Therapeutic Exercise on Metabolic and Renal Outcomes in Patients with Chronic Kidney Disease: A Narrative Review

BACKGROUND

Chronic kidney disease (CKD) affects 11-13% of the world population. The main risk factors for CKD include diabetes, hypertension, and obesity. Metabolic syndrome (MS) is associated with the onset of CKD in the nondiabetic population. Obesity and MS are also risk factors for a worse progression of established CKD. Therapeutic exercise is an effective option to treat and manage obesity, MS, and diabetes in the general population. However, the evidence on the effect of exercise on patients with CKD, obesity, and MS is scarce.

SUMMARY

We evaluated available evidence on the effect of therapeutic exercise in patients with CKD, excluding dialysis, particularly in improving the metabolic risk factors and main renal outcomes: renal function loss and albuminuria/proteinuria. This review includes prospective studies and clinical trials. A total of 44 studies were analysed in 1,700 subjects with renal disease (2-5), including patients with renal transplantation. Most studies did not prove a major effect of exercise on albuminuria/proteinuria, glomerular filtration rate (GFR), obesity, or MS. These results are intriguing and deserve attention. The exploratory nature of most studies, including a low number of cases and short follow-up, might explain the lack of efficacy of exercise in our analysis. Specific aspects like the type of exercise, frequency, intensity, duration, accommodation during follow-up, individualization, safety, and adherence are crucial to the success of therapeutic exercise. The beneficial role of exercise in patients with CKD remains to be determined.

KEY MESSAGES

Key messages of this review are as follows. (1) The effect of therapeutic exercise on renal and metabolic outcomes in patients with CKD remains to be determined. (2) According to the evidence selected, therapeutic exercise seems to be safe to treat patients with CKD. (3) Most studies are exploratory by nature, with results that need further investigation. (4) Therapeutic exercise is a complex procedure that must be specifically designed to treat patients with CKD.

Efficacy and durability of multifactorial intervention on mortality and MACEs: a randomized clinical trial in type-2 diabetic kidney disease

BACKGROUND

Multiple modifiable risk factors for late complications in patients with diabetic kidney disease (DKD), including hyperglycemia, hypertension and dyslipidemia, increase the risk of a poor outcome. DKD is associated with a very high cardiovascular risk, which requires simultaneous treatment of these risk factors by implementing an intensified multifactorial treatment approach. However, the efficacy of a multifactorial intervention on major fatal/non-fatal cardiovascular events (MACEs) in DKD patients has been poorly investigated.

METHODS

Nephropathy in Diabetes type 2 (NID-2) study is a multicentre, cluster-randomized, open-label clinical trial enrolling 395 DKD patients with albuminuria, diabetic retinopathy (DR) and negative history of CV events in 14 Italian diabetology clinics. Centres were randomly assigned to either Standard-of-Care (SoC) (n = 188) or multifactorial intensive therapy (MT, n = 207) of main cardiovascular risk factors (blood pressure < 130/80 mmHg, glycated haemoglobin < 7%, LDL, HDL and total cholesterol < 100 mg/dL, > 40/50 mg/dL for men/women and < 175 mg/dL, respectively). Primary endpoint was MACEs occurrence by end of follow-up phase. Secondary endpoints included single components of primary endpoint and all-cause death.

RESULTS

At the end of intervention period (median 3.84 and 3.40 years in MT and SoC group, respectively), targets achievement was significantly higher in MT. During 13.0 years (IQR 12.4-13.3) of follow-up, 262 MACEs were recorded (116 in MT vs. 146 in SoC). The adjusted Cox shared-frailty model demonstrated 53% lower risk of MACEs in MT arm (adjusted HR 0.47, 95%CI 0.30-0.74, P = 0.001). Similarly, all-cause death risk was 47% lower (adjusted HR 0.53, 95%CI 0.29-0.93, P = 0.027).

CONCLUSION

MT induces a remarkable benefit on the risk of MACEs and mortality in high-risk DKD patients. Clinical Trial Registration ClinicalTrials.gov number, NCT00535925. https://clinicaltrials.gov/ct2/show/NCT00535925.

Clinical update: The important role of dual kidney function testing (ACR and eGFR) in primary care: Identification of risk and management in type 2 diabetes

Diabetic kidney disease (DKD) is common complication of type 1 and type 2 diabetes and may lead to progressive kidney dysfunction culminating in end-stage kidney disease. Kidney function is evaluated less frequently than other care procedures in patients with diabetes, even though the opportunity to identify DKD early and slow or even halt renal damage early in the disease progression represents a potentially important clinical opportunity for early intervention. The following review provides an overview of the under-recognised importance of kidney function in T2D and current best-practice to support the identification of DKD as part of primary care T2D management.

An updated overview of diabetic nephropathy: Diagnosis, prognosis, treatment goals and latest guidelines

Diabetic nephropathy (DN) is a major healthcare challenge. It occurs in up to 50% of those living with diabetes, is a major cause of end-stage kidney disease (ESKD) that requires treatment with dialysis or renal transplantation, and is associated with significantly increased cardiovascular morbidity and mortality. DN is a clinical syndrome characterized by persistent albuminuria and a progressive decline in renal function, but it is increasingly recognized that the presentation and clinical course of kidney disease in diabetes is heterogeneous. The term diabetic kidney disease (DKD) is now commonly used to encompass the spectrum of people with diabetes who have either albuminuria or reductions in renal function. In this article, the clinical presentation and approach to diagnosis of DKD will be discussed, as will its prognosis. The general principles of management of DKD will also be reviewed with reference to current international guidelines.

Mouse Umbilical Cord Mesenchymal Stem Cell Paracrine Alleviates Renal Fibrosis in Diabetic Nephropathy by Reducing Myofibroblast Transdifferentiation and Cell Proliferation and Upregulating MMPs in Mesangial Cells

Transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) is currently considered a novel therapeutic strategy for diabetic nephropathy (DN). However, the mechanisms by which UC-MSCs ameliorate renal fibrosis in DN are not well understood. Herein, we firstly investigated the therapeutic effects of mouse UC-MSC infusion on kidney structural and functional impairment in streptozotocin- (STZ-) induced diabetic mice. We found that the repeated injection with mUC-MSCs alleviates albuminuria, glomerulus injury, and fibrosis in DN mouse models. Next, mesangial cells were exposed to 5.6 mM glucose, 30 mM glucose, or mUC-MSC-conditioned medium, and then we performed western blotting, immunofluorescence, wound healing assay, and cell proliferation assay to measure extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs), myofibroblast transdifferentiation (MFT), and cell proliferation. We demonstrated that mUC-MSC paracrine decreased the deposition of fibronectin and collagen I by inhibiting TGF-β1-triggered MFT and cell proliferation mediated by PI3K/Akt and MAPK signaling pathways, and elevating the levels of MMP2 and MMP9. Importantly, we provided evidence that the antifibrosis role of mUC-MSC paracrine in DN might be determined by exosomes shed by MSCs. Together, these findings reveal the mechanisms underlying the therapeutic effects of UC-MSCs on renal fibrosis in DN and provide the evidence for DN cell-free therapy based on UC-MSCs in the future.

Intensive multifactorial intervention improved renal impairment in short-duration type 2 diabetes: A randomized, controlled, 7-year follow-up trial

AIMS

To investigate the effect of multifactorial intervention on the urinary albumin to creatinine ratio (UACR) and the estimated glomerular filtration rate (eGFR) in short-duration type 2 diabetes.

METHODS

A total of 150 type 2 diabetes patients, with disease duration <1 year and with no evidence of atherosclerosis were randomized to either the intensive intervention group (IG, n = 75), or the conventional group (CG, n = 75) for 7 years. The predefined endpoint of microvascular complications was the progression of renal impairments (the development of albuminuria and the change of eGFR).

RESULTS

The incidence of progression to albuminuria (UACR ≥30 mg/g) was 12% in IG and 28% in CG (HR 0.37, 95% CI: 0.19-0.70, P = .0025). eGFR was significantly lower in IG than that in CG in the year 2 (P = .043) and 3 (P = .032) follow-up. Sex, fasting plasma glucose (FPG), HbA1c, and systolic blood pressure (SBP) were independently associated with the UACR (β = -5.112, P = .015; β = 0.908, P = .045; β = 2.087, P = .038; and β = 2.787, P = .002, respectively); aging was independently associated with eGFR (β = -0.447, P = .000).

CONCLUSIONS

Intensive multifactorial intervention delayed the progression to albuminuria, and reduced eGFR rapidly in early stage of intervention in short-duration type 2 diabetes. FPG, HbA1c, and SBP were risk factors for UACR increase; aging was a risk factor for eGFR decline.

