Thursday

The effect of diabetic medications on creatine kinase-myocardial band levels in patients undergoing coronary artery bypass surgery.

Engoren M, Zacharias A, Habib RH, Schwann TA, Riordan CJ, Durham SJ, Shah A.
St Vincent Mercy Medical Center, Toledo, OH, USA.

Ischemic preconditioning has been shown to attenuate the rise in creatine kinase-myocardial band levels that occur with coronary artery bypass surgery (CABG). Recently, concerns have been raised that some sulfonylureas particularly glibenclamide may block ischemic preconditioning.

The purpose of this study was to determine the effect of various diabetic medicines on creatine kinase-myocardial band levels after CABG. In this retrospective study of 799 patients undergoing CABG, patients continued their routine diabetic medicines up to the day of surgery. Intra-operatively and postoperatively, tight glycemic control was maintained with an insulin infusion.

Anesthesia was maintained with isoflurane supplemented by fentanyl. Creatine kinase-myocardial band levels were determined the day after surgery at 5 AM and the mean levels compared between diabetics and non-diabetics and further compared by type of diabetic medicine. After univariable comparisons, linear regression was used to determine the statistically significant predictors of creatine kinase-myocardial band levels.

After correction for other factors, none of the diabetic medicines was a statistically significant predictor of creatine kinase-myocardial band levels. We found that the use of glibenclamide or other diabetic medications had no effect on creatine kinase-myocardial band levels the morning after patients underwent CABG.


Keywords: Ischemic preconditioning; Diabetes mellitus; Sulfonylureas; Coronary artery bypass surgery; Isoflurane; Creatine kinase-myocardial band.

Monday

Metabolic biomarkers related to energy metabolism in Saudi autistic children.

OBJECTIVES: Energy metabolism is usually manipulated in many neurodegenerative diseases. Autism is considered a definable systemic disorder resulting in a number of diverse factors that may affect the brain development and functions both pre and post natal. The increased prevalence of autism will have enormous future public implications and has stimulated intense research into potential etiologic factors. This study aims to establish a connection between autism and the deterioration accompanied it, especially in the brain cognitive areas through a postulation of energy manipulation.

MATERIALS AND METHODS: The biochemical changes in activities of enzymes and pathways that participate in the production of ATP as the most important high-energy compound needed by the human brain were measured in Saudi autistic children. Na(+)/K(+)ATPase, ectonucleotidases (NTPDases) (ADPase and ATPase) and CREATINE KINASE (CK), were assessed in plasma of 30 Saudi autistic patients and compared to 30 age-matching control samples. In addition, adenosine mono, di and trinucleotides (ATP, ADP, and AMP) were measured calorimetrically in the red blood cells of both groups and the adenylate energy charge (AEC) was calculated. Moreover, lactate concentration in plasma of both groups was monitored.

RESULTS: The obtained data recorded 148.77% and 72.35% higher activities of Na(+)/K(+)ATPase and CREATINE KINASE respectively in autistic patients which prove the impairment of energy metabolism in these children compared to age and sex matching healthy controls. While ADPase was significantly higher in autistic patients, ATPase were non-significantly elevated compared to control. In spite of the significant increase of Na(+)/K(+)ATPase activity in autistic patients, there was no significant difference in the levels of ATP, ADP, and AMP in both groups and the calculated AEC values were 0.814+/-0.094 and 0.806+/-0.081 for autistic and control groups respectively. The unchanged AEC value in autistic patients was easily correlated with the induced activity of CK and ADPase as two enzymes playing a critical role in the stabilization of AEC. Lactate as an important energy metabolite for the brain was significantly higher in autistic patients compared to control showing about 40% increase.

CONCLUSION: The present study confirmed the impairment of energy metabolism in Saudi autistic patients which could be correlated to the oxidative stress previously recorded in the same investigated samples. The identification of biochemical markers related to autism would be advantageous for earlier clinical diagnosis and interventio