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Ratsma DMA, Muller M, Koedam M, van Leeuwen JPTM, Zillikens MC, van der Eerden BCJ. Organic phosphate but not inorganic phosphate regulates Fgf23 expression through MAPK and TGF-ꞵ signaling. iScience 2024; 27:109625. [PMID: 38883842 PMCID: PMC11178987 DOI: 10.1016/j.isci.2024.109625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/12/2024] [Accepted: 03/26/2024] [Indexed: 06/18/2024] Open
Abstract
One of the main regulators of phosphate homeostasis is fibroblast growth factor 23 (FGF23), secreted by osteocytes. The effects of organic versus inorganic dietary phosphate on this homeostasis are unclear. This study used MC3T3-E1 FGF23-producing cells to examine the transcriptomic responses to these phosphates. Most importantly, the expression and secretion of FGF23 were only increased in response to organic phosphate. Gene ontology terms related to a response to environmental change were only enriched in cells treated with organic phosphate while cells treated with inorganic phosphate were enriched for terms associated with regulation of cellular phosphate metabolism. Inhibition of MAPK signaling diminished the response of Fgf23 to organic phosphate, suggesting it activates FGF23. TGF-β signaling inhibition increased Fgf23 expression after the addition of organic phosphate, while the negative TGF-β regulator Skil decreased this response. In summary, the observed differential response of FGF23-producing to phosphate types may have consequences for phosphate homeostasis.
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Affiliation(s)
- Danielle M A Ratsma
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Max Muller
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Marijke Koedam
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Johannes P T M van Leeuwen
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - M Carola Zillikens
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Bram C J van der Eerden
- Laboratory for Calcium and Bone Metabolism and Erasmus MC Bone Centre, Department of Internal Medicine, Erasmus MC, Erasmus University Medical Center, Rotterdam, the Netherlands
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2
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Abstract
Aging is often associated with chronic inflammation and declining health. Both veterinarians and owners of aging dogs and cats are interested in nutritional solutions and strategies to prevent signs of age-related disease, increase longevity, and improve quality of life. Physiological decreases in muscle mass, decreased immunity, and a decrease in sense acuity are some of the changes often seen in otherwise healthy senior pets; however, there may also be an increase in risk for pathologies such as renal, cardiovascular, musculoskeletal, and neoplastic diseases. Aging may also lead to cognitive decline and even cognitive dysfunction. Some nutritional strategies that may be helpful with the prevention and treatment of age-related diseases include supplementation with ω3 polyunsaturated fatty acids and antioxidant nutrients that can help modulate inflammation and benefit osteoarthritis, renal disease, cancer, and more. Supplementation with medium-chain triglycerides shows promise in the treatment of canine cognitive dysfunction as these may be metabolized to ketone bodies that are utilized as an alternative energy source for the central nervous system. Additionally, a high intake of dietary phosphorus in soluble and bioavailable forms can lead to renal disease, which is of greater concern in senior pets. There are no published guidelines for nutritional requirements specific to senior pets and as a result, products marketed for senior dogs and cats are highly variable.
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Affiliation(s)
- Jonathan Stockman
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Long Island University, Old Brookville, NY, 11548, US.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences at Colorado State University, Fort Collins, CO, 80523, US.
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences at Colorado State University, Fort Collins, CO, 80523, US.
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Summers S, Quimby J, Gagné J, Lappin M. The Effect of Dietary Protein Concentration on the Fecal Microbiome and Serum Concentrations of Gut-Derived Uremic Toxins in Healthy Adult Cats. Vet Sci 2023; 10:497. [PMID: 37624284 PMCID: PMC10457753 DOI: 10.3390/vetsci10080497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/03/2023] [Accepted: 07/19/2023] [Indexed: 08/26/2023] Open
Abstract
The purpose of this study was to evaluate the effect of feeding healthy adult cats with foods containing variable protein concentrations on the fecal microbiome and serum concentrations of the gut-derived uremic toxins indoxyl sulfate, p-cresol sulfate (pCS), and trimethylamine-n-oxide. Twenty healthy young adult cats were randomized into two groups and fed either a low-protein diet (LPD; 7.4 g/100 kcal ME) or a high-protein diet (HPD; 11.0 g/100 kcal ME) for a 12-week period. Serum uremic toxin concentrations were measured via liquid chromatography tandem mass spectrometry, and the fecal microbiome was characterized using shallow sequence shotgun metagenomics. Cats that consumed the HPD had higher pCS concentrations at 8 weeks (p = 0.028) when compared to baseline. After 12 weeks, cats fed the HPD had higher fecal alpha diversity indices at both the taxonomic and functional levels and lower fecal Bifidobacterium relative abundance compared to those cats fed the LPD. In conclusion, a change in diet and dietary protein concentration shifted the fecal microbial community and microbial function. Feeding cats a high amount of protein increased serum concentrations of the uremic toxin pCS; however, the effect was short-lived.