Beneficial impact of intensified multifactorial intervention on risk of stroke: outcome of 21 years of follow-up in the randomised Steno-2 Study

AIMS/HYPOTHESIS

Epidemiological studies have shown that diabetes is a well-established independent but modifiable risk factor for stroke. The aim of this post hoc analysis of data from the Steno-2 Study was to examine whether multiple risk factor intervention reduced the risk for stroke in individuals with type 2 diabetes and microalbuminuria.

METHODS

In the Steno-2 Study, 160 individuals with type 2 diabetes and microalbuminuria were randomised to intensified or conventional multiple risk factor intervention, targeting classical cardiovascular disease risk factors for a mean of 7.8 years, and then followed for a total mean of 21.2 years. The primary endpoint in this post hoc analysis was time to first stroke event.

RESULTS

During follow-up, 30 participants experienced a total of 39 strokes. Individuals randomised to conventional therapy were more likely to experience a stroke than those in the intensive-therapy group, with 29 total strokes occurring in 21 participants (26%) in the conventional-therapy group vs a total of ten strokes in nine participants (11%) in the intensive-therapy group (HR 0.31 [95% CI 0.14, 0.69]; p = 0.004). Also, the number of recurrent strokes was significantly reduced with intensive therapy.

CONCLUSIONS/INTERPRETATION

Intensified multiple risk factor intervention in patients with type 2 diabetes and microalbuminuria reduces the risk for strokes as well as the number of recurrent cerebrovascular events.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00320008.

Elevated levels of circulating microvesicles in coronary artery disease patients with type 2 diabetes and albuminuria: Effects of exercise training

OBJECTIVE

Circulating microvesicles, released from activated/apoptotic cells, are involved in vascular complications and may be looked upon as biomarkers. Albuminuria is characteristic of disease progression in type 2 diabetes mellitus. We aimed to investigate quantitative and qualitative differences of circulating microvesicles in type 2 diabetes mellitus with and without albuminuria and whether 12-month exercise training influenced expression of circulating microvesicles.

METHODS

Coronary artery disease patients with type 2 diabetes mellitus (n = 75), of which 25 had albuminuria, were included. Annexin V⁺ (AV⁺) circulating microvesicles were analysed by flow cytometry in citrated plasma. The exercise volume was 150 min per week.

RESULTS

In albuminuria patients, circulating microvesicles from endothelial-(CD146⁺/CD62E⁺/AV⁺) and endothelial-progenitor-(CD309⁺/CD34⁺/AV⁺) cells were significantly higher compared to those without (p ⩽ 0.01, both). Receiver operating characteristic curve analysis of the endothelial circulating microvesicles shows an area under the curve of 0.704 (95% confidence interval: 0.57-0.84; p = 0.004). Albuminuria patients had more circulating microvesicles derived from activated leukocytes and monocytes and monocytes carrying tissue factor (CD11b⁺/AV⁺, CD11b⁺/CD14⁺/AV⁺, CD142⁺/CD14⁺/AV⁺, respectively, p ⩽ 0.05, all) and higher number of circulating microvesicles from activated platelets (CD62P⁺/AV⁺). Within exercising patients, circulating microvesicles from progenitor cells increased (p = 0.023), however, not significantly different from controls.

CONCLUSION

Coronary artery disease patients with type 2 diabetes mellitus and albuminuria had elevated number of circulating microvesicles from activated blood and vascular cells, rendering them as potential predictors of disease severity. The circulating microvesicles were limitedly affected by long-term exercise training in our population.

A cost analysis of intensified vs conventional multifactorial therapy in individuals with type 2 diabetes: a post hoc analysis of the Steno-2 study

AIMS/HYPOTHESIS

Long-term follow-up of the Steno-2 study demonstrated that intensified multifactorial intervention increased median lifespan by 7.9 years and delayed incident cardiovascular disease by a median of 8.1 years compared with conventional multifactorial intervention during 21.2 years of follow-up. In this post hoc analysis of data from the Steno-2 study, we aimed to study the difference in direct medical costs associated with conventional vs intensified treatment.

METHODS

In 1993, 160 Danish individuals with type 2 diabetes and microalbuminuria were randomised to conventional or intensified multifactorial target-driven intervention for 7.8 years. Information on direct healthcare costs was retrieved from health registries, and the costs in the two groups of participants were compared by bootstrap t test analysis.

RESULTS

Over 21.2 years of follow-up, there was no difference in total direct medical costs between the intensified treatment group, €12,126,900, and the conventional treatment group, €11,181,700 (p = 0.48). The mean cost per person-year during 1996-2014 was significantly lower in the intensified treatment group (€8725 in the intensive group and €10,091 in the conventional group, p = 0.045). The main driver of this difference was reduced costs associated with inpatient admissions related to cardiovascular disease (p = 0.0024).

CONCLUSIONS/INTERPRETATION

Over a follow-up period of 21.2 years, we found no difference in total costs and reduced cost per person-year associated with intensified multifactorial treatment for 7.8 years compared with conventional multifactorial treatment. Considering the substantial gain in life-years and health benefits achieved with intensified treatment, we conclude that intensified multifaceted intervention in high-risk individuals with type 2 diabetes seems to be highly feasible when balancing healthcare costs and treatment benefits in a Danish healthcare setting.

Indicator of RNA oxidation in urine for the prediction of mortality in patients with type 2 diabetes and microalbuminuria: A post-hoc analysis of the Steno-2 trial

OBJECTIVE

The RNA oxidation product, 8-oxo-7,8-dihydroguanosine (8-oxoGuo), has been associated with mortality in patients with type 2 diabetes (T2D). However, the identification and the potential effect of approved treatments decreasing urine 8-oxoGuo level remain unraveled. In the Steno-2 study intensified multifactorial treatment compared with conventional multifactorial treatment reduced mortality in T2D patients with microalbuminuria by 45%. We assessed association between 8-oxoGuo at advanced baseline and total mortality with up to 19.9 years follow-up and from end of intervention to end of follow-up up to (up to 13.9 years).

MATERIALS AND METHODS

In 1993, 160 T2D patients with microalbuminuria were included in the Steno-2 trial. Urine samples from baseline were not available, but samples were available from 155 patients (97%) in 1995 (advanced baseline) and from 125 patients (96%) in 2001 (end of intervention). Hazard ratios (HR) for log2-transformed 8-oxoGuo and dichotomized (cut-off at median; low vs. high RNA oxidation) were estimated using Cox regressions.

RESULTS

During follow-up of 19.9 years after advanced baseline, 89 died and no association between 8-oxoGuo and mortality was found (p = 0.40). From the end of 7.8 years of intervention and during remaining 13.9 years of observation, 61 died and doubling the urine 8-oxoGuo level was associated with mortality with a HR 3.08 (95% CI [1.86 -5.12]; p < 0.001) after multiple adjustments. Patients with low 8-oxoGuo in the intensified-treatment had the lowest risk of dying compared with high 8-oxoGuo in the conventional-treatment both from advanced baseline onwards, adjusted HR 0.40 (95% CI [0.21 -0.75]; p = 0.004), and from end of intervention onwards, adjusted HR 0.28 (95% CI [0.13 -0.61]; p = 0.001).

CONCLUSIONS

In T2D patients with microalbuminuria, high levels of urine 8-oxoGuo after 7.8 years of multifactorial intervention was associated with higher mortality during 13.9 years of post-trial follow-up. Patients with low 8-oxoGuo in the intensified treatment group had the lowest risk of dying.

Effects of intensive interventions compared to standard care in people with type 2 diabetes and microalbuminuria on risk factors control and cardiovascular outcomes: A systematic review and meta-analysis of randomised controlled trials

AIMS

The effect of intensive glycaemic control, blood pressure control and lipid levels control alone or as part of a multifactorial intervention has not been fully evaluated. We aimed to estimate the effects of more intensive interventions, compared with standard care, on risk factor control and cardiovascular outcomes in people with type 2 diabetes and microalbuminuria.

METHODS

We searched MEDLINE, Embase and the Cochrane library without language restrictions from inception to August 10, 2018. We included randomised controlled trials that evaluated intensive interventions in adults with type 2 diabetes and microalbuminuria. The review was registered on PROSPERO (registration number 42017055208). We used random effects meta-analysis to calculate overall pooled effect estimates across studies.

