Impact at left ventricular diastolic dysfunction on maximal treadmill performance in normotensive subjects with well-controlled type 2 diabetes mellitus

Patients with type 2 diabetes often have impaired exercise capacity compare d with nondiabetic subjects. Left ventricular (LV) diastolic dysfunction ha s been shown to limit exercise performance in nondiabetic subjects. Men wit h well-controlled type 2 diabetes were divided into 2 groups: normal LV dia stolic function (group 1, n = 9) or LV diastolic dysfunction (group 2, n = 10) based on standard echocardiographic criteria using pulmonary veins and transmitral flow recordings. They were matched for age and had no evidence of systemic hypertension, macroalbuminuria, coronary artery disease, conges tive heart failure, clinical diabetic complications, and thyroid disease. G ood metabolic control was demonstrated by glycated hemoglobin levels of 6.7 +/- 1.6% and 6.6 +/- 2.5% (means a SD) in patients with LV diastolic dysfu nction and in controls, respectively. Each subject performed a symptom-limi ted modified Bruce protocol treadmill exercise test. Maximal treadmill perf ormance was higher in subjects with normal diastolic function compared with subjects with LV diastolic dysfunction when expressed in time (803 +/- 29 vs 662 +/- 44 seconds, respectively, p <0.02) or in METs (11.4 +/- 1.2 vs 9 .5 +/- 1.9 METs, respectively, p <0.02). Moreover, there was a correlation between E/A ratio and exercise duration (r = 0.64, p = 0.004) or E/A ratio and METs (r = 0.658, p = 0.003). There were no significant differences in m aximal heart rate, maximal systolic and diastolic blood pressure, or maxima l rate-pressure product attained during the exercise test. In conclusion, t his study demonstrated that Lv diastolic dysfunction influences maximal tre admill performance and could explain lower maximal performance observed in patients with type 2 diabetes. (C)2000 by Excerpta Medico, Inc.