Muscle wasting and increased proteolysis is a major problem in chronic kidney disease (CKD). Exercise is potentially beneficial, but has been under-investigated in pre-dialysis CKD and could theoretically worsen acidosis through exercise-induced lactic acid generation. We therefore investigated effects of 6 months walking exercise with and without additional alkali therapy. 40 patients were recruited (23 male and 17 female, median age 58, range 20-83, mean eGFR±SEM 25.7±1.2ml/min/1.73m2). 20 undertook walking exercise at a Borg Rating of Perceived Exertion Rate (RPE) of 12-14 for at least 30 minutes, 5 times a week. The other 20 continued with normal physical activity (non-exercising controls). In addition to standard oral bicarbonate therapy (STD), 10 patients in each group were randomised to receive additional bicarbonate (XS). Blood and vastus lateralis muscle biopsies were drawn at baseline, one and six months. 18 exercisers (including 8 in XS group) and 14 controls (6 in XS group) completed the 6 month study. Exercise tolerance increased after 1 and 6 months in the exercisers, but not the controls, accompanied by a reduced acute lactate response in the XS, but not the STD exercising group. After 6 months of exercise, 9 intramuscular free amino acids showed striking depletion in the STD, but not XS bicarbonate group. This suggests an inhibition of active amino acid transporters, possibly the SNAT2 transporters that are inhibited by acidosis. Studies with cultured myotubes identified glucocorticoid as a possible mediator of acid s inhibitory effect on SNAT2. The preservation of amino acid concentrations in the XS exercising group was accompanied by strong suppression of ubiquitin E3-ligases MuRF-1 and MAFbx which activate proteolysis through the ubiquitin-proteasome pathway. However, other anabolic indicators (Protein Kinase B activation and suppression of the 14kDa actin fragment) were unaffected in the exercising XS group. Possibly because of this, overall suppression of myofibrillar proteolysis (3-methyl histidine excretion) and increased lean body mass (DEXA) were not observed in the exercising patients. As XS alkali had no effect in non-exercisers, it is concluded that alkali effects in the exercisers arose by countering exercise-induced acidosis. Sulphuric acid produced from the catabolism of sulphur-containing amino acids ingested in the diet is the main contributor to the daily titratable acid load and hence acidosis in CKD. In these patients the amount of sulphate excreted in urine over 24h varied widely between individuals. This directly correlated with 3-methyl histidine excretion suggesting that sulphate excretion may be a better clinical indicator of acidotic patients at long-term risk of cachexia than conventional measures such as venous bicarbonate. Studies with cultured myotubes confirmed that skeletal muscle is a source of sulphuric acid and showed that production of this acid is partly suppressed by L-Glutamine a potential novel way to control acidosis in CKD.

Master of Science / Biomedical Sciences / Gregory F. Grauer / Chronic kidney disease (CKD) is a potentially life-threatening disease that reportedly affects 10% of dogs and 30% of cats over the age of 15. There is no cure available for CKD, but medical management is available for patients with this disease. Research has focused on earlier detection of CKD with the goal of instituting medical management and monitoring as early in the disease course as possible. Symmetric dimethylarginine (SDMA) has recently emerged as a novel renal excretory biomarker that may aid in early detection of CKD in cats and dogs. SDMA is non-protein bound and is freely filtered by the glomerulus, is not secreted or reabsorbed, and has greater than 90% excretion by the kidneys, making it a potential target for measurement of glomerular filtration rate (GFR). Previous studies have demonstrated a close parallel between SDMA and serum creatinine (sCr), which is the currently favored serum biomarker for assessment of GFR. Research has also demonstrated a correlation between SDMA and GFR. Serum concentrations of SDMA increase above normal when GFR is decreased by 25-40%; much earlier than the 75% decrease in GFR typically required for sCr to increase above its reference interval. The studies reported here demonstrate a potential use for the SDMA:sCr ratio as a predictor of volume responsive azotemia. Furthermore, longitudinal assessment of older dogs and cats for early detection of CKD showed that SDMA was a more sensitive indicator of CKD than sCr. The evaluation of SDMA reported in this thesis presents a novel perspective on SDMA and its use clinically.