RESULTS

A total of seven (n = 1210) randomised controlled trials were included, four studies (n = 758) reported HbA1c, six studies (n = 950) reported blood pressure measurements, and three studies (n = 896) examined non-fatal MI, non-fatal stroke, cardiovascular mortality, and all-cause mortality. Intensive interventions indicated statistically significant reductions in both systolic and diastolic blood pressure, and a nonsignificant trend for reduction in HbA1c, total cholesterol, LDL, triglycerides and urinary albumin excretion rate. There was no evidence to suggest that compared with standard care, intensive interventions reduced the risk of non-fatal MI [risk ratio (RR) 0·50; 95% CI 0·20, 1·22; P = 0·127], non-fatal stroke (RR 0·44; 95% CI 0·10, 1·91; P = 0·275), CV mortality (RR 0·95; 95% CI 0·48, 1·86; P = 0·874) or all-cause mortality (RR 0·80; 95% CI 0·51, 1·25; P = 0·324).

CONCLUSIONS

Apart from blood pressure outcomes, there was no evidence that intensive interventions improve or worsen HbA1c, total cholesterol, LDL, triglycerides, urinary albumin excretion rate, risk of cardiovascular or mortality outcomes in people with type 2 diabetes and microalbuminuria. Results of this review are mainly influenced by one small trial, hence uncertainty surrounding the effect of intensive interventions in people with type 2 diabetes and microalbuminuria still exists. Large studies are urgently required in this high risk cardiovascular group of patients.

Reduced risk of heart failure with intensified multifactorial intervention in individuals with type 2 diabetes and microalbuminuria: 21 years of follow-up in the randomised Steno-2 study

AIMS/HYPOTHESIS

In type 2 diabetes mellitus, heart failure is a frequent, potentially fatal and often forgotten complication. Glucose-lowering agents and adjuvant therapies modify the risk of heart failure. We recently reported that 7.8 years of intensified compared with conventional multifactorial intervention in individuals with type 2 diabetes and microalbuminuria in the Steno-2 study reduced the risk of cardiovascular disease and prolonged life over 21.2 years of follow-up. In this post hoc analysis, we examine the impact of intensified multifactorial intervention on the risk of hospitalisation for heart failure.

METHODS

One hundred and sixty individuals were randomised to conventional or intensified multifactorial intervention, using sealed envelopes. The trial was conducted using the Prospective, Randomised, Open, Blinded Endpoints (PROBE) design. After 7.8 years, all individuals were offered intensified therapy and the study continued as an observational follow-up study for an additional 13.4 years. Heart-failure hospitalisations were adjudicated from patient records by an external expert committee blinded for treatment allocation. Event rates were compared using a Cox regression model adjusted for age and sex.

RESULTS

Eighty patients were assigned to each treatment group. Ten patients undergoing intensive therapy vs 24 undergoing conventional therapy were hospitalised for heart failure during follow-up. The HR (95% CI) was 0.30 (0.14, 0.64), p = 0.002 in the intensive-therapy group compared with the conventional-therapy group. Including death in the endpoint did not lead to an alternate overall outcome; HR 0.51 (0.34, 0.76), p = 0.001. In a pooled cohort analysis, an increase in plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) during the first two years of the trial was associated with incident heart failure.

CONCLUSIONS/INTERPRETATION

Intensified, multifactorial intervention for 7.8 years in type 2 diabetic individuals with microalbuminuria reduced the risk of hospitalisation for heart failure by 70% during a total of 21.2 years of observation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00320008.

Regression of albuminuria and its association with incident cardiovascular outcomes and mortality in type 1 diabetes: the FinnDiane Study

AIMS/HYPOTHESIS

Our aim was to assess regression of albuminuria and its clinical consequences in type 1 diabetes.

METHODS

The analysis included 3642 participants from the Finnish Diabetic Nephropathy (FinnDiane) Study with a 24 h urine sample and a history of albuminuria available at baseline. A total of 2729 individuals had normal AER, 438 a history of microalbuminuria and 475 a history of macroalbuminuria. Regression was defined as a change from a higher category of albuminuria pre-baseline to a lower category in two out of the three most recent urine samples at baseline. The impact of regression on cardiovascular events (myocardial infarction, stroke, coronary procedure) and mortality was analysed over a follow-up of 14.0 years (interquartile range 11.9-15.9).

RESULTS

In total, 102 (23.3%) individuals with prior microalbuminuria and 111 (23.4%) with prior macroalbuminuria had regressed at baseline. For individuals with normal AER as a reference, the age-adjusted HRs (95% CI) for cardiovascular events were 1.42 (0.75, 2.68) in individuals with regression from microalbuminuria, 2.62 (1.95, 3.54) in individuals with sustained microalbuminuria, 3.15 (2.02, 4.92) in individuals with regression from macroalbuminuria and 5.49 (4.31, 7.00) in individuals with sustained macroalbuminuria. Furthermore, for all-cause and cardiovascular mortality rates, HRs in regressed individuals were comparable with those with sustained renal status at the achieved level (i.e. those who did not regress but remained at the most advanced level of albuminuria noted pre-baseline).

CONCLUSIONS/INTERPRETATION

Progression of diabetic nephropathy confers an increased risk for cardiovascular disease and premature death. Notably, regression reduces the risk to the same level as for those who did not progress.

Moderate salt restriction with or without paricalcitol in type 2 diabetes and losartan-resistant macroalbuminuria (PROCEED): a randomised, double-blind, placebo-controlled, crossover trial

BACKGROUND

Macroalbuminuria predicts renal and cardiovascular events in patients with type 2 diabetes. We aimed to assess the albuminuria-lowering effects of salt restriction, paricalcitol therapy, or both, in this population.

METHODS

In this randomised, double-blind, placebo-controlled, crossover trial, we recruited adult patients with type 2 diabetes from six diabetology outpatient clinics in northern Italy, with 24 h albuminuria of more than 300 mg despite 100 mg per day losartan therapy, blood pressure of less than 140/90 mm Hg, serum creatinine concentration of less than 2 mg/dL, stable renal function on stable renin-angiotensin system inhibitor therapy with a fixed dose of losartan, parathyroid hormone concentration of 20 pg/mL to <110 pg/mL, serum calcium concentration of less than 9·5 mg/dL, and serum phosphate concentration of less than 5 mg/dL, who had been more than 80% compliant with placebo treatment during a 1 month placebo run-in. We allocated patients 1:1 with computer-generated randomisation to an open-label 3 month high-sodium (>200 mEq [4·8 g] per day) or low-sodium (<100 mEq [2·4 g] per day) diet and, within each diet group, to a 1 month double-blind treatment period of oral paricalcitol (2 μg per day) or placebo, followed by 1 month of placebo washout and then a further 1 month double-blind treatment period of paricalcitol or placebo in which patients crossed over to the opposite treatment period. The primary outcome was 24 h albuminuria (median of three consecutive measurements). Analyses were modified intention-to-treat (including all randomly allocated patients who took at least one dose of study drug and had an efficacy measurement after the first treatment period). Patients and investigators were masked to paricalcitol and placebo assignment. Those assessing outcomes were masked to both study drug and diet assignment. This study is registered with ClinicalTrials.gov, number NCT01393808, and the European Union Clinical Trials Register, number 2011-001713-14.

FINDINGS

Between Dec 13, 2011, and Feb 17, 2015, we randomly allocated 57 (50%) patients to a low-sodium diet (28 [49%] to paricalcitol then placebo and 29 [51%] to placebo then paricalcitol) and 58 (50%) to a high-sodium diet (29 [50%] to paricalcitol then placebo and 29 [50%] to placebo then paricalcitol). In the low-sodium group (30 mEq of daily sodium intake reduction, equivalent to approximately 1·7-1·8 g per day), 24 h albuminuria was reduced by 36·6% (95% CI 28·5-44·9) from 724 mg (441-1233) at baseline to 481 mg (289-837) at month 3 (p<0·0001), but no significant change occurred in the high-sodium group (from 730 mg [416-1227] to 801 mg [441-1365]; 2·9% [-16·8 to 16·4] increase; p=0·50). Changes between diet groups differed by 32·4% (17·2-48·8; p<0·0001) and correlated with changes in natriuresis (r=0·43; p<0·0001). On the high-sodium diet, paricalcitol reduced the salt-induced albuminuria increase by 17·8% (3·9-32·3) over the month of treatment compared with placebo (p=0·02), whereas on the low-sodium diet, paricalcitol did not have a significant effect versus placebo (increase of 4·1% [-9·3 to 21·6]; p=0·59). During placebo treatment, albuminuria decreased with the low-sodium diet (p=0·0002) and did not significantly change with the high-sodium diet, but changes were significantly different between diet groups (p=0·0004). Treatment was well tolerated and no patients withdrew from the study because of treatment-related effects. 67 adverse events occurred in 52 (45%) patients during paricalcitol treatment and 44 events occurred in 36 (31%) patients during placebo treatment. During paricalcitol therapy, 14 cases of hypercalciuria, six cases of hypercalcaemia, and five cases of hyperphosphataemia were reported in one patient each, all of which were possibly treatment related. One case of hypercalciuria was reported in one patient during the placebo treatment period. One stroke and one coronary event occurred during paricalcitol therapy. No patients died during the study.