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Affiliation(s)
- Stacie Summers
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
| | - Jessica Quimby
- College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA;
| | - Jason Gagné
- Nestlé Purina Pet Care Company, St. Louis, MO 63102, USA;
| | - Michael Lappin
- College of Veterinary Medicine, Colorado State University, Fort Collins, CO 80523, USA;
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4
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Yi KC, Heseltine JC, Jeffery ND, Cook AK, Nabity MB. Effect of withholding food versus feeding on creatinine, symmetric dimethylarginine, cholesterol, triglycerides, and other biochemical analytes in 100 healthy dogs. J Vet Intern Med 2023; 37:626-634. [PMID: 36786663 DOI: 10.1111/jvim.16630] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 01/05/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Withholding food is often recommended before collection of blood for routine biochemical analysis in dogs despite a paucity of evidence to support this requirement. OBJECTIVES To compare measurements of selected biochemical analytes collected before and after feeding in clinically healthy dogs. ANIMALS One hundred clinically healthy staff- and student-owned dogs weighing ≥15 kg. METHODS Prospective observational study. Food was withheld from the dogs for 10-26 hours. Preprandial serum was collected, and then dogs were fed their usual food at an amount equivalent to at least 2/3 resting energy requirement (RER). Selected serum analytes were measured at 2-, 4-, 6-, and 8-hours postprandially. The proportion of postprandial values that exceeded either the reported allowable total error (TEa), or for symmetric dimethylarginine (SDMA), the reference change value (RCV), was determined. As neither TEa nor RCV is available for lipase, comparison was made to the high end of the reference interval (RI). RESULTS The proportion of dogs with at least 1 postprandial measurement that exceeded the TEa or RCV was 92/100 for triglycerides, 66/100 for blood urea nitrogen (BUN), 46/100 for phosphorus, 17/100 for glucose, 9/100 for bilirubin, 5/100 for SDMA, 2/100 for creatinine, and 0/100 for cholesterol and albumin. Postprandial lipase never exceeded the RI in dogs with normal fasted lipase. CONCLUSIONS AND CLINICAL IMPORTANCE Withholding food is generally not necessary before performing routine biochemical analysis in clinically healthy dogs. Withholding food might be helpful to limit variability in analytes impacted by feeding, such as triglycerides and phosphorus.
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Affiliation(s)
- Katarina C Yi
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Johanna C Heseltine
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Nicholas D Jeffery
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Audrey K Cook
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Mary B Nabity
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Wallace O, Summers S, Quimby J, Lappin M. Short-term postprandial changes in select serum biochemistry analytes in healthy adult cats. J Feline Med Surg 2022; 24:e459-e464. [PMID: 36219454 PMCID: PMC10812365 DOI: 10.1177/1098612x221121929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the magnitude, duration and significance of postprandial changes to select serum biochemistry analytes in healthy adult cats in the 12 h period after a meal. METHODS Nine adult research cats fed commercial food were included. Blood samples were taken after a 12 h fast (hour 0), cats were offered and consumed a meal, and postprandial samples were obtained over a 12 h period starting 2 h after the baseline blood draw (hours 2, 4, 6, 8, 10 and 12). Serum samples were run on a Roche Cobas C501 chemistry analyzer to obtain concentrations of blood urea nitrogen (BUN), creatinine, phosphorus, total calcium, bicarbonate, cholesterol, magnesium, sodium, potassium and chloride. Serum concentrations of each analyte at hours 2, 4, 6, 8, 10 and 12 were compared with concentrations prior to feeding. RESULTS Serum concentration for at least one postprandial time point was different from baseline fasted concentration for BUN (hour 2, P = 0.006; hour 4, P <0.0001; hour 6, P = 0.002; hour 8, P = 0.026), phosphorus (hour 2, P = 0.019), bicarbonate (hours 2, 4, 6, 8 and 10; all P <0.01), glucose (hour 12, P = 0.014), magnesium (hour 10, P = 0.029) and chloride (hour 2, P = 0.026; hour 4, P = 0.044; hour 12, P = 0.019). No significant difference was seen at any postprandial sampling point compared with baseline for serum creatinine, total calcium, cholesterol, sodium or potassium concentrations. CONCLUSIONS AND RELEVANCE Short-term postprandial serum concentrations of BUN, phosphorus, bicarbonate and chloride differed at multiple time points within a 12 h period compared with the fasted state at baseline, with most values remaining within the reference intervals. Veterinarians should be aware of these alterations, though they are unlikely to be mistaken for pathological disease states in healthy adult cats.
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Affiliation(s)
- Olivia Wallace
- College of Veterinary Medicine, Department of Clinical Sciences, Oregon State University, Corvallis, OR, USA
| | - Stacie Summers
- College of Veterinary Medicine, Department of Clinical Sciences, Oregon State University, Corvallis, OR, USA
| | - Jessica Quimby
- College of Veterinary Medicine, Department of Clinical Sciences, The Ohio State University, Columbus, OH, USA
| | - Michael Lappin
- College of Veterinary Medicine, Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
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High Intake of Sodium Chloride for 28 Days Causes No Effect on Serum FGF23 Concentrations in Cats. Animals (Basel) 2022; 12:ani12223195. [PMID: 36428422 PMCID: PMC9686773 DOI: 10.3390/ani12223195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND FGF23 is an acknowledged parameter to assess kidney health. As chronic kidney failure is one of the most common diseases in aging cats, dietary influences on renal health warrant investigation. The purpose of this study was therefore to investigate potential correlations between dietary sodium chloride and FGF23. METHODS In a total of two trials, 11 cats were included. In the first trial, the cats were fed a complete and balanced control diet; in the second trial, sodium chloride was added (8 g/kg/DM)). Blood, urinary, feed, and faecal samples were analysed for major minerals. FGF23 and creatinine were measured in blood and urine samples. RESULTS Serum phosphate and FGF23 were unaffected by high sodium chloride intake, thus showing no correlation between serum FGF23 and sodium concentrations. Apparent phosphorus digestibility was significantly increased, however, by high sodium chloride intake, whereas apparent digestibility of calcium was unaffected. The present study confirms differences in FGF23 and sodium chloride interaction in cats compared with other species. Further research regarding the correlation between sodium chloride and phosphate homeostasis is warranted.
