Modern Western diets, with higher contents of animal compared to fruits and vegetable products, have a greater content of acid precursors vs. base precursors, which results in a net acid load to the body. To prevent inexorable accumulation of acid in the body and progressively increasing degrees of metabolic acidosis, the body has multiple systems to buffer and titrate acid, including bone which contains large quantities of alkaline salts of calcium. Both in vitro and in vivo studies in animals and humans suggest that bone base helps neutralize part of the dietary net acid load. This raises the question of whether decades of eating a high acid diet might contribute to the loss of bone mass in osteoporosis. If this idea is true, then additional alkali ingestion in the form of net base-producing foods or alkalinizing salts could potentially prevent this acid-related loss of bone. Presently, data exists that support both the proponents as well as the opponents of this hypothesis. Recent literature reviews have tended to support either one side or the other. Assuming that the data cited by both sides is correct, we suggest a way to reconcile the discordant findings. This overview will first discuss dietary acids and bases and the idea of changes in acid balance with increasing age, then review the evidence for and against the usefulness of alkali therapy as a treatment for osteoporosis, and finally suggest a way of reconciling these two opposing points of view.

Background: Next-generation implantable and wearable KRTs may revolutionize the lives of patients undergoing dialysis by providing more frequent and/or prolonged therapy along with greater mobility compared with in-center hemodialysis. Medical device innovators would benefit from patient input to inform product design and development. Our objective was to determine key risk/benefit considerations for patients with kidney failure and test how these trade-offs could drive patient treatment choices. Methods: We developed a choice-based conjoint discrete choice instrument and surveyed 498 patients with kidney failure. The choice-based conjoint instrument consisted of nine attributes of risk and benefit pertinent across KRT modalities. Attributes were derived from literature reviews, patient/clinician interviews, and pilot testing. The risk attributes were serious infection, death within 5 years, permanent device failure, surgical requirements, and follow-up requirements. The benefit attributes were fewer diet restrictions, improved mobility, pill burden, and fatigue. We created a random, full-profile, balanced overlap design with 14 choice pairs plus five fixed tasks to test validity. We used a mixed-effects regression model with attribute levels as independent predictor variables and choice decisions as dependent variables. Results: All variables were significantly important to patient choice preferences, except follow-up requirements. For each 1% higher risk of death within 5 years, preference utility was lower by 2.22 (β=−2.22; 95% confidence interval [CI], −2.52 to −1.91), while for each 1% higher risk of serious infection, utility was lower by 1.38 (β=−1.46; 95% CI, −1.77 to −1.00) according to comparisons of the β coefficients. Patients were willing to trade a 1% infection risk and 0.5% risk of death to gain complete mobility and freedom from in-center hemodialysis (β=1.46; 95% CI, 1.27 to 1.64). Conclusions: Despite an aversion to even a 1% higher risk of death within 5 years, serious infection, and permanent device rejection, patients with kidney failure suggested that they would trade these risks for the benefit of complete mobility.

High dietary phosphorus intake (P-In) and high acid loads may adversely affect kidney function. In animal models, excessive phosphorus intake causes renal injury, which, in humans, is also inducible by chronic metabolic acidosis. We thus examined whether habitually high P-In and endogenous acid production during childhood and adolescence may be early indicators of incipient renal inflammatory processes later in adulthood. P-In and acid–base status were longitudinally and exclusively determined by biomarker-based assessment in 277 healthy children, utilizing phosphate and net acid excretion (NAE) measurements in 24 h urine samples repeatedly collected between the ages of 3 and 17 years. Standard deviation scores (by sex and age) were calculated for anthropometric data and for the urinary biomarkers available within age range 3–17 years. Multivariable linear regression was used to analyze the relations of phosphate excretion and NAE with the adulthood outcome circulating interleukin-18 (IL-18), a marker of inflammation and kidney dysfunction. After adjusting for growth- and adulthood-related covariates and pro-inflammatory biomarkers to rule out confounding by non-renal inflammatory processes, regression models revealed a significant positive relationship of long-term NAE (p = 0.01), but not of long-term phosphate excretion with adult serum IL-18. Similar significant positive regression results were obtained after replacing NAE with 24 h urinary ammonium excretion as the exposition variable. Our results suggest that even moderate elevations in renal ammonia production, as caused by habitually higher acid loading during growth, may affect the intrarenal pro-inflammatory system in the long-term, known to be boosted by acidosis-induced raised ammoniagenesis.