The incidence and mortality from cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) far exceeds that seen in the general population. Whilst a number of risk factors and associations have been identified in patients with CKD that may contribute to the increased risk of CVD, our understanding of the underlying pathophysiology remains poor. It has previously been reported that uraemic animals sustain larger myocardial infarcts and that this ‘reduced ischaemia tolerance’ may in part explain the excess mortality from CVD seen in CKD patients. The aim of this work was to establish an in vivo model of uraemic myocardial infarction in order to further explore the pathophysiology of uraemic CVD with particular focus on ameliorating myocardial ischaemia-reperfusion injury using ischaemic and pharmacological preconditioning. An increase in myocardial infarct size was demonstrated in the sub-total nephrectomy model of chronic uraemia, confirming previous reports in the literature. However, infarct size was not found to be increased in adenine diet induced renal failure. In addition, it was demonstrated for the first time, that the techniques of ischaemic preconditioning (IPC) and remote ischaemic preconditioning (RIPC) are both efficacious and not attenuated by chronic uraemia induced by sub-total nephrectomy or adenine diet (IPC only). Investigations were undertaken using an agent (a HIF stabiliser, FG4497) to induce pharmacological preconditioning in both animals with renal insufficiency and those without. These studies demonstrate that stabilisation of hypoxia inducible factor (HIF) may be a promising strategy to induce pharmacological preconditioning. It is hoped that this work may lay the foundations for future investigations to determine why sub-totally nephrectomised rats have larger infarcts whilst those with adenine induced renal failure, with a substantially greater degree of renal dysfunction, do not. Moreover, it is hoped that; by demonstrating that uraemia 3 does not prevent or attenuate the myocardial protection afforded by ischaemic preconditioning, the recruitment of patients with CKD will be encouraged to clinical trials of both ischaemic preconditioning and other therapies to limit myocardial infarction.

Cardiovascular disease is the leading cause of death in patients with underlying chronic kidney disease (CKD). Up to one third of patients presenting with an acute coronary syndrome have CKD stage 3-5. Outcomes following acute myocardial infarction in patients with underlying CKD remain poor. CKD patients are routinely excluded from clinical trials in novel cardioprotective strategies resulting in a paucity of prospective data on which to base guidelines for clinical practice. The aims of this work were to: • Establish and characterise two models of chronic uraemia in rodents: the subtotal nephrectomy model and the adenine diet model. • Determine the effects of underlying chronic uraemia on myocardial ischaemia tolerance. • Examine pharmacological cardioprotective strategies in the context of underlying uraemia using a PARP inhibitor • Investigate the cardioprotective effects of ischaemic conditioning in the context of uraemia. Ischaemic preconditioning and postconditioning protocols were used in both uraemic and non-uraemic animals in a model of acute myocardial infarction. • Preliminary work, using standard molecular biological techniques, was carried out in order to confirm the putative survival pathways responsible for the effect of preconditioning. • Investigate the effect of combining early and late remote ischaemic preconditioning to identify whether summation of these strategies could provide additional tissue protection in a model of acute kidney injury. The results demonstrate that both models develop a uraemic phenotype. Subtotal nephrectomy animals exhibit reduced ischaemia tolerance. PARP inhibition as a pharmacological post conditioning agent was shown to be ineffective at conferring tissue protection, whereas both ischaemic preconditioning and postconditioning were effective cytoprotective strategies in both non-uraemic and uraemic animals. Furthermore, additional benefit was seen when early and late remote preconditioning were summated in a rodent model of acute kidney injury. This work provides a basis for future clinical trials in cardioprotection in the context of underlying CKD.

archives@tulane.edu / Background Ankle brachial index (ABI) is a noninvasive measure of subclinical cardiovascular disease (CVD) and atherosclerosis of the lower extremities. Low and high levels of ABI are associated with cardiovascular mortality and vascular calcification in dialysis chronic kidney disease (CKD) patients. However, the association of the spectrum of vascular calcification with low and high ABI is not well studied in pre-dialysis CKD patients. The purpose of this study is to investigate the association of both low and high ABI with the risk of vascular calcification in CKD patients. Methods We recruited 243 patients with pre-dialysis CKD from the great New Orleans area between 2010 and 2012. Our study used a cross-sectional design with ABI and CAC measured at the same visit. Continuous ABI measurements were taken and further classified into four categories : <=0.9 (low ABI) >0.9-<1.0 (borderline), 1.0-<1.4 (normal), >=1.4 (high). Level of vascular calcification were considered as the outcome and calculated by agatston score. Three categories of CAC is defined as: CAC agaston score=0, 0-100, >100. Three cumulative logit models were applied to the data. The first is an unadjusted univariate model, the second adjusts for baseline demographics, and the third adjusts for baseline demographics and covariates that are associated with CAC. Logistic regression methods were used to calculate the odds ratio of having a higher CAC score for CKD patients. Results We found a significant association between ABI and vascular calcification. All three models returned consistently significant result (p=0.0005, 0.0005, 0.0037, respectively) for the association between ABI and CAC. In addition, low ABI (ABI≤0.9) is also associated with an increased risk of CAC and severe CAC (OR=6.183, 95%CI(1.085, 35.228)). High ABI (>1.4) is also associated with an increase in CAC and severe CAC (OR=5.064, 95%CI (1.696, 15.122)). Borderline ABI (0.9<ABI<1.0) is not associated with an increase in CAC or severe CAC (OR=2.704, 95% CI (0.702, 10.418). Conclusion Compared to normal ABI level, low and high ABIs are both significantly associated with an increased risk of coronary artery calcification and severe coronary artery calcification in CKD patients. / 1 / Shuo Bai

