The prognostic significance of proteinuria: the Framingham study

Kidney Failure Events, Cardiovascular Disease Events, and All-Cause Mortality in Patients with IgA Nephropathy in a Real-World Database

Key Points

In our US real-world cohort study of patients with IgA nephropathy, elevated proteinuria and progression to kidney failure (KF) were associated with a higher risk of cardiovascular disease/mortality events. Elevated pre-KF proteinuria was also associated with progression to KF/mortality events. Incremental costs associated with CKD stage, nephrotic syndrome, and cardiovascular disease events and of these events were high.

Background

IgA nephropathy (IgAN)–associated glomerular injury leads to proteinuria, hematuria, and progressive loss of GFR, with progression to kidney failure (KF). This retrospective study evaluated the prognostic effects of proteinuria and progression to KF on cardiovascular disease (CVD)/mortality events and KF/mortality events in the United States.

Methods

We conducted a noninterventional, retrospective cohort study in adult patients with IgAN using Optum's deidentified Market Clarity Data (January 1, 2007, to March 31, 2021). Adult (age ≥18 years) patients with at least two signs, disease, symptoms natural language processing term entries for IgAN, within 180 and ≥30 days apart within the identification period were included. Outcomes were assessed by time-dependent proteinuria (≥1 versus <1 g/d) and KF status (pre versus post). Descriptive statistics were used for categorical and continuous variables. Multivariable Cox proportional hazard models with time-dependent predictors were used to estimate differences across groups.

Results

Patients with pre-KF status and proteinuria ≥1 g/d were more likely to have a CVD/mortality event during follow-up (adjusted hazard ratio [HR; 95% confidence interval (CI)]: 1.80 [1.12 to 2.89]; P < 0.001) or a KF/mortality event (adjusted HR [95% CI]: 2.10 [1.73 to 2.56]; P < 0.001). Patients with post-KF status were more likely to have a CVD/mortality event during follow-up (adjusted HR [95% CI]: 3.28 [2.82 to 3.81]; P < 0.001).

Conclusions

Elevated proteinuria and progression to KF were associated with a higher risk of CVD/mortality events. Elevated pre-KF proteinuria was also associated with progression to KF/mortality events. On the basis of our real-world retrospective database analysis, we hypothesize that novel IgAN therapies that reduce proteinuria and slow the rate of progression to KF have the potential to reduce CVD risk, improve kidney outcomes, and prolong/increase overall survival.

Body Mass Index and the Risk of Persistent Proteinuria in Middle-Aged Men: The Kansai Healthcare Study

INTRODUCTION

Proteinuria is a risk factor for end-stage renal failure. However, it is not known whether body mass index (BMI) is prospectively associated with the risk of future developing proteinuria, taking into account transient proteinuria.

METHODS

We enrolled 9,320 nondiabetic Japanese middle-aged men who had no proteinuria, an estimated glomerular filtration rate ≥60 mL/min/1.73 m2, no history of cancer, and no use of antihypertensive medications at baseline. "Any proteinuria" was defined as proteinuria detected for the first time during the follow-up period regardless of its frequency. "Persistent proteinuria" was defined as proteinuria that was detected at least twice consecutively at annual examinations and did not return to negative until the end of the follow-up.

RESULTS

During the 11-year follow-up period, 1,972 cases of any proteinuria and 151 cases of persistent proteinuria were confirmed. Both lower and higher BMI were associated with the risk of any proteinuria. As for persistent proteinuria, in those with a BMI ≥20 kg/m2, higher BMI was associated with a higher risk of future persistent proteinuria. The association between BMI and the risk of persistent proteinuria was stronger than that between BMI and any proteinuria. In multiple-adjusted model, hazard ratios of persistent proteinuria for BMI <18.0, 18.0-19.9, 20.0-21.9, 22.0-23.9, 24.0-25.9, 26.0-27.9, and ≥28.0 kg/m2 were 1.52 (95% confidence interval 0.51-4.49), 1.07 (0.49-2.29), 1.00 (reference), 1.14 (0.64-2.01), 1.89 (1.09-3.27), 2.12 (1.15-3.93), and 3.85 (2.03-7.30), respectively.

DISCUSSION/CONCLUSION

In those with a BMI ≥20 kg/m2, higher BMI was associated with a higher risk of future persistent proteinuria and any proteinuria. This relationship was stronger for persistent proteinuria than for any proteinuria.

Reduction in proteinuria after immunosuppressive therapy and long-term kidney outcomes in patients with immunoglobulin A nephropathy

BACKGROUND/AIMS

Despite controversy regarding the benefits of immunosuppressive therapy in immunoglobulin A nephropathy (IgAN), clinical outcomes may vary depending on the patient's responsiveness to this therapy. This study evaluated long-term kidney outcomes according to the extent of proteinuria reduction after immunosuppression in IgAN patients.

METHODS

Among 927 patients with biopsy-proven IgAN, 127 patients underwent immunosuppression. Time-averaged urine protein-creatinine ratio before and within 1 year after start of immunosuppression were calculated, and responsiveness to immunosuppression was assessed as the reduction of proteinuria between the two periods. Patients were classified into tertiles according to the extent of proteinuria reduction. We compared the slopes of estimated glomerular filtration rate (eGFR) decline using a linear mixed model, and estimated hazard ratios (HRs) for disease progression (defined as development of a ≥ 30% decline in eGFR or end-stage renal disease) using a Cox proportional hazard model.

RESULTS

Median extent of proteinuria reduction was -2.1, -0.9, and -0.2 g/gCr in the first, second, and third tertiles, respectively. There were concomitant changes in the slopes of annual eGFR decline: -2.03, -2.44, and -4.62 mL/min/1.73 m2 among the first, second, and third tertiles, respectively. In multivariable Cox analysis, the HRs (95% confidence intervals) for disease progression were 0.30 (0.12 to 0.74) in the first tertile and 0.70 (0.34 to 1.45) in the second tertile compared with the thirdtertile.

CONCLUSION

This study showed that greater proteinuria reduction after immunosuppression was associated with a lower risk of disease progression in patients with IgAN, suggesting that responsiveness to immunosuppression may be an important determinant of kidney outcomes.

Association of microalbuminuria with left ventricular dysfunction in type 2 diabetes mellitus

Background

The prevalence of diabetes mellitus is on rising trend in developing countries like India. In type 2 diabetes patients, albuminuria has been shown to predict development of dysfunction in other organ systems such as kidneys, nervous system, and retina and increase risk of cardiovascular (CV) morbidity and mortality. In this study, we plan to assess association of microalbuminuria with left ventricular dysfunction in type 2 diabetes mellitus.

Results

This cross-sectional study was conducted among 100 type 2 diabetes mellitus patients attending a tertiary care hospital in Gujarat, Western India. Based on urine albumin excretion status, they were divided in two groups of 50 each—normoalbuminuric and microalbuminuric patients. The mean FBS, PPBS, and HbA1c level was significantly lower in normoalbuminuric group compared to microalbuminuric group. There was an increase in cholesterol, triglyceride, VLDL, and LDL levels and decrease in HDL levels in microalbuminuric group as compared to normoalbuminuric group. Multivariate logistic regression analysis revealed that increase in age and a decrease in E/A ratio in patients with microalbuminuria was significantly associated with left ventricular diastolic dysfunction (LVDD).

Conclusion

The presence of microalbuminuria is associated with increased likelihood of LVDD in type 2 diabetes patients. Increase in age and decrease in E/A ratio show direct and independent association with LVDD in normotensive diabetic patients with microalbuminuria. Therefore, diabetes patients who have microalbuminuria should be regularly (or more frequently) evaluated for development of LVDD using Echocardiography. This can allow early identification of myocardial diastolic dysfunction.

Insulin resistance in glomerular podocytes: Potential mechanisms of induction

Glomerular podocytes are a target for the actions of insulin. Accumulating evidence indicates that exposure to nutrient overload induces insulin resistance in these cells, manifested by abolition of the stimulatory effect of insulin on glucose uptake. Numerous recent studies have investigated potential mechanisms of the induction of insulin resistance in podocytes. High glucose concentrations stimulated reactive oxygen species production through NADPH oxidase activation, decreased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, and reduced deacetylase sirtuin 1 (SIRT1) protein levels and activity. Calcium signaling involving transient receptor potential cation channel C, member 6 (TRPC6) also was demonstrated to play an essential role in the regulation of insulin-dependent signaling and glucose uptake in podocytes. Furthermore, podocytes exposed to diabetic environment, with elevated insulin levels become insulin resistant as a result of degradation of insulin receptor (IR), resulting in attenuation of insulin signaling responsiveness. Also elevated levels of palmitic acid appear to be an important factor and contributor to podocytes insulin resistance. This review summarizes cellular and molecular alterations that contribute to the development of insulin resistance in glomerular podocytes.

