Acute ascorbic acid infusion increases left ventricular diastolic function in postmenopausal women

Abstract

Objectives We tested the hypothesis that oxidative stress contributes to reductions in left ventricular diastolic function in estrogen-deficient postmenopausal women, related in part to reduced nitric oxide (NO) bioavailability. Study design LV diastolic function – recorded using transthoracic echocardiography and determined as the peak early (E) to late (A) mitral inflow velocity ratio and the E to peak early (e’) mitral annular velocity ratio – and brachial artery flow mediated dilation (FMD), a biomarker of NO bioavailability, were measured during acute systemic infusions of saline (control) and ascorbic acid (experimental model to decrease oxidative stress) in healthy premenopausal women (N=14, 18-40 years) and postmenopausal women (N=23, 45-75 years). Results The E/A ratio was lower (1.16[1.06−1.33] vs 1.65[1.5−2.3]; median[interquartile range]) and the E/e’ ratio was elevated (8.8[7.6−9.9] vs. 6.6[5.5−7.3]) in postmenopausal compared with premenopausal women, indicating reduced LV diastolic function. E/A and E/e’ were correlated with FMD (r=0.54 and r=−0.59, respectively, both P<0.01). Ascorbic acid infusion improved both FMD (5.4±2.0% to 7.8±2.6%) and E/e’ (to 8.1[7.2−9.7], P=0.01) in postmenopausal women but not in premenopausal women. Ascorbic acid did not change E/A in either group. Conclusion The current study provides evidence that oxidative stress contributes to reduced LV diastolic function in estrogen-deficient postmenopausal women, possibly by reducing the availability of NO.

Acute vitamin C improves cardiac function, not exercise capacity, in adults with type 2 diabetes

“…In cardiac myocytes, a decrease in nitric oxide disrupts calcium kinetics [ 33 ] and impairs cardiac relaxation [ 34 ]. Previous investigations have also demonstrated improved cardiac function with acute [ 16 ] and chronic [ 13 – 15 ] antioxidant therapy administration. Thus, it is possible that the beneficial effect of vitamin C on diastolic function in this study was through modulation of oxidant burden.…”

“…Cardiovascular function is a primary contributor to exercise capacity and it is impaired in people with T2D, providing a logical potential cause of the impaired cardiorespiratory fitness of T2D. In previous studies, supplementation with antioxidants has augmented cardiac function [ 13 – 16 ] and vasodilation [ 17 – 19 ] which may impact tissue oxygen delivery in both central and peripheral circulations and affect the utilization of oxygen during exercise. However, to date we have not determined the isolated effects of cardiovascular function, per se, on cardiorespiratory fitness in persons with T2D.…”

Vitamin C May Improve Left Ventricular Ejection Fraction: A Meta-Analysis

“…A few of the included trials reported effects of vitamin C on measures of cardiac physiology other than LVEF and found that vitamin C increased cardiac perfusion after PCI (43,44), improved diastolic function in an exercise test (52), and increased systolic myocardial velocity during hyperoxia (48). In addition to the included trials, a few other trials have reported that vitamin C had an effect on the mechanical function of the heart (76)(77)(78)(79).…”

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

“…Finally, in physiological laboratories vitamin C administration has shown a wide range of effects that are relevant to the cardiac system, such as increasing coronary artery diameter [ 45 – 49 ], coronary flow [ 195 – 201 ], improving effects of inotropic agents [ 202 – 206 ], increasing baroreflex sensitivity [ 207 – 210 ], alleviating postural tachycardia [ 211 ], increasing left ventricular diastolic function [ 212 ] and preventing nitrate tolerance [ 213 – 215 ]. Most of these physiological studies were short.…”