Dietary Phosphate Impact on Phosphate Overload
Recruiting in Palo Alto (17 mi)
Overseen ByWanpen Vongpatanasin, MD
Age: 18+
Sex: Any
Travel: May be covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: University of Texas Southwestern Medical Center
Must not be taking: Antihypertensives, Vasoactive agents
Disqualifiers: Diabetes, Chronic kidney disease, Cardiopulmonary, others
No Placebo Group
Approved in 3 jurisdictions
Trial Summary
What is the purpose of this trial?Studies in mice demonstrated that dietary phosphate (Pi) loading that mimic the level of US adult consumption leads to reduced spontaneous locomotor activity, exercise capacity, and reduced resting metabolic rate when in normal mice by impairing skeletal muscle mitochondrial function and fat oxidation. However, relevance of this findings in humans remains unknown.
Will I have to stop taking my current medications?
The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are on antihypertensive medications or any vasoactive agents that affect cardiovascular responses to exercise.
What evidence supports the effectiveness of the treatment for phosphate overload?
Research shows that oral phosphate therapy can reduce certain blood markers in patients with primary hyperparathyroidism, suggesting it may help manage phosphate levels. However, oral sodium phosphate has been effective as a colon cleansing agent, but it can cause shifts in blood volume and other side effects, indicating the need for careful use.
12345Is sodium phosphate safe for human use?
Sodium phosphate is often used for bowel cleansing, but it can cause serious side effects like high phosphate levels in the blood, low calcium levels, and kidney problems, especially in people with certain health conditions or when used in high doses.
16789How does the drug Sodium Phosphate differ from other treatments for phosphate overload?
Sodium Phosphate is unique because it directly affects appetite and organ growth by altering dietary phosphate levels, which may influence how the body handles phosphate, unlike other treatments that primarily focus on reducing phosphate intake or absorption.
37101112Eligibility Criteria
This trial is for healthy adults without diabetes, chronic kidney disease, heart disease, or those on blood pressure medications. Participants should not be pregnant, have normal phosphate levels in their blood, and no history of psychiatric illness, active cancer or substance abuse including smoking.Inclusion Criteria
I am healthy without diabetes, kidney disease, heart disease, or taking heart-related meds.
Exclusion Criteria
I have a history of cancer.
I have a history of heart, lung, or kidney disease.
My kidney function is reduced.
Participant Groups
The study tests the effects of dietary phosphate (found in many foods) on exercise ability and belly fat. It compares taking sodium phosphate to sodium chloride (table salt), looking at how these supplements might affect physical activity and metabolism.
2Treatment groups
Experimental Treatment
Group I: Sodium Phosphate (NaPO4) then sodium chloride (NaCl)Experimental Treatment2 Interventions
Participants will be asked to take 2 capsules daily of Sodium Phosphate (containing a total of 500 mg of Pi, 372mg of sodium) ) for 4 weeks during the high Pi phase (total Pi intake 1,200 mg/d). Then, participants will be asked to take 2 capsules of Sodium Chloride (NaCl, containing a total of 372mg of sodium) to match Na content to Sodium Phosphate without extra Pi daily for 4 weeks during the low Pi phase (total Pi intake = 700 mg/d).
Group II: NaCl then NaPO4Experimental Treatment2 Interventions
Participants will be asked to take 2 capsules daily of Sodium Chloride (NaCl, containing a total of 372mg of sodium) for 4 weeks during the low Pi phase (total Pi intake = 700 mg/d). Then, participants will be asked to take 2 capsules of Sodium Phosphate daily for 4 weeks Sodium Phosphate (containing a total of 500 mg of Pi, 372mg of sodium) for 4 weeks during the high Pi phase (total Pi intake 1,200 mg/d).
Sodium Phosphate is already approved in United States, European Union, Canada for the following indications:
🇺🇸 Approved in United States as Sodium Phosphate for:
- Electrolyte imbalance
- Acidosis
- Urinary acidification
🇪🇺 Approved in European Union as Sodium Phosphate for:
- Electrolyte disturbances
- Metabolic acidosis
🇨🇦 Approved in Canada as Sodium Phosphate for:
- Electrolyte imbalance
- Acidosis
Find A Clinic Near You
Research locations nearbySelect from list below to view details:
University of Texas SouthwesternDallas, TX
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Who is running the clinical trial?
University of Texas Southwestern Medical CenterLead Sponsor
References
Recognizing the clinical contraindications to the use of oral sodium phosphate for colon cleansing: a case study. [2019]Oral sodium phosphate has been demonstrated in numerous clinical trials to be an effective and well-tolerated colonic cleansing agent. However, there exists a potential to induce shifts in intravascular volume. The phosphate load often results in hyperphosphatemia, which may precipitate hypocalcemia. A review at the authors' institution identified four patients with adverse events related to oral sodium phosphate. Three of these cases had pre-existing comorbidities that predisposed them to the adverse event, or had received doses higher than that used or recommended in previous trials. Recommendations for relative and absolute contraindications to the use of oral sodium phosphate are described.