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Abstract
The impact of dietary phosphorus on chronic renal disease in cats, humans and other species is receiving increasing attention. As Ca and P metabolism are linked, the ratio of Ca:P is an important factor for consideration when formulating diets for cats and other animals. Here, we describe a fully randomised crossover study including twenty-four healthy, neutered adult cats, investigating postprandial responses in plasma P, ionised Ca and parathyroid hormone (PTH) following one meal (50 % of individual metabolic energy requirement) of each of six experimental diets. Diets were formulated to provide P at either 0·75 or 1·5 g/1000 kcal (4184 kJ) from the soluble phosphorus salt sodium tripolyphosphate (STPP, Na5P3O10), variable levels of organic Ca and P sources, and an intended total Ca:P of about 1·0, 1·5 or 2·0. For each experimental diet, baseline fasted blood samples were collected prior to the meal, and serial blood samples collected hourly for 6 h thereafter. For all diets, a significant increase from baseline was observed at 120 min in plasma PTH (P < 0·001). The diet containing the highest STPP inclusion level and lowest Ca:P induced the highest peaks in postprandial plasma P and PTH levels (1·8 mmol/l and 27·2 pg/ml, respectively), and the longest duration of concentrations raised above baseline were observed at 3 h for P and 6 h for PTH. Data indicate that Ca:P modulates postprandial plasma P and PTH. Therefore, when formulating diets containing soluble P salts for cats, increasing the Ca:P ratio should be considered.
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8
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Sinha S, Haque M. Obesity, Diabetes Mellitus, and Vascular Impediment as Consequences of Excess Processed Food Consumption. Cureus 2022; 14:e28762. [PMID: 36105908 PMCID: PMC9441778 DOI: 10.7759/cureus.28762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2022] [Indexed: 12/15/2022] Open
Abstract
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.
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9
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Duong CN, Akinlawon OJ, Gung J, Noel SE, Bigornia S, Flanagan K, Pourafshar S, Lin PH, Davenport CA, Pendergast J, Scialla JJ, Tucker KL. Bioavailability of phosphorus and kidney function in the Jackson Heart Study. Am J Clin Nutr 2022; 116:541-550. [PMID: 35511217 PMCID: PMC9348986 DOI: 10.1093/ajcn/nqac116] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 04/26/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND High phosphorus (P) exposure may have negative effects on kidney function. Nutrient databases provide total P, but bioavailability varies by source. OBJECTIVES We aimed to assess natural, added, and bioavailable P intake, and to relate these to estimated glomerular filtration rate (eGFR) in the Jackson Heart Study (JHS). METHODS A total of 3962 African-American participants of the JHS, aged 21-84 y, with urine albumin:creatinine ratio < 30 mg/g, and eGFR ≥ 60 mL · min-1 · 1.73 m-2, and without self-reported kidney disease, were included. Diet was assessed by FFQ. We assigned P in foods as naturally occurring or added, and weighted intake by P bioavailability, based on published literature. Relations between P variables and eGFR were assessed using multivariable regression. RESULTS Mean ± SE intakes were 1178 ± 6.7 mg and 1168 ± 5.0 mg for total P, 296 ± 2.8 mg and 291 ± 2.1 mg for bioavailable added P, and 444 ± 2.9 mg and 443 ± 2.2 mg for bioavailable natural P, in participants with eGFR = 60-89 and ≥90 mL · min-1 · 1.73 m-2, respectively. Major sources of total P included fish, milk, beef, eggs, cheese, and poultry; and of added P, fish, beef, processed meat, soft drinks, and poultry. After adjustment for confounders, P intakes, including total (β ± SE: -0.32 ± 0.15; P = 0.03), added (β ± SE: -0.73 ± 0.27; P = 0.01), bioavailable total (β ± SE: -0.62 ± 0.23; P = 0.01), and bioavailable added (β ± SE: -0.77 ± 0.29; P = 0.01), were significantly associated with lower eGFR. However, neither total nor bioavailable P from natural sources were associated with eGFR. CONCLUSIONS Added, but not natural, P was negatively associated with kidney function, raising concern about P additives in the food supply. Further studies are needed to improve estimation of dietary P exposure and to clarify the role of added P as a risk factor for kidney disease.
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Affiliation(s)
- Chi N Duong
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, MA, USA
| | - Oladimeji J Akinlawon
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, MA, USA
| | - Joseph Gung
- Gillings School of Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Sabrina E Noel
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, MA, USA
| | - Sherman Bigornia
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH, USA
| | - Kaylea Flanagan
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, MA, USA
| | - Shirin Pourafshar
- Departments of Medicine and Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Pao-Hwa Lin
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Clemontina A Davenport
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- Department of Biostatistics & Bioinformatics, Duke University School of Medicine, Durham, NC, USA
| | - Jane Pendergast
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- Department of Biostatistics & Bioinformatics, Duke University School of Medicine, Durham, NC, USA
| | - Julia J Scialla
- Departments of Medicine and Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Katherine L Tucker
- Department of Biomedical and Nutritional Sciences and Center for Population Health, University of Massachusetts Lowell, Lowell, MA, USA
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10
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Elliott J, Geddes RF. New concepts in phosphorus homeostasis and its impact on renal health with particular reference to the cat. Vet J 2022; 283-284:105842. [PMID: 35577278 DOI: 10.1016/j.tvjl.2022.105842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
New discoveries relating to phosphorus homeostasis include the hormones fibroblast growth factor-23 and klotho produced by bone and kidney. These hormones, together with novel understanding of how calcium and phosphate ions are carried in colloidal form as calciprotein particles, have changed our view of how phosphorus is regulated. Recognition that high dietary intake of inorganic forms of phosphorus in humans is a risk factor for both cardiovascular and renal diseases have led to re-examination of the impact of inorganic sources of phosphorus in prepared cat foods on renal health. Data suggest that when homeostatic mechanisms lead to proximal tubular (S3 segment) phosphate concentrations exceeding 3.25mmol/L for a significant part of the day, tubular stress and structural kidney damage ensues. Recent experimental rodent studies support the concept that calciprotein particles form in the proximal tubule at these prevailing phosphate concentrations and trigger proximal tubular damage. Long-term feeding studies in cats suggest that carefully formulated prepared diets containing 1g/Mcal of inorganic phosphorus (in the form of sodium tripolyphosphate or potassium monophosphate and pyrophosphate), resulting in estimated tubular phosphate concentrations <2.5mmol/L can be fed to healthy adult cats without detectable adverse effects on renal health.
