Microalbuminuria reflects a generalized transvascular albumin leakiness in clinically healthy subjects

Proteinuria and risk of ocular motor cranial nerve palsy: a nationwide population-based study

Understanding the association between dipstick-detected proteinuria and oculomotor cranial nerve palsy (CNP) could have significant implications for understanding the mechanism of CNP development and for developing preventive strategies against CNP development in patients with proteinuria. This study aimed to determine the relationship between dipstick-determined proteinuria and ocular motor CNP using National Sample Cohort (NSC) database from Korea's National Health Insurance Service (NHIS). A nationwide population-based cohort study was conducted using data from the NSC database of Korea's NHIS. These data were collected from 2009 to 2018. A one-year time lag was established to prevent a situation in which the causal link was inverted. Participants aged 20 years or more who were diagnosed with proteinuria in 2009 were included. Individuals with specific pre-existing CNP, missing data, and those who were newly diagnosed with CNP or who died within one year of being tested were excluded. The study population was classified into six groups according to the degree of proteinuria (negative, trace, or between 1 + and 4 +) based on the urine dipstick test. A Cox proportional hazard regression analysis was performed to determine the linkage between the degree of proteinuria and ocular motor CNP. A total of 5,807 (0.14% of subjects) with ocular motor CNP were assigned to the ocular motor CNP group and 4,047,205 subjects were assigned to the control group. After full adjustment of comorbidities, hazard ratios (HRs) for 1 + , 2 + , 3 + and 4 + proteinuria groups were 1.449 (95% confidence interval [CI] 1.244-1.687), 2.081 (1.707-2.538), 1.96 (1.322-2.904), and 3.011 (1.507-6.014), respectively, for developing ocular motor CNP compared to the proteinuria-negative group. In subgroup analysis, the HR of patients with proteinuria for the development of ocular motor CNP was higher in the younger age group (less than 40 years) (P = 0.0242) and the group with DM (P = 0.04). Our population-based cohort study demonstrated a significant association between proteinuria and the incidence of CNP, suggesting that urine protein level could be a new clinical marker for predicting the development of CNP.

The Associations between Kidney Function and Sexual Dysfunction among Males and Females with Type 2 Diabetes Mellitus

Background and Objectives: Diabetic kidney disease (DKD), expressed either as albuminuria, low estimated glomerular filtration rate (eGFR) or both, and sexual dysfunction (SD), are common complications among type 2 diabetes mellitus (T2DM) patients. This study aims to assess whether an association exists between DKD and SD, erectile dysfunction (ED) or female sexual dysfunction (FSD) in a T2DM population. Materials and Methods: A cross-sectional study was designed and conducted among T2DM patients. The presence of SD was assessed using the International Index of Erectile Function and the Female Sexual Function Index questionnaires for males and females, respectively, and patients were evaluated for DKD. Results: Overall, 80 patients, 50 males and 30 females, agreed to participate. Sexual dysfunction was present in 80% of the study population. Among the participants, 45% had DKD, 38.5% had albuminuria and/or proteinuria and 24.1% had an eGFR below 60 mL/min/1.73 m². The eGFR was associated with SD, ED and FSD. Moreover, SD and ED were proven as significant determinants for lower eGFR values in multiple linear regression analyses. DKD was associated with lower lubrication scores and eGFR was associated with lower desire, arousal, lubrication and total scores; however, the multivariate linear regression analyses showed no significant associations between them. Older age resulted in significantly lower arousal, lubrication, orgasm and total FSFI scores. Conclusions: SD is commonly encountered in older T2DM patients and DKD affects almost half of them. The eGFR has been significantly associated with SD, ED and FSD, while SD and ED were proven to be significant determinants for the eGFR levels.

Effects of sodium-glucose cotransporter 2 inhibitors, mineralocorticoid receptor antagonists, and their combination on albuminuria in diabetic patients

AIMS

Diabetes mellitus (DM) is the leading cause of chronic kidney disease. Albuminuria is associated with an increased risk of cardiovascular mortality. Sodium-glucose cotransporter 2 inhibitors (SGLT2-Is) and mineralocorticoid receptor antagonists (MRAs) protect against albuminuria; however, their combined effects on albuminuria are unclear. We performed a network meta-analysis to investigate the effects of SGLT2-Is, MRAs and their combination on albuminuria in type 2 DM.

METHODS

We systematically searched PubMed, Medline, EMBASE and the Cochrane Library from inception up to 20 November 2022. We selected randomized control and crossover trials that compared MRAs, SGLT2-Is, MRAs + SGLT2-Is, or a placebo in patients with type 2 DM with a urinary albumin-creatinine ratio (UACR) ≥30 mg/g creatinine. The primary outcome was the change in the UACR.

