HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ramanathan, T. Articles by Hunyor, S. N. Search for Related Content PubMed PubMed Citation Articles by Ramanathan, T. Articles by Hunyor, S. N. Related Collections Myocardial protection

Ann Thorac Surg 2004;77:1408-1414
© 2004 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Glucose-insulin-potassium solution improves left ventricular energetics in chronic ovine diabetes

^a Cardiac Technology Centre, Department of Cardiology, Royal North Shore Hospital, Sydney, Australia

Accepted for publication October 2, 2003.

^* Address reprint requests to Dr Ramanathan, C/O Professor Stephen Hunyor, Cardiac Technology Centre, Block 4, Level 3, Royal North Shore Hospital, St Leonards, Sydney NSW 2065, Australia
e-mail: indranrama{at}yahoo.com

BACKGROUND: Therapeutic modulation of myocardial metabolism improves outcomes in diabetic patients following myocardial infarction and coronary artery surgery. However, the mechanism of this beneficial effect has not been fully elucidated. This study evaluated the effect of glucose-insulin-potassium solution (GIK) on left ventricular (LV) energetics and oxygen utilization efficiency in a chronic ovine model of diabetes.

METHODS: Diabetes was induced in sheep with streptozotocin. Experiments were performed following 12 months untreated diabetes (n = 6) and in controls (n = 6). Open-chest anesthetized sheep were instrumented to determine the LV pressure-volume relationship, oxygen consumption, and free fatty acid uptake. Glucose-insulin-potassium was infused at 1.5 mL · kg⁻¹ · h⁻¹ for 60 minutes and assessment repeated.

RESULTS: Glucose-insulin-potassium decreased LV free fatty acid uptake in control: 0.090 ± 0.047 µg/beat/100 g to 0.024 ± 0.022 µg/beat/100 g, p = 0.02 and diabetes: 0.33 ± 0.32 µg/beat/100 g to 0.11 ± 0.13 µg/beat/100 g, p = 0.04. Similarly, GIK decreased unloaded left ventricular oxygen consumption (LVVO₂) in both control (0.42 ± 0.05 to 0.37 ± 0.13J/beat/100 g, p < 0.001) and diabetic sheep (0.40 ± 0.24 to 0.23 ± 0.23J/beat/100 g, p < 0.001). The slope of the LVVO₂-pressure-volume area relation (contractile efficiency) was unchanged in either group. Glucose-insulin-potassium improved LV contractility 58% ± 37% (p = 0.005) and stroke work efficiency 18% ± 10% (p = 0.009) in diabetic animals but not controls. Therefore, oxygen utilization efficiency (stroke work-LVVO₂) increased only in diabetic animals (16.6% ± 4.8% to 26.9% ± 3.6%, p = 0.002) following GIK.

CONCLUSIONS: This study provides in vivo evidence that GIK improves LV energetics in diabetes. Oxygen utilization efficiency is improved as a result of improved stroke work efficiency and decreased unloaded LVVO₂. Improved efficiency of oxygen utilization provides a physiologic rationale for the beneficial effect of GIK in diabetic patients.

This article has been cited by other articles:

				A. D. Hafstad, A. M. Khalid, O.-J. How, T. S. Larsen, and E. Aasum Glucose and insulin improve cardiac efficiency and postischemic functional recovery in perfused hearts from type 2 diabetic (db/db) mice Am J Physiol Endocrinol Metab, May 1, 2007; 292(5): E1288 - E1294. [Abstract] [Full Text] [PDF]