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Affiliation(s)
- Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK
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11
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Coltherd JC, Alexander JE, Pink C, Rawlings J, Elliott J, Haydock R, Carvell-Miller LJ, Biourge VC, Molina L, Butterwick R, Logan DW, Watson P, Bakke AM. Towards establishing no observed adverse effect levels (NOAEL) for different sources of dietary phosphorus in feline adult diets: results from a 7-month feeding study. Br J Nutr 2021; 126:1626-1641. [PMID: 33550999 DOI: 10.1017/s0007114521000477] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
High dietary phosphorus (P), particularly soluble salts, may contribute to chronic kidney disease development in cats. The aim of the present study was to assess the safety of P supplied at 1 g/1000 kcal (4184kJ) from a highly soluble P salt in P-rich dry format feline diets. Seventy-five healthy adult cats (n 25/group) were fed either a low P control (1·4 g/1000 kcal [4184kJ]; Ca:P ratio 0·97) or one of two test diets with 4 g/1000 kcal (4184 kJ); Ca:P 1·04 or 5 g/1000 kcal (4184kJ); Ca:P 1·27, both incorporating 1 g/1000 kcal (4184 kJ) sodium tripolyphosphate (STPP) - for a period of 30 weeks in a randomised parallel-group study. Health markers in blood and urine, glomerular filtration rate, renal ultrasound and bone density were assessed at baseline and at regular time points. At the end of the test period, responses following transition to a commercial diet (total P - 2·34 g/1000 kcal [4184kJ], Ca:P 1·3) for a 4-week washout period were also assessed. No adverse effects on general, kidney or bone (skeletal) function and health were observed. P and Ca balance, some serum biochemistry parameters and regulatory hormones were increased in cats fed test diets from week 2 onwards (P ≤ 0·05). Data from the washout period suggest that increased serum creatinine and urea values observed in the two test diet groups were influenced by dietary differences during the test period, and not indicative of changes in renal function. The present data suggest no observed adverse effect level for feline diets containing 1 g P/1000 kcal (4184 kJ) from STPP and total P level of up to 5 g/1000 kcal (4184 kJ) when fed for 30 weeks.
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Affiliation(s)
- Jennifer C Coltherd
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Janet E Alexander
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Claire Pink
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - John Rawlings
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, LondonNW1 0TU, UK
| | - Richard Haydock
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | | | | | | | - Richard Butterwick
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Darren W Logan
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Phillip Watson
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
| | - Anne Marie Bakke
- Waltham Petcare Science Institute, Melton Mowbray, LeicestershireLE14 4RT, UK
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12
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Schauf S, Coltherd JC, Atwal J, Gilham M, Carvell-Miller LJ, Renfrew H, Elliott J, Elliott D, Bijsmans ES, Biourge VC, Watson P, Bakke AM. Clinical progression of cats with early-stage chronic kidney disease fed diets with varying protein and phosphorus contents and calcium to phosphorus ratios. J Vet Intern Med 2021; 35:2797-2811. [PMID: 34545958 PMCID: PMC8692190 DOI: 10.1111/jvim.16263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 08/06/2021] [Accepted: 08/30/2021] [Indexed: 12/28/2022] Open
Abstract
Background Dietary protein and phosphorus (P) restriction is the mainstay for nutritional management of chronic kidney disease (CKD). However, adequate restriction levels for cats with early CKD remain unclear. Objectives To investigate responses in cats with early CKD to varying dietary protein, P, and calcium (Ca) : P ratio. Animals Nineteen research colony cats with International Renal Interest Society stages 1‐2 CKD. Methods In an opportunistic longitudinal case study, cats were fed a low protein (59 g/Mcal), low P (0.84 g/Mcal) dry diet (LP‐LP; Ca : P = 1.9) for 18 months and later transitioned onto a moderate protein (76‐98 g/Mcal), moderate P (1.4‐1.6 g/Mcal) dry‐wet diet regimen (MP‐MP; Ca : P = 1.4‐1.6) for 22 months. Fold‐changes in serum creatinine, total Ca (tCa) and P (primary outcomes) and fibroblast growth factor 23 (FGF23) were assessed by linear‐mixed models. Results While feeding LP‐LP, mean serum creatinine decreased (0.87‐fold, 95% confidence interval [CI] 0.81, 0.93, P < .001) to within reference range after 6 months, while increases in total Ca (tCa; 1.16‐fold, 95% CI 1.11, 1.22, P < .001) and FGF23 (2.72‐fold, 95% CI 1.72, 4.31, P < .001), but not in P (1.03‐fold, 95% CI 0.945, 1.124, P = .94), were observed after 17 months. On MP‐MP, mean creatinine, tCa and P remained within reference ranges and did not significantly change (P = .11, P = .98, and P = 1, respectively), while FGF23 significantly decreased (0.58‐fold, 95% CI 0.36, 0.95, P = .02) after 22 months. Conclusions and Clinical Importance Cats with early CKD developed hypercalcemia after long‐term feeding of a highly P‐restricted diet. Increasing dietary P and reducing Ca : P ratio maintained renal markers, while improving Ca‐P balance. Cats with early CKD could benefit from moderately protein‐ and P‐restricted diets.
