Association of prediabetes with impaired left atrial contractility in patients with never-treated hypertension.

Abstract

Prediabetes defined by HbA1c 5.7-6.4 has been shown to be associated with left ventricular (LV) hypertrophy and diastolic dysfunction in hypertensive patients. We hypothesized HbA1c prediabetes may be related to the alterations of LA contractility or volume in nondiabetic hypertension. Nondiabetic individuals on sinus rhythm were enrolled; 107 patients with never-treated hypertension, 134 patients with treated hypertension, and 71 normotensive subjects. Participants were classified as normal glucose tolerance (NGT, HbA1c<5.7), prediabetes (HbA1c 5.7-6.4) according to the ADA criteria. They underwent echocardiography to measure left atrial (LA) phasic volumes and functions, as well as mitral E/e' and mitral e'. In nondiabetic patients with never-treated hypertension, prediabetes saw lower LA total emptying fraction (53.7 ± 8.2 vs. 48.3 ± 9.9*) and mitral e' (7.38 ± 2.18 vs. 6.17 ± 1.50*) than NGT, implicating that the association of prediabetes with reduced LA contractility and LV stiffness. On the other hand, in nondiabetic patients with treated hypertension, prediabetes saw higher maximum LA volume/BSA (29.7 ± 7.1 vs. 32.9 ± 6.2* ml/mm2) and mitral E/e' (10.72 ± 3.08 vs. 12.37 ± 3.35*) than NGT, suggesting the relationship of prediabetes with increased LA preload. Prediabetes may be involved in the progression of LA structural and functional alterations in nondiabetic hypertensive patients.