RESULTS

This meta-analysis analysed 17 studies with 34 412 patients. The use of combination treatment with SGLT2-Is and MRAs was associated with lower albuminuria compared with the use of SGLT2-Is, MRAs, or the placebo alone [mean difference (95% CI): -34.19 (-27.30; -41.08), -32.25 (-24.53; -39.97) and -65.22 (-57.97; -72.47), respectively]. Treatment with SGLT2-Is or MRAs alone caused a significant reduction in UACR compared with the placebo [mean difference (95% CI): -31.03 (-28.35; -33.72) and -32.97 (-29.68; -36.27), respectively]. The effects of MRAs on the UACR are comparable with those of SGLT2-Is. Sensitivity analyses showed similar results.

CONCLUSION

Combination therapy with SGLT2-Is and MRAs was associated with lower albuminuria in patients with type 2 DM compared with monotherapy with SGLT2-Is or MRAs alone.

Association between urinary albumin creatinine ratio and cardiovascular disease

INTRODUCTION

The association between microalbuminuria and cardiovascular disease (CVD) is accumulating in various patient populations. However, when stratified by sex, the relationship between microalbuminuria and CVD remains unclear.

METHOD

We obtained data from the 2011-2014 and 2019-2020 Korea National Health and Nutrition Examination Survey (KNHANES). Microalbuminuria was measured based on spot urine albumin-creatinine ratio (UACR). The Framingham risk score (FRS) model was implemented to evaluate the CVD risk. Linear and logistic regression models were used to identify the associations of microalbuminuria status with cardiometabolic predictors and CVD status determined by the FRS score.

RESULTS

Among 19,340 representative Korean participants, the (UACR) in Korean women and men with history of CVD was higher than in those without history of CVD. Among patients without history of CVD, multivariate regression analysis showed that a high UACR was related to older age, lower high-density lipoprotein cholesterol level, higher total cholesterol level, higher systolic blood pressure, higher prevalence of current smoking, higher prevalence of diabetes, and higher anti-hypertensive medication use in both women and men. The UACR showed a positive linear correlation with the Framingham risk score in both women and men.

CONCLUSION

The presence of microalbuminuria was significantly associated with the cardiometabolic risk factors and the increased risk of CVD evaluated by FRS model in both women and men in a nationally representative sample of Korea.

Correlation between microalbuminuria and atherosclerotic intracranial and extracranial arterial stenosis in patients with cerebral infarction

BACKGROUND AND AIMS

Microalbuminuria (MAU) reflects the generalized vascular endothelial dysfunction. Whether MAU has correlation with atherosclerotic intracranial and extracranial arterial stenosis in cerebral infarction patients is not known and is explored in the present investigation.

METHODS

We enrolled 255 cerebral infarction patients hospitalized at the department of neurology. All patients underwent digital subtraction angiography (DSA) to evaluate the severity and distribution of intracranial and extracranial arterial stenosis. MAU was expressed as the urine albumin-to-creatinine ratio (UACR). We collected basic information, medical history reviews and laboratory results of each participant. The multivariate logistic regression analysis was utilized to analyze the risk factors for severity and distribution of cerebral arterial stenosis.

RESULTS

The prevalence of MAU in patients with cerebral infarction was 39.2%, patients with MAU had older age, lower blood uric acid, higher systolic blood pressure (SBP), higher prevalence of hypertension and diabetes (p < 0.05) and higher incidence of atherosclerotic intracranial and extracranial arterial stenosis (χ2 = 5.900, p = 0.015). In multiple logistic regression analysis for intracranial and extracranial arterial stenosis more than 50% or occlusion groups, UACR (OR 1.088 95%CI 1.012-1.170p = 0.022), male (OR 2.196 95%CI 1.085-4.442p = 0.029) as well as SBP (OR 5.870 95%CI 1.026-1.048p = 0.015) showed statistical significance. But UACR had no correlation with the distribution of intracranial and extracranial artery stenosis after adjusting for all potential confounders.

CONCLUSIONS

Microalbuminuria was an independent risk factor for intracranial and extracranial arterial stenosis more than 50% or occlusion.

Doxycycline can reduce glycocalyx shedding by inhibiting matrix metalloproteinases in patients undergoing cardiopulmonary bypass: A randomized controlled trial

BACKGROUND

Cardiopulmonary bypass (CPB) leads to shedding of the glycocalyx of endothelial cells, resulting in a series of complications such as tissue edema and coagulatory and microcirculatory dysfunctions. Matrix metalloproteinases (MMPs) can cause glycocalyx shedding in a variety of pathological processes, but their role in the process of CPB is still unclear. We hypothesized that the MMPs inhibitor doxycycline would reduce glycocalyx shedding by inhibiting MMPs during CPB.

