Plasma Glucose Levels and Left Ventricular Diastolic Function in Nondiabetic Hypertensive Patients

BACKGROUND: Changes in left ventricular (LV) diastolic filling anticipate diastolic heart failure and are frequently detected in patients with hypertension or diabetes. We tested the hypothesis that increased fasting and postload glucose levels are associated with diastolic dysfunction as assessed by tissue Doppler imaging (TDI) in hypertensive patients. METHODS: In 104 untreated, nondiabetic, hypertensive patients free of cardiovascular complications, we measured glucose and insulin at fast and after an oral glucose load, calculated the Homeostatic Model Assessment (HOMA) index, and performed electrocardiogram (ECG), conventional echocardiography, and TDI. RESULTS: Thirty-one patients who had impaired fasting glucose/impaired glucose tolerance had more frequent LV strain at ECG and worse TDI markers of diastolic function than patients with normal plasma glucose but no differences in variables LV mass, LV geometry, systolic function, and early-/late-wave transmitral diastolic velocity. TDI detected diastolic dysfunction in 46 patients who were older and had greater body mass index, blood pressure, fasting and postload glucose, insulin, HOMA index, LV mass, and left atrial diameter than patients with preserved diastolic function. Variables of diastolic function measured at TDI were significantly related with age, body mass index, LV mass, and fasting and postload plasma glucose. Stepwise regression analysis showed that the relationship of markers of diastolic dysfunction with both fasting and postload glucose levels was independent of possible confounders. CONCLUSIONS: Initially abnormal fasting and postload glucose levels are associated with more prominent diastolic impairment in uncomplicated hypertensive patients, suggesting that hyperglycemia might increase the risk of diastolic heart failure even in the absence of diabetes.