Androgen Deprivation Therapy Differentially Impacts Bone and Muscle in the Short Term in Physically Active Men With Prostate Cancer.

Androgen deprivation therapy (ADT) is a cornerstone of advanced prostate cancer (PCa) therapy. Its use is associated with a loss of bone mineral density (BMD) and a greater risk of falls and osteoporotic fractures. In this prospective cohort study, we examined the impact of ADT on muscle and bone strength in men initiating ADT for PCa.

Dietary effects on urinary physicochemistry in Navy bottlenose dolphins () for the prevention of ammonium urate kidney stones.

Bottlenose dolphins are susceptible to developing ammonium urate (NHU) kidney stones. The current study was designed to test the hypothesis that diet influences the urinary physicochemistry risk factors associated with nephrolithiasis in dolphins. A comprehensive nutrient analysis was performed revealing that the baseline diet (BD) commonly fed to dolphins under professional care had a greater purine content and a more negative dietary cation-anion difference (DCAD) when compared with a model diet consumed by free-ranging dolphins.

Spot urinary citrate-to-creatinine ratio is a marker for acid-base status in chronic kidney disease.

Due to multiple compensating mechanisms, the serum bicarbonate concentration is a relatively insensitive marker of acid-base status; especially in chronic kidney disease (CKD). This is a major drawback that impairs the ability to diagnose acid excess or monitor alkali therapy. We postulated that it is more logical to measure the compensatory defense mechanism(s) rather than the defended parameter, which remains normal if the compensation is successful.

Rising occurrence of hypocitraturia and hyperoxaluria associated with increasing prevalence of stone disease in calcium kidney stone formers.

Objective: To evaluate metabolic risk factors in calcium kidney stone formers from two different decades, comparing changes in metabolic profiles over time.

Methods: A retrospective analysis was performed of calcium kidney stone formers who underwent metabolic evaluation of urolithiasis with 24-hour urine collections at a single institution. There were 309 patients evaluated from 1988 to 1994 (Group A), and 229 patients from 2007 to 2010 (Group B).

Increased production and reduced urinary buffering of acid in uric acid stone formers is ameliorated by pioglitazone.

Idiopathic uric acid nephrolithiasis is characterized by an overly acidic urine pH caused by the combination of increased acid production and inadequate buffering of urinary protons by ammonia. A large proportion of uric acid stone formers exhibit features of the metabolic syndrome. We previously demonstrated that thiazolidinediones improved the urinary biochemical profile in an animal model of the metabolic syndrome.

Net Acid Excretion and Urinary Organic Anions in Idiopathic Uric Acid Nephrolithiasis.

Background And Objectives: Idiopathic uric acid nephrolithiasis, which is closely associated with obesity and the metabolic syndrome, is increasing in prevalence. Unduly acidic urine pH, the quintessential pathophysiologic feature of this disease, is in part explained by inadequate excretion of the principal urinary buffer ammonium. The role of net acid excretion in the pathogenesis of uric acid nephrolithiasis is incompletely understood.

Impact of Potassium Citrate vs Citric Acid on Urinary Stone Risk in Calcium Phosphate Stone Formers.

Purpose: To our knowledge no medication has been shown to be effective for preventing recurrent calcium phosphate urinary stones. Potassium citrate may protect against calcium phosphate stones by enhancing urine citrate excretion and lowering urine calcium but it raises urine pH, which increases calcium phosphate saturation and may negate the beneficial effects. Citric acid can potentially raise urine citrate but not pH and, thus, it may be a useful countermeasure against calcium phosphate stones.

Comparison of potential dietary and urinary risk factors for ammonium urate nephrolithiasis in two bottlenose dolphin ( Tursiops truncatus) populations.

Dietary and urinary risk factors have been implicated in conditions favoring ammonium urate nephrolithiasis in managed dolphins compared with free-ranging dolphins. In this study, urine samples were collected from 16 dolphins (8 cases, 8 controls) from the U.S.

The Differential Effects of Human Immunodeficiency Virus and Hepatitis C Virus on Bone Microarchitecture and Fracture Risk.

Background: Human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected individuals have a significantly greater osteoporotic fracture risk than HIV-monoinfected persons, despite the fact that HIV/HCV coinfection has not been associated with lower bone mineral density (BMD) than HIV or HCV alone. To evaluate if changes in bone microarchitecture, measured by trabecular bone score (TBS), could explain these differences, we performed a prospective, cross-sectional cohort study of virologically suppressed HIV-infected subjects, untreated HCV-infected subjects, HIV/HCV-coinfected subjects, and uninfected controls.

Methods: We enrolled 532 male subjects: 57 HIV/HCV coinfected, 174 HIV infected, 123 HCV infected, and 178 controls.

Temporal Changes in Kidney Stone Composition and in Risk Factors Predisposing to Stone Formation.

Purpose: The prevalence of kidney stones has increased globally in recent decades. However, studies investigating the association between temporal changes in the risk of stone formation and stone types are scarce. We investigated temporal changes in stone composition, and demographic, serum and urinary parameters of kidney stone formers from 1980 to 2015.

Relationship between Urinary Calcium and Bone Mineral Density in Patients with Calcium Nephrolithiasis.

Purpose: Calcium nephrolithiasis is associated with an increased risk of osteoporosis and fracture. Hypercalciuria has been assumed to be pathogenic for bone loss in kidney stone formers, although this association was shown in small cross-sectional studies. We explored the association of urine calcium with bone mineral density in kidney stone formers.