METHODS

Thirty-six patients were randomized to receive either 100 mg oral doxycycline (an MMPs inhibitor) or a matching placebo pill twice a day for three days before CPB. The primary outcome was the concentration of plasma syndecan-1. Secondary outcomes included heparan sulphate, MMP-2, MMP-9, ratio of urinary albumin to creatinine, and short-term clinical outcomes. In order to further prove that MMPs in plasma caused the glycocalyx shedding, human umbilical vein endothelial cells were cultured with plasma obtained from cardiac surgery patients before or after CPB (with or without MMPs inhibitor GM6001). The change in glycocalyx content was detected by immunofluorescence.

RESULTS

CPB resulted in an increase of MMPs and shedding of the glycocalyx. Plasma syndecan-1 was higher in the control group than in the doxycycline group (median difference:15.04 μg/L; 95% CI: 9.14-20.94 μg/L; P < 0.001). Similar to syndecan-1, plasma heparan sulphate, MMP-2, and MMP-9 concentrations in the doxycycline group were significantly lower than those in the control group during CPB. Doxycycline was also correlated with a reduction in the ratio of urinary albumin to creatinine and improved the short-term clinical outcomes of patients. Endothelial cells cultured with plasma from patients after CPB showed significant shedding of syndecan-1 and heparan sulphate (post-CPB group vs pre-CPB group, P < 0.001). GM6001 was shown to reduce shedding of syndecan-1 and heparan sulphate by inhibiting MMPs (post-CPB + GM6001 group vs post-CPB group, P < 0.001).

CONCLUSION

Doxycycline can reduce glycocalyx shedding by inhibiting MMPs during CPB.

Low-grade albuminuria is associated with high cardiovascular risk in CVD-free and normoalbuminuric Chinese adults: Results from the REACTION study

BACKGROUND

Data are limited with regard to the association between low-grade albuminuria (below the threshold of microalbuminuria) and high cardiovascular risk in normoalbuminuric Chinese adults free of cardiovascular disease (CVD).

METHODS

A total of 32 650 participants aged over 40 years from seven regional centers in China were included in this study. The single-void first morning urine sample was collected to measure the urinary albumin to creatinine ratio (UACR) and the data were divided into sex-specific quartiles. The Framingham Risk Score (FRS) was used to identify participants at high risk of developing coronary heart disease (CHD) over the next 10 years and the association between low-grade albuminuria and high 10-year Framingham risk for CHD (FRS ≥20%) was investigated.

RESULTS

Among males and females, the prevalence of cardiometabolic risk factors (diabetes, hypertension, and dyslipidemia) increased markedly with the elevation of UACR quartiles. Logistic regression analysis showed that the odds ratios (ORs) for high 10-year risk of CHD increased significantly from the second quartile in males (UACR: 4.78 ~ 7.53 mg/g, OR = 1.21, 95% confidence interval [CI]: 1.05-1.40) and the third quartile in females (UACR: 9.13 ~ 15.04 mg/g, OR = 3.07, 95% CI: 1.75-5.40). Stratified analysis showed that in males, the association was especially pronounced in elderly, overweight/obese participants and those without diabetes and hypertension whereas in females, the association was especially pronounced in elderly, overweight/obese participants and those without diabetes and with hypertension.

CONCLUSIONS

Low-grade albuminuria was significantly associated with high 10-year cardiovascular risk among CVD-free and normoalbuminuric Chinese adults.

Protective effect of sevoflurane on vascular endothelial glycocalyx in patients undergoing heart valve surgery: A randomised controlled trial

BACKGROUND

The glycocalyx plays an important physiological role and may be damaged during cardiopulmonary bypass. Sevoflurane can protect the glycocalyx; however, its relevance in a clinical setting is unknown.

OBJECTIVE

Glycocalyx degradation during cardiopulmonary bypass in patients was investigated. On the basis of the available experimental data, we hypothesised that sevoflurane-based anaesthesia would confer additional protection against cardiopulmonary bypass-induced glycocalyx damage.

DESIGN

Randomised controlled study.

SETTING

Clinical study at The First Affiliated Hospital of Wenzhou Medical University between June 2018 and March 2019.

PATIENTS

Fifty-one patients.

INTERVENTIONS

After intubation and mechanical ventilation, patients undergoing elective heart valve surgery were maintained under general anaesthesia with either propofol or sevoflurane during surgery.