INTERPRETATION

In patients with macroalbuminuria and type 2 diabetes, moderate salt restriction enhances the antialbuminuric effect of losartan, an effect that could be nephroprotective and cardioprotective in the long term. The finding that paricalcitol prevents a sodium-induced increase in albuminuria provides support for trials to test the long-term risk-benefit profile of paricalcitol add-on therapy in patients with type 2 diabetes and macroalbuminuria refractory to dietary salt restriction, including patients refractory to even moderate salt restriction.

FUNDING

AbbVie.

Chronic organ failure in adult sickle cell disease

Sickle cell disease is now a chronic adult illness characterized by progressive multiorgan failure, particularly involving the brain and kidney. The etiology is multifactorial; it includes hemolysis and nitric oxide deficiency. As patients age, most experience neurologic insult. Twenty-five percent of older adults have had a clinical stroke and at least half of the population have had a silent infarct, cortical atrophy, and neurocognitive impairment. Periodic screening with neuroimaging and neurocognitive testing is recommended. Identification and correction of modifiable risk factors such as nocturnal hypoxemia, obstructive sleep apnea, and physical exercise programs should be implemented. Patients with neurocognitive impairment require cognitive remediation and educational accommodations. Chronic renal disease occurs in 25% of older adults and results in 50% of their deaths. Renal failure often develops insidiously. It can be prevented or minimized by early screening and treatment of modifiable risk factors including hypertension and microalbuminuria. There is an increasing number of therapeutic options, including inhibitors of the renin angiotensin system, angiotensin-II receptor blockers, endothelin-1 receptor antagonist, and haptoglobin therapy. Patients with sickle cell disease have increased mortality rates from renal failure compared with nonsickle cell patients, in part from a lack of access to early multidisciplinary care, including timely initiation of dialysis and renal transplantation.

A Population-Based Analysis of Quality Indicators in CKD

BACKGROUND AND OBJECTIVES

Awareness of CKD remains low in comparison with other chronic diseases, such as diabetes, leading to low use of preventive medications and appropriate testing. The objective of this study was to evaluate the quality of care provided to people with and at risk of CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a population-based analysis of all Albertans with eGFR=15-59 ml/min per 1.73 m2 between April 1, 2011 and March 31, 2012 as well as patients with diabetes (as of March 31, 2012). We assessed multiple quality indicators in people with eGFR=15-59 ml/min per 1.73 m2, including appropriate risk stratification with albuminuria testing and preventive medication use and screened people with diabetes using urine albumin-to-creatinine ratio and serum creatinine measurements.

RESULTS

Among 96,480 adults with eGFR=15-59 ml/min per 1.73 m2, we found that 17.0% of those without diabetes were appropriately risk stratified with a measure of albuminuria compared with 64.2% of those with diabetes (P<0.001). Of those with eGFR=15-59 ml/min per 1.73 m2 and moderate or severe albuminuria, 63.2% of those without diabetes received an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker compared with 82.1% in those with diabetes (P<0.001). Statin use was also significantly lower in patients with eGFR=15-59 ml/min per 1.73 m2 without diabetes (39.2%) compared with those with diabetes (64.6%; P<0.001). Among 235,649 adults with diabetes, only 41.8% received a urine albumin-to-creatinine ratio and 73.2% received a serum creatinine measurement over 1 year.

CONCLUSIONS

We identified large gaps in care, especially in those with CKD but no diabetes. The largest gap was in the prescription of guideline-concordant medication in those with CKD as well as appropriate screening for albuminuria in those with diabetes. Our work illustrates the importance of measuring health system performance as the first step in a quality improvement process to improve care and outcomes in CKD.

Years of life gained by multifactorial intervention in patients with type 2 diabetes mellitus and microalbuminuria: 21 years follow-up on the Steno-2 randomised trial

AIMS/HYPOTHESIS

The aim of this work was to study the potential long-term impact of a 7.8 years intensified, multifactorial intervention in patients with type 2 diabetes mellitus and microalbuminuria in terms of gained years of life and years free from incident cardiovascular disease.

METHODS

The original intervention (mean treatment duration 7.8 years) involved 160 patients with type 2 diabetes and microalbuminuria who were randomly assigned (using sealed envelopes) to receive either conventional therapy or intensified, multifactorial treatment including both behavioural and pharmacological approaches. After 7.8 years the study continued as an observational follow-up with all patients receiving treatment as for the original intensive-therapy group. The primary endpoint of this follow-up 21.2 years after intervention start was difference in median survival time between the original treatment groups with and without incident cardiovascular disease. Non-fatal endpoints and causes of death were adjudicated by an external endpoint committee blinded for treatment allocation.

RESULTS

Thirty-eight intensive-therapy patients vs 55 conventional-therapy patients died during follow-up (HR 0.55 [95% CI 0.36, 0.83], p = 0.005). The patients in the intensive-therapy group survived for a median of 7.9 years longer than the conventional-therapy group patients. Median time before first cardiovascular event after randomisation was 8.1 years longer in the intensive-therapy group (p = 0.001). The hazard for all microvascular complications was decreased in the intensive-therapy group in the range 0.52 to 0.67, except for peripheral neuropathy (HR 1.12).

CONCLUSIONS/INTERPRETATION

At 21.2 years of follow-up of 7.8 years of intensified, multifactorial, target-driven treatment of type 2 diabetes with microalbuminuria, we demonstrate a median of 7.9 years of gain of life. The increase in lifespan is matched by time free from incident cardiovascular disease.

TRIAL REGISTRATION

ClinicalTrials.gov registration no. NCT00320008.

FUNDING

The study was funded by an unrestricted grant from Novo Nordisk A/S.

[Diagnosis and management of chronic kidney disease in children: Guidelines of the French Society of Pediatric Nephrology]

These guidelines are intended to assist physicians in the care of children with chronic kidney disease (CKD), defined in children as in adults, regardless of its cause. Often silent for a long time, CKD can evolve to chronic renal failure or end-stage renal disease. Its management aims at slowing disease progression and treating CKD complications as soon as they appear. The different aspects of pediatric CKD care are addressed in these guidelines (screening, treatment, monitoring, diet, quality of life) as proposed by the French Society of Pediatric Nephrology. Highly specialized care provided in the hospital setting by pediatric nephrologists is not detailed.

Mechanisms underpinning remission of albuminuria following bariatric surgery

PURPOSE OF REVIEW

Albuminuria is a biomarker of renal injury commonly used to monitor progression of diabetic kidney disease. The appearance of excess albumin in the urine reflects alterations in the structure and permeability of the glomerular filtration barrier. The present article summarizes the clinical evidence base for remission of albuminuria after bariatric surgery. It furthermore focuses on how beneficial impacts on glomerular podocyte structure and function may explain this phenomenon.

RECENT FINDINGS

A coherent clinical evidence base is emerging demonstrating remission of albuminuria following bariatric surgery in patients with obesity and diabetes. The impaired metabolic milieu in diabetic kidney disease drives podocyte dedifferentiation and death through glucotoxic, lipotoxic proinflammatory, and pressure-related stress. Improvements in these parameters after surgery correlate with improvements in albuminuria and preclinical studies provide mechanistic data that support the existence of cause-effect relationship.

SUMMARY

The benefits of bariatric surgery extend beyond weight loss in diabetes to encompass beneficial effects on diabetic renal injury. Attenuation of the toxic metabolic milieu that the podocyte is exposed to postbariatric surgery suggests that the restitution of podocyte health is a key cellular event underpinning remission of albuminuria.

Reversibility of albuminuria and continuous positive airway pressure compliance in patients of obstructive sleep apnea syndrome

A positive correlation between albuminuria and severity of obstructive sleep apnea syndrome (OSAS) has been demonstrated, as indexed by urine albumin-to-creatinine ratios (UACRs). However, the effect of continuous positive airway pressure (CPAP) treatment on albuminuria in OSAS patients has not been established.Sixty subjects, with apnea-hypopnea indices >15 events per hour and no other diagnoses associated with albuminuria, underwent overnight polysomnography for sleep apnea and were examined for UACR at baseline and after 6 months of CPAP therapy. CPAP compliance rates were also recorded.Significant improvement in UACR was found in OSAS patients with good compliance to CPAP treatment after 6 months of therapy (baseline vs 6-month follow-up, 32.0 ± 9.5 vs 19.2 ± 6.5 mg/g, respectively, P = 0.007), whereas slight worsening in UACRs was noted in patients with poor compliance to CPAP treatment (baseline vs 6-month follow-up, respectively, 16.7 ± 4.4 vs 19.1 ± 6.3 mg/g, respectively, P = 0.39). Change in UACR was significant between poor compliance versus good compliance groups (2.4 ± 2.7 vs -12.8 ± 4.4 mg/g, respectively, t = 2.9, P = 0.005). A significant correlation between improvement in UACR and CPAP compliance rates was also noted (Spearman's correlation coefficient: -0.37, P = 0.007). Baseline UACR, good CPAP compliance, and body mass index were independent predictors of changes in UACR.Adequate CPAP treatment improves albuminuria in OSAS patients. In addition to monitoring CPAP adherence and subjective sleepiness, UACR may offer an objective physiological index of CPAP therapeutic effectiveness.