The kidney stone and increased water intake trial in steel workers: results from a pilot study.

Preventing dehydration in subjects at risk may provide a means of primary prevention of kidney stones. The purpose of this pilot study was to assess the hydration status of an at-risk group of steel plant workers based on end-of-shift ('post-shift') spot urine osmolality and 24-h urinary stone risk parameters. 100 volunteers were recruited from Gerdau Midlothian steel mill in Texas on 11/14/14 and 12/5/14.

Assessment of Urinary Inhibitor or Promoter Activity in Uric Acid Nephrolithiasis.

Purpose: We assessed decreased inhibitor activity or increased promoter activity in the urine of idiopathic uric acid stone formers compared to nonstone formers independent of urinary pH.

Materials And Methods: A total of 30 idiopathic uric acid stone formers, and 9 obese and 12 lean nonstone formers collected 24-hour urine while on a metabolic diet. Three urine aliquots per subject were used to assess spontaneous nucleation (de novo crystal formation), crystal growth using a 0.

The effects of bariatric surgery on bone and nephrolithiasis.

The impact of bariatric surgery on cardiovascular and diabetic complications associated with an improvement in survival has overshadowed the adverse skeletal health and development of kidney stone disease in this population. All longitudinal based studies in the literature reporting the incidence of bone fractures or kidney stones following bariatric surgery were reviewed. Moreover, all publications over the past decade which assessed changes in bone mineral density and bone quality, or explored underlying pathophysiologic mechanisms of bone and kidney stone disease were carefully reviewed.

Relationship between serum uric Acid and bone mineral density in the general population and in rats with experimental hyperuricemia.

Unlabelled: Higher serum uric acid concentrations have been associated with higher bone mineral density (BMD) in observational studies of older men and perimenopausal or postmenopausal women, prompting speculation of a potential protective effect of uric acid on bone. Whether this relationship is present in the general population has not been examined and there is no data to support causality. We conducted a cross-sectional analysis of a probability sample of the U.

Animal protein and the risk of kidney stones: a comparative metabolic study of animal protein sources.

Purpose: We compared the effect of 3 animal protein sources on urinary stone risk.

Materials And Methods: A total of 15 healthy subjects completed a 3-phase randomized, crossover metabolic study. During each 1-week phase subjects consumed a standard metabolic diet containing beef, chicken or fish.

Pathophysiological and physicochemical basis of ammonium urate stone formation in dolphins.

Purpose: Nephrolithiasis is increasingly reported in bottle-nosed dolphins. All cases to date have been ammonium urate nephrolithiasis.

Materials And Methods: A case-control study was performed in dolphins with and without evidence of nephrolithiasis to identify biomarkers and risk factors associated with stone formation in a managed population.

Defining variation in urinary oxalate in hyperoxaluric stone formers.

Background And Purpose: The development of effective preventive therapy for renal calculi in patients with secondary hyperoxaluria (2°HO) relies on establishing the pattern of normal variation in urinary oxalate (uOx) and attempting to reduce it. Therefore, we evaluated uOx at baseline and at subsequent time points in stone formers with 2°HO.

Methods: We reviewed the charts of 201 recurrent stone formers with 2°HO (uOx ≥ 40 mg/day).

The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers.

Many biological functions follow circadian rhythms driven by internal and external cues that synchronize and coordinate organ physiology to diurnal changes in the environment and behavior. Urinary acid-base parameters follow diurnal patterns and it is thought these changes are due to periodic surges in gastric acid secretion. Abnormal urine pH is a risk factor for specific types of nephrolithiasis and uric acid stones result from excessively low urine pH.

Metabolic syndrome and the risk of calcium stones.

Background: The metabolic syndrome (MS) is associated with increased prevalence of kidney stones, yet the specific stone type remains largely unknown. This study was conducted to assess whether risk factors associated with calcium nephrolithiasis increase with individual characteristics of the MS.

Methods: A retrospective analysis was performed in 109 non-stone-forming subjects and 128 recurrent calcium stone formers from Dallas, Texas.

Defining hypercalciuria in nephrolithiasis.

The classic definition of hypercalciuria, an upper normal limit of 200  mg/day, is based on a constant diet restricted in calcium, sodium, and animal protein; however, random diet data challenge this. Here our retrospective study determined the validity of the classic definition of hypercalciuria by comparing data from 39 publications analyzing urinary calcium excretion on a constant restricted diet and testing whether hypercalciuria could be defined when extraneous dietary influences were controlled. These papers encompassed 300 non-stone-forming patients, 208 patients with absorptive hypercalciuria type I (presumed due to high intestinal calcium absorption), and 234 stone formers without absorptive hypercalciuria; all evaluated on a constant restricted diet.

Comparison of semi-empirical and computer derived methods for estimating urinary saturation of calcium oxalate.

Purpose: Estimating calcium oxalate saturation in human urine is critical for nephrolithiasis clinical research and practice. The Joint Expert Speciation System (Mayhem Unit Trust and Council for Scientific and Industrial Research, Pretoria, South Africa) computer program has questioned the validity of the widely used EQUIL 2 program in estimating calcium oxalate urinary saturation. To attempt resolution the computer model based supersaturation index (by the Joint Expert Speciation System) and the relative saturation ratio (by EQUIL 2) were compared with the experimentally derived activity product ratio, that is the ratio of activity products before and after incubating urine with synthetic calcium oxalate.