MAIN OUTCOME MEASURES

Glycocalyx markers (such as syndecan-1, heparan sulphate and hyaluronan), sheddases responsible for the degradation of the endothelial glycocalyx (such as matrix metalloproteinase-9 and cathepsin-B), urine albumin-to-creatinine ratio and levels of lactic acid and myocardial enzymes were all measured. Postoperative mechanical ventilation time and length of stay in the cardiac care unit and hospital were also measured. Morbidity and mortality after 30 days and 1 year were evaluated.

RESULTS

The vascular endothelial glycocalyx was damaged during cardiopulmonary bypass. The glycocalyx damage in the sevoflurane group was less extensive than that in the propofol group. The urine albumin-to-creatinine ratio increased in both groups but was lower in the sevoflurane group. Enzymes including matrix metalloproteinase-9 and cathepsin-B were positively correlated with glycocalyx marker concentrations. After operation, the sevoflurane group showed lower levels of lactic acid and myocardial enzyme, as well as shorter duration of postoperative mechanical ventilation than the propofol group.

CONCLUSION

Sevoflurane can decrease glycocalyx degradation in patients undergoing heart valve surgery under cardiopulmonary bypass.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, chictr.org.cn, identifier: ChiCTR1800016367.

Proteinuria Is Associated with the Development of Crohn's Disease: A Nationwide Population-Based Study

BACKGROUND AND AIMS

The impact of proteinuria and its severity on the incidence of inflammatory bowel disease (IBD) has not yet been studied. We aimed to determine the association between proteinuria measured by urine dipstick tests and the development of IBD.

METHODS

This nationwide population-based study was conducted using the Korean National Health Insurance Service (NHIS) database. A total of 9,917,400 people aged 20 years or older who had undergone a national health examination conducted by the NHIS in 2009 were followed up until 2017. The study population was classified into four groups-negative, trace, 1+, and ≥ 2+-according to the degree of proteinuria measured by the urine dipstick test. The primary endpoint was newly diagnosed IBD, Crohn's disease (CD), or ulcerative colitis (UC) during the follow-up period.

RESULTS

Compared with the dipstick-negative group, the incidence of CD significantly increased according to the degree of proteinuria (adjusted hazard ratio [aHR] with 95% confidence interval [CI], 1.01 [0.703-1.451], 1.515 [1.058-2.162], and 2.053 [1.301-3.24] in the trace, 1+, and ≥ 2+ dipstick groups, respectively; p for trend 0.007). However, there was no significant difference in the incidence of UC according to the degree of proteinuria (aHR with 95% CI, 1.12 [0.949-1.323], 0.947 [0.764-1.174], and 1.009 [0.741-1.373] in the trace, 1+, and ≥ 2+ dipstick groups, respectively; p for trend 0.722). In the subgroup analysis, dipstick-positive proteinuria independently increased the incidence of CD regardless of the subgroup. However, dipstick-positive proteinuria was associated with the risk of UC in those with diabetes mellitus and not in those without diabetes mellitus (aHR, 1.527 vs. 0.846; interaction p-value 0.004). The risk of CD was increased or decreased according to proteinuria changes but not associated with the risk of UC.

CONCLUSION

Proteinuria, measured by the dipstick test, is strongly associated with the development of CD.

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.

The Relationship Between Earlier Onset of Natural Menopause and Elevated Urinary Albumin-Creatinine Ratio in Postmenopausal Chinese Women

PURPOSE

There is a close correlation between menopausal age and cardiovascular disease (CVD) risk. Some research suggests that this risk is attributable to an elevated urinary albumin-creatinine ratio (UACR), but further work is needed to explore the link between UACR and age at time of menopause.

PATIENTS AND METHODS

Data analyzed in the present study were derived from seven regional centers participating in the REACTION study. A total of 21,672 postmenopausal women met with our study inclusion and exclusion criteria, and were split into three groups based upon their age at onset of natural menopause. A UACR ≥ 30 mg/g was the primary outcome measure for this study. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a logistic regression approach.

RESULTS

Relative to women who were 46-50 years old at time of natural menopause, those with an earlier onset of menopause (≤45 years) exhibited an increased risk of UACR elevation following adjustment for confounding variables (OR: 1.18, 95% CI: 1.04-1.33), whereas the opposite was true for women with a later age of menopause onset (>50 years) (OR: 0.86, 95% CI: 0.78-0.94). For every 1-year delay in the onset of menopause, UACR risk fell by 3% (OR: 0.97, 95% CI: 0.96-0.98).