Role of Albuminuria in Detecting Cardio-Renal Risk and Outcome in Diabetic Subjects

The clinical significance of albuminuria in diabetic subjects and the impact of its reduction on the main cardiorenal outcomes by different drug classes are among the most interesting research focuses of recent years. Although nephrologists and cardiologists have been paying attention to the study of proteinuria for years, currently among diabetics, increased urine albumin excretion ascertains the highest cardio-renal risk. In fact, diabetes is a condition by itself associated with a high-risk of both micro/macrovascular complications. Moreover, proteinuria reduction in diabetic subjects by several treatments lowers both renal and cardiovascular disease progression. The 2019 joint ESC-EASD guidelines on diabetes, prediabetes and cardiovascular (CV) disease assign to proteinuria a crucial role in defining CV risk level in the diabetic patient. In fact, proteinuria by itself allows the diabetic patient to be staged at very high CV risk, thus affecting the choice of anti-hyperglycemic drug class. The purpose of this review is to present a clear update on the role of albuminuria as a cardio-renal risk marker, starting from pathophysiological mechanisms in support of this role. Besides this, we will show the prognostic value in observational studies, as well as randomized clinical trials (RCTs) demonstrating the potential improvement of cardio-renal outcomes in diabetic patients by reducing proteinuria.

Distinct eGFR trajectories are associated with risk of myocardial infarction in people with diabetes or prediabetes

BACKGROUND

The relationship between estimated glomerular filtration rate (eGFR) trajectories and myocardial infarction (MI) has so far been unclear in people with diabetes or prediabetes. We aimed to identify common eGFR trajectories in people with diabetes or prediabetes and to examine their association with MI risk.

METHODS

The data of this analysis were derived from the Kailuan study, which was a prospective community-based cohort study. The eGFR trajectories of 24 723 participants from the year 2006 to 2012 were generated by latent mixture modeling. Cox proportional hazards models were used to calculate hazard ratios (HR) and their 95% CI for the subsequent risk of MI of different eGFR trajectories.

RESULTS

We identified five distinct eGFR trajectories during 2006 to 2012 and named them according to their eGFR range and pattern over time: low-stable (9.4%), moderate-stable (31.4%), moderate-increasing (29.5%), high-decreasing (13.9%), and high-stable (15.8%). During a mean follow-up of 4.61 years, there were a total of 235 incident MI. Although the high-decreasing group had similar eGFR levels to the moderate-stable group during the last exposure period, the risk was much higher (adjusted HR, 3.57; 95% CI, 1.63-7.85 vs adjusted HR, 2.88; 95% CI, 1.36-6.08). Notably, the moderate-increasing group had reached the normal range, but still had a significantly increased risk (adjusted HR, 2.63; 95% CI, 1.24-5.55).

CONCLUSIONS

eGFR trajectories were associated with MI risk in people with diabetes or prediabetes. These observations suggest that long-term trajectories of eGFR may be important for risk prediction of MI and should be highlighted in primary prevention.

Metformin reduces proteinuria in spontaneously hypertensive rats by activating the HIF-2α-VEGF-A pathway

Metformin has protective effects on diabetic nephropathy. However, the mechanism underlying the renoprotective action of metformin in spontaneously hypertensive rats (SHR) is not completely understood. We determined the role of metformin in proteinuria and investigated the mechanism. We measured the urinary protein concentration (mg/day) in 48-week-old SHR. Matched control animals were of the same genetic strain, Wistar-Kyoto (WKY). The rats received metformin (100 mg/kg/day) or vehicle for 10 months. Metformin improved renal function and reduced the proteinuria (urine protein: 48.4 ± 3.7 vs. 25.4 ± 1.8 mg, P < 0.01) induced by long-term high blood pressure. Metformin increased the production of vascular endothelial growth factor (VEGF)-A in rat kidneys and cultured rat podocytes. Metformin activated hypoxia-inducible factor-2α (Hif-2α) in response to VEGF but did not affect Hif-1α in rat kidneys and cultured rat podocytes. Metformin reduced the proteinuria induced by long-term high blood pressure in vivo and increased the VEGF-A production in rat kidneys and cultured rat podocytes, probably by activating the Hif-2α-VEGF signaling pathway. These findings provide a new mechanism for the renoprotective effects of metformin.

Patients With Primary Aldosteronism Respond to Unilateral Adrenalectomy With Long-Term Reduction in Salt Intake

CONTEXT

High dietary salt intake is known to aggravate arterial hypertension. This effect could be of particular relevance in the setting of primary aldosteronism (PA), which is associated with cardiovascular damage independent of blood pressure levels. The aim of this study was to determine the impact of therapy on salt intake in PA patients.

PATIENTS AND METHODS

A total of 148 consecutive PA patients (66 with unilateral and 82 with bilateral PA) from the database of the German Conn's Registry were included. Salt intake was quantified by 24-hour urinary sodium excretion before and after initiation of PA treatment.

STUDY DESIGN

Observational longitudinal cohort study.

SETTING

Tertiary care hospital.

RESULTS

At baseline, unilateral PA patients had a significantly higher urinary sodium excretion than patients with bilateral disease (205 vs 178 mmol/d, P = 0.047). Higher urinary sodium excretion correlated with an increased cardiovascular risk profile including proteinuria, impaired lipid, and glucose metabolism and was associated with higher daily doses of antihypertensive drugs to achieve blood pressure control. In unilateral disease, urinary sodium excretion dropped spontaneously to 176 mmol/d (P = 0.012) 1 year after unilateral adrenalectomy and remained low at 3 years of follow-up (174 mmol/d). In contrast, treatment with mineralocorticoid receptor antagonists (MRA) in bilateral PA patients was not associated with a significant change in urinary sodium excretion at follow-up (179 mmol/d vs 183 mmol/d).

CONCLUSION

PA patients consuming a high-salt diet, estimated based on urinary sodium excretion, respond to adrenalectomy with a significant reduction of salt intake, in contrast to MRA treatment.

Left Ventricular Mass and Incident Chronic Kidney Disease

Chronic kidney disease (CKD) is associated with incident cardiovascular morbidity and mortality. Whether subclinical cardiovascular disease and target organ damage is associated with incident CKD is unknown. We investigated the relations of echocardiographic left ventricular mass (LVM) with incident CKD. We evaluated 2258 Framingham Offspring cohort participants (mean age, 57 years; 56% women) who underwent echocardiography at a routine examination and had an estimated glomerular filtration rate ≥60 mL/min per 1.73 m². We used Cox proportional hazards regression with discrete time intervals to relate sex-standardized LVM (independent variable) to the incidence of CKD, defined as estimated glomerular filtration rate <60 L/min per 1.73 m², on follow-up. During a median follow-up of 14.6 years, 373 (16.5%) participants developed incident CKD. Higher LVM was associated with higher risk of CKD after adjusting for prevalent cardiovascular disease, body mass index, systolic blood pressure, total and HDL (high-density lipoprotein) cholesterol, antihypertensive medication, smoking, and diabetes mellitus (hazard ratio, 1.15 [95% CI, 1.03-1.29]; P=0.017) per 1-SD increase in LVM g/m². Further adjustment for baseline estimated glomerular filtration rate (adjusted hazard ratio, 1.16 [95% CI, 1.04-1.31]; P=0.010) and baseline urine albumin/creatinine ratio (adjusted hazard ratio, 1.18 [95% CI, 1.04-1.33]; P=0.009) slightly attenuated the association. In our community-based sample, LVM was associated with incident CKD prospectively, which suggests that the relations between CKD and subclinical cardiovascular disease may be bidirectional. Further studies are needed to confirm our findings.

Sleep debt and prevalence of proteinuria in subjects with short sleep duration on weekdays: a cross-sectional study

STUDY OBJECTIVE

Short sleep duration is a risk factor of chronic kidney disease, along with cardiovascular diseases and all-cause mortality. Several studies reported that many people sleep longer on weekends than on weekdays, suggesting that they should be compensated for their sleep debt on weekdays on the weekends. Few studies have reported the clinical impact of sleep debt on the kidney.