Albuminuria is Not an Appropriate Therapeutic Target in Patients with CKD: The Con View

Albuminuria is a risk factor for progression of kidney disease. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers slow the progression to ESRD, an effect that is correlated with reduction in albuminuria. This has led to the hypothesis that albuminuria should be a target for therapy. This work argues that there are issues with this hypothesis. The previously reported studies were not designed to test the hypothesis that achieving a specific albuminuria target would be beneficial in and of itself irrespective the mechanism used to achieve that goal. One cannot assume that the beneficial effect observed was causally related to the effect on albuminuria or that it would extend to other interventions. Most importantly, it is not known if the approach of maximizing therapy to reduce proteinuria is safe. Recent studies have shown that combining renin-angiotensin system therapies decreases albuminuria without significant clinical benefit but with increased risk of adverse events. More studies are needed, but at this time, albuminuria has not jumped the hurdle needed to be accepted as a surrogate end point or target for treatment. Primum non nocere, first do no harm.

[Clinical controlled trial on chronic nephritis albuminuria treated with acupuncture and moxibustion at DONG's extra points, "Xiasanhuana"]

OBJECTIVE

Io compare the difference on the clinical efficacy in treatment of chronic nephritis albuminuria between acupuncture and moxibustion at "Xiasanhuang", DONG's extra points and benazepril hydrochloride so as to provide the effective therapeutic method for the treatment of chronic nephritis albuminuria. Methods One hundred and six cases of nephritis albuminuria were randomized into an acupuncture and moxibustion group and a western medication group, 53 cases in each one. In the acupuncture and moxibustion group, acupuncture and moxibustion were applied to "Xiasanhuang" (Tianhuang fuxue namely "shenguan", "Dihuang", "Renhuang"), once a day, the interval of 2 days once every 10 treatments. In the western medication group, benazepril hydrochloride was prescribed for oral administration, 5 to 10 mg each time, once a day. The treatment of 2 months made, one session in the two groups. After 1 session treatment, the clinical efficacy, red blood cell count (RBC) of urinary sediment, 24 h urine protein quantitation and creatinine clearance rate (Ccr) before and after treatment were observed in the two groups.

RESULTS

The total effective rate was 84. 9% (45/53) in the acupuncture and moxibustion group, superior to 52. 8% (28/53) in the western medication group (P<0. 01). After treatment, RBC of urinary sediment and 24 h urine protein quantitation were reduced as compared with those before treatment (P< 0. 01, P<0. 05), and the results in the acupuncture and moxibustion group were lower than those in the western medication group (P<0. 05, P<0. 01). After treatment, Ccr in the acupuncture and moxibustion group was higher than that before treatment (P<0. 05) and higher than that in the western medication group (P<0. 05). Ccr was not different significantly before and after treatment in the western medication group (P>0. 05).

CONCLUSION

Acupuncture and moxibustion at DONG's extra points (Xiasanhuang) reduce proteinuria and improve kidney, function in patients of chronic nephritis and the efficacy is better than that with benazepril hydrochloride.

Relationship between the brain natriuretic peptide (BNP) level and remission of diabetic nephropathy with microalbuminuria: a 3-year follow-up study

The aim of the study was to examine the relationship between the brain natriuretic peptide (BNP) level and progression or remission of diabetic nephropathy with microalbuminuria for 3 years. The subjects were 100 Japanese type 2 diabetes mellitus outpatients with microalbuminuria. Associations between metabolic parameters at baseline [HbA1c, systolic blood pressure (SBP), urine albumin-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and BNP] and the progression or remission of diabetic nephropathy were examined for 3 years. A total of 83 patients were examined at the end of the 3-year period, including 17 with remission to normoalbuminuria, 47 with continuing microalbuminuria, and 19 with progression to macroalbuminuria. HbA1c, ACR, and BNP differed significantly among the 3 groups (p=0.024, p<0.001, p=0.002, respectively). Among baseline factors, HbA1c and BNP were significant predictors of the percentage increase in ACR for 3 years in multiple linear regression analysis (β=0.259, p=0.02; β=0.299, p=0.007, respectively). In multivariate logistic regression analysis, HbA1c and ACR were independently associated with progression of diabetic nephropathy (p=0.008, p=0.023, respectively), and ACR and BNP were independently associated with remission of diabetic nephropathy (p=0.029, p=0.012, respectively). ROC curve analysis gave a cutoff value for BNP of 14.9 pg/ml for prediction of remission of diabetic nephropathy (p=0.016). The BNP level has a relationship with diabetic nephropathy and a low BNP level predicts remission of diabetic nephropathy. Therefore, monitoring of BNP can play an important role in management of diabetic nephropathy.

Helicobacter pylori eradication reduces microalbuminuria in type-2 diabetic patients: a prospective study

AIM

To evaluate the effect of Helicobacter Pylori (H. pylori) eradication on microalbuminuria in type 2 diabetic patients.

METHODS

Consecutive patients with dyspepsia, type 2 diabetes mellitus and microalbuminuria were recruited. Upper gastrointestinal endoscopy and rapid urease test (H. pylori fast) were performed for detecting H. pylori infection. Patients with H. pylori infection were given triple treatment. Urea breath tests were performed for all patients after eradication treatment. According to the eradication status, patients were divided into two groups, as H. pylori negative, group 1 (successful eradication group) and H. pylori positive, group 2 (unsuccessful eradication group). Twenty-four hour urine was also collected from all patients at baseline and after H. pylori eradication treatment.

RESULTS

A total of 69 patients were included in the study. There were no significant differences between groups for anthropometric measurements and laboratory tests at baseline (p > 0.05). An expected significant difference was found for microlabuminuria and fasting glucose between the two groups. Microalbuminuria and fasting glucose levels were signicantly reduced in the H. pylori negative group compared with the H. pylori positive group after eradication treatment (p < 0.05). Although there was no significant decline in HbA1c levels in the H. pylori negative group, there were relatively lower HbA1c levels compared with baseline for both groups. The rate of attaining normoalbuminuria after eradication was significantly higher in group 1 compared to group 2 (p < 0.05).

CONCLUSION

H. Pylori eradication was found to have a favorable effect on reducing microalbuminuria in diabetic patients.

Long-term survival and dialysis dependency following acute kidney injury in intensive care: extended follow-up of a randomized controlled trial

BACKGROUND

The incidence of acute kidney injury (AKI) is increasing globally and it is much more common than end-stage kidney disease. AKI is associated with high mortality and cost of hospitalisation. Studies of treatments to reduce this high mortality have used differing renal replacement therapy (RRT) modalities and have not shown improvement in the short term. The reported long-term outcomes of AKI are variable and the effect of differing RRT modalities upon them is not clear. We used the prolonged follow-up of a large clinical trial to prospectively examine the long-term outcomes and effect of RRT dosing in patients with AKI.

METHODS AND FINDINGS

We extended the follow-up of participants in the Randomised Evaluation of Normal vs. Augmented Levels of RRT (RENAL) study from 90 days to 4 years after randomization. Primary and secondary outcomes were mortality and requirement for maintenance dialysis, respectively, assessed in 1,464 (97%) patients at a median of 43.9 months (interquartile range [IQR] 30.0-48.6 months) post randomization. A total of 468/743 (63%) and 444/721 (62%) patients died in the lower and higher intensity groups, respectively (risk ratio [RR] 1.04, 95% CI 0.96-1.12, p = 0.49). Amongst survivors to day 90, 21 of 411 (5.1%) and 23 of 399 (5.8%) in the respective groups were treated with maintenance dialysis (RR 1.12, 95% CI 0.63-2.00, p = 0.69). The prevalence of albuminuria among survivors was 40% and 44%, respectively (p = 0.48). Quality of life was not different between the two treatment groups. The generalizability of these findings to other populations with AKI requires further exploration.