CONCLUSION

In summary, early menopause (≤45 years old) was linked to a higher risk of UACR elevation in postmenopausal women. However, further work will be needed to understand the mechanistic basis for these findings.

Association between microalbuminuria and outcome of non-diabetic population aged 40 years and over: The reaction study

AIMS

The goal of this study was to analyze the association between microalbuminuria (MAU) and the outcome of non-diabetic populations among Chinese people.

METHODS

A cohort of 2042 Chinese individuals without diabetes, aged 40 years or older were included. We identified people with impaired fasting glucose and/or impaired glucose tolerance by conducting an oral glucose tolerance test, and then followed them up after 3years. We defined MAU as a urinary albumin-to-creatinine ratio (ACR) exceeding the normal range of 2.5-25mg/mmol (males) or 3.5-35mg/mmol (females).

RESULTS

Among 2042 adults aged 40 years or older in an urban fringe area of Luzhou city (1984 cases were followed up), 262 (12.8%) developed diabetes over 3years. MAU was significantly associated with age, fasting plasma glucose, 2-h glucose, hemoglobin A1c, and triglycerides (P<0.05). Follow-up FBG, 2hPG, TG, and HbA1c levels in the IGR+MAU group were higher than those in other groups (P<0.05). If the relative risk of the isolated normal glucose tolerance (NGT) group progressing to diabetes was set to 1, the risk of progression to diabetes in the NGT+MAU, isolated impaired glucose regulation (IGR), and IGR+MAU groups increased 1.1, 3.9, and 7.5 times, respectively.

CONCLUSIONS

Our study found that MAU is associated with increased risk of diabetes in NGT and IGR populations, especially in the IGR populations, MAU may predict adulthood at very high risk for diabetes.

Low-grade albuminuria in pulmonary arterial hypertension

Low-grade albuminuria, determined by the urinary albumin to creatinine ratio, has been linked to systemic vascular dysfunction and is associated with cardiovascular mortality. Pulmonary arterial hypertension is related to mutations in the bone morphogenetic protein receptor type 2, pulmonary vascular dysfunction and is increasingly recognized as a systemic disease. In a total of 283 patients (two independent cohorts) diagnosed with pulmonary arterial hypertension, 18 unaffected BMPR2 mutation carriers and 68 healthy controls, spot urinary albumin to creatinine ratio and its relationship to demographic, functional, hemodynamic and outcome data were analyzed. Pulmonary arterial hypertension patients and unaffected BMPR2 mutation carriers had significantly elevated urinary albumin to creatinine ratios compared with healthy controls ( P < 0.01; P = 0.04). In pulmonary arterial hypertension patients, the urinary albumin to creatinine ratio was associated with older age, lower six-minute walking distance, elevated levels of C-reactive protein and hemoglobin A1c, but there was no correlation between the urinary albumin to creatinine ratio and hemodynamic variables. Pulmonary arterial hypertension patients with a urinary albumin to creatinine ratio above 10 µg/mg had significantly higher rates of poor outcome ( P < 0.001). This study shows that low-grade albuminuria is prevalent in pulmonary arterial hypertension patients and is associated with poor outcome. This study shows that albuminuria in pulmonary arterial hypertension is associated with systemic inflammation and insulin resistance.

Proteinuria is an independent predictor of rapid progression of mild to moderate aortic stenosis in patients with preserved renal function

Although proteinuria is a well-known risk factor for cardiovascular disease, its relationship with the progression of aortic stenosis (AS) has not been established. Our aim was to investigate the relationship between proteinuria (detected by urine dipstick test) and AS progression (assessed by the annualized reduction rate of aortic valve area [AVA]). A total of 460 patients with mild to moderate AS (defined by a peak velocity of 2.0-4.0 m/s) without end-stage renal disease who underwent two echocardiograms at least 3 months apart were included. The progression of AS was significantly faster in patients with proteinuria than those without (108 patients vs. 352 patients; annualized reduction rate of AVA, - 7.7 ± 13.5% vs. - 4.5 ± 11.6%; p = 0.017). The relationship between the presence of proteinuria and the accelerated progression of AS was significant among patients with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² (- 11.0 ± 17.5% vs. - 4.2 ± 10.0%; p < 0.001), but not among those with eGFR 15-60 mL/min/1.73 m² (- 5.8 ± 10.3 vs. - 5.3 ± 14.8%; p = 0.822). When stratified by the presence of diabetes, the association of proteinuria with AS progression was only significant in patients without diabetes (- 8.1 ± 12.0% vs. - 8.1 ± 15.7%; p = 0.018). Multivariable logistic regression analysis identified that the presence of proteinuria was an independent predictor of AS progression. The progression of AS was accelerated in patients with mild to moderate AS and proteinuria, particularly among those with preserved renal function and no diabetes.