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Affiliation(s)
- Sofia Schauf
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
| | - Jennifer C Coltherd
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
| | - Jujhar Atwal
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
| | - Matthew Gilham
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
| | | | | | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | | | | | | | - Phillip Watson
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
| | - Anne Marie Bakke
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire, United Kingdom
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Soutar L, Coltherd JC, Steele VR, Staunton R, Carvell-Miller L, Hughes KR, Bakke AM, Marshall JW. Comparisons of In Vitro and In Vivo Digestibility Assays for Phosphorus in Feline Diets and Associations with Dietary Nutrient Content. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10688-10699. [PMID: 34472353 DOI: 10.1021/acs.jafc.1c03308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Phosphorus (P) is an essential nutrient; however, potential health impacts of high dietary levels of added soluble, highly bioavailable P salts especially are a concern. P sources with lower bioavailability are considered safer. Yet, speciation of different P sources to assess diets' risk to health is challenging. This investigation tested the value of in vitro water extraction and digestion assays to predict in vivo P apparent bioavailability/digestibility in feline diets. Thirty wet (n = 18) and dry (n = 12) format experimental and commercial cat foods were analyzed for nutrient content. Triplicate samples were subjected to in vitro water extraction, single-phase acidic (gastric; G) digestion, and dual-phase gastric and small intestinal (G-SI) digestion assays. Soluble and insoluble P were determined in the supernatant and pellet, respectively. A subset of the diets (seven wet, nine dry diets) was fed to healthy, adult cats (n = 7-24) to determine in vivo apparent P digestibility. Information on the soluble P salt sources and their contribution to total dietary P was available for some diets. Associations between data from the different in vitro assays and in vivo digestibility trials and the influence of different diet parameters were obtained using Pearson correlation and linear regression modeling. The % soluble P obtained from G-SI digestion assay correlated well with in vivo apparent P digestibility for wet (Pearson coefficient 0.926, p = 0.003), but not for dry diets (Pearson coefficient -0.074, p = 0.849). In contrast, the % soluble P determined by water extraction correlated well with the % soluble P salt contribution to total P for dry (Pearson coefficient 0.901, p < 0.001), but not for wet diets (Pearson coefficient -0.407, p = 0.365). Thus, 20 min water extraction can be used to predict soluble P salt content in dry diets; however, differing Ca:P ratios and water solubility of the P sources may affect the outcome and false-positive results can occur. The G-SI digestion assay employed can also be used to predict in vivo P digestibility. However, again, diet format, Ca:P ratios in diets, and possibly other factors can impact the results. Thus, data from in vitro assays to assess P sources and bioavailability need to be interpreted with care.
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Affiliation(s)
- Lyndsay Soutar
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Jennifer C Coltherd
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Victoria R Steele
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Ruth Staunton
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Laura Carvell-Miller
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Kevin R Hughes
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - Anne Marie Bakke
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
| | - James W Marshall
- Waltham Petcare Science Institute, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray LE14 4RT, Leicestershire, United Kingdom
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14
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Dobenecker B. [Phosphate intake with complete food and diets for chronic kidney disease available on the German market]. TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2021; 49:247-254. [PMID: 34425603 DOI: 10.1055/a-1487-8625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Complete foods and renal diets for dogs and cats available on the German market were analyzed for their concentrations of total phosphorus as well as highly soluble and therefore highly available phosphorus due to the possible effects of this element on the animal's health. MATERIAL AND METHODS A total of 133 complete foods for healthy dogs and cats, 8 snacks and 43 diets for patients with chronic kidney disease were analyzed for total phosphorus and the fraction of phosphorus soluble in water after 1 minute (Psol1). RESULTS In the tested compound food, the amount of phosphorus in relation to the recommended daily allowance ranged from 90 to 740 %. More than 90 % of the products supplied twice the required amounts; in 6 dog feeds the nutritional maximum wasexceeded. For almost 75 % of the products, the recommended daily allowance for phosphorus was already met vollby Psol1. More than 50 % of the tested renal diets contained more than twice the recommended amounts for healthy individuals and with this also exceeded the legal limits. Even in the renal diets, the amount of Psol1 alone exceeded the recommended daily allowance for this element. CONCLUSION This work demonstrates that compound food and renal diets available on the German market may contain a multiple of the recommended or legally permitted phosphorus concentrations. Therefore, a considerable number of products may be expected to not meet the expectations of customers and veterinarians.
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Affiliation(s)
- Britta Dobenecker
- Lehrstuhl für Tierernährung und Diätetik, Veterinärmedizinisches Department, Ludwig-Maximilians-Universität München
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15
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Tang PK, Geddes RF, Jepson RE, Elliott J. A feline-focused review of chronic kidney disease-mineral and bone disorders - Part 2: Pathophysiology of calcium disorder and extraosseous calcification. Vet J 2021; 275:105718. [PMID: 34329743 DOI: 10.1016/j.tvjl.2021.105718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 06/23/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Abstract
Derangements in mineral metabolism are one of the main entities in chronic kidney disease-mineral and bone disorder (CKD-MBD). This is the second of a two-part review of the physiology and pathophysiology of calcium homeostasis in feline CKD-MBD. While dysregulation in calcium homeostasis is known to contribute to the development of vascular calcification in CKD, evidence characterising the relationship between serum calcium concentration and nephrocalcinosis and nephrolithiasis is limited. Recently, fibroblast growth factor 23 (FGF23) and α-Klotho have gained increased research interest and been shown to be important biomarkers for the prediction of CKD progression in human patients. However, conflicting evidence exists on their role in calcium homeostasis and vascular and soft tissue calcification. This review details the pathophysiology of calcium disorders associated with CKD-MBD and its implications on vascular and soft tissue mineralisation in human and feline patients. Further prospective studies investigating the clinical consequences of calcium disturbances in cats with CKD are warranted and this may provide additional insight into the pathophysiology of feline CKD-MBD.