The renal safety of bowel preparations for colonoscopy: a comparative study of oral sodium phosphate solution and polyethylene glycol. [2018]Rare cases of nephrotoxicity have been reported with oral sodium phosphate solution (OSPS).
Distinctive features of dietary phosphate supply. [2013]Dietary phosphate has profound effects on growth and renal handling of the compound. On the basis of changes in growth rate and food intake, after alterations in phosphate load, our laboratory previously suggested that these effects are mediated by intestinal signals (Landsman A, Lichtstein D, Bacaner M, and Ilani A. Br J Nutr 86: 217-223, 2001). The aim of this study was to further evaluate the role of dietary phosphate on food intake and appetite and specific organ growth, and to test for the presence of a serum factor that may affect renal phosphate handling in phosphate-resupplied rats. The experimental design was based on a comparison between groups of rats receiving identical low-phosphate diets but drinking water containing either phosphate or chloride. We show that 1) changes in food intake after alterations in phosphate load occurred in parallel with variations in digestive system distention, suggesting that dietary phosphate has also a direct effect on appetite; 2) dietary phosphate-dependent growth has a specific effect on the growth of liver and epididymal fat; and 3) serum of rats supplied with phosphate contains a factor that inhibits sodium-dependent phosphate transport in a model of renal proximal tubule cells. Collectively, these observations are in accord with the hypothesis that factor(s) emanating from the digestive system in response to dietary phosphate load may be involved in growth, appetite and renal handling of phosphate.
The extra-phosphate intestinal load from medications: is it a real concern? [2018]Reduction of intestinal load of phosphorus is important for the prevention and treatment of chronic kidney disease (CKD)-mineral and bone disorder (MBD). However, this strategy is limited by patients' poor adherence to dietary prescription and by the existence of hidden sources of phosphorus. In addition to food containing phosphate-based additives, it was recently claimed that medications may contribute to increase the load of phosphate (P), mainly present as an excipient. To identify medications containing P as an excipient, we performed a systematic screening of medications which could potentially be prescribed for chronic oral therapies in CKD patients.
A detailed evaluation of oral phosphate therapy in selected patients with primary hyperparathyroidism. [2015]Recent studies have emphasized the pathophysiological importance of circulating 1,25-dihydroxyvitamin D ((1,25-(OH)2D] in the pathogenesis of hypercalciuria and renal stone formation in primary hyperparathyroidism. Reasoning that phosphate administration might be capable of reducing the plasma concentration of 1,25-(OH)2D in patients with a prominent 1,25-(OH)2D-mediated absorptive component to their disease, 10 carefully selected patients were treated with oral phosphate (1500 mg elemental phosphorus daily) for 1 yr. Phosphate treatment significantly reduced circulating 1,25-(OH)2D levels (84 to 56 pg/ml), the calciuric response to an oral calcium tolerance test (0.30 to 0.21 delta mg calcium/dl GF), and calcium excretion on an unrestricted calcium diet (438-269 mg/day), in essence reversing the absorptive pattern of abnormalities observed before treatment. This response, however, was accompanied by an increase in biochemical hyperparathyroidism, as assessed by circulating immunoreactive PTH and nephrogenous cAMP excretion. In patients with biochemical evidence of an increase in bone resorption before therapy, histomorphometric, radiographic, and biochemical data revealed a trend toward a reduction in bone turnover during phosphorus therapy, with an apparent maintenance of coupled bone resorption and bone formation. This trend, however, was of marginal statistical significance in the patient group as a whole. It is concluded 1) that phosphate therapy represents a viable medical alternative in selected patients with primary hyperparathyroidism, 2) that the net response in treated patients is multifaceted and complex, and 3) that the efficacy of phosphate therapy will ultimately depend upon its long term effects on skeletal homeostasis.
Increased serum phosphate levels and calcium fluxes are seen in smaller individuals after a single dose of sodium phosphate colon cleansing solution: a pharmacokinetic analysis. [2013]Sodium phosphate containing colonoscopy preparations may cause electrolyte disturbances and calcium-phosphate nephropathy. Decreased body weight is an unexplored risk factor for complications with sodium phosphate ingestion.
Common Dietary Sources of Natural and Artificial Phosphate in Food. [2022]The Recommended Dietary Allowance (RDA) for phosphate in the U.S. is around 700 mg/day for adults. The majority of healthy adults consume almost double the amount of phosphate than the RDA. Lack of awareness, and easy access to phosphate-rich, inexpensive processed food may lead to dietary phosphate overload with adverse health effects, including cardiovascular diseases, kidney diseases and tumor formation. Nutritional education and better guidelines for reporting phosphate content on ingredient labels are necessary, so that consumers are able to make more informed choices about their diets and minimize phosphate consumption. Without regulatory measures, dietary phosphate toxicity is rapidly becoming a global health concern, and likely to put enormous physical and financial burden to the society.