METHODS

This cross-sectional study included 5799 employees of Osaka University who visited its Health Care Center for their annual health examinations and answered ≤ 6 h of sleep duration on weekdays. The independent variable was the sleep debt index defined as a gap in self-reported sleep duration (≤ 5, 5-6, 6-7, 7-8, 8-9, and ≥ 9 h) between weekdays and weekends, which was categorized into ≤ 0, + 1, + 2, + 3 and ≥+4. An association between the sleep debt index and a prevalence of proteinuria defined as dipstick proteinuria of ≥ 1 + was assessed using logistic regression models adjusting for clinically relevant factors.

RESULTS

More than four-fifths of the subjects had a positive sleep debt index (≤ 0, + 1, + 2, + 3, and ≥+4 recorded for 19%, 36%, 28%, 11%, and 6%, respectively). The multivariable-adjusted logistic regression models showed the sleep debt index ≥ 3 + was significantly associated with the prevalence of proteinuria (sleep debt index ≤ 0, adjusted odds ratio 1.13 [0.77, 1.65]; + 1, 1.00 [reference]; + 2, 1.29 [0.93, 1.79]; + 3, 1.54 [1.02, 2.33]; ≥ + 4, 1.87 [1.15, 3.05]).

CONCLUSIONS

Sleep debt was associated with the prevalence of proteinuria in a dose-dependent manner.

Report of health checkup system for chronic kidney disease in general population in Okayama city: effect of health guidance intervention on chronic kidney disease outcome

BACKGROUND

From 2011, Okayama municipal government started the health checkup follow-up project to find those who were unaware of suffering chronic kidney disease and to prevent from aggravation of CKD stage. In this study, we aimed to evaluate the effect of 2 years' CKD-follow-up project regarding renal function and CKD risks.

PATIENTS AND METHODS

Those who received a health checkup by the national health insurance in Okayama city in 2011 were recruited. The patients with lifestyle-related diseases or metabolic syndrome were excluded. Subjects who had an estimated glomerular filtration rate<50 mL/min/1.73 m2 or urinary protein positive by dipstick test were defined as compromised renal function group. They were recommended to visit a medical institution. Non-compromised renal function participants with two or more risks for CKD (hyperglycemia, higher blood pressure, dyslipidemia, hyperuricemia) were recommended to receive a health guidance (risk group). The change of renal function and CKD risks between 2011 and 2013 in each group was examined.

RESULTS

A total of 28,309 people received a health checkup in 2011. In compromised renal function group, 39.5% (96/243) of the subjects improved their CKD stages in 2013 regardless of the visit of medical institutions or the frequency of receiving health checkup. In risk group, 63.4% (260/410) of the subjects decreased their CKD risks in 2013 independent of the reception of health guidance.

CONCLUSION

In both compromised renal function group and risk group, more than half of subjects kept their kidney function (217/243) and decreased the number of CKD risks (260/410) in 2 years' follow-up. Receiving a health checkup itself and notification of one's own health condition could exert a protective effect on kidney function.

Mild to moderate proteinuria is a heralding sign for acute kidney injury and mortality for intensive care unit patients

Background/aim

Lack of early predictors of acute kidney injury is currently delaying timely diagnosis.This study was done to evaluate the relationship between mild to moderate proteinuria and incidence of acute kidney injury (AKI) and 28-day mortality in intensive care unit (ICU) patients.

Materials and methods

This observational, retrospective study was conducted in the internal medicine ICU. A total of 796 patients were screened and 525 patients were used for this analysis. Proteinuria was measured by urine dipstick test. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

Results

Patients with dipstick urine protein positivity on admission had higher proportion of AKI and 28-day mortality compared to dipstick urine protein negative group [164 (59.6%) vs. 111 (44.4%) and 101 (36.7%) vs. 54 (21.6%), P = 0.01 and P < 0.01, respectively]. Urine dipstick protein positivity was also a significant predictor of 28-day mortality in patients with GFR > 60 mL/min (hazard ratio: 1.988, 95% confidence interval 1.380–2.862).

Conclusion

Proteinuria before ICU admission is a risk factor for development of AKI within seven days of ICU stay and also is a risk factor for 28-day mortality, even in patients with GFR > 60 mL/min.

Preliminary analysis of the effect of Stevia (Stevia rebaudiana) in patients with chronic kidney disease (stage I to stage III)

Background

Stevia, Stevia rebaudiana (Bertoni), has become an important economic plant for its commercial use as a sweetener. Stevia plays a significant role in the healthcare practice of different cultures and in population. Previous animal and clinical studies demonstrated the efficacy of Stevia against chronic diseases like diabetes and hypertension. This study aimed to investigate the beneficial effect of Stevia in chronic kidney disease (CKD) patients after three (3) months of treatment along with the conventional antihypertensive and anti diabetic medications.

Methods

A prospective, interventional, randomized, single-blind, placebo-controlled trial has been done with 97 participants. Stevia capsule (250 mg) or matching placebo was given to the participants twice daily along with Angiotensin-II Receptor Blocker (ARB) and/or Ca²⁺ Channel Blocker (CCB). First follow up visits were done after 3 months of the interval. Blood and urine samples were collected for the biochemical tests. A structured questionnaire was used for the baseline assessment. Informed consent was taken from each participant.

Results

Both hypertension and diabetes were found to be associated with CKD. Most of the participants (52.3%) of Stevia group were in CKD Stage II. Significant changes were found in Serum creatinine (p < 0.027), Serum Uric acid (p < 0.009), Fasting blood sugar (p < 0.041) and Postprandial blood sugar (p < 0.013) and Microalbumin (p < 0.041) level in the treatment group.

Conclusion

The initial result demonstrated that Stevia has the potential for a significant improvement of some biochemical parameters in CKD patients. After completion of the nine (9) months clinical trial, the constructive effect of Stevia can be confirmed in this group of patients.

Dietary Influence on Body Fluid Acid-Base and Volume Balance: The Deleterious "Norm" Furthers and Cloaks Subclinical Pathophysiology

The popular modern diet, characterized by an excess of animal protein and salt but insufficient in fruits, vegetables and water, is a poor fit for human physiological and homeostatic regulatory systems. Sustained net acid and sodium retention, coupled with an insufficient intake of cardiovascular protective potassium-rich foods and hydration in the modern diet can give rise to debilitating chronic organ dysfunction and ultimately, mortality. This holds true, especially in our aging population who are already facing inevitable decline in organ functional reserve. Importantly, in most cases, despite the mismatch and adverse effects to multiple organ systems, plasma electrolyte and acid-base parameters can, on the surface, be maintained within a “normal” reference range, primarily by activating (often maximally activating) compensatory homeostatic mechanisms. These diet-induced effects can thus be clinically silent for decades. Embodied in the chronic corrective homeostatic processes, however, are real risks for multiorgan damage. According to the Dietary Guideline Advisory Committee (DGAC), half of American adults have one or more chronic diseases that are preventable with dietary modification. Here, homeostasis of body fluid acid-base, sodium, potassium and water is examined. Our current dietary habits and their required regulatory adaptation, maladaptation and relevant physiology and pathophysiology are discussed. A framework of dietary modifications to avoid a propensity for maladaptation and thus lowers the risks of common modern diseases (primary prevention) and minimizes the risk of chronic and age-related disease progression (secondary prevention) is emphasized. Although there are other variables at play, a key to restoring the all-important dietary potassium to sodium ratio is greater consumption of vegetables/fruits and adopting salt temperance. Dietary and nutritional optimization is an under-emphasized area of health care that has an enormous potential to temper the epidemics of prevalent chronic diseases in modern society and improve population health.

Two-year changes in proteinuria and risk for myocardial infarction in patients with hypertension: a prospective cohort study

OBJECTIVE

To assess whether changes in proteinuria are associated with the incidence of myocardial infarction (MI) in patients with hypertension.

METHODS

The Kailuan study was a prospective longitudinal cohort study on cardiovascular risk factors and events. Hazard ratios with 95% confidence intervals (CIs) were calculated using Cox regression models.

RESULTS

A total of 24 926 hypertensive patients (mean age: 55.2 ± 10.9 years) without previous MI were included. After a mean follow-up of 6.8 years, 382 (1.5%) individuals developed MI. Participants with proteinuria at baseline had a 60% higher risk for developing MI as compared with participants without proteinuria at baseline (hazard ratio: 1.60, 95% CI: 1.12-2.29) after adjusting for dyslipidemia, diabetes mellitus and other cardiovascular risk factors. Compared with participants without proteinuria, individuals with incident proteinuria or persistent proteinuria during the follow-up had 54 and 141% higher risks for developing MI, respectively (hazard ratio: 1.54, 95% CI: 1.14-2.09 and hazard ratio: 2.41, 95% CI: 1.59-3.66; all P < 0.05).

