Introduction:
Endothelial dysfunction plays a central role in the pathogenesis of diabetic vascular disease.
Hypothesis:
Although resultant left ventricular diastolic dysfunction is hypothesized to reduce exercise capacity, limited data exist on the relation between endothelial function, left ventricular diastolic function and exercise capacity in patients with type 2 diabetes.
Methods:
We recruited 231 subjects with type 2 diabetes, a preserved ejection fraction, a negative stress test and a sodium-restricted diet. All subjects underwent a brachial artery flow-mediated dilation (FMD) measurement, a transthoracic echocardiography and a standard submaximal Bruce protocol treadmill exercise test during the hospitalization period for diabetes education program.
Results:
Impaired FMD (%FMD 8) were found in 193 subjects (84%) and 174 subjects (75%), respectively, of which 11 (5%) had diastolic dysfunction (E/E’ >15). Mean E/E’ by quartile (Q) were: Q1 6.9, Q2 8.9, Q3 10.4, and Q4 14.0. E/E’ was inversely correlated with %FMD (2.9 ± 4.3%, r = -0.19, p = 0.003) and exercise duration (460 ± 150 sec, r = -0.30, p <0.001). Compared with subjects in Q4, those in Q1, Q2 and Q3 had longer exercise duration (Q1 500 ± 150 sec, Q2 510 ± 140 sec, Q3 460 ± 140 sec and Q4 390 ± 140 sec, p <0.001). After adjustment for potential confounders including age, gender, smoking, body mass index, medication for hypertension, diabetes duration of more than 5 years, HbA1c and systolic blood pressure, %FMD and exercise duration were significantly associated with E/E’ (β = -0.17 and -0.18, p = 0.006 and 0.014) in all subjects.
Conclusions:
Diabetes patients with impaired endothelial function have impaired left ventricular diastolic function potentially leading to exercise intolerance.
Predictors of left ventricular diastolic dysfunction in type 2 diabetes patients: A 4-year prospective study
