The online version of this article (doi:10.1186/1758-5996-6-36) contains supplementary material, which is available to authorized users.
The authors declare that they have no competing interests.
RB has been involved in the planning of the study, the recruitment and follow-up of the study participants, the acquisition and interpretation of clinical and laboratory data and in the drafting and intellectual content of the manuscript. EE has contributed to the acquisition and interpretation of the cardiopulmonary exercise test data. IUN has been involved in the recruitment and screening of potential participants, acquisition of clinical and laboratory data and in the clinical follow-up of study patients. HA and IS have contributed to the design of the study, the interpretation of the results and the intellectual content of the manuscript. SS has been involved in drafting of the manuscript, interpretation of the results and the intellectual content. All authors read and approved the final manuscript.
Previous studies on type 2 diabetes have shown an association between exercise capacity and insulin resistance. In patients with coronary artery disease (CAD) exercise capacity is often reduced due to exercise-induced ischemia. We have investigated the association between glucometabolic control, including the homeostatic model assessment (HOMA) of insulin resistance, and exercise capacity in patients with type 2 diabetes and CAD with and without exercise-induced ischemia.
In 137 patients (age 63.1 ± 7.9) cardiopulmonary exercise testing on treadmill was performed using a modified Balke protocol. The highest oxygen uptake (VO2peak) was reported as 30-s average. Fasting blood samples were drawn for determination of glucose, insulin and HbA1c. Insulin resistance (IR) was assessed by the HOMA2-IR computer model. Exercise-induced ischemia was defined as angina and/ or ST-depression in ECG ≥ 0.1 mV during the exercise test.
HOMA2-IR was inversely correlated to VO2peak (r = -0.328, p < 0.001), still significant after adjusting for age, gender, smoking and BMI. Patients with HOMA2-IR above the median value (1.3) had an adjusted odds ratio of 3.26 (95 % CI 1.35 to 7.83, p = 0.008) for having VO2peak below median (23.8 mL/kg/min). Insulin levels were inversely correlated to VO2peak (r = -0.245, p = 0.010), also after adjusting for age and gender, but not after additional adjustment for BMI. The correlation between HOMA2-IR and VO2peak was also significant in the subgroups with (n = 51) and without exercise-induced ischemia (n = 86), being numerically stronger in the group with ischemia (r = -0.430, p = 0.003 and r = -0.276, p = 0.014, respectively). Fasting glucose and HbA1c were not correlated with VO2peak or AT.
Insulin resistance, as estimated by fasting insulin and the HOMA index, was inversely associated with exercise capacity in patients with type 2 diabetes and CAD, the association being more pronounced in the subgroup with exercise-induced ischemia. These results indicate that insulin resistance is related to exercise capacity in type 2 diabetic patients with CAD, possibly even more so in patients with exercise-induced ischemia compared to those without.
Authors’ original file for figure 113098_2013_410_MOESM1_ESM.pdf
Wasserman K, Hansen JE, Sue DY, Stringer WW, Whipp BJ: Principles of execise testing and interpretation including pathophysiology and clinical applications. 2005, Philadelphia: Lippincott Williams & Wilkins
Ryden L, Standl E, Bartnik M, Van den Berghe G, Betteridge J, de Boer MJ, Cosentino F, Jonsson B, Laakso M, Malmberg K, Priori S, Ostergren J, Tuomilehto J, Thrainsdottir I, Vanhorebeek I, Stramba-Badiale M, Lindgren P, Qiao Q, Priori SG, Blanc JJ, Budaj A, Camm J, Dean V, Deckers J, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, et al: Guidelines on diabetes, pre-diabetes, and cardiovascular diseases: executive summary. The Task Force on Diabetes and Cardiovascular Diseases of the European Society of Cardiology (ESC) and of the European Association for the Study of Diabetes (EASD). Eur Heart J. 2007, 28: 88-136. CrossRefPubMed
Fletcher GF, Balady GJ, Amsterdam EA, Chaitman B, Eckel R, Fleg J, Froelicher VF, Leon AS, Pina IL, Rodney R, Simons-Morton DA, Williams MA, Bazzarre T: Exercise standards for testing and training: a statement for healthcare professionals from the American Heart Association. Circulation. 2001, 104: 1694-1740. 10.1161/hc3901.095960. CrossRefPubMed
Balke B, WARE RW: An experimental study of physical fitness of Air Force personnel. U S Armed Forces Med J. 1959, 10: 675-688. PubMed
HOMA2 Score Calculator Web site: Oxford, UK, diabetes trial unit, the Oxford centre for diabetes, endocrinology and metabolism. 1-5-2013. 2012, http://www.dtu.ox.ac.uk/homacalculator/index.php,
- Insulin levels and HOMA index are associated with exercise capacity in patients with type 2 diabetes and coronary artery disease
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