CONCLUSION

Proteinuria is associated with an increased incidence of MI, but the association is likely to be underestimated if baseline measurements of proteinuria are used. Measures of changes in proteinuria, particular persistent proteinuria, are more likely to reflect the lifetime risk for MI.

The Patterns, Risk Factors, and Prediction of Progression in Chronic Kidney Disease: A Narrative Review

Chronic kidney disease (CKD) is a global public health problem that is associated with excess morbidity, mortality, and health resource utilization. The progression of CKD is defined by a decrease in glomerular filtration rate and leads to a variety of metabolic abnormalities including acidosis, hypertension, anemia, and mineral bone disorder. Lower glomerular filtration rate also bears a strong relationship with an increased risk of cardiovascular events, end-stage renal disease, and death. Patterns of CKD progression include linear and nonlinear trajectories, but kidney function can remain stable for years in some individuals. Addressing modifiable risk factors for the progression of CKD is needed to attenuate its associated morbidity and mortality. Developing effective risk prediction models for CKD progression is critical to identify patients who are more likely to benefit from interventions and more intensive monitoring. Accurate risk-prediction algorithms permit systems to best align health care resources with risk to maximize their effects and efficiency while guiding overall decision making.

Decrease in toe pinch force in male type 2 diabetic patients with diabetic nephropathy

BACKGROUND

The purpose of this cross-sectional study was to investigate the toe pinch force (TPF) of type 2 diabetic patients with diabetic nephropathy by disease stage, and to clarify the factors affecting the TPF.

METHODS

Seventy-four men with diabetic nephropathy (age: 62.7 ± 8.9 years, duration of diabetes: 14.2 ± 8.6 years) were enrolled. According to the staging of diabetic nephropathy, TPF and knee extension force (KEF) were compared among three groups: normoalbuminuria, microalbuminuria, and overt nephropathy. In addition, we investigated factors influencing TPF and KEF by performing multiple regression analysis.

RESULTS

Normoalbuminuria group, microalbuminuria group, and overt nephropathy group included 26, 25, and 23 patients, respectively. The TPF of the overt nephropathy group (3.15 ± 0.75 kg) was significantly lower than that of the normoalbuminuria (4.2 ± 0.7 kg, p < 0.001) and microalbuminuria groups (3.65 ± 0.81 kg, p = 0.022). The KEF of the overt nephropathy group (37.1 ± 8.3 kgf) was significantly lower than that of the normoalbuminuria group (44.8 ± 8.3 kgf, p = 0.010). Multiple regression analysis revealed that diabetic polyneuropathy (DPN) and diabetic nephropathy were determinant factors of the TPF; and age, body mass index, and diabetic nephropathy were determinant factors of the KEF.

CONCLUSION

We found in male patients with diabetic nephropathy, the TPF and KEF decreased with progression of diabetic nephropathy. Furthermore, our findings suggest diabetic nephropathy and DPN are critically involved in the reduction of TPF and KEF.

Blood pressure components and the risk for proteinuria in Japanese men: The Kansai Healthcare Study

Background

We examined prospectively which of the four blood pressure (BP) components (systolic BP [SBP], diastolic BP [DBP], pulse pressure [PP], and mean arterial pressure [MAP]) was best in predicting the risk of proteinuria.

Methods

This prospective study included 9341 non-diabetic Japanese middle-aged men who had no proteinuria and an estimated glomerular filtration rate ≥60 mL/min/1.73 m² and were not taking antihypertensive medications at entry. Persistent proteinuria was defined if proteinuria was detected two or more times consecutively and persistently at the annual examination until the end of follow-up. We calculated the difference in values of Akaike's information criterion (ΔAIC) in comparison of the BP components-added model to the model without them in a Cox proportional hazards model.

Results

During the 84,587 person-years follow-up period, we confirmed 151 cases of persistent proteinuria. In multiple-adjusted models that included a single BP component, the hazard ratios for persistent proteinuria for the highest quartile of SBP, PP, and MAP were 3.11 (95% confidence interval [CI], 1.79–5.39), 1.87 (95% CI, 1.18–2.94), and 2.21 (95% CI, 1.33–3.69) compared with the lowest quartile of SBP, PP, and MAP, respectively. The hazard ratio for the highest quartile of DBP was 2.69 (95% CI, 1.65–4.38) compared with the second quartile of DBP. Of all models that included a single BP component, those that included SBP alone or DBP alone had the highest values of ΔAIC (14.0 and 13.1, respectively) in predicting the risk of persistent proteinuria.

Conclusions

Of all BP components, SBP and DBP were best in predicting the risk of persistent proteinuria in middle-aged Japanese men.

•

We examined which blood pressure (BP) components increased risk of proteinuria.

•

We used systolic BP, diastolic BP, pulse pressure, and mean arterial pressure.

•

Systolic and diastolic BP were the best predictors of persistent proteinuria.

Two-Year Changes in Proteinuria and the Risk of Stroke in the Chinese Population: A Prospective Cohort Study

Background

Whether changes in proteinuria are associated with incident stroke in the general population is unclear. This study aimed to investigate the association between changes in proteinuria and incident stroke and its subtypes.

Methods and Results

The current study included 60 940 Chinese participants (mean age, 50.69 years) who were free of stroke at the time of surveys (2006–2007 and 2008–2009). Participants were divided into 4 categories according to 2‐year changes in proteinuria: no proteinuria, remittent proteinuria, incident proteinuria, and persistent proteinuria. Cox proportional hazards models were used to calculate hazard ratios and their 95% CIs for stroke. After a median follow‐up period of 6.92 years, 1769 individuals developed stroke. After adjustment for confounding factors, incident proteinuria and persistent proteinuria were associated with increased risk of stroke (hazard ratio, 1.46 [95% CI, 1.26–1.68] and hazard ratio, 1.71 [95% CI, 1.42–2.06], respectively) compared with no proteinuria, which were higher than proteinuria detected at one single point (hazard ratio, 1.25; 95% CI, 1.09–1.43). The effect size for risk of stroke subtypes including ischemic stroke and hemorrhagic stroke was similar.

Conclusions

Changes in proteinuria exposure, particularly persistent proteinuria, are more likely to reflect the risk of stroke, compared with proteinuria collected at a single time point in the general population.

Association between Overall Lifestyle Changes and the Incidence of Proteinuria: A Population-based, Cohort Study

Objective This study aimed to examine the association between the changes in an overall healthy lifestyle, as quantified by the number of unhealthy lifestyle factors and obesity status, and the incidence of proteinuria in the general Japanese population. Methods A retrospective cohort study was conducted among 99,404 (men, 36.9%) participants aged from 40-74 years of age who underwent two health check-ups with a 1-year interval in Japan between 2008 and 2009. Any participants with chronic kidney disease at baseline were excluded. The smoking status, body mass index, physical activity, alcohol consumption, and healthy eating habits were combined into a simple overall healthy lifestyle score ranging from 0 to 5. The changes in overall healthy lifestyle scores from baseline (range, -5 to +5) and the incidence of proteinuria, defined by a dipstick urinalysis (score ≥1+), were assessed at the second check-up. A logistic regression analysis was used to examine the association between the changes in overall healthy lifestyle scores and the incidence of proteinuria. Results After one year of follow-up, 3.9% of men and 2.4% of women developed proteinuria. Each increase (or decrease) in the changes in overall healthy lifestyle scores was associated with a reduced (or increased) risk of proteinuria in both men (odds ratio (OR) 0.87; 95% confidence interval (CI), 0.81-0.94) and women (OR 0.87; 95%CI, 0.80-0.94) after adjusting for age, baseline lifestyle scores, hypertension, diabetes mellitus, and hypercholesterolemia. Stratified analyses based on age, the presence or absence of hypertension, or diabetes mellitus revealed similar results. Conclusion Overall lifestyle changes, even within a year, were found to influence the incidence of proteinuria.