CONCLUSIONS

Patients with AKI requiring RRT in intensive care have high long-term mortality but few require maintenance dialysis. Long-term survivors have a heavy burden of proteinuria. Increased intensity of RRT does not reduce mortality or subsequent treatment with dialysis.

TRIAL REGISTRATION

www.ClinicalTrials.govNCT00221013.

[Albuminuria in the diabetic patient: practical management]

Diabetic Nephropathy is the most common cause of end stage renal disease in Western countries. An increased urinary albumin excretion represents a characteristic sign of diabetic kidney damage. Regular screening for microalbuminuria allows early detection and timely intervention. In overt diabetic nephropathy, quantification of albuminuria helps monitoring disease progression. Therapeutic interventions to reduce albuminuria retard progression of nephropathy and reduce cardiovacular mortality, since albuminuria represents an independent cardiovascular risk factor. This review article describes the natural history of diabetic nephropathy and discusses practical issues for the measurement of albuminuria. Available prophylactic and therapeutic measures, particularly glycemic control and inhibition of the renin-angiotensin-aldosteron system, are reviewed using an evidence based approach.

The role of urinary TGF-β₁, TNF-α, IL-6 and microalbuminuria for monitoring therapy in posterior urethral valves

BACKGROUND

Long-term renal deterioration is common in patients with posterior urethral valves (PUV), and early identification of detrimental factors can help in counselling patients as well as in guiding future therapy. The aim of our study was (1) to evaluate urinary transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) levels and microalbuminuria before and after ablation of PUV and (2) to examine the effect of early induction of angiotensin-converting enzyme inhibitors (ACE-I) on renal recovery.

METHODS

The study included 30 patients with diagnosed PUV. Urinary cytokines were measured pre-operatively and post-operatively for 1 year. The study group was subdivided into two subgroups at 6 months after surgery. Group 1 included 16 patients whose urinary TGF-β1 level showed a declining trend. Group 2 included 14 patients whose urinary TGF-β1 showed a rising trend or plateaued; these patients were started on ACE-I therapy, which they received for at least 6 months.

RESULTS

Urinary TGF-β1, TNF-α and microalbumin levels were high in patients with PUV. In Group 1 patients, urinary TGF-β1, TNF-α and microalbumin levels fell significantly following valve ablation and continued to decline for 12 months. In Group 2 patients, after an initial fall following valve ablation, urinary TGF-β1, TNF-α and microalbumin showed a continued rise until 6 months post-surgery. After ACE-I therapy, there was 53.43 % fall in urinary TGF-β1, 43.15 % fall in microalbuminuria, 28.57 % improvement in split renal function and 35.80 % improvement in GFR.

CONCLUSIONS

Based on our results, urinary TGF-β1, urinary TNF-α and microalbuminuria can be used as biomarkers for the early recognition of ongoing renal damage in patients with PUV. ACE-I plays a role in retarding renal damage in these patients.

Microalbuminuria as a risk factor for cardiovascular disease in healthy individuals: a case report and review of the literature

Cardiovascular disease without significant traditional risk factors is uncommon. Microalbuminuria has been linked with an increased risk of cardiovascular disease in the diabetic and hypertensive patient. However, a similar influence of microalbuminuria on risk for cardiovascular disease occurs in individuals without diabetes or hypertension, and predicts all-cause and cardiovascular disease mortality in the nondiabetic and general population. Microalbuminuriais a risk factor commonly overlooked despite evidence of being an independent marker for cardiovascular disease. We report a case of a myocardial infarction occurring in an otherwise healthy 64-year-old male with microalbuminuria, without traditional cardiovascular risk factors. Awareness of microalbuminuria as an early diagnostic marker for cardiovascular disease (CVD) is essential in the risk assessment of otherwise healthy individuals.

Albuminuria and its correlates in type 2 diabetic patients

INTRODUCTION

The aim of this study was to determine the prevalence of albuminuria and its correlates and investigate disease management for patients with type 2 diabetes mellitus in Ahvaz.

MATERIALS AND METHODS

This was a cross-sectional study on the 350 patients with type 2 diabetes mellitus attending the Diabetes Clinic at Golestan Hospital, from October 2010 to September 2011. Demographic characteristics were recorded and height, weight, and blood pressure were measured. Blood urea nitrogen and serum levels of creatinine, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, and glycosylated hemoglobin A were measured in fasting blood samples. Spot urine and 24-hour urine collection were tested for albumin and kidney ultrasonography was done.

RESULTS

A total of 72 of 350 patients (20.6%) had microalbuminuria and 18 (5.1%) had macroalbuminuria. Elevated serum creatinine was seen in 6.9% and azotemia in 6.0%. In multivariable analysis, blood urea nitrogen level, glycosylated hemoglobin A, and duration of diabetes mellitus were associated with urinary albumin excretion (P = .04). A small proportion of the participants achieved optimal treatment goals for modifiable risk factors.

CONCLUSIONS

Abnormal urinary albumin excretion is seen in one-quarter of type 2 diabetic patients and a small but important number of them have azotemia. Albuminuria was found to be associated with long-term duration of diabetes mellitus, poor glucose control (revealed by high glycosylated hemoglobin A levels), and high blood urea nitrogen. Poor glycemic control may have a significant role in the progression of diabetic nephropathy in these patients.

CD40 gene silencing reduces the progression of experimental lupus nephritis modulating local milieu and systemic mechanisms

Lupus nephritis (LN) is an autoimmune disorder in which co-stimulatory signals have been involved. Here we tested a cholesterol-conjugated-anti-CD40-siRNA in dendritic cells (DC) in vitro and in a model of LPS to check its potency and tissue distribution. Then, we report the effects of Chol-siRNA in an experimental model of mice with established lupus nephritis. Our in vitro studies in DC show a 100% intracellular delivery of Chol-siRNA, with a significant reduction in CD40 after LPS stimuli. In vivo in ICR mice, the CD40-mRNA suppressive effects of our Chol-siRNA on renal tissue were remarkably sustained over a 5 days after a single preliminary dose of Chol-siRNA. The intra-peritoneal administration of Chol-siRNA to NZB/WF1 mice resulted in a reduction of anti-DNA antibody titers, and histopathological renal scores as compared to untreated animals. The higher dose of Chol-siRNA prevented the progression of proteinuria as effectively as cyclophosphamide, whereas the lower dose was as effective as CTLA4. Chol-siRNA markedly reduced insterstitial CD3+ and plasma cell infiltrates as well as glomerular deposits of IgG and C3. Circulating soluble CD40 and activated splenic lymphocyte subsets were also strikingly reduced by Chol-siRNA. Our data show the potency of our compound for the therapeutic use of anti-CD40-siRNA in human LN and other autoimmune disorders.

Microalbuminuria: a useful marker of cardiovascular disease

Leakage of small amounts of proteins in urine has been considered since 1980s a crucial sign of early kidney disease, especially in diabetic patients. An increasing interest in microalbuminuria as a cardiovascular risk marker has been more recently considered. Many studies linked microalbuminuria to early cardiovascular disease, as a marker of endothelial dysfunction, not only in diabetic patients, but also in hypertensive patients and in general population. Microalbuminuria is considered nowadays by guidelines as a cost-effective marker of subclinical organ damage in hypertensive patients and should be checked routinely in hypertensive patients. Assessing subclinical organ damage is recommended not only at the level of screening, but also during treatment. Microalbuminuria is also considered as a treatment outcome marker and useful for understanding the ability of a given therapeutic intervention to regress organ damage or slow down its progression.

Prevalence, risk factors and awareness of albuminuria on a Canadian First Nation: a community-based screening study

BACKGROUND

Both diabetic and non-diabetic end stage renal disease (ESRD) are more common among Canadian First Nations people than among the general Canadian population. The purpose of this research was to determine the prevalence of and risk factors for albuminuria in a Canadian First Nation population at high risk for ESRD and dialysis.

METHODS

Data from a community-based screening study of 483 residents of a Plains Ojibway First Nation in Manitoba was used. Participants provided random urine samples. Proteinuria was defined as any dipstick positive for protein (≥1 g/L) or those with ACR in the macroalbuminuric range (≥30 mg/mmol) on at least one sample. Microalbuminuria was defined as ACR ≥2 mg/mmol for males and ≥2.8 mg/mmol for females. Other measures included fasting glucose, haemoglobin A1c, triglycerides, cholesterol, blood pressure, height, weight and waist and hip circumferences.