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Affiliation(s)
- Pak-Kan Tang
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom.
| | - Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, United Kingdom
| | - Rosanne E Jepson
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, United Kingdom
| | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom
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Atwal J, Stockman J, Gilham M, Allaway D, Renfrew H, Bakke AM, Watson P. No Observed Adverse Effects on Health Were Detected in Adult Beagle Dogs When Fed a High-Calcium Diet for 40 Weeks. Animals (Basel) 2021; 11:ani11061799. [PMID: 34208630 PMCID: PMC8234157 DOI: 10.3390/ani11061799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/04/2021] [Accepted: 06/11/2021] [Indexed: 11/29/2022] Open
Abstract
Simple Summary Calcium (Ca) is an essential mineral that plays a vital role in many bodily functions. There is evidence that high levels of dietary Ca for puppies and growing dogs can result in adverse growth and health effects, with certain breeds and dog size categories being most susceptible, for example, large breed sizes or beagles. Until recently, little was known about the health consequences of high Ca diets to adult dog, however, a study in the large sized breed Labrador retriever found no adverse health consequences when feeding diets containing levels of Ca near maximum levels set by pet food regulators (2.5 g per 100 g dry matter) for 40 weeks. This current study fed a similar high Ca diet to adult beagles, a medium sized breed for 40 weeks and monitored the dogs’ health using an extensive suite of health parameters. All dogs remained healthy and did not display any clinically relevant signs of adverse health relating to diet at any point during or following completion of the study. Abstract The implications of long-term high calcium (Ca) intake are well documented in growing dogs and in adult dogs of large breed size, however, the consequences on other breeds and breed sizes are yet to be determined. Eighteen neutered adult beagles, nine males and nine females aged 1.4–4.4 years, were randomized to control or test diets providing in g∙4184 kJ−1 (1000 kcal−1): 1.44 and 7.19 total Ca balanced with 1.05 and 4.25 total phosphorus, respectively, for 40 weeks. Health parameters, ultrasound scans, radiographs, glomerular filtration rate, and mineral balance were measured at eight-week intervals. All dogs remained healthy with no measured evidence of orthopedic, urinary, or renal disease. The test diet resulted in a 5.2 fold increase in fecal Ca excretion. Apparent Ca digestibility (%) and Ca balance (g/d) did not significantly (p > 0.05) change from baseline in the test diet group, although dogs displayed a positive Ca balance (maximum at week 8, 1.11 g/d with 95% CI (0.41, 1.80)) before a neutral Ca balance was restored at week 32. Despite an initial positive Ca balance, we can conclude that no measurable adverse health effects were observed as a result of the test diet fed in this study in beagles over a period of 40 weeks.
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Affiliation(s)
- Jujhar Atwal
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
- Correspondence:
| | - Jonathan Stockman
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
| | - Matthew Gilham
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
| | - David Allaway
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
| | - Helen Renfrew
- Renfrew Imaging, Grove Road, Bladon, Woodstock OX20 1RD, UK;
| | - Anne Marie Bakke
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
| | - Phillip Watson
- WALTHAM Petcare Science Institute, Melton Mowbray, Leicestershire LE14 4RT, UK; (J.S.); (M.G.); (D.A.); (A.M.B.); (P.W.)
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Stockman J, Villaverde C. Concerns related to dietary phosphorus intake in cats. J Am Vet Med Assoc 2021; 258:1325-1331. [PMID: 34061616 DOI: 10.2460/javma.258.12.1325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Stockman J, Villaverde C, Corbee RJ. Calcium, Phosphorus, and Vitamin D in Dogs and Cats: Beyond the Bones. Vet Clin North Am Small Anim Pract 2021; 51:623-634. [PMID: 33653533 DOI: 10.1016/j.cvsm.2021.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Calcium, phosphorus, and vitamin D are nutrients that play a key role in maintaining normal organ, cell, and tissue function. Much is known about their role in bone metabolism, but these nutrients are also important in renal health, urinary tract disease, and multiple other organ systems. It is nutritionally important to meet the physiologic requirements for each of these nutrients, but the interplay between them should also be considered.
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Affiliation(s)
- Jonathan Stockman
- Department of Clinical Veterinary Sciences, LIU College of Veterinary Medicine, Long Island University, 720 Northern Boulevard, Brookville, NY 11548, USA
| | | | - Ronald Jan Corbee
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, Utrecht 3584 CM, The Netherlands.
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Dobenecker B, Reese S, Herbst S. Effects of dietary phosphates from organic and inorganic sources on parameters of phosphorus homeostasis in healthy adult dogs. PLoS One 2021; 16:e0246950. [PMID: 33606750 PMCID: PMC7894875 DOI: 10.1371/journal.pone.0246950] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/28/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The impact of dietary phosphorus (P) excess, especially on renal and cardiovascular health, has been investigated in several species, but little is known in dogs. OBJECTIVE The aim of this study was to examine effects of different P sources on concentration and postprandial kinetics of selected parameters of P homeostasis in dogs. METHODS Eight beagles received one control diet (P 0.5% dry matter [DM]) and three high P diets (poultry meal, NaH2PO4, and KH2PO4; P 1.7% DM) for 18d. Urine samples were collected pre- and postprandially while faeces were collected quantitatively for 5d and analysed for minerals. On day 18, blood was sampled 1h pre- and 0.5, 1, 1.5, 2, 3, 5 and 7h postprandially. RESULTS Pi (KH2PO4, NaH2PO4) but not organic P caused an increased apparent P digestibility and significantly influenced kinetics of serum FGF23, parathyroid hormone, P, CrossLaps and bonespecific alkaline phosphatase, demonstrating a disrupted calcium (Ca) and P homeostasis with potential harm for renal, cardiovascular and skeletal health. CONCLUSIONS Results of feeding Pi to dogs indicate distinct disturbances of Ca and P metabolism, in contrast to organic sources. The use of Pi in food can therefore not be considered as safe. Further research, especially on dose and long-term effects, is warranted.