Association of genetic polymorphisms of angiopoietin-like 4 with severity of posttransplant proteinuria in kidney allograft recipients

BACKGROUND

Proteinuria is a hallmark of glomerular injury, and persistent proteinuria is associated with graft failure in kidney transplant patients. Recently, it is known that the level of circulating angiopoietin-like 4 (ANGPTL4) is elevated in the patients with human nephrotic syndrome, in which ANGPTL4 is responsible for relieving proteinuria.

PURPOSE

The purpose of this study is to determine effects of clinical factors and genetic polymorphism of ANGPTL4 on proteinuria after kidney transplantation.

METHODS

A total of 282 patients out of 400 renal transplant patients between 2008 and 2012 at St. Vincent Medical Center, CA were studied in a retrospective study design. The level of proteinuria was measured by random urine protein to creatinine ratio, and divided into two groups (Group 1: UPC<500mg/day, Group 2: ≥500mg/day). Single nucleotide polymorphisms of ANGPTL4 genes (rs1044250, rs2278236, rs116843064, rs11672433, rs4076317) were determined by real time PCR with sequence specific primers.

RESULTS

Among various clinical factors, only delayed graft function, mTOR inhibitor use and fish oil use were significantly associated with posttransplant proteinuria. Statistical differences were found in genetic polymorphisms of ANGPTL4 (rs1044250, rs2278236) in regards to proteinuria among tested patients. rs1044250 (C/T, T228M, missense mutation) alleles showed multiple significant differences (Group 1 vs. Group 2: C vs. T: OR=1.893, CI=1.322-2.710, p<0.001). Similar trends were found in rs2278236 (A/G) alleles with statistical significances (Group 1 vs. Group 2: A vs. G: OR=0.620, CI=0.443-0.867, p=0.005). With multiple logistic regression, rs1044250 was still a significant risk factor of moderate/severe proteinuria (p=0.021).

CONCLUSIONS

This study suggests that the presence of C allele of rs1044250 and G allele of rs2278236 in ANGPTL4 gene is associated with higher risk of moderate/severe proteinuria in renal transplant patients.

Plasma matrix metalloproteinase-9 and ACE-inhibitor-induced improvement of urinary albumin excretion in non-diabetic, microalbuminuric subjects

Introduction. Elevated plasma matrix metalloproteinase-9 (MMP-9) levels have been suggested to precede the development of microalbuminuria. As angiotensin-converting enzyme (ACE) inhibitors effectively reduce urinary albumin excretion (UAE), in the present study we have investigated the potential association of plasma MMP-9 levels with UAE and treatment effects of ACE-inhibition. Material and methods. In a placebo-controlled

randomised trial we determined plasma MMP-9 levels at baseline and after three months of randomisation to either placebo (n=202) or fosinopril (20 mg/day, n=204) treatment.

Results. Baseline plasma MMP-9 levels were not related to baseline UAE (r=-0.008, p=0.871).Three months of fosinopril treatment effectively reduced UAE compared to placebo treatment (-10.4±2.4 vs. 1.8±1.3 mg/24 hours, p<0.001, respectively). However, fosinopril treatment failed to significantly change plasma MMP-9 levels compared to placebo (-0.47±7.68 vs. 0.06±9.20, p=0.646, respectively) . In addition, the change in UAE was not related with change in MMP-9 levels.

Conclusion. The effective reduction of UAE with fosinopril was not related to plasma MMP-9 levels.

Renoprotective effects of renin-angiotensin system inhibitor combined with calcium channel blocker or diuretic in hypertensive patients: A PRISMA-compliant meta-analysis

OBJECTIVES

To conduct a meta-analysis of studies comparing the renoprotective effects of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) combined with either calcium channel blocker (CCB) or diuretic, but not both, in hypertensive patients.

DATA SOURCES

Pubmed, Embase, Medline, and Cochrane databases were searched to identify randomized controlled trials (RCTs) of blood pressure lowering treatments in patients with hypertension.

STUDY SELECTION

RCTs comparing the renoprotective effects of ACEI/ARB plus CCB with ACEI/ARB plus diuretic in hypertensive patients, with at least one of the following reported outcomes: urinary protein, estimated glomerular filtration rate/creatinine clearance (eGFR/CrCl), or serum creatinine.

RESULTS

Based on 14 RCTs with 18,125 patients, statistically significant benefits were found in ACEI/ARB plus CCB for maintaining eGFR/CrCl (standardized mean difference [SMD] = 0.36; 95% confidence interval [CI]: 0.20-0.53; P < 0.001), serum creatinine reduction (mean difference [MD] = -0.05 mg/dL; 95% CI: -0.07 to -0.03; P < 0.001). However, no statistical differences were found between the 2 therapeutic strategies in terms of urinary protein (MD = 7.48%; 95% CI: -6.13% to 21.08%; P = 0.28; I = 92%).

CONCLUSIONS

This meta-analysis concluded that ACEI/ARB plus CCB have a stronger effect on the maintenance of renal function in patients with hypertension than ACEI/ARB plus diuretic.

Effects of acute and chronic hypohydration on kidney health and function

The kidneys play a critical role in the homeostasis of body fluid tonicity and effective circulating volume. Renal homeostatic mechanisms are frequently challenged in acutely ill people. Fluid depletion causing hypovolemia may result in renal hypoperfusion that, if left untreated, may lead to acute kidney failure. Some populations, notably older people and neonates, are less tolerant of extremes in fluid loading and deprivation, similar to those with established chronic kidney disease. Risk of kidney injury during fluid depletion is increased by medications including diuretics, nonsteroidal antiinflammatory drugs, and renin-angiotensin system blockers. There is no consistent evidence indicating that lower-than-average fluid intake can cause chronic kidney disease, nor accelerate progression of established kidney disease. Increasing consumption of sugar-containing beverages is, however, a major concern for kidney health as a precursor of obesity and diabetes. There is no evidence that high dietary protein intake can cause chronic kidney disease, nor accelerate progression of established kidney disease. Idiosyncratic, adverse renal responses have been described with creatine supplements. There are only a few clinical conditions for which high fluid intake should be considered. These include recurrent kidney stones or urinary tract infections and, possibly, polycystic kidney disease.

[Cardiovascular risk study in patients with renin-angiotensin system blockade by means of the proteone of circulating extracellular vesicles]

INTRODUCTION

Extracellular vesicles (EVs) are released to the bloodstream by certain cell types due to transport, activation and cell death processes. Blood count of EVs from platelet and endothelial origin has been proved to be a cardiovascular risk biomarker. Thus, EVs proteome might reflect the underlying cellular processes in hypertensive patients with albuminuria.

MATERIAL AND METHODS

Protein content of circulating EVs was analyzed by liquid chromatography coupled to mass spectrometry. EVs were isolated by an ultracentrifugation protocol optimized in order to avoid contamination by blood plasma proteins. Purity of the isolated fraction was verified by electronic and confocal microscopy, and by flow cytometry.

RESULTS

We hereby show a method to isolate circulating EVs from hypertensive patients with/without albuminuria with high yield and purity. Besides, we provide a reference proteome of the EVs of these patients, composed of 2,463 proteins, and prove that the proteins carried by these vesicles are associated with crucial processes involved in the inherent cardiovascular risk.

CONCLUSION

The proteome of circulating EVs is an interesting source of indicators in the evaluation of cardiovascular risk in hypertensive patients with renin-angiotensin system blockage.

Estimated Glomerular Filtration Rate Within the Normal or Mildly Impaired Range and Incident Cardiovascular Disease

BACKGROUND

The association between lower estimated glomerular filtration rate (eGFR) and incident cardiovascular disease is less clear within the normal or mildly impaired range.

METHODS

Using the Chronic Kidney Disease EPIdemiology collaboration (CKD-EPI) and the Modification of Diet in Renal Disease (MDRD) eGFR formulas, we analyzed outpatients ≥ 22 years old from 2004-2006 with 60 mL/min/1.73 m(2) < eGFR < 130 mL/min/1.73 m(2), without prior cardiovascular disease, and with and without proteinuria.