RESULTS

Twenty percent of study participants had albuminuria, (5% proteinuria and 15% microalbuminuria). Of participants with diabetes, 42% (56/132) had albuminuria compared to 26% (7/27) among those with impaired fasting glucose and 10% (30/303) among those with normal glucose tolerance. Only 5.3% of those with albuminuria were aware of any degree of renal disease. In a multivariate logistic regression, independent associations with albuminuria were male gender [p = 0.002], increasing fasting glucose [p <0.0001], years diagnosed with diabetes [p = 0.03], increasing systolic blood pressure [p = 0.009], and increasing body mass index (BMI) [p = 0.04].

CONCLUSIONS

The independent association between BMI and albuminuria has not been previously reported among indigenous populations. There is a high prevalence of albuminuria in this Canadian First Nation population; the high proportion of patients with diabetes and undiagnosed kidney disease demonstrates the need for screening, education and intervention to halt the progression and development of albuminuria and ultimately ESRD and CVD.

Weight loss improves renal hemodynamics in patients with metabolic syndrome

OBJECTIVE

We investigated the impact of weight loss on urinary albumin excretion (UAE) and creatinine clearance in obese patients with metabolic syndrome.

METHODS

Thirty-five obese patients undertook a 12-week calorie-restricted diet. The patients underwent a metabolic (oral glucose tolerance test, plasma lipids, and uric acid) and renal hemodynamic evaluations (creatinine clearance and urinary albumin excretion) before (phase 1), and after the 12-week diet (phase 2).

RESULTS

After the dietary intervention, the subjects were divided into two groups: patients who achieved the target weight reduction (R: responders, n = 14), and patients who did not (NR: non-responders, n = 21). The patients in Group R showed an improvement in lipid profile, a decrease in UAE (median = 162.5 mg/24 hours, range: 0.8 to 292 mg/24 hours, at phase 1 versus 10.4 mg/24 hours, range: 1.6 to 22.4 mg/24 hours, at phase 2), and a significant reduction in creatinine clearance (121.4 ± 66.5 mL/min. in phase 1 to 92.9 ± 35.6 mL/min. at the end of phase 2, p = 0.001). In Group NR, no statistically significant differences were observed between phases 1 and 2.

CONCLUSION

Body weight reduction has a positive impact on renal hemodynamics, decreasing urinary albumin excretion as well as glomerular hyperfiltration in obese patients with metabolic syndrome.

Recognition, pathogenesis, and treatment of different stages of nephropathy in patients with type 2 diabetes mellitus

Nephropathy is a common microvascular complication among patients with type 2 diabetes mellitus and a major cause of kidney failure. It is characterized by albuminuria (≥ 300 mg/d) and a reduced glomerular filtration rate and is often present at the time of diabetes diagnosis after the kidney has been exposed to chronic hyperglycemia during the prediabetic phase. A low glomerular filtration rate (<60 mL/min/1.73 m(2)) is also an independent risk factor for cardiovascular events and death. Detection of diabetic nephropathy during its initial stages provides the opportunity for early therapeutic interventions to prevent or delay the onset of complications and improve outcomes. An intensive and multifactorial management approach is needed that targets all risk determinants simultaneously. The strategy should comprise lifestyle modifications (smoking cessation, weight loss, increased physical activity, and dietary changes) coupled with therapeutic achievement of blood glucose, blood pressure, and lipid goals that are evidence-based. Prescribing decisions should take into account demographic factors, level of kidney impairment, adverse effects, risk of hypoglycemia, tolerability, and effects on other risk factors and comorbidities. Regular and comprehensive follow-up assessments with appropriate adjustment of the therapeutic regimen to maintain risk factor control is a vital component of care, including referral to specialists, when required.

[Value of microalbuminuria in fluid balance after abdominal surgery]

OBJECTIVE

To evaluate the relationship among the microalbuminuria, surgical stress and postoperative fluid balance after abdominal surgery.

METHODS

A total of 191 patients undergoing an elective abdominal operation were studied. According to the extent of operative trauma, all patients were divided into 4 groups. GroupI: laparoscopic cholecystectomy (n=64); Group II: laparotomy of cholecyst and biliary tract (n=36); Group III: radical surgery of colorectal cancer (n=43); Group IV: distal subtotal gastrectomy (D2) or total gastectomy (D3) or pancreaticoduodenectomy (n=48). The operative severities were predicated by surgical stress score (SSS). Urine albumin-creatinine ratio (ACR) was measured at both pre- and post-operation. The levels of ACR were compared by ANOVA among these 4 groups. The correlation of ACR and SSS was analyzed. In Groups III and IV, body weight was measured by weight-bed simultaneously. The correlation of variation of ACR at 0 and 6 hours post-operation (ΔACR) and the volume of positive fluid balance in the first 24 hour post-operation were studied. We also compared the varied durations of ACR levels returning to normal or the pre-operative level and body weight reaching peak values.

RESULTS

The levels of ACR increased in all groups. The level of ACR was the highest in Group IV and the lowest in Group I, significantly different from the levels of group II and III. There was a significant positive correlation between the increase in ACR and the severity of surgical trauma as measured by SSS. A positive correlation was observed between the volume of positive fluid balance in the first 24 hour post-operation and ΔACR at 0 and 6 hours post-operation. The varied duration of ACR levels returning normal or the pre-operative level was earlier than that of reaching the peak values.

CONCLUSION

ACR has a positive correlation with the extent of surgical stress and volume of positive fluid balance. The fact that the ACR comes earlier than the change of body weight indicates that the change of ACR is a more sensitive and simpler parameter than body weight to predict the onset of negative fluid balance.

Managing vascular risk in hypertension with a focus on microalbuminuria: attitude and practices

INTRODUCTION

Elevated blood pressure is a principal risk factor for cardiovascular and renal diseases. Early detection and adequate treatment of hypertension are essential components in the primary prevention of these end-stage events. Microalbuminuria is recognised as an early marker of renal disease and increased cardiovascular risk. Screening alerts physicians to implement timely intervention strategies to delay disease progression and minimise consequent complications. Although the value and significance of microalbuminuria screening has been widely documented, its use is still suboptimal.

METHODS

Survey forms were sent to randomly-selected general practitioners in Singapore to capture their self-reported attitudes and practices regarding microalbuminuria screening in the management of hypertension.

RESULTS

Results from this survey revealed that microalbuminuria screening was practised by 88 percent of the physicians surveyed; however, only 56 percent of hypertensive patients without risk factors were screened. Quantitative analysis of urine samples was the preferred screening method of 90 percent of the physicians surveyed.

CONCLUSION

A concerted effort should be made to address the lack of public awareness on the importance of screening for microalbuminuria. Continuing medical education should also emphasise the usefulness of surrogate markers in the therapeutic prevention of end-organ damage in hypertensive patients. There is also a need to form a consensus guideline on microalbuminuria screening, to aid in the standardisation of practice.

[Clinical guidelines on identification, management and complications of chronic kidney disease]

The key messages of these guidelines on chronic kidney disease are: Chronic kidney disease (CKD) is a public health problem due to its wide distribution, high rate of complications and cost. CKD is a common condition, its prevalence being about 10%, and is treatable if it is detected on time. A patient with CKD has a higher risk of cardiovascular mortality than of progression of its underlying renal disease. A new definition of CKD, based on estimated Glomerular Filtration Rate (eGFR) and kidney damage, facilitates its detection and management. CKD is detected with three simple tests: 1) Blood pressure measurement, 2) Detection of proteinuria or albuminuria in an isolated urine sample, and 3) Estimation of renal function (eGFR), based on serum creatinine, age, gender and race. The CKD risk groups are individuals with diabetes, hypertension and a family history of renal disease. The most cost-effective measures are to detect and treat diabetic and hypertensive patients in the community. Therapy must emphasize the maximal reduction of cardiovascular risk. The complications of CKD such as anemia and renal osteodystrophy can be identified and treated on time. Most patients with chronic kidney disease are detected in the community, therefore their initial care must be organized at the level of primary care, along with programs for hypertension and diabetes.

Relationship between albuminuria and total proteinuria in systemic lupus erythematosus nephritis: diagnostic and therapeutic implications

BACKGROUND AND OBJECTIVES

Albuminuria is regarded a sensitive measure of progression of glomerular disease. This study was undertaken in patients who had systemic lupus erythematosus glomerulonephritis (n = 57) and were followed in the Ohio SLE Study to determine whether measuring albuminuria offered clinical advantages over that of total proteinuria.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Twenty-four-hour urine collections (n = 127) were obtained at baseline and annually for measurement of microalbumin, total protein, and creatinine.

RESULTS

There was a strong linear relationship between microalbumin-creatinine and protein-creatinine ratios over the entire range of protein-creatinine ratios; however, in the protein-creatinine ratio range 0.0 to 0.3, as the protein-creatinine ratio increased, the microalbumin-protein ratio increased much more than the protein-creatinine ratio. Also, the greater the protein-creatinine ratio, the greater was the evidence for nonselective proteinuria (protein-creatinine ratio--microalbumin-creatinine ratio).

