The top 10 things nephrologists wish every primary care physician knew

Can SGLT2 inhibitors answer unmet therapeutic needs in chronic kidney disease?

Chronic kidney disease (CKD) is a global health problem, affecting more than 850 million people worldwide. The number of patients receiving renal replacement therapy (dialysis or renal transplantation) has increased over the years, and it has been estimated that the number of people receiving renal replacement therapy will more than double from 2.618 million in 2010 to 5.439 million in 2030, with wide differences among countries. The main focus of CKD treatment has now become preserving renal function rather than replacing it. This is possible, at least to some extent, through the optimal use of multifactorial therapy aimed at preventing end-stage kidney disease and cardiovascular events. Sodium/glucose cotransporter 2 inhibitors (SGLT2i) reduce glomerular hypertension and albuminuria with beneficial effects on progression of renal damage in both diabetic and non-diabetic CKD. SGLT2 inhibitors also show great benefits in cardiovascular protection, irrespective of diabetes. Therefore, the use of these drugs will likely be extended to the whole CKD population as a new standard of care.

Prognostic significance of dipstick proteinuria in heart failure with preserved ejection fraction: insight from the PURSUIT-HFpEF registry

OBJECTIVE

The semiquantitative urine dipstick test is a simple and convenient method that is available in the smallest community-based healthcare clinics. We sought to clarify the prognostic significance of dipstick proteinuria in patients with heart failure (HF) with preserved ejection fraction (HFpEF).

DESIGN

A Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with preserved Ejection Fraction (PURSUIT-HFpEF) registry.

PARTICIPANTS AND SETTING

We assessed 851 discharged-alive patients in the PURSUIT-HFpEF registry who were initially hospitalised due to an acute decompensated HFpEF (EF≥50%) and elevated N-terminal-pro-brain natriuretic peptide (≥400 ng/L) at Osaka University Hospital and other 30 affiliated hospitals in the Kansai region of Japan. Patients received a urine dipstick test, and were divided into two groups according to the absence or presence of proteinuria. A trace or more of dipstick proteinuria was defined as the presence of proteinuria.

MAIN OUTCOME MEASURES

A composite of cardiac death or HF rehospitalisation.

RESULTS

Median age was 83 years and 473 patients (55.6%) were female. Five hundred and two patients (59%) were proteinuria (-) and 349 patients (41%) were proteinuria (+). The composite endpoint and HF rehospitalisation occurred more often in proteinuria (+) individuals than proteinuria (-) individuals (log-rank p=0.006 and p=0.007, respectively); but cardiac death did not (log-rank p=0.139). Multivariable Cox regression analysis showed that the presence of proteinuria was associated with the composite endpoint (HR: 1.47, 95% CI 1.07 to 2.01, p=0.016), and HF rehospitalisation (HR: 1.48, 95% CI 1.07 to 2.05, p=0.020), but not with cardiac death (HR: 1.52, 95% CI 0.83 to 2.76, p=0.172).

CONCLUSIONS

Dipstick proteinuria may be a prognostic marker in patients with HFpEF. Evaluation of proteinuria by a urine dipstick test may be a simple but useful method for risk stratification in HFpEF.

UMIN-CTR ID

UMIN000021831.

Hypotensive and Antihypertensive Properties and Safety for Use of Annona muricata and Persea americana and Their Combination Products

Introduction

In the management of hypertension (a cardiovascular disease and the leading metabolic risk factor in noncommunicable diseases) with herbal medicines, efficacy and safety are of uttermost concern. This study sought to establish hypotensive, antihypertensive, drug interaction, and safety for use of the aqueous leaf extracts of Annona muricata (AME), Persea americana (PAE), or their combination products (CAPE). Methodology. Systolic and diastolic blood pressure (SBP and DBP), mean arterial blood pressure (MAP), and heart rate (HR) were measured in normotensive Sprague-Dawley rats treated with 50-150 mg/kg of AME, PAE, or CAPE to establish a hypotensive effect. "Combination index" was calculated to establish interaction between AME and PAE. The antihypertensive effect of CAPE was established by measuring SBP, DBP, MAP, and HR in ethanol-sucrose- and epinephrine-induced hypertension. Full blood count, liver and kidney function tests, and urinalysis were determined in ethanol/sucrose-induced hypertension to establish safety for use.

Results

AME, PAE, and CAPE significantly (p ≤ 0.001) decreased BP in both normotensive and hypertensive animals. Effects of CAPE 1, CAPE 2, and CAPE 3 were synergistic (combination indices of 0.65 ± 0.07, 0.76 ± 0.09, and 0.87 ± 0.07, respectively). There was a significant decrease (p ≤ 0.01 - 0.001) in SBP and MAP with 100 mg/kg CAPE 1 and 75 mg/kg CAPE 2 treatment in hypertension as well as with nifedipine (p ≤ 0.001) treatment. Epinephrine-induced hypertension in anesthetized cats was significantly and dose-dependently inhibited (p < 0.05 - 0.001) by 25-100 mg/ml CAPE 1 and 37.5-75 mg/ml CAPE 2. CAPE administration had no deleterious effect (p > 0.05) on full blood count, liver and kidney function, and urine composition in hypertensive rats.

Conclusion

The aqueous leaf extracts of Annona muricata, Persea americana, and their combination products possess antihypertensive properties, with combination products showing synergism and safety with use.

Knowledge and awareness of nonpharmacist salespersons regarding over-the-counter drug use in patients with chronic kidney disease in Japan

Introduction

Patients with chronic kidney disease (CKD) depend on advice from healthcare professionals to avoid using unsuitable over-the-counter (OTC) drugs. Recently, qualified, registered nonpharmacist salespersons became licensed to sell OTC drugs in Japan. However, registered salespersons’ knowledge and awareness of precautions regarding unsuitable OTC drugs for use in patients with CKD are unclear.

Objectives

This study aimed to clarify the awareness, knowledge, and implementation of precautions by registered salespersons regarding OTC drugs used by patients with CKD. Additionally, we evaluated the change of registered salespersons’ knowledge and awareness of this topic generated by a pharmacist intervention.

Methods

A questionnaire survey and pharmacist intervention were applied to 175 registered salespersons. The intervention comprised a 50-minute lecture imparted by a pharmacist who was trained in nephrology. The knowledge, awareness, and implementation of precautions by participants with respect to nonsteroidal anti-inflammatory drugs (NSAIDs) and antacids were evaluated before and after the intervention.

Results

Approximately half of the registered salespersons reported previous experience with selling OTC drugs that were inappropriate for patients with CKD (NSAIDs, 48.0%; antacids, 39.7%). Few participants recognized the need to check renal function when selling those drugs to such patients (NSAIDs, 25.7%; antacids, 47.5%). The registered salespersons’ awareness and knowledge were significantly higher after the intervention than before it.

Conclusion

The results indicate that before the intervention, the registered salespersons had low levels of awareness and knowledge regarding OTC drug use in patients with CKD despite having prior experience selling unsuitable OTC drugs. However, the pharmacist intervention improved the registered salespersons’ awareness and knowledge. The educational program for registered salespersons might be necessary to prevent inappropriate OTC drug use by patients with CKD.

Agreement between cystatin-C and creatinine based eGFR estimates after a 12-month exercise intervention in patients with chronic kidney disease

BACKGROUND

Estimation of GFR (eGFR) using formulae based on serum creatinine concentrations are commonly used to assess kidney function. Physical exercise can increase creatinine turnover and lean mass; therefore, this method may not be suitable for use in exercising individuals. Cystatin-C based eGFR formulae may be a more accurate measure of kidney function when examining the impact of exercise on kidney function. The aim of this study was to assess the agreement of four creatinine and cystatin-C based estimates of GFR before and after a 12-month exercise intervention.

METHODS

One hundred forty-two participants with stage 3-4 chronic kidney disease (CKD) (eGFR 25-60 mL/min/1.73 m2) were included. Subjects were randomised to either a Control group (standard nephrological care [n = 68]) or a Lifestyle Intervention group (12 months of primarily aerobic based exercise training [n = 74]). Four eGFR formulae were compared at baseline and after 12 months: 1) MDRDcr, 2) CKD-EPIcr, 3) CKD-EPIcys and 4) CKD-EPIcr-cys.

RESULTS

Control participants were aged 63.5[9.4] years, 60.3% were male, 42.2% had diabetes, and had an eGFR of 40.5 ± 8.9 ml/min/1.73m2. Lifestyle Intervention participants were aged 60.5[14.2] years, 59.5% were male, 43.8% had diabetes, and had an eGFR of 38.9 ± 8.5 ml/min/1.73m2. There were no significant baseline differences between the two groups. Lean mass (r = 0.319, p < 0.01) and grip strength (r = 0.391, p < 0.001) were associated with serum creatinine at baseline. However, there were no significant correlations between cystatin-C and the same measures. The Lifestyle Intervention resulted in significant improvements in exercise capacity (+ 1.9 ± 1.8 METs, p < 0.001). There were no changes in lean mass in both Control and Lifestyle Intervention groups during the 12 months. CKD-EPIcys was considerably lower in both groups at both baseline and 12 months than CKD-EPIcr (Control = - 10.5 ± 9.1 and - 13.1 ± 11.8, and Lifestyle Intervention = - 7.9 ± 8.6 and - 8.4 ± 12.3 ml/min/1.73 m2), CKD-EPIcr-cys (Control = - 3.6 ± 3.7 and - 4.5 ± 4.5, and Lifestyle Intervention = - 3.6 ± 3.7 and - 2.5 ± 5.5 ml/min/1.73 m2) and MDRDcr (Control = - 9.3 ± 8.4 and - 12.0 ± 10.7, Lifestyle Intervention = - 6.4 ± 8.4 and - 6.9 ± 11.2 ml/min/1.73 m2).

CONCLUSIONS

In CKD patients participating in a primarily aerobic based exercise training, without improvements in lean mass, cystatin-C and creatinine based eGFR provided similar estimates of kidney function at both baseline and after 12 months of exercise training.

TRIAL REGISTRATION

The trial was registered at www.anzctr.org.au (Registration Number ANZCTR12608000337370) on the 17/07/2008 (retrospectively registered).

Quantification of renal function following stereotactic body radiotherapy for pancreatic cancer: secondary dosimetric analysis of a prospective clinical trial

BACKGROUND

This is the first known study examining renal function following stereotactic body radiotherapy (SBRT) for pancreatic head adenocarcinoma.

METHODS

Thirty-eight borderline-resectable/unresectable patients, part of an ongoing prospective trial, underwent 3 cycles of gemcitabine/5-fluorouracil followed by SBRT (5 daily fractions of 5/6/7/8 Gy) and concurrent nelfinavir. Thereafter, in resectable cases, surgery was performed within 4-8 weeks. The last available pre-SBRT creatinine was recorded, along with the highest post-SBRT value. Glomerular filtration rate (GFR) was calculated by the commonly-utilized Modification of Diet in Renal Disease formula. GFR decline was defined as the post-SBRT nadir GFR minus the pre-SBRT GFR. Correlations with the V5-V30, and mean/maximum kidney doses was performed. Statistics included Pearson correlation, Mann-Whitney, and Fisher's exact tests.

RESULTS

The median total kidney volume was 355 cm³. Median dosimetric values were as follows: V5 (209 cm³), V10 (103 cm³), V15 (9 cm³), V20 (0 cm³), V25 (0 cm³); and mean (6.7 Gy) & maximum kidney dose (18.3 Gy). Median GFR change was -23 (range, -105 to 25) mL/min/1.73 cm². Of all dosimetric parameters, only V5 was significantly associated with changes in GFR (Pearson r = -0.40, p = 0.012). In patients with V5 < 210 cm³, median GFR change was -11.8 mL/min/1.73 cm², as compared with -37.1 mL/min/1.73 cm² change in those with V5 ≥ 210 cm³ (p = 0.02). A GFR change < -23 mL/min/1.73 cm² was observed in 6/20 (30%) patients with V5 < 210 cm³, versus 15/18 (83%) of those with V5 ≥ 210 cm³. Patients with V5 ≥ 210 cm³ were over ten times as likely to have GFR change < -23 mL/min/1.73 cm² (p = 0.003). Using linear regression, GFR change ≈ -0.1748 × V5(cm³) + 8.63.

CONCLUSIONS

In the first known analysis of renal function after pancreatic SBRT, evaluating patients on a prospective study, V5 ≥ 210 cm³ was associated with a post-SBRT GFR decline of >23 mL/min/1.73 cm². If V5 is kept <210 cm³, median GFR decline was only 11.8 mL/min/1.73 cm². Further validation is needed to ascertain definite dose-volume parameters and examine late renal decline.

Establishment of a integrative multi-omics expression database CKDdb in the context of chronic kidney disease (CKD)

Complex human traits such as chronic kidney disease (CKD) are a major health and financial burden in modern societies. Currently, the description of the CKD onset and progression at the molecular level is still not fully understood. Meanwhile, the prolific use of high-throughput omic technologies in disease biomarker discovery studies yielded a vast amount of disjointed data that cannot be easily collated. Therefore, we aimed to develop a molecule-centric database featuring CKD-related experiments from available literature publications. We established the Chronic Kidney Disease database CKDdb, an integrated and clustered information resource that covers multi-omic studies (microRNAs, genomics, peptidomics, proteomics and metabolomics) of CKD and related disorders by performing literature data mining and manual curation. The CKDdb database contains differential expression data from 49395 molecule entries (redundant), of which 16885 are unique molecules (non-redundant) from 377 manually curated studies of 230 publications. This database was intentionally built to allow disease pathway analysis through a systems approach in order to yield biological meaning by integrating all existing information and therefore has the potential to unravel and gain an in-depth understanding of the key molecular events that modulate CKD pathogenesis.

