Acute High Phosphate Intake Impairs Endothelial‐Dependent Vasodilation in Young Premenopausal Women

Abstract

In the United States, the growing abundance of processed foods has led to Americans consuming more than double the recommended dietary intake of inorganic phosphate (Pi). Chronic consumption of Pi is associated with a higher risk of cardiovascular disease in the general population; however, studies investigating underlying mechanisms are limited. Recently, our lab has reported an impairment in brachial artery flow‐mediated dilation (FMD) following acute high Pi consumption in young, healthy men. To our knowledge, the effect of acute high Pi on vascular function in women remains unknown. This becomes important, as previous longitudinal work suggests that women may be protected from the greater cardiovascular risk associated with high serum phosphorus. Therefore, the aim of this study was to determine the effect of acute high Pi consumption on vascular function in young, healthy women. Eight healthy premenopausal women ingested a high‐Pi drink containing 2,000 mg of phosphorus (23 ± 2 yrs; mean ± SEM). Heart rate (HR) (ECG) and arterial blood pressure (BP) (finger photoplethysmography and automated sphygmomanometer) were measured during a 10 min baseline. FMD was used to assess conduit artery endothelial function and microvascular function was quantified as reactive hyperemic velocity AUC following cuff release. In addition, Pulse Wave Velocity (PWV) was used to assess large artery stiffness. All measures were performed before (pre) and 60 min after (post) Pi drink consumption (a time period our lab has shown to elicit peak elevations in serum phosphate following Pi consumption). Resting mean arterial BP and HR were not different pre‐ vs. post‐ Pi consumption (BP= pre, 80 ± 1; post, 81 ± 2 mmHg; p=0.28; HR= pre, 62 ± 4; post, 62 ± 4 beats/min; p=0.64). In contrast, FMD was significantly attenuated post‐Pi consumption, (pre, 6.7 ± 0.5%; post, 4.8 ± 0.8%; p=0.04), whereas, reactive hyperemic velocity AUC remained unchanged (pre, 2590 ± 488 arbitrary units; post, 2056 ± 221 arbitrary units; p=0.30), indicating that acute high Pi consumption had no effect on microvascular function. In addition, PWV was also unaffected by acute high Pi (p=0.18). Collectively, our preliminary findings suggest that, similar to men, exposure to acute high Pi impairs conduit artery endothelial function, but not microvascular function, in young healthy women.Support or Funding InformationUniversity of Texas at Arlington College of Nursing and Health Innovation