Chronic hyperkalemia in non-dialysis CKD: controversial issues in nephrology practice

Chronic hyperkalemia is a major complication of chronic kidney disease (CKD) that occurs frequently, heralds poor prognosis, and necessitates careful management by the nephrologist. Current strategies aimed at prevention and treatment of hyperkalemia are still suboptimal, as evidenced by the relatively high prevalence of hyperkalemia in patients under stable nephrology care, and even in the ideal setting of randomized trials where best treatment and monitoring are mandatory. The aim of this review was to identify and discuss a range of unresolved issues related to the management of chronic hyperkalemia in non-dialysis CKD. The following topics of clinical interest were addressed: diagnosis, relationship with main comorbidities of CKD, therapy with inhibitors of the renin-angiotensin-aldosterone system, efficacy of current dietary and pharmacological treatment, and the potential role of the new generation of potassium binders. Opinion-based answers are provided for each of these controversial issues.

Diabetic Microvascular Disease: An Endocrine Society Scientific Statement

Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.

Urinary albumin and 8-oxo-7,8-dihydroguanosine as markers of mortality and cardiovascular disease during 19 years after diagnosis of type 2 diabetes - A comparative study of two markers to identify high risk patients

Urinary albumin is an important biomarker used to identify high risk patients with diabetes, but there is a need for new biomarkers that alone or in combination with urinary albumin could give an even better prediction of clinical patient outcomes. One promising biomarker is 8-oxo-7,8-dihydroguanosine (8-oxoGuo) that represents intracellular oxidative stress. We investigated the ability of microalbuminuria (MA) and urinary 8-oxoGuo, alone and in combination, to predict mortality and cardiovascular disease (CVD) in patients with type 2 diabetes. We used data from 1381 newly diagnosed diabetes patients, and urinary albumin and 8-oxoGuo were assessed in morning urine collected at the time of diabetes diagnosis and at a follow-up visit 6 years later. Associations between the urinary markers and mortality and CVD were assessed in Cox proportional hazards regression models. Test performance was assessed using sensitivity, specificity, positive predictive value and negative predictive value for 10-year mortality and 10-year incidence of CVD. Both 8-oxoGuo and urinary albumin were statistically significantly associated with all-cause mortality at diagnosis as well as at 6-year follow-up. At diagnosis only urinary albumin was associated with CVD. In contrast, only 8-oxoGuo was associated with CVD at 6-year follow-up. When investigating test performance, we found that by combining information from MA and 8-oxoGuo the ability to correctly identify patients at risk could be improved. The findings suggest that measurement of urinary 8-oxoGuo provides additional information about risk to that obtained from urinary albumin, and that the combined use of 8-oxoGuo and urinary albumin could be useful for a better identification of patients at risk of CVD and death.

Recent advances in understanding hypertension development in sub-Saharan Africa

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and

Dipstick albuminuria and acute kidney injury recovery in critically ill septic patients

AIM

Acute kidney injury (AKI) is a frequent complication of sepsis, a pro-inflammatory state that alters tubular handling of filtered albumin. We hypothesized that dipstick albuminuria (DA) is associated with a lower rate of AKI recovery in septic patients.

METHODS

This was a single-centre, retrospective cohort study of adults with sepsis-associated AKI in an urban academic intensive care unit (ICU). Patients with unknown baseline serum creatinine (SCr), absent urinalysis, and those with estimated glomerular filtration rate (eGFR) <15 mL/min per 1.73m(2) or receiving chronic renal replacement therapy (RRT) were excluded. The independent variable was DA (negative or trace, 30 mg/dL, and ≥100 mg/dL) within the first 72 h of ICU stay. The outcome variable was AKI recovery at 30 days following hospital discharge, defined as the last SCr returning to a level less than 1.5 times the baseline SCr level and independence of RRT.

RESULTS

A total of 988 patients were included in the study. The median length of hospitalization was 11 days. The patients with higher degree of DA had worse critical illness scores. After adjustment for several confounders, DA ≥30 mg/dL was independently associated with "no AKI recovery" at 30 days post-discharge (adjusted OR 1.40, 95% CI, 1.01-1.95 for DA =30 mg/dL and 1.67, 1.15-2.42 for DA ≥100 mg/dL, P = 0.02). Other independent predictors of "no AKI recovery" were cumulative fluid balance, Sequential Organ Failure Assessment (SOFA) score, exposure to diuretics, and the need for mechanical ventilation.