RESULTS

During a median follow-up of 96 months and > 10 million patient-years of follow-up, 103,506 and 104,315 cardiovascular events were recorded using CKD-EPI (n = 1,341,400, mean age 49.2 years, 42.6% male) and MDRD (n = 1,284,762, mean age 50.2 years, 43.4% male) formulas, respectively (incident event rates 4.4% and 4.6%, respectively). Adjusting for age, sex, and major cardiovascular risk factors, a 10-unit eGFR increase was independently associated with a mean decrease of 3.0% and 1.0% in incident cardiovascular events, using CKD-EPI and MDRD, respectively (P < .001 for both), with a sharp decrease in events in the 100-mL/min/1.73 m(2) < eGFR < 130 mL/min/1.73 m(2) range in the CKD-EPI, but not the MDRD, cohort. Using net reclassification analysis, CKD-EPI was more accurate in predicting events than MDRD (Net Reclassification Improvement 0.39, P < .001 stratifying patients to eGFR deciles and 0.64, P < .001 as a continuous variable). Using both formulas, eGFR was predictive of incident cardiovascular disease for patients without proteinuria, but not for the 2.4% with proteinuria (P < .001 for interaction).

CONCLUSION

Higher eGFR is associated with fewer cardiovascular events in adults without prior cardiovascular disease and without proteinuria, particularly in the 100-mL/min/1.73 m(2) < eGFR < 130 mL/min/1.73 m(2) range, indicating that eGFR, especially using the CKD-EPI formula, may be an independent risk marker for incident cardiovascular disease.

Chronic kidney disease: New paradigms in diagnosis and management

This article provides a step-by-step approach to evaluating kidney function and appropriately treating chronic kidney disease (CKD) in a primary care setting. Early detection and management of CKD will decrease the rate of progression to end-stage renal disease.

Diagnostic accuracy of urine dipstick for proteinuria in older outpatients

BACKGROUND

The urine dipstick is widely used as an initial screening tool for the evaluation of proteinuria; however, its diagnostic accuracy has not yet been sufficiently evaluated. Therefore, we evaluated its diagnostic accuracy using spot urine albumin/creatinine ratio (ACR) and total protein/creatinine ratio (PCR) in proteinuria.

METHODS

Using PCR ≥0.2 g/g or ≥0.5 g/g and ACR ≥300 mg/g or ≥30 mg/g as the reference standard, we calculated the diagnostic accuracy profile: sensitivity, specificity, positive and negative predictive value, and the area under the curve (AUC) of the receiver operating characteristic curve.

RESULTS

PCR and ACR were available for 10,348 and 3,873 instances of dipstick testing. The proportions with PCR ≥0.2 g/g, ≥0.5 g/g and ACR ≥300 mg/g, ≥30 mg/g were 38.2%, 24.6% and 8.9%, 31.7%, respectively. The AUCs for PCR ≥0.2 g/g, ≥0.5 g/g, and ACR ≥300 mg/g were 0.935 (trace: closest to ideal point), 0.968 (1+), and 0.983 (1+), respectively. Both sensitivity and specificity were >80% except for PCR ≥0.5 g/g with trace cutoff. For the reference standard of ACR ≥30 mg/g, the AUC was 0.797 (trace) and the sensitivity was 63.5%.

CONCLUSION

Urine dipstick test can be used for screening in older outpatients with ACR ≥300 mg/g or PCR as the reference standard for proteinuria. However, we cannot recommend the test as a screening tool with ACR ≥30 mg/g as the reference owing to its low sensitivity.

Chronic kidney disease and intensive glycemic control increase cardiovascular risk in patients with type 2 diabetes

Results of the main Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial indicate that intensive glucose lowering increases cardiovascular and all-cause mortality. As the contribution of mild-to-moderate chronic kidney disease (CKD) to these risks is not known, we assessed the impact on cardiovascular outcomes in this population. Renal function data were available on 10,136 patients of the original ACCORD cohort. Of those, 6,506 were free of CKD at baseline and 3,636 met the criteria for CKD. Participants were randomly assigned to a treatment strategy of either intensive or standard glycemic goal. The primary outcome, all-cause and cardiovascular mortality, and prespecified secondary outcomes were evaluated. Risk for the primary outcome was 87% higher in patients with than in those without CKD (hazard ratio of 1.866; 95% CI: 1.651-2.110). All prespecified secondary outcomes were 1.5 to 3 times more frequent in patients with than in those without CKD. In patients with CKD, compared with standard therapy, intensive glucose lowering was significantly associated with both 31% higher all-cause mortality (1.306: 1.065-1.600) and 41% higher cardiovascular mortality (1.412: 1.052-1.892). No significant effects were found in patients without CKD. Thus, in high-risk patients with type II diabetes, mild and moderate CKD is associated with increased cardiovascular risk. Intensive glycemic control significantly increases the risk of cardiovascular and all-cause mortality in this population.

Impact of combined losartan/hydrochlorothiazide on proteinuria in patients with chronic kidney disease and hypertension

It is unknown whether the use of diuretics is optimal over other antihypertensive agents in patients with chronic kidney disease (CKD) whose blood pressure remains uncontrolled despite treatment with renin-angiotensin system (RAS) inhibitors. In this study, we assessed the additive effects of hydrochlorothiazide (HCTZ) on reducing proteinuria in CKD patients under treatment with losartan (LS). We conducted a multicenter, open-labeled, randomized trial. One hundred and two CKD patients with hypertension and overt proteinuria were recruited from nine centers and randomly assigned to receive either LS (50 mg, n=51) or a combination of LS (50 mg per day) and HCTZ (12.5 mg per day) (LS/HCTZ, n=51). The primary outcome was a decrease in the urinary protein-to-creatinine ratio (UPCR). The target blood pressure was <130/80 mm Hg, and antihypertensive agents (other than RAS inhibitors and diuretics) were added if the target was not attained. Baseline characteristics of the two groups were similar. After 12 months of treatment, decreases in the UPCR were significantly greater in the LS/HCTZ group than in the LS group. There were no significant differences in blood pressure or the estimated glomerular filtration rate between the two groups. LS/HCTZ led to a greater reduction in proteinuria than treatment with LS, even though blood pressure in the LS group was similar to that in the LS/HCTZ group following the administration of additive antihypertensive agents throughout the observation period. This finding suggests that LS/HCTZ exerts renoprotective effects through a mechanism independent of blood pressure reduction.

Reduction of albumin urinary excretion is associated with reduced cardiovascular events in hypertensive and/or diabetic patients. A meta-regression analysis of 32 randomized trials

BACKGROUND

The association between renal dysfunction and risk of cardiovascular (CV) events and mortality has been reported in several studies. However, it is unclear whether reduction in urinary albumin excretion (UAE) is associated with reduced risk of clinical events. Therefore, we sought to investigate, in a meta-regression analysis of randomized studies enrolling hypertensive and/or diabetic patients, whether changes in UAE are associated with changes in CV outcomes and all-cause mortality.

METHODS

MEDLINE, ISI Web of Science, Cochrane Database and Scopus were searched for randomized trials enrolling more than 200 diabetic and/or hypertensive patients, reporting UAE at baseline and at end of follow-up and CV events [CV death, myocardial infarction (MI), and stroke], as well all-cause mortality.

RESULTS

Thirty-two trials enrolling 80,812 participants were included in analyses. Meta-regression analysis showed that each 10% reduction of UAE was significantly associated with 13% reduction of MI (Regression Coefficient [RC]:0.0055; 95% Confidence Interval [CI]:0.0014 to 0.0095; p=0.010), with 29% reduction of stroke (RC:0.0124; CI:0.0030 to 0.0218; p=0.013) and with 14% reduction of the composite outcome (CV death, MI, stroke)(RC:0.0059; CI:0.0027 to 0.0090; p=0.001), whereas not significantly associated with all-cause (RC:0.0028; CI:-0.0047 to 0.0103; p=0.486) and CV mortality (RC:0.0028; CI:-0.0047 to 0.0103; p=0.447). Results were mostly confirmed by sensitivity analysis. No heterogeneity or publication bias was detected.

CONCLUSIONS

Reduction in UAE is associated with reduced risk of MI and stroke in diabetic and/or hypertensive patients. These findings suggest that UAE changes may represent a valuable intermediate end-point for CV risk evaluation in clinical practice.

The effect of febuxostat to prevent a further reduction in renal function of patients with hyperuricemia who have never had gout and are complicated by chronic kidney disease stage 3: study protocol for a multicenter randomized controlled study

BACKGROUND

Hyperuricemia is a risk factor for the onset of chronic kidney disease (CKD) and is significantly associated with the progression of CKD. However, there is no sufficient evidence by interventional research supporting a cause-effect relationship. Hyperuricemic patients without gouty arthritis, whose serum urate (SUA) concentration is ≥8.0 mg/dL and who have a complication, are treated by pharmacotherapy in addition to lifestyle guidance. Nevertheless, there is no evidence that rationalizes pharmacotherapy for patients with hyperuricemia who have no complication and whose SUA concentration is below 9.0 mg/dL.