Bone disease and fractures are common in men and women with chronic kidney disease (CKD). The etiology of fractures in CKD is multi-factorial; identifying risk factors for fracture is important in CKD, so that patients who are at high risk can be treated before they fracture. The majority of studies have focused on risk factors associated with fracture in patients with stage 5 CKD on dialysis–there is a need for studies in pre-dialysis CKD. Three novel, non-radiological factors were assessed in 211 men and women with stage 3-5 CKD: cytokines osteoprotegerin (OPG) and receptor activator of nuclear factor kappa beta ligand (RANKL); tests of neuromuscular function including the timed up and go (TUG), 6 minute walk (6MW), and grip strength; and daily activity levels by accelerometry. Fractures were defined as self-reported low-trauma fractures since the age of 40 and/or prevalent vertebral fractures identified by morphometry. Logistic regression and receiver operating characteristic curves (ROC) were performed using STATA version 11.0. Those with fractures had elevated OPG compared to those without fractures (9.37±4.23 vs. 8.13±3.04 pmol/L, p=0.03), however, after adjusting for age OPG did not differ by fracture status. After adjusting for age, weight, and sex, impairments in both the TUG and 6MW tests were associated with fractures (TUG odds ratio (OR): 1.68, 95% confidence interval (CI): 1.40-2.02; 6MW OR: 0.53, 95% CI: 0.52-0.54). The diagnostic tests characteristics of the TUG and 6MW tests were excellent; both could discriminate fracture status (TUG AUROC: 0.90, 95% CI: 0.84-0.95; 6MW AUROC: 0.87, 95% CI: 0.84-0.95). Overall, subjects were primarily sedentary. After adjusting for stage of CKD, increased sedentary activity and decreased light intensity activity could discriminate fracture status (sedentary AUROC: 0.72, 95% CI: 0.56 to 0.87; light activity AUROC: 0.71, 95% CI: 0.55 to 0.87). In conclusion, non-radiological, novel factors including the TUG, the 6MW, and daily activity, but not OPG or RANKL were able to discriminate fracture status in men and women with stage 3-5 CKD.

Bone disease and fractures are common in men and women with chronic kidney disease (CKD). The etiology of fractures in CKD is multi-factorial; identifying risk factors for fracture is important in CKD, so that patients who are at high risk can be treated before they fracture. The majority of studies have focused on risk factors associated with fracture in patients with stage 5 CKD on dialysis–there is a need for studies in pre-dialysis CKD. Three novel, non-radiological factors were assessed in 211 men and women with stage 3-5 CKD: cytokines osteoprotegerin (OPG) and receptor activator of nuclear factor kappa beta ligand (RANKL); tests of neuromuscular function including the timed up and go (TUG), 6 minute walk (6MW), and grip strength; and daily activity levels by accelerometry. Fractures were defined as self-reported low-trauma fractures since the age of 40 and/or prevalent vertebral fractures identified by morphometry. Logistic regression and receiver operating characteristic curves (ROC) were performed using STATA version 11.0. Those with fractures had elevated OPG compared to those without fractures (9.37±4.23 vs. 8.13±3.04 pmol/L, p=0.03), however, after adjusting for age OPG did not differ by fracture status. After adjusting for age, weight, and sex, impairments in both the TUG and 6MW tests were associated with fractures (TUG odds ratio (OR): 1.68, 95% confidence interval (CI): 1.40-2.02; 6MW OR: 0.53, 95% CI: 0.52-0.54). The diagnostic tests characteristics of the TUG and 6MW tests were excellent; both could discriminate fracture status (TUG AUROC: 0.90, 95% CI: 0.84-0.95; 6MW AUROC: 0.87, 95% CI: 0.84-0.95). Overall, subjects were primarily sedentary. After adjusting for stage of CKD, increased sedentary activity and decreased light intensity activity could discriminate fracture status (sedentary AUROC: 0.72, 95% CI: 0.56 to 0.87; light activity AUROC: 0.71, 95% CI: 0.55 to 0.87). In conclusion, non-radiological, novel factors including the TUG, the 6MW, and daily activity, but not OPG or RANKL were able to discriminate fracture status in men and women with stage 3-5 CKD.