CONCLUSIONS

For the diagnosis of proteinuria renal flare, measuring albuminuria offers no advantage over measuring total proteinuria because changes in protein-creatinine and microalbumin-creatinine ratios are highly correlated over the designated ranges for systemic lupus erythematosus glomerulonephritis proteinuric flares. In those with normal-range proteinuria, subsequent changes in microalbumin-protein ratio might be a better forecaster of renal flare than changes in protein-creatinine or microalbumin-creatinine ratio. High protein-creatinine ratios are associated with evidence of nonselective proteinuria, which may increase the nephrotoxicity of proteinuria. Thus, using high-threshold criteria for systemic lupus erythematosus flare (allowing greater proteinuria increase before flare is declared) may expose the kidney to greater nephrotoxicity than using the low-threshold criteria for systemic lupus erythematosus flare.

[Microalbuminuria and urinary albumin excretion: French guidelines]

Measurement of urinary albumin excretion (UAE) may be done on a morning urinary sample or on a 24 hour-urine sample. Values defining microalbuminuria are: - 24-hour urine sample: 30-300 mg/24 hours - Morning urine sample: 20-200 mg/mL or 30-300 mg/g creatinine or 2.5-25 mg/mmol creatinine (men) or 3.5-35 mg/mol (women). - Timed urine sample: 20-200 mug/min. The optimal use of semi-quantitative urine test-strip is not clearly defined. It is generally believed that microalbuminuria reflects a generalized impairment of the endothelium; however, no definite proof has been shown in humans. In diabetic subjects, microalbuminuria is a marker of increased risk of cardiovascular (CV) and renal morbidity and mortality in type 1 and type 2 diabetic subjects. The increase in UAE during follow-up is also a marker of CV and renal risk in type 1 and type 2 diabetic subjects; its decrease during follow-up is associated with lower risks. In non-diabetic subjects, microalbuminuria is a marker of increased risk for diabetes mellitus, deterioration of the renal function, CV morbidity and all-cause mortality. It is a marker of increased risk for the development of hypertension in normotensive subjects, and is associated with unfavorable outcome in patients with cancer and lymphoma. Persistence or elevation of UAE overtime is associated with deleterious outcome in some hypertensive subjects. Measurement of UAE may be recommended in hypertensive subjects with 1 or 2 CV risk factors in whom CV risk remains difficult to assess, and in those with refractory hypertension: microalbuminuria indicates a high CV risk and must lead to strict control of arterial pressure. Studies focused on microalbuminuria in non-diabetic, non-hypertensive subjects are limited; most of them suggest that microalbuminuria predicts CV complications and deleterious outcome as it is in diabetic or hypertensive subjects. Subjects with a history of CV or cerebrovascular disease have an even greater CV risk if microalbuminuria is present than if it is not; however, in all cases, therapeutic intervention must be aggressive regardless of whether microalbuminuria is present or not. It is not recommended to measure UAE in non-diabetic non-hypertensive subjects in the absence of history of renal disease. Monitoring of renal function (UAE, serum creatinine and estimation of GFR) is annually recommended in all subjects with microalbuminuria.

MANAGEMENT

in patients with microalbuminuria, weight reduction, sodium restriction (< 6 g/day), smoking cessation, strict glucose control in diabetic subjects, strict arterial pressure control are necessary; in diabetic subjects: use of maximal doses of ACEI or ARB are recommended; ACEI/ARB and thiazides have synergistic actions on arterial pressure and reduction of UAE; in non-diabetic subjects, any of the five classes of anti-hypertensive medications (ACEI, ARB, thiazides, calcium channel blockers or beta-blockers) can be used.

The assessment and management of albuminuria in primary care

BACKGROUND

While CKD is a common finding in patients with type 2 diabetes, the clinical response to its identification is often problematic. This study aims to determine the frequency of albuminuria in patients with type 2 diabetes in the primary care setting and examine the factors which influence its management.

METHODS

Expressions of interest were invited from all registered GPs across Australia, from whom 500 investigators were randomly selected. Investigators were requested to document the clinical characteristics of 10-15 consecutively presenting patients with type 2 diabetes. Results from the most recent urinalysis were classified according to guidelines, then systematically compared to classifications provided by GPs themselves and their management strategies.

RESULTS

One in three patients had an elevated urinary albumin excretion (UAE, 34.6%, 95% CI, 33.3-35.9%) on their most recent urinalysis. The presence of microalbuminuria or proteinuria, as identified by the GP, was not associated with a perceived increase in cardiovascular risk. In addition, the use of aspirin and the prescribing of agents to block the RAS were not significantly linked to UAE. Similarly, the perceived adequacy of blood pressure control was not significantly different whether or not microalbuminuria or proteinuria was identified to be present.

CONCLUSION

An elevated UAE is a common finding in general practice. However, it fails to significantly influence their clinical care. Additional education to ensure appropriate case recognition and management of kidney disease is needed, focusing on the significance of albuminuria to the care of patients with type 2 diabetes.

Microalbuminuria and cardiovascular disease

To reduce the burden of cardiovascular disease (CVD), management strategies are increasingly focusing on preventive measures following early detection of markers of atherosclerosis. This review focuses on microalbuminuria, which is gaining recognition as a simple marker of an atherogenic milieu. Prospective and epidemiologic studies have found that microalbuminuria is predictive, independently of traditional risk factors, of all-cause and cardiovascular mortality and CVD events within groups of patients with diabetes or hypertension, and in the general population. The pathophysiologic mechanism underlying the association between albumin excretion and CVD is not fully defined. One hypothesis is that microalbuminuria may be a marker of CVD risk because it reflects subclinical vascular damage in the kidneys and other vascular beds. It may also signify systemic endothelial dysfunction that predisposes to future cardiovascular events. Based on this theory, periodic screening for microalbuminuria could allow early identification of vascular disease and help stratify overall cardiovascular risk, especially in patients with risk factors such as hypertension or diabetes. A positive test for urinary albumin excretion could signify the need for an intensive multifactorial intervention strategy, including behavior modification and targeted pharmacotherapy, aimed at preventing further renal deterioration and improving the overall CVD risk factor profile. Data from intervention studies suggest that treatment with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, statins, and/or strict glycemic control (in diabetics) offer significant reductions in cardiovascular and/or renal morbidity in patients with albuminuria. Use of this (old) marker may allow improved use of medications and strategies for secondary prevention.

Lack of management of cardiovascular risk factors in type 2 diabetic patients

Effective management of diabetic patients includes comprehensive control for not only blood sugar, but also other cardiovascular risk factors. We assessed whether haemoglobin A1c (A1C) concentrations, blood pressure, low density lipoprotein (LDL) cholesterol levels and microalbuminuria were regularly measured in 281 patients with type 2 diabetes who received care for over 1 year in the Department of Family Medicine located in an urban area of Korea. Subsequently, in patients with A1C > 7%; blood pressure >130/80 mmHg; LDL cholesterol levels >100 mg/dl; or microalbuminuria, we evaluated the status of management for those cardiovascular risk factors. Physicians were most likely to measure A1C levels (98.6%), but less likely to measure microalbuminuria (56.2%), LDL cholesterol (73.7%), or blood pressure (74.4%). Patients whose A1C levels were above the goal (78.2%) were likely to receive optimal therapy. In contrast, only 21.1% of patients with uncontrolled blood pressure and 5.3% of patients with LDL cholesterol levels above the target range received optimal management. Of the 36 patients with microalbuminuria or overt proteinuria, 66.7% took angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Measurement of parameters indicating cardiovascular risk factors in type 2 diabetic patients was not optimal, particularly regular measurements for microalbuminuria and for controlling LDL-cholesterol and blood pressure. These findings indicate a need for greater education of comprehensive cardiovascular management in type 2 diabetic patients and their physicians.

Microalbuminuria

Microalbuminuria, originally described more than 3 decades ago as a predictor of nephropathy in patients who had type 1 diabetes mellitus and associated with higher cardiovascular risk, is now linked with increased risk for cardiovascular events rather than progression to end-stage kidney disease. This article reviews the role of microalbuminuria in the context of atherosclerotic vascular disease. It presents the methods for microalbuminuria assessment in clinical practice, its relations with other cardiovascular risk factors, and the pathophysiologic associations between microalbuminuria and vascular damage. In addition, this article discusses the prognostic significance of microalbuminuria for cardiovascular disease as well as existing therapeutic interventions for reducing urine albumin excretion in patients who are at high cardiovascular risk.