Symptomatic hypocalcemia after sodium phosphate preparation in an adult with asymptomatic hypoparathyroidism. [2013]Sodium phosphate is widely used as a bowel cleansing preparation. Its use is, however, not without risk. It can induce serious adverse effects like hypocalcemia, hyperphosphatemia and renal failure. In this case, a 75-year-old woman without known contraindications developed hypocalcemic tetany, hyperphosphatemia and renal failure after oral sodium phosphate. Asymptomatic hypoparathyroidism owing to previous thyroid surgery was identified as a new contributing risk factor for this complication.
Severe hyperphosphataemia and associated electrolyte and metabolic derangement following the administration of sodium phosphate for bowel preparation. [2022]Sodium phosphate is widely used as an effective bowel preparation agent. It is used in smaller volumes, leading to improved patient tolerance. Although it is generally safe, cases of severe hyperphosphataemia following sodium phosphate administration have been reported in the literature. The common risk factors identified are advanced age, impaired renal function, impaired colonic motility and multiple doses. However, many doctors remain unaware of the dangers associated with this agent. We report six cases of severe electrolyte and metabolic derangement due to sodium phosphate bowel preparation: two patients had delayed awakening from general anaesthesia, and four patients suffered life-threatening consequences.
Obesity, Diabetes Mellitus, and Vascular Impediment as Consequences of Excess Processed Food Consumption. [2022]Regular intake of ready-to-eat meals is related to obesity and several noninfectious illnesses, such as cardiovascular diseases, hypertension, diabetes mellitus (DM), and tumors. Processed foods contain high calories and are often enhanced with excess refined sugar, saturated and trans fat, Na+ andphosphate-containing taste enhancers, and preservatives. Studies showed that monosodium glutamate (MSG) induces raised echelons of oxidative stress, and excessive hepatic lipogenesis is concomitant to obesity and type 2 diabetes mellitus (T2DM). Likewise, more than standard salt intake adversely affects the cardiovascular system, renal system, and central nervous system (CNS), especially the brain. Globally, excessive utilization of phosphate-containing preservatives and additives contributes unswervingly to excessive phosphate intake through food. In addition, communities and even health experts, including medical doctors, are not well-informed about the adverse effects of phosphate preservatives on human health. Dietary phosphate excess often leads to phosphate toxicity, ultimately potentiating kidney disease development. The mechanisms involved in phosphate-related adverse effects are not explainable. Study reports suggested that high blood level of phosphate causes vascular ossification through the deposition of Ca2+ and substantially alters fibroblast growth factor-23 (FGF23) and calcitriol.
Lack of awareness among future medical professionals about the risk of consuming hidden phosphate-containing processed food and drinks. [2021]Phosphate toxicity is an important determinant of mortality in patients with chronic kidney disease (CKD), particularly those undergoing hemodialysis treatments. CKD patients are advised to take a low phosphate-containing diet, and are additionally prescribed with phosphate-lowering drugs. Since these patients usually seek guidance from their physicians and nurses for their dietary options, we conducted a survey to determine the levels of awareness regarding the high phosphate content in commercially processed food and drinks among medical and nursing students at the Hirosaki University School of Medicine in Japan. For this survey, 190 medical and nursing students (average age 21.7±3 years) were randomly selected, and provided with a list of questions aimed at evaluating their awareness of food and drinks containing artificially added phosphate ingredients. While 98.9% of these students were aware of the presence of sugar in commercially available soda drinks, only 6.9% were aware of the presence of phosphate (phosphoric acid). Similarly, only 11.6% of these students were aware of the presence of phosphate in commercially processed food, such as hamburgers and pizza. Moreover, around two thirds of the surveyed students (67.7%) were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. About 28% of the surveyed students consume such "fast food" once a week, while 40% drink at least 1∼5 cans of soda drinks/week. After realizing the potential long-term risks of consuming excessive phosphate-containing food and drinks, 40.5% of the survey participants considered reducing their phosphate intake by minimizing the consumption of commercially processed "fast food" items and soda drinks. Moreover, another 48.4% of students showed interest in obtaining more information on the negative health effects of consuming excessive amounts of phosphate. This survey emphasizes the need for educational initiative to raise awareness of the health risks posed by excessive consumption of phosphate additives.
Hidden sources of phosphorus in the typical American diet: does it matter in nephrology? [2022]Elevated serum phosphorus is a major, preventable etiologic factor associated with the increased cardiovascular morbidity and mortality of dialysis patients. An important determinant of serum phosphorus is the dietary intake of this mineral; this makes dietary restriction of phosphorus a cornerstone for the prevention and treatment of hyperphosphatemia. The average daily dietary intake of phosphorus is about 1550 mg for males and 1000 mg for females. In general, foods high in protein are also high in phosphorus. These figures, however, are changing as phosphates are currently being added to a large number of processed foods including meats, cheeses, dressings, beverages, and bakery products. As a result, and depending on the food choices, such additives may increase the phosphorus intake by as a much as 1 g/day. Moreover, nutrient composition tables usually do not include the phosphorus from these additives, resulting in an underestimate of the dietary intake of phosphorus in our patients. Our goal is to convey an understanding of the phosphorus content of the current American diet to better equip nephrologists in their attempt to control hyperphosphatemia.