Due to high frequency and occurrence of chronic kidney diseases in Taiwan, as well as the low public awareness, this research aims to explore the knowledge construction process of Hemodialysis in health broadcasting programs from a health communication point of view. This research intended to answer the following questions: 1) What are health radio program audience types? 2) How does the knowledge on hemodialysis differ among audiences? 3) What is the knowledge construction process among audience in regards to hemodialysis? Data were collected by ten episodes of the Kaohsiung Police Ration Station¡¦s ¡§Medical Network¡¨ program for a six month period (January ~ June 2011). This research has utilized content analysis method on the audience type, quantitative description on questions identified by the audience and qualitative methods to summarize and interpret the audience¡¦s knowledge construction process on hemodialysis. The results showed that the main audiences for health broadcast programs are mostly male, age 31 to 50 years, holding profession as drivers, service personnel and potential patients. Among them, the potential patients and their family members most often times ask diagnostic questions, falling into the compelled group in seek of knowledge. Those who have not been diagnosed with the disease often times bring up knowledge confirmation questions, belonging to the proactive knowledge chaser group. These two groups also demonstrated different hemodialysis knowledge construction processes. While the radio program host plays the role of knowledge enhancer to the diagnostic-need group (potential patients), the role transfers to a knowledge transformation model for the knowledge confirmation group (non-patients). Participating physicians follow the treatment process of ¡V examination, diagnosis and treatment to deliver information. The research process shall provide broadcasters or other media professionals a best practice on how the audience absorbs information - to study the distribution and motives of the audience and to deliver the knowledge of health and illnesses.

Meeting the health care needs of people with chronic conditions presents one of the greatest challenges for 21st century health care system renewal. Appropriate redesign of health care delivery with this complex patient population in mind requires information from many sources. Although much is known about the patient experience of chronic illness much less is understood about how patients navigate their health care delivery context. The purpose of this qualitative study was to examine the point of view of patients dealing with multi-morbidity. These people have a unique understanding of how health care delivery links across time, place, and settings because of the care they require for their multiple chronic conditions. An interpretive descriptive design was used to examine patient navigation from the perspective of 20 adult patients with chronic kidney disease, and co-existing diagnoses of diabetes mellitus and/or cardiovascular disease. The findings generated from iterative, constant comparative analysis add important patient perspectives about health care system navigation. From the consumer perspective health care navigation is challenging, requiring (a) ongoing discovery about the complex social structures that make up the health care system, and (b) learning how to strategically use this knowledge to manage the health care system. The findings highlight the disjunctures and misalignments in the health care delivery system, the cumulative health care-related burden of multiple chronic conditions for consumers, and consumer concerns about subtle inequities in the health care system. As health care renewal efforts gain momentum new knowledge from the perspective of consumers, such as that captured in this research, is important. The consumer perspective provides a valuable opportunity for stakeholders in health care policy- and decision-making to contextualize and make greater sense of the information used in making decisions about health care service delivery for vulnerable populations, like patients with multiple chronic conditions.

Chronic kidney disease (CKD) is a worldwide health problem with rising incidence and high cardiovascular mortality. CKD compromises cardiovascular function, in part, characterized by vascular calcification (VC), elevated pulse wave velocity (PWV) and pulse pressure (PP). Through manipulation of dietary adenine, we produced a model characterized by graded severity of CKD, VC and hyperphosphatemia. To our knowledge, we are the first to explore the relationship between aortic calcium content and changes in circulatory function in rodents with CKD. Fourteen-week old Sprague-Dawley rats received a diet containing an adenine concentration (0.25-0.75%) plus high-normal dietary phosphate (1%), for up to 10 weeks. Circulatory changes were determined by arterial radiotelemetry (n=6) and by assessment of aortic pulse wave velocity (PWV, n=32). VC was assessed using the calcium-O-cresophthalein-complexone assay. At sacrifice, kidney function (creatinine (µmol/L)) was worst in the group with VC (251.3±60.2 µmol/L), compared to non-calcifying CKD (200.3±68.8 µmol/L) or control (50.0±16.2 µmol/L). PWV (cm/s) adjusted for blood pressure (BP) was markedly elevated in animals with VC (3.23±0.33 log(cm/s)) versus non-calcifying CKD (2.85± 0.12 log(cm/s)) or control (2.96±0.08 log(cm/s)). Arterial pressure radiotelemetry revealed that there was an increase in pulse pressure (38±4.7 mmHg to 58 ±15.2 mmHg) during the development of VC. Systolic pressure remained relatively stable throughout (129±8.7 mmHg), diastolic pressure fell during weeks 9 and 10 of the study (91±6.0 mmHg down to 74±9.1 mmHg), a fall that almost fully accounted for the changes in pulse pressure. The calcifying CKD animals also exhibited left ventricular hypertrophy (LVH) compared to CKD or control animals (2.32±0.3 vs 2.03±0.2, 1.80±0.1 g/kg respectively). Manipulating dietary adenine produces a graded severity of CKD with calcification which impact circulatory changes (PP and PWV). These altered circulatory functions are likely to be key factors in the enhanced LVH. This model appears to be a useful for the study of CKD-associated VC. / Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2009-12-16 15:10:49.384