Potassium, Hydration, Cardiovascular, and Kidney Study — PHACKs  

Blood Pressure Clinical Trial

Official title: The Effects of Water and Potassium Supplementation on Cardiovascular and Kidney Function in Young Black Adults

Status Not yet recruiting

Clinical Trial Summary

Compared with White Adults, Non-Hispanic Black Adults are at an elevated risk of developing cardiovascular disease (CVD) and end stage chronic-kidney disease (CKD), two of the leading causes of death in the United States. Inadequate hydration status is associated with risk factors for both CVD and CKD. Prior data show that Black individuals are less likely to be adequately hydrated when compared with their White counterparts. Further, socioeconomic factors have been shown to influence hydration practices. Inadequate hydration influences certain hormones that regulate blood volume and impact blood pressure, but increasing potassium intake may provide some positive effects on normalizing these hormones and blood pressure. Black adults, in particular, are more likely to consume less potassium, have inadequate hydration, and tend to have higher blood pressure. As such, there is a critical need for effective strategies to address racial disparities in hydration and resultant health consequences; as well as establish the role of socioeconomic factors contributing to hydration. Therefore, the investigators are seeking to test the investigators' central hypothesis that both water, and to a greater extent, water with a potassium supplement will improve hydration and cardiovascular health in young Black adults (n = 40, 20 females, 20 males). The investigators will assess measures of blood pressure, arterial stiffness, and biomarkers in the urine and blood samples prior to and following a 14-day hydration intervention of either a) bottled water or b) bottled water with potassium supplementation (2000mg potassium/day).

Clinical Trial Description

Compared with White adults, Non-Hispanic Black adults are at an elevated risk of developing cardiovascular disease (CVD) and end-stage chronic kidney disease (CKD) two of the leading causes of mortality in the United States (U.S.). Inadequate hydration status is associated with all-cause mortality and several risk factors for CVD and CKD including obesity, insulin resistance, hypertension, and metabolic syndrome. Prior data demonstrate Black American individuals are more likely to be hypohydrated (i.e., inadequately hydrated) when compared with White individuals. One study in emerging adults (18-25 years old) indicates that Black adults are more likely to be hypohydrated compared with White adults when assessed using gold-standard 24-hour urine collections. Socioeconomic factors influence hydration practices. For example, there are well-justified increased perceptions of unsafe tap water among racial and ethnic minorities. Indeed, the recent Flint, Michigan, and Jackson, Mississippi water crises have raised public awareness over these environmental injustices and ways to increase safe drinking water availability and access. However, there remains a critical need for empirical studies on 1) strategies to address racial disparities in hydration and resultant health consequences; and 2) the role socioeconomic factors in contributing to hydration.

Importantly, hypohydration is associated with increased production of arginine vasopressin (AVP), a peptide hormone produced in the hypothalamus that influences body water balance via anti-diuretic effects. Plasma copeptin is an established surrogate marker of circulating AVP concentration. Plasma copeptin is associated with incident type 2 diabetes, metabolic syndrome, the progression of CKD, and CVD. Some, but not all, studies have demonstrated racial differences in circulating AVP/copeptin. Further, prior studies that aimed at increasing water resulted in reductions in copeptin and improvements in cardiometabolic health. For example, in a cohort with high plasma copeptin, increased water intake also reduced fasting plasma glucose. In a cohort of adults with overweight and obesity, increased water or low-calorie beverage intake reduced fasting plasma glucose and contributed to modest weight loss. Lastly, over 90% of adults do not meet recommendations for potassium intake. Importantly, potassium improves blood pressure (BP), particularly in Black adults, who tend to consume less potassium and have higher BP. Yet, there remains a knowledge gap regarding whether hydration intervention(s) inclusive of water (with or without) potassium could attenuate racial disparities in hydration status and circulating AVP/copeptin. Therefore, the investigators are seeking to test the investigators' central hypothesis that both water and water along with a potassium supplement (2000mg/day) will improve hydration and cardiovascular health in young Black adults (n = 40, 20 females, 20 males). The investigators will utilize three complementary specific aims to address the investigators' hypotheses:

Aim 1: Determine whether water alone, or water with potassium supplementation improve hydration status and reduce circulating copeptin. The investigators hypothesize that two weeks of consuming water, and to a greater extent, water and potassium supplementation will improve hydration and renal biomarkers, including increased urine volume, and reduced urine specific gravity, urine osmolality, and plasma copeptin.

Aim 2: Determine whether water and to a greater extent, water and potassium supplementation improve BP and vascular health. The investigators hypothesize that two weeks of consuming water or water and potassium supplementation will reduce resting laboratory BP and ambulatory BP (awake, asleep, and nocturnal BP dipping), and reduce arterial stiffness assessed via pulse wave velocity.

Aim 3: Determine whether socioeconomic factors are associated with hydration perceptions, knowledge, and practices. The investigators hypothesize that area deprivation index (ADI, i.e., more deprivation) will be associated with hydration perceptions (e.g., greater distrust of tap water) and inadequate hydration assessed by self-reported fluid intake and urine-specific gravity.

In summary, a knowledge gap remains in determining the underlying reasons for the consistently reported racial differences in hydration. To restate, the purpose of this study is to determine 1) whether prescribing water and/or water with potassium supplementation are efficacious at improving hydration and reducing plasma copeptin in Black adults; 2) the comparative effectiveness of water and potassium supplementation vs. water alone in improving fluid intake and hydration status; 3) whether improving hydration alone or in combination with supplemental potassium improves BP and vascular function in young Black adults; 4) Another area of innovation in the investigators' proposal is determining whether area deprivation index (ADI, i.e., more deprivation) is associated with and 4a) beliefs and practices around hydration and 4a) hydration status. ;

Related Conditions & MeSH terms

• Blood Pressure
• Hydration

• NCT number: NCT06062017
• Study type: Interventional
• Source: Auburn University
• Contact: Nina L Stute, M.S.
• Phone: 9373071608
• Email: NLS0028@auburn.edu
• Status: Not yet recruiting
• Phase: N/A
• Start date: June 2024
• Completion date: May 2026