CONCLUSION

Dipstick albuminuria ≥30 mg/dL is independently associated with lower rate of AKI recovery at 30 days post-discharge. Our findings emphasize the potential utility of a simple routine test of DA in the risk-stratification of AKI recovery in ICU septic patients.

Association between low-grade albuminuria and frailty among community-dwelling middle-aged and older people: a cross-sectional analysis from I-Lan Longitudinal Aging Study

Frailty is characterized by decreased physiological reserve and increased vulnerability to atherosclerosis and subsequent mortality. Recently, low-grade albuminuria has been proposed as an atherosclerotic risk factor. We aimed to investigate the relationship between low-grade albuminuria and frailty by using cross-sectional data among community-dwelling middle-aged and older people. Totally, 1,441 inhabitants of I-Lan County with normal urinary albumin excretion (urine albumin to urine creatinine ratio [UACR] <30 mg/g) were enrolled (677 men; mean age 63 ± 9 years, range from 50 to 91 years old). Assessment of frailty was based on the ‘Fried frailty phenotype’ criteria, including weight loss, grip strength, exhaustion, slowness and low physical activity. The study population was stratified into quartiles according to UACR levels. Age, body mass index, hypertension, diabetes, systolic blood pressure, insulin resistance, fasting glucose and high-sensitivity C-reactive protein levels were increased with the increment of UACR (P for trend <0.05). The prevalence of prefrailty/frailty and its components increased across the UACR quartiles. A multivariate stepwise logistic regression analysis revealed that UACR was independently associated with the likelihood of prefrailty/frailty (odds ratio 1.13, 95% CI 1.01–1.27). In conclusion, low-grade albuminuria is associated with the increased prevalence of prefrailty/frailty.

Prevention of post-traumatic clinical capillary leak syndrome

Systemic capillary leak is an early feature of the inflammatory response to localized injury, and is proportional to the severity of the inflammatory insult. Loss of local control of inflammation leads to an exaggerated systemic inflammatory response known as systemic inflammatory response syndrome (SIRS). SIRS is associated with multiple organ failure and death when there is failure to maintain homeostasis.

Whilst the application of molecular biology and recombinant techniques have produced major advances in our understanding of the mediation of the inflammatory response, there is no agent currently available which will prevent SIRS and reduce the incidence of post-traumatic multiple organ failure. In the meantime, a more practical approach to the avoidance of SIRS and its attendant capillary leak syndrome is to attempt to reduce the deleterious effects of interstitial oedema by tailoring treatment to the rapid changes in capillary permeability.

Effect and mechanism of hydrocortisone on organ function in patients with severe burns

INTRODUCTION

In patients with severe burns, resuscitation with large volumes of fluid is needed, partly because of an increase in capillary leakage. Corticosteroids might be beneficial by diminishing capillary leakage. This study aimed to assess in severely burned nonseptic patients whether hydrocortisone (HC) improved outcome and diminished capillary leakage.

METHODS

Retrospective analyses of a prospectively collected database were performed, including 39 patients (age 52 [35-62] years, 72% male). Patients were divided based on HC therapy. First, in patients in whom HC was started late, that is when deteriorating (late; 5-12 days postburn) data before and after start of HC were compared. Second, patients in whom HC was started day 0 or 1 postburn (upfront; within 48 hours) were compared with patients who did not receive HC (control). Outcome was assessed as organ dysfunction by Denver Multiple Organ Failure (MOF) score and Sequential Organ Failure Assessment (SOFA) score. As markers for capillary leakage and hydration state, proteinuria, B-type natriuretic peptide (BNP), and fluid administration were assessed. Follow-up was 20 days postburn. Possible adverse effects including mortality were recorded. Repeated measurement regression analyses were performed using MLwiN.

RESULTS

In the late group, Denver MOF and SOFA scores significantly decreased after HC (P<.001). Proteinuria tended to decrease (P=.13), BNP increased on the days HC was used (P<.001), and amounts of fluids diminished (P<.001). In the upfront vs control group, Denver MOF and SOFA scores (P<.001) decreased more quickly. Proteinuria (P=.006) and administered fluids decreased more rapidly (P<.001). Mortality rate, numbers of positive blood cultures, incidence of pneumonia, and graft loss were similar in all groups.

CONCLUSIONS

Hydrocortisone treatment in severe burned patients without sepsis might improve organ dysfunction possibly because of a reduction in capillary leakage, as reflected by a decrease of proteinuria, an increase of BNP, and diminished fluid resuscitation volumes.