METHODS/DESIGN

The FEATHER (FEbuxostat versus placebo rAndomized controlled Trial regarding reduced renal function in patients with Hyperuricemia complicated by chRonic kidney disease stage 3) study is a prospective, multicenter, double-blind, randomized, placebo-controlled trial of febuxostat-a novel, nonpurine, selective, xanthine oxidase inhibitor. The present study will enroll, at 64 medical institutions in Japan, 400 Japanese patients aged 20 years or older who have hyperuricemia without gouty arthritis, who present CKD stage 3, and whose SUA concentration is 7.1-10.0 mg/dL. Patients are randomly assigned to either the febuxostat or the control group, in which febuxostat tablets and placebo are administered orally, respectively. The dosage of the study drugs should be one 10-mg tablet/day at weeks 1 to 4 after study initiation, increased to one 20-mg tablet/day at weeks 5 to 8, and elevated to one 40-mg tablet/day at week 9 and then maintained until week 108. The primary endpoint is estimated glomerular filtration rate (eGFR) slope. The secondary endpoints include the amount and percent rate of change in eGFR from baseline to week 108, the amount and percent rate of change in SUA concentration from baseline to week 108, the proportion of patients who achieved an SUA concentration≤6.0 mg/dL, and the incidence of renal function deterioration.

DISCUSSION

The present study aims to examine whether febuxostat prevents a further reduction in renal function as assessed with eGFR in subjects and will (1) provide evidence to indicate the inverse association between a reduction in SUA concentration and an improvement in renal function and (2) rationalize pharmacotherapy for subjects and clarify its clinical relevance.

TRIAL REGISTRATION

UMIN Identifier: UMIN000008343.

Screening and management of renal disease in human immunodeficiency virus-infected patients in Australia

BACKGROUND

Renal disease has become one of the most important comorbidities observed in the human immunodeficiency virus (HIV)-infected patient cohort. Data are lacking on the current screening and management of renal disease in patients with HIV. We evaluated HIV-infected Australian adults in primary care to determine current practices.

METHODS

This prospective, multicentre observational study included two rounds of data collection; the first was followed by an educational programme. Outcomes included screening for renal disease; management of risk factors for kidney disease and other comorbidities associated with renal disease.

RESULTS

Fifty-three general practitioners participated with 733 patients enrolled. Most were male (94%); almost 40% were 41-50 years of age, and 6% and 84% were receiving antiretroviral therapy. Comorbidities were common; 19% had hypertension, 5% were diabetic, 32% were dyslipidaemic, and 40% were smokers. Estimated glomerular filtration rate was commonly measured in both rounds of data collection (96% vs 95%). Proteinuria was assessed less frequently; this improved after education (48% vs 71%). Almost 10% of patients tested had proteinuria on urinalysis. Of the 45 patients (6%) with renal impairment (estimated glomerular filtration rate <60 mL/min), none was referred for assessment by a renal specialist.

CONCLUSIONS

This large observational study provides important information on renal disease in HIV-infected patients, an area with a paucity of clinical data. Current screening and management practices fall short of suggested guidelines. Failure to refer patients to specialists is a major deficiency. Improvements with education suggest the need to promote awareness of guidelines in primary care doctors.

Renal participation in cardiovascular risk inessential hypertension

The kidney plays a relevant role in the origin of essential hypertension in humans, and it suffers the consequences of sustained elevated blood pressure in the absence of therapy. Recently, a relevant prevalence of mild renal insufficiency both in general population than in hypertensive patients has been described. A direct relationship seems to exist between the level of cardiovascular risk and the prevalence of the renal disorder, whether this is detected as an elevation in serum creatinine or as a diminution of estimated creatinine clearance. This renal function impairment is a strong predictor of cardiovascular risk in patients with chronic heart failure and following myocardial infarction. Prevention of renal and cardiovascular damage in these patients will be one of the most relevant tasks in the future. The aim of this short review is to discuss the evidence in favor of a relevant prevalence of mild renal insufficiency in hypertensive patients, as well as the association of this disorder with a very significant increment in global cardiovascular risk.

Stroke and renal dysfunction

Stroke is the most frequent neurological disease and represents a continuously evolving medical and social problem. Chronic kidney disease (CKD) is also an important worldwide public health problem. Renal dysfunction carries a substantial risk of cardiovascular morbidity and mortality and an independent, graded association between renal function and cardiovascular events was found. In the last 15years the link between CKD and cerebrovascular disease has become more apparent. Patients with end stage renal disease treated with maintenance hemodialysis have a much higher incidence of stroke than the general population and stroke is one of the major causes of death in these patients. Nowadays ischemic subtype of stroke is present in approximately 70% of dialysis patients. In population based studies conflicting results have been reported about the association between stroke and CKD before replacement therapy. However, in high risk patients, defined by the presence of either cardiovascular disease or cardiovascular risk factors, different stages of CKD are clearly associated with subsequent stroke. In patients with stroke the exact prevalence of renal dysfunction is not known. Reported prevalence from a few published studies is up to 38% and it is higher than that in age-matched control groups. Furthermore, in patients suffering from stroke renal dysfunction is associated with short and long term mortality. The most effective treatment of stroke in patients with CKD is not known and further studies are needed.

Proteinuria and its relation to cardiovascular disease

Chronic kidney disease (CKD) and its associated morbidity pose a worldwide health problem. As well as risk of endstage renal disease requiring renal replacement therapy, cardiovascular disease is the leading cause of premature death among the CKD population. Proteinuria is a marker of renal injury that can often be detected earlier than any tangible decline in glomerular filtration rate. As well as being a risk marker for decline in renal function, proteinuria is now widely accepted as an independent risk factor for cardiovascular morbidity and mortality. This review will address the prognostic implications of proteinuria in the general population as well as other specific disease states including diabetes, hypertension and heart failure. A variety of pathophysiological mechanisms that may underlie the relationship between renal and cardiovascular disease have been proposed, including insulin resistance, inflammation, and endothelial dysfunction. As proteinuria has evolved into a therapeutic target for cardiovascular risk reduction in the clinical setting we will also review therapeutic strategies that should be considered for patients with persistent proteinuria.

Prevalence and associated factors of microalbuminuria in Chinese individuals without diabetes: cross-sectional study

OBJECTIVE

To investigate the prevalence of microalbuminuria (MAU) among Chinese individuals without diabetes and the relationship between MAU and metabolic factors, individual socioeconomic status (SES), and regional economic development level.

DESIGN

Cross-sectional study of prevalence of MAU.

SETTING

152 urban street districts and 112 rural villages from northeast, north, east, south central, northwest and southwest China.

PARTICIPANTS

46 239 participants were recruited using a multistage stratified sampling design from 2007 to 2008. A total of 41 290 participants without diabetes determined by oral glucose tolerance test were included in the present study. Urine albumin/creatinine ratio results of 35 430 individuals were available.

PRIMARY AND SECONDARY OUTCOME MEASURES

Positive detection of MAU was determined using an ACR of 22.1-299.9 mg/g in men 30.9-299.9 mg/g in women.

RESULTS

The prevalence of MAU in men was 22.4% and 24.5% in women. In developed, intermediate-developed and under-developed areas, the prevalence of MAU in men was 20.7%, 21.9% and 32.5%, respectively; in women the prevalence was 19.6%, 26.0% and 29.5%, respectively. The prevalence of MAU increased as the number of metabolic disorders present increased, and as the number of lower SES components increased (farmer, below university education level and low income). Prevalence of MAU in developed and intermediate developed areas had adjusted risk ratios of 0.52 (95% CI 0.42 to 0.60) and 0.65 (95% CI 0.57 to 0.76), respectively. Multivariate logistic analyses demonstrated MAU was strongly associated with older age, high-blood pressure, higher blood glucose low education level, low occupational level and residence in under-developed region.

CONCLUSIONS

Several factors had independent correlations to MAU in China: older age, metabolic abnormalities, lower SES level and living in economically under-developed areas, which encourage the development of strategies to lower the risk for MAU in these susceptible populations.

Titration of telmisartan, but not addition of amlodipine, reduces urine albumin in diabetic patients treated with telmisartan-diuretic

OBJECTIVES

Microalbuminuria is closely associated with an increased risk of renal and cardiovascular adverse outcomes. The present study tested the hypothesis that titration of telmisartan reduces urinary excretion of albumin more than does addition of amlodipine in patients treated with a standard dose of telmisartan combined with a low-dose diuretic for the same degree of blood pressure (BP) reduction.