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Affiliation(s)
- Britta Dobenecker
- Chair of Animal Nutrition and Dietetics, Department of Animal Science, Ludwig-Maximilians- Universität, Munich, Germany
| | - Sven Reese
- Chair of Anatomy, Histology and Embryology, Department of Animal Science, Ludwig-Maximilians- Universität, Munich, Germany
| | - Sarah Herbst
- Chair of Animal Nutrition and Dietetics, Department of Animal Science, Ludwig-Maximilians- Universität, Munich, Germany
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20
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Geddes RF, van den Broek DHN, Chang YM, Biourge V, Elliott J, Jepson RE. The effect of attenuating dietary phosphate restriction on blood ionized calcium concentrations in cats with chronic kidney disease and ionized hypercalcemia. J Vet Intern Med 2021; 35:997-1007. [PMID: 33527601 PMCID: PMC7995425 DOI: 10.1111/jvim.16050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 12/30/2022] Open
Abstract
Background Hypercalcemia is commonly observed in cats with azotemic chronic kidney disease (CKD). Dietary phosphate restriction is considered standard of care but may contribute to the development of hypercalcemia. The optimal dietary management strategy for these cats is unclear. Objectives To describe the effect of feeding a moderately phosphate‐restricted diet (MP; 1.5 g/Mcal phosphorus; Ca : P ratio, 1.3) to cats with concurrent azotemic CKD and ionized hypercalcemia. Animals Client‐owned cats with ionized hypercalcemia (ionized calcium [iCa] concentration >1.4 mmol/L) at diagnosis of CKD (n = 11; baseline hypercalcemics) or after CKD diagnosis while eating a phosphate‐restricted clinical renal diet (0.8 g/Mcal phosphorus; Ca : P ratio, 1.9; n = 10; RD hypercalcemics). Methods Changes in variables over time, after starting MP at visit 1, were assessed using linear mixed model analysis within each group of cats. Data are reporte as median [25th, 75th percentiles]. Results At visit 1, iCa was 1.47 [1.42, 1.55] mmol/L for baseline hypercalcemics and 1.53 [1.5, 1.67] mmol/L for RD hypercalcemics. Blood iCa decreased (P < .001) when RD hypercalcemics were fed MP, with iCa <1.4 mmol/L in 8/10 cats after 2.2 [1.8, 3.7] months. Plasma phosphate concentrations did not change. In contrast, the baseline hypercalcemic group overall showed no change in iCa but a decrease in plasma phosphate concentration during 8.8 [5.5, 10.6] months on the MP diet, although 4/11 individual cats achieved iCa <1.4 mmol/L by 3.4 [1.0, 6.2] months. Conclusions and Clinical Importance Attenuation of dietary phosphate restriction could result in normalization of iCa in cats that develop hypercalcemia while eating a clinical renal diet.
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Affiliation(s)
- Rebecca F Geddes
- Department of Clinical Science and Services, Royal Veterinary College, University of London, North Mymms, Hertfordshire, UK
| | - D Hendrik N van den Broek
- Department of Clinical Science and Services, Royal Veterinary College, University of London, North Mymms, Hertfordshire, UK
| | - Yu-Mei Chang
- Research Support Office, Royal Veterinary College, University of London, London, UK
| | | | - Jonathan Elliott
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, UK
| | - Rosanne E Jepson
- Department of Clinical Science and Services, Royal Veterinary College, University of London, North Mymms, Hertfordshire, UK
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Lundin MT, Bressendorff I, Kristensen B, Jørgensen NR, Butt R, Hansen D. Randomized Trial of Acute Changes in Plasma Phosphate After Phosphorus-Standardized Meals in Peritoneal Dialysis. Kidney Int Rep 2021; 6:304-312. [PMID: 33615055 PMCID: PMC7879124 DOI: 10.1016/j.ekir.2020.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/14/2020] [Accepted: 11/03/2020] [Indexed: 11/27/2022] Open
Abstract
Introduction Hyperphosphatemia is associated with increased morbidity and mortality in patients with chronic kidney disease. The aim of this study was to assess whether a meal with high phosphorus content would affect plasma phosphate in the hours that follow among subjects with end-stage kidney disease on peritoneal dialysis. Methods This was a single-blinded randomized cross-over trial of 12 subjects on maintenance peritoneal dialysis, in which subjects were randomized to consume a meal with either high or low phosphorus content on 2 separate trial days. On each trial day, plasma phosphate was measured immediately before consumption of the standardized meal and after 1, 2, 3, and 5 hours. Results The mean fasting plasma phosphate at baseline was 1.69 ± 0.22 mmol/l. Plasma phosphate was similar between the 2 meals at baseline, as well as at 1, 2, 3, and 5 hours after consumption. The largest observed difference in plasma phosphate between the 2 meals was 0.15 mmol/l, which occurred 5 hours after consumption (high-phosphorus meal 1.75 ± 0.32 mmol/l vs. low-phosphorus meal 1.60 ± 0.14 mmol/l (P = 0.06)). Using summary analyses for repeated measures, we observed a significant difference in the plasma phosphate between the 2 meals (P = 0.03). Conclusion Our results show that in subjects with end-stage kidney disease, a meal with high phosphorus content has only a negligible effect on plasma phosphate compared to a meal with low phosphorus content. Thus, large increases in plasma phosphate cannot be accounted for by a high intake of phosphorus in the hours before blood sampling.