Evaluation of Renal-Hepatic Functional Indices and Blood Pressure Based on the Progress of Time in a Rat Model of Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is defined as either kidney damage or a decline in renal function as determined by a decreased glomerular filtration rate (GFR) for three months or longer. CKD is an important risk factor for mortality.

OBJECTIVES

The aim of this study was to evaluate the effects of CKD on renal-hepatic functional indices and blood pressure in 5/6 nephrectomized (5/6 Nx) rats over the course of nine months.

MATERIALS AND METHODS

Male Wistar rats were subjected to either 5/6 Nx or sham operations (n = 8). Members of the sham group underwent the same procedure without surgical reduction of the kidney mass. For all animals, body weight (BW), serum creatinine (Cr), blood urea nitrogen (BUN), alanine transaminase (ALT), and aspartate transaminase (AST) levels were measured before and after surgery. After two-, three-, six-, and nine-month intervals, blood was collected to assay renal and hepatic functional indices. Tail-cuff blood pressure was recorded in each month after surgery.

RESULTS

BW was lower for the 5/6 Nx group rats after the operations compared with the BW of those in the sham operation group. Furthermore, the 5/6 Nx group showed elevations in blood pressure, Cr, BUN, ALT, and AST levels compared with the sham group over the course of time.

CONCLUSIONS

In summary, CKD induced by the 5/6 Nx model caused hypertension and increased serum levels of Cr, BUN, ALT, and AST. These changes are augmented by the progress of time.

Blood disorders typically associated with renal transplantation

Renal transplantation has become one of the most common surgical procedures performed to replace a diseased kidney with a healthy kidney from a donor. It can help patients with kidney failure live decades longer. However, renal transplantation also faces a risk of developing various blood disorders. The blood disorders typically associated with renal transplantation can be divided into two main categories: (1) Common disorders including post-transplant anemia (PTA), post-transplant lymphoproliferative disorder (PTLD), post-transplant erythrocytosis (PTE), and post-transplant cytopenias (PTC, leukopenia/neutropenia, thrombocytopenia, and pancytopenia); and (2) Uncommon but serious disorders including hemophagocytic syndrome (HPS), thrombotic microangiopathy (TMA), therapy-related myelodysplasia (t-MDS), and therapy-related acute myeloid leukemia (t-AML). Although many etiological factors involve the development of post-transplant blood disorders, immunosuppressive agents, and viral infections could be the two major contributors to most blood disorders and cause hematological abnormalities and immunodeficiency by suppressing hematopoietic function of bone marrow. Hematological abnormalities and immunodeficiency will result in severe clinical outcomes in renal transplant recipients. Understanding how blood disorders develop will help cure these life-threatening complications. A potential therapeutic strategy against post-transplant blood disorders should focus on tapering immunosuppression or replacing myelotoxic immunosuppressive drugs with lower toxic alternatives, recognizing and treating promptly the etiological virus, bacteria, or protozoan, restoring both hematopoietic function of bone marrow and normal blood counts, and improving kidney graft survival.

Potential drug-drug interactions in prescriptions to patients over 45 years of age in primary care, southern Brazil

BACKGROUND

Few cross-sectional studies involving adults and elderly patients with major DDIs have been conducted in the primary care setting. The study aimed to investigate the prevalence of potential drug-drug interactions (DDIs) in patients treated in primary care.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional study involving patients aged 45 years or older was conducted at 25 Basic Health Units in the city of Maringá (southern Brazil) from May to December 2010. The data were collected from prescriptions at the pharmacy of the health unit at the time of the delivery of medication to the patient. After delivery, the researcher checked the electronic medical records of the patient. A total of 827 patients were investigated (mean age: 64.1; mean number of medications: 4.4). DDIs were identified in the Micromedex® database. The prevalence of potential DDIs and major DDIs was 63.0% and 12.1%, respectively. In both the univariate and multivariate analyses, the number of drugs prescribed was significantly associated with potential DDIs, with an increasing risk from three to five drugs (OR = 4.74; 95% CI: 2.90-7.73) to six or more drugs (OR = 23.03; 95% CI: 10.42-50.91). Forty drugs accounted for 122 pairs of major DDIs, the most frequent of which involved simvastatin (23.8%), captopril/enalapril (16.4%) and fluoxetine (16.4%).

CONCLUSIONS/SIGNIFICANCE

This is the first large-scale study on primary care carried out in Latin America. Based on the findings, the estimated prevalence of potential DDIs was high, whereas clinically significant DDIs occurred in a smaller proportion. Exposing patients to a greater number of prescription drugs, especially three or more, proved to be a significant predictor of DDIs. Prescribers should be more aware of potential DDIs. Future studies should assess potential DDIs in primary care over a longer period of time.