METHODS

Hypertensive patients with type 2 diabetes mellitus and microalbuminuria under treatment with a combination of a standard dose of telmisartan (40 mg/day) and trichlormethiazide (1 mg/day) were randomly assigned to receive either an increased dose of telmisartan (80 mg/day) combined with trichlormethiazide [increased dose angiotensin receptor blocker (ARB) group, n = 20] or a combination consisting of telmisartan (40 mg/day), trichlormethiazide, and amlodipine (5 mg/day) (triple combination group, n = 20) for 6 months. The primary endpoint was a reduction in urinary albumin levels.

RESULTS

Although BP was reduced to a similar extent by the two regimens, patients receiving the increased dose ARB showed a higher reduction in urinary albumin (-37.4 ± 16.9%) than those on the triple combination regimen (-8.9 ± 23.7%; P < 0.0001). The reduction in urinary albumin was correlated with the drop in BP in the latter group, but not in the increased dose ARB group.

CONCLUSION

Uptitration of telmisartan more effectively reduces urinary albumin than addition of amlodipine in hypertensive patients with diabetes treated with a combination of telmisartan and diuretic for the same degree of BP reduction.

Significance of urine diagnostic tests after renal transplantation

BACKGROUND

Validity, reliability and clinical value of classical urinary parameters for transplant monitoring are controversial. Urinary parameters were analyzed regarding cost-effectiveness, frequency of urinary tract infection and prediction of renal graft function and rejection.

METHODS

Urinary parameters of the first two postoperative weeks of 120 renal transplant patients were retrospectively correlated with the postoperative course.

RESULTS

Creatinine levels were significantly different on each postoperative day between the groups with and without rejection. Osmolaluria, diuresis and serum creatinine are equivalent in predicting graft rejection. Osmolaluria is not suitable as a distinguishing criterion between graft rejection and other complications. Measurement of glucosuria has no diagnostic value. Proteinuria has no prognostic relevance regarding rejection, although proteinuria >0.5g/l occurred more often in patients with rejection. Despite antibiotic prophylaxis with co-trimoxazole, 41 of 120 patients (34%) suffered from urinary tract infection (UTI; mostly E. coli) within the first 14 days after transplantation.

CONCLUSIONS

The measurement of some classical urinary parameters delivers no diagnostic gain. UTIs are frequent despite antibiotic prophylaxis, but the use of urine cultures makes sense only if a (cheaper) semiquantitative test is positive.

Kidney-protective effects of azelnidipine versus a diuretic in combination with olmesartan in hypertensive patients with diabetes and albuminuria: a randomized study

BACKGROUND

A thiazide diuretic used in combination with benazepril is superior to amlodipine plus benazepril in reducing albuminuria in hypertensive patients with diabetes. However, calcium channel blockers have diverse characteristics. Thus, we investigated whether combining an angiotensin receptor blocker with either azelnidipine or a thiazide diuretic produced similar reductions in albuminuria in hypertensive diabetic patients for the same levels of blood pressure achieved.

METHODS

Hypertensive patients with type 2 diabetes and albuminuria (30-600 mg/g creatinine) under antihypertensive treatment (mean age 67.0±7.6 years) were instructed to stop all antihypertensive treatment and take a combination of olmesartan (20 mg/day) and amlodipine (5 mg/day) for 3 months (run-in period). Then, patients were randomly assigned to receive either olmesartan plus azelnidipine (16 mg/day; n=71) or olmesartan plus trichlormethiazide (1 mg/day; n=72) for an additional 6 months. The primary end point was urinary excretion of albumin at 6 months after randomization.

RESULTS

At the time of randomization, urinary albumin was 116.0 and 107.8 mg/g creatinine (geometric mean) in the azelnidipine and diuretic arms, respectively, and was reduced to a similar extent [79.8 (95% confidence interval 66.4-96.0) and 89.7 (74.6-107.7) mg/g creatinine, respectively, after adjustment for baseline values]. Blood pressure did not differ between the two groups throughout the study period.

CONCLUSIONS

Azelnidipine is equally effective as a thiazide diuretic in reducing urinary albumin when used in combination with olmesartan.

Trichostatin A, an HDAC class I/II inhibitor, promotes Pi-induced vascular calcification via up-regulation of the expression of alkaline phosphatase

AIM

Vascular calcification, a major complication of chronic kidney disease (CKD), refers to the mineralization of vascular smooth muscle cells (VSMCs), resulting from a phenotypic change towards osteoblast-like cells. Histone deacetylase inhibitors (HDIs), potential therapeutic agents for CKD, are known to promote the differentiation and mineralization of osteoblasts. In this study, we aimed to determine the effects of an HDI on the phenotypic change of VSMCs and the development of vascular calcification.

METHODS

The effect of trichostatin A (TSA), an HDI, on human aortic smooth muscle cells (HASMCs) was determined. The mineralization of HASMCs was induced by inorganic phosphorus (Pi), and was confirmed by quantitation of Ca levels and by von Kossa staining. Furthermore, we examined the effect of alkaline phosphatase (ALP) suppression using siRNA on Pi-induced vascular calcification in the presence or absence of TSA.

RESULTS

TSA increased the expression and activity of ALP in HASMCs at a concentration which showed an inhibitory effect of histone deacetylase (HDAC) activity but not on cell viability. Moreover, TSA promoted the Pi-induced mineralization of HASMCs. In addition, both phosphonoformic acid (PFA), which is a sodium-dependent phosphate transporter inhibitor, and suppression of ALP expression by siRNA markedly inhibited the TSA-promoted mineralization of HASMCs.

CONCLUSION

These data show that inhibition of HDAC activity promotes Pi-induced vascular calcification via the up-regulation of ALP expression. Taken together, HDIs may increase the risk of vascular calcification in CKD patients.

Prevalence of chronic kidney disease and its association with risk factors in disadvantageous population

The prevalence of kidney disease, particularly diabetic and hypertensive kidney disease is increasing rapidly specially in the disadvantageous group of population throughout the world. A cross sectional survey was carried out at certain selected slum areas of Mirpur in Dhaka city of Bangladesh over the period from July 2003 to June 2005, and a total of participants ranging from 15 to 65 years were studied. The analysis discovered that 4.1% of the participants were diabetic, 11.6% were hypertensive, and 7.7% had proteinuria. Based on MDRD equation, 13.1% of the participants were detected as having chronic kidney disease (CKD) while with Cockcroft-Gault equation 16% had CKD. Accordingly, the difference between the two equations was not significant. Association of sociodemographic factors with CKD was not significant except age more than 40 years and marital status. The association between CKD and risk factors like proteinuria, obese and overweight, use of tobacco, diabetes mellitus, and hypertension was highly significant. Combined prevalence of DM, hypertension, and proteinuria among CKD group was also demonstrated to be significantly higher (3.8% with Cockcroft-Gault equation and 5.3% with MDRD equation) than that of normal population. The survey data revealed that CKD and its risk factors like DM and hypertension are alarmingly high in disadvantageous population and adding further pressure to the existing burden of CKD.

Endothelial dysfunction and cardiovascular disease in early-stage chronic kidney disease: cause or association?

Chronic kidney disease (CKD) is strongly associated with cardiovascular disease (CVD); a graded inverse relationship between estimated glomerular filtration rate (eGFR) and cardiovascular event rates has emerged from large-scale observational studies. Chronic kidney disease is also associated with endothelial dysfunction (ED) although the precise relationship with GFR and the "threshold" at which ED begins are contentious. Abnormal endothelial function is certainly present in late-stage CKD but data in early-stage CKD appear confounded by disease states such as diabetes and hypertension which themselves promote ED. Thus, the direct effect of a reduction in GFR on endothelial function and, therefore, cardiovascular (CV) risk is far from completely established. In human studies, the precise duration of kidney impairment is seldom known and the onset of CVD often insidious, making it difficult to determine exactly when CVD first appears in the context of CKD. Kidney donors provide a near-ideal experimental model of CKD; subjects undergo an acute change from normal to modestly impaired renal function at the time of nephrectomy and lack the confounding co-morbidity that has made observational studies of CKD patients so challenging to interpret. By examining changes in endothelial function in living kidney donors before and after nephrectomy, useful insight might be gained into the pathophysiology of CVD in CKD and help determine whether targeting ED or the renal disease itself has the potential to reduce CV risk.