393)