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Affiliation(s)
| | - Iain Bressendorff
- Department of Nephrology, Herlev and Gentofte Hospital, Herlev, Denmark
| | - Bent Kristensen
- Department of Nuclear Medicine, Herlev and Gentofte Hospital, Herlev, Denmark
| | - Niklas Rye Jørgensen
- Department of Clinical Biochemistry, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rizwan Butt
- Department of Nephrology, Herlev and Gentofte Hospital, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ditte Hansen
- Department of Nephrology, Herlev and Gentofte Hospital, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Laflamme D, Backus R, Brown S, Butterwick R, Czarnecki-Maulden G, Elliott J, Fascetti A, Polzin D. A review of phosphorus homeostasis and the impact of different types and amounts of dietary phosphate on metabolism and renal health in cats. J Vet Intern Med 2020; 34:2187-2196. [PMID: 33159358 PMCID: PMC7694857 DOI: 10.1111/jvim.15961] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 10/11/2020] [Accepted: 10/27/2020] [Indexed: 12/14/2022] Open
Abstract
Elevated concentrations of serum phosphate are linked with progression and increased case fatality rate in animals and humans with chronic kidney disease. Elevated concentrations of serum phosphate can be a risk factor for development of renal and cardiovascular diseases or osteoporosis in previously healthy people. In rodents, an excess intake of dietary phosphorus combined with an inverse dietary calcium : phosphorus ratio (<1 : 1) contributes to renal calcification. Renal injury also has occured in cats fed experimental diets supplemented with highly soluble phosphate salts, especially in diets with inverse calcium : phosphorus ratios. However, not all phosphorus sources contribute similarly to this effect. This review, which focuses on cats, summarizes the published evidence regarding phosphorus metabolism and homeostasis, including the relative impact of different dietary phosphorus sources, and their impact on the kidneys. No data currently shows that commercial cat foods induce renal injury. However, some diets contain high amounts of phosphorus relative to recommendations and some have inverse Ca : P ratios and so could increase the risk for development of kidney disease. While limiting the use of highly soluble phosphates appears to be important, there are insufficient data to support a specific upper limit for phosphate intake. This review also proposes areas where additional research is needed in order to strengthen conclusions and recommendations regarding dietary phosphorus for cats.
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Affiliation(s)
| | - Robert Backus
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Scott Brown
- College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | | | | | - Jonathan Elliott
- Royal Veterinary College, University of London, London, United Kingdom
| | - Andrea Fascetti
- Department of Molecular Biosciences, University of California, Davis, California, USA
| | - David Polzin
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, St Paul, Minnesota, USA
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23
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Summers SC, Stockman J, Larsen JA, Zhang L, Rodriguez AS. Evaluation of phosphorus, calcium, and magnesium content in commercially available foods formulated for healthy cats. J Vet Intern Med 2019; 34:266-273. [PMID: 31883277 PMCID: PMC6979088 DOI: 10.1111/jvim.15689] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/11/2019] [Indexed: 01/06/2023] Open
Abstract
Background High dietary phosphorus (P) and low calcium‐to‐phosphorus ratio (Ca:P) are associated with kidney damage in cats. There are no established guidelines for dietary P maximum for cats. Objectives To quantify crude protein, P, Ca, and magnesium (Mg) concentrations in cat foods and compare among food formats (dry, canned, raw), primary protein ingredients, protein concentrations (low, moderate, high), grain‐free versus grain‐containing foods, foods intended for adult maintenance versus all life stages, and cost. Samples Eighty‐two commercial nonprescription cat foods. Methods Descriptive study. Mineral concentrations were measured using inductively coupled argon plasma‐optical emission spectroscopy. Crude protein was measured using the Dumas nitrogen combustion method. Mineral and crude protein concentrations were compared among food categories. Results Twenty‐seven foods contained ≥3.6 g P/1000 kcal metabolizable energy (ME), of which 7 exceeded 4.8 g/1000 kcal ME. Thirteen foods had low Ca:P ratio (≤1.0). The low‐protein diet group had no products ≥3.6 g P/1000 kcal ME, which was significantly different compared to the high‐protein diet group (52% of products had ≥3.6 g P/1000 kcal ME; P = .01). No significant differences in P content and Ca:P ratio were found among other diet categories. Canned foods had significantly lower Mg compared to dry (P < .001) and raw (P = .007) foods. Declared minimum P and Ca were significantly lower than analyzed concentrations (P = .0005 and P = .003, respectively). Conclusions and Clinical Importance The high number of foods with high P and low Ca suggest that pet food regulatory reform should be considered.
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Affiliation(s)
| | | | | | - Lei Zhang
- Colorado State University, Fort Collins, Colorado
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Brunetto MA, Zafalon RVA, Teixeira FA, Vendramini THA, Rentas MF, Pedrinelli V, Risolia LW, Macedo HT. Phosphorus and sodium contents in commercial wet foods for dogs and cats. Vet Med Sci 2019; 5:494-499. [PMID: 31273944 PMCID: PMC6868456 DOI: 10.1002/vms3.183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
It has been reported that wet foods for dogs and cats have high levels of sodium and phosphorus due to their composition. Therefore, this study aimed to evaluate the sodium and phosphorus contents in wet pet foods, and compare it to daily requirements for both species. Twenty‐five commercial wet foods for adult animals were evaluated, 13 for dogs and 12 for cats. The analyses’ results were compared to the European Pet Food Industry Federation (FEDIAF 2018) recommendations. All foods contained phosphorus and sodium amounts above minimum requirements. Three wet foods for dogs exceeded the safe upper limit for phosphorus, and four wet foods for dogs and three for cats exceeded 3.75 g of sodium/1,000 kcal metabolizable energy (ME), considered safe by FEDIAF. No studies were found at the present time evaluating whether higher sodium levels are safe for dogs and cats; however, consumption of high phosphorus diets has been associated with adverse effects on renal function parameters. Therefore, more studies are necessary to investigate the health implications of phosphorus and sodium concentrations observed in some foods evaluated in this research. It has been reported that wet foods for dogs and cats have high levels of sodium and phosphorus due to their composition. Therefore, this study aimed to evaluate the sodium and phosphorus contents in wet pet foods, and compared to daily requirements for both species.![]()
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Affiliation(s)
- Marcio A Brunetto
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Rafael V A Zafalon
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Fabio A Teixeira
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Thiago H A Vendramini
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Mariana F Rentas
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Vivian Pedrinelli
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Larissa W Risolia
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
| | - Henrique T Macedo
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo/Pirassununga, Brazil
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