Proteinuria, but Not eGFR, Predicts Stroke Risk in Chronic Kidney Disease: Chronic Renal Insufficiency Cohort Study

BACKGROUND AND PURPOSE

Chronic kidney disease is associated with an increased risk of cardiovascular events. However, the impact of chronic kidney disease on cerebrovascular disease is less well understood. We hypothesized that renal function severity would be predictive of stroke risk, independent of other vascular risk factors.

METHODS

The study population included 3939 subjects enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study, a prospective observational cohort. Stroke events were reported by participants and adjudicated by 2 vascular neurologists. Cox proportional hazard models were used to compare measures of baseline renal function with stroke events. Multivariable analysis was performed to adjust for key covariates.

RESULTS

In 3939 subjects, 143 new stroke events (0.62 events per 100 person-years) occurred over a mean follow-up of 6.4 years. Stroke risk was increased in subjects who had worse baseline measurements of renal function (estimated glomerular filtration rate and total proteinuria or albuminuria). When adjusted for variables known to influence stroke risk, total proteinuria or albuminuria, but not estimated glomerular filtration rate, were associated with an increased risk of stroke. Treatment with blockers of the renin-angiotensin system did not decrease stroke risk in individuals with albuminuria.

CONCLUSIONS

Proteinuria and albuminuria are better predictors of stroke risk in patients with chronic kidney disease than estimated glomerular filtration rate. The impact of therapies targeting proteinuria/albuminuria in individuals with chronic kidney disease on stroke prevention warrants further investigation.

Association of de novo dipstick albuminuria with severe acute kidney injury in critically ill septic patients

BACKGROUND

Acute kidney injury (AKI) occurs frequently in septic patients. Albuminuria may play a role as an early marker of septic AKI. The potential association between de novo dipstick albuminuria (DA) and septic AKI has not been examined.

METHODS

We conducted a single-center observational cohort study of 423 critically ill septic patients without chronic kidney disease (CKD) or prior positive DA within 3 months before admission. The association between de novo DA within the first 24 h of presentation and AKI at 72 h was examined.

RESULTS

AKI was identified in 268/423 (63%) patients and 20/423 (4.7%) required dialysis. De novo DA was associated with AKI (univariate OR 1.91; 95% CI 1.27-2.86, p = 0.002). The association persisted in a multivariate logistic regression model adjusted for demographics, baseline kidney function, comorbidities, critical illness parameters, and exposure to nephrotoxins (adjusted OR 1.87; 95% CI 1.21-2.89, p = 0.005). The association between de novo DA and AKI was stronger for severe AKI, i.e. Acute Kidney Injury Network (AKIN) stage 3 (adjusted OR 2.99; 95% CI 1.52-5.85, p = 0.001) and AKIN stage 2 (adjusted OR 1.79; 95% CI 1.002-3.21, p = 0.049) but not AKIN stage 1 (adjusted OR 1.41; 95% CI 0.87-2.29, p = 0.16).

CONCLUSIONS

De novo DA within the first 24 h of admission was independently associated with severe AKI in critically ill septic patients. Future studies are required to fully elucidate the utility of DA testing in the early detection and stratification of AKI.

Compliance Index, a Marker of Peripheral Arterial Stiffness, may Predict Renal Function Decline in Patients with Chronic Kidney Disease

BACKGROUND

Compliance index derived from digital volume pulse (CI-DVP), measuring the relationship between volume and pressure changes in fingertip, is a surrogate marker of peripheral arterial stiffness. This study investigated if CI-DVP can predict renal function deterioration, cardiovascular events and mortality in patients with chronic kidney disease (CKD).

METHODS

In this prospective observational study, 149 CKD patients were included for final analysis. CI-DVP and brachial-ankle pulse wave velocity (baPWV) were measured, decline in renal function was assessed by the estimated glomerular filtration rate (eGFR) slope. Composite renal and cardiovascular outcomes were evaluated, including ≥50% eGFR decline, start of renal replacement therapy, and major adverse events.

RESULTS

Patients in CKD stages 3b to 5 had higher baPWV and lower CI-DVP values than those in patients with CKD stages 1 to 3a. Stepwise multivariate linear regression analysis showed that lower CI-DVP (p =0.0001) and greater proteinuria (p =0.0023) were independent determinants of higher eGFR decline rate. Multivariate Cox regression analysis revealed that CI-DVP (HR 0.68, 95% CI 0.46-1.00), baseline eGFR (HR 0.96, 95% CI 0.94-0.98) and serum albumin (HR 0.17, 95% CI 0.07-0.42) were independent predictors for composite renal and cardiovascular outcomes.

CONCLUSIONS

Compliance index, CI-DVP, