Browsing by Author "Wiese, Gretchen N."

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    Effects of Plant-Based Protein Consumption on Kidney Function and Mineral Bone Disorder Outcomes in Adults With Stage 3-5 Chronic Kidney Disease: A Systematic Review
    (Elsevier, 2023) Burstad, Kendal M.; Cladis, Dennis P.; Wiese, Gretchen N.; Butler, Mary; Hill Gallant, Kathleen M.; Medicine, School of Medicine
    Introduction Plant-based protein is of growing interest for dietary management of chronic kidney disease (CKD) and is hypothesized to preserve kidney function and reduce CKD-mineral bone disorder (MBD) complications, among other benefits. This systematic review aimed to summarize the available clinical trial evidence for the effect of plant-based protein on kidney function and CKD-MBD outcomes in adults with stage 3-5 CKD not on dialysis. Methods Searches of Medline, Embase, Agricola, CAB abstracts, Web of Science, Scopus, and hand searching were performed. Clinical trials with ≥8 participants ≥18 years of age with an estimated glomerular filtration rate <60 mL/min/1.73 m2 but not on dialysis were included. Additionally, only clinical trials with ≥1-week interventions with ≥50% dietary protein from plant-based sources and reported at least one outcome for both kidney function and CKD-MBD outcomes were included. Of the 10,962 identified abstracts, 32 met inclusion criteria and were assessed for risk of bias. Results Results for kidney function and CKD-MBD outcomes were heterogenous, with most studies having suboptimal methodological quality. In most of the studies (27/32), protein source was altered only secondarily to low-protein diet interventions. Thus, data synthesis and interpretation were focused on a subset of five studies that investigated a change in protein source only (i.e., animal vs. plant). Of this subset, four studies reported no change in kidney function, while one study reported a decrease. Three studies reported no change in serum phosphorus, and one study reported lower serum phosphorus following a vegetarian diet. Further, limited data and inconclusive results were observed for phosphaturic hormones, parathyroid hormone, and fibroblast growth factor-23. Conclusion Current clinical trial evidence on plant-based protein interventions for preserving kidney function and preventing CKD-MBD is limited to inform clinical guidelines at this time. This systematic review emphasizes the ongoing need to research the effects of plant-based protein on kidney function and CKD-MBD outcomes.
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    Intestinal Phosphorus Absorption in Moderate CKD and Healthy Adults Determined Using a Radioisotopic Tracer
    (Wolters Kluwer, 2021) Stremke, Elizabeth R.; Wiese, Gretchen N.; Moe, Sharon M.; Wastney, Meryl E.; Moorthi, Ranjani N.; Hill Gallant, Kathleen M.; Medicine, School of Medicine
    Background: Reducing intestinal phosphorus absorption is a cornerstone in CKD-MBD management. Yet, knowledge gaps include how CKD pathophysiology affects intestinal phosphorus absorption. In vivo rodent studies suggest that intestinal phosphorus absorption remains inappropriately normal in early-moderate CKD, despite declining 1,25-dihydroxyvitamin D (1,25D). We measured intestinal phosphorus absorption in patients with moderate CKD versus healthy adults using a direct radiotracer method. Methods: Patients with CKD and healthy adults matched for age, sex, and race were enrolled in this 8-day controlled diet study: the first 6 days outpatient and the final 2 days inpatient. Oral and intravenous doses of 33P and serial blood and urine sampling determined intestinal phosphorus absorption during the final 2 days. Secondary outcomes included fasting biochemistries and 24-hour urine phosphorus (uP). Results: In total, n=8 patients with CKD (eGFR=29-55 ml/min per 1.73 m2) and n=8 matched healthy controls completed the study. On a controlled diet, no difference in fractional intestinal phosphorus absorption was detected between patients with CKD and healthy adults (0.69 versus 0.62, respectively; P=0.52), and this was similar for 24-hour uP (884 versus 935 mg/d, respectively; P=0.70). Fractional intestinal phosphorus absorption was not significantly related to 24-hour uP. Patients with CKD had higher serum intact PTH and intact FGF23 and lower 1,25D. The relationship between 1,25D and fractional intestinal phosphorus absorption was not statistically significant. Conclusions: Intestinal phosphorus absorption with typical dietary intake did not differ in patients with moderate CKD compared with controls, despite lower serum 1,25D levels. In this setting, a relationship between 24-hour uP and fractional or absolute intestinal absorption was not evident. Further investigation is needed to determine what factors influence intestinal phosphorus absorption in CKD and the apparent lack of compensation by the intestine to limit phosphorus absorption in the face of declining kidney function and reduced 1,25D. Whether this is evident across a range of dietary phosphorus intakes, as well as CKD severity, also needs to be determined.
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    Pilot Study of the Effects of High-Protein Meals During Hemodialysis on Intradialytic Hypotension in Patients Undergoing Maintenance Hemodialysis
    (Elsevier, 2019-03) Choi, Mun Sun; Kistler, Brandon; Wiese, Gretchen N.; Stremke, Elizabeth R.; Wright, Amy J.; Moorthi, Ranjani N.; Moe, Sharon M.; Hill Gallant, Kathleen M.; Medicine, School of Medicine
    Objective Hemodialysis (HD) patients have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of hemodialysis treatment; but, eating during HD may be discouraged due to concerns of postprandial hypotension. However, little data is available to support this practice. In this study, we hypothesized that high protein meals during HD does not lead to symptomatic intradialytic hypotension events. Design A 9-week, non-randomized, parallel-arm study. Setting A single in-center HD clinic. Subjects 18 HD patients from two shifts completed the study. Patients were 62±16 years-old in age with dialysis vintage 3.4±2.6 years. Intervention The intervention group (n=9) received meals of ~30g protein and ~1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid for hemodialysis patients during dialysis for 25 consecutive HD sessions. The control group (n=9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions prior to the start of the intervention/control phase were used as a baseline comparison for each patient. Main Outcome Measure Symptomatic hypotension event frequency. Results In the intervention arm, there were 19 symptomatic hypotension events in 5 patients pre-study and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients pre-study and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from pre-study to during study was not different between groups (P=0.71). There was no effect of meals on nutritional status, but patients reported positive attitudes towards receiving meals during dialysis. Conclusion High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer-term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes.
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    Plant-Based Diets, the Gut Microbiota, and Trimethylamine N-Oxide Production in Chronic Kidney Disease: Therapeutic Potential and Methodological Considerations
    (Elsevier, 2021) Wiese, Gretchen N.; Biruete, Annabel; Moorthi, Ranjani N.; Moe, Sharon M.; Lindemann, Stephen R.; Hill Gallant, Kathleen M.; Anatomy, Cell Biology and Physiology, School of Medicine
    High circulating trimethylamine-N-oxide (TMAO) is associated with an increased risk of cardiovascular disease and mortality in people with chronic kidney disease (CKD). In individuals with CKD, reduced kidney function leads to decreased excretion of TMAO, which results in accumulation in the circulation. Higher circulating TMAO has been linked to higher intake of animal-based foods in omnivorous diets. Thus, plant-based diets have been suggested as an intervention to slow the progression of CKD and reduce cardiovascular risk, perhaps explained in part by reduced TMAO production. This article reviews the current evidence on plant-based diets as a dietary intervention to decrease gut-derived TMAO production in patients with CKD, while highlighting methodological issues that present challenges to advancing research and subsequent translation of this approach. Overall, we find that plant-based diets are promising for reducing gut-derived TMAO production in patients with CKD but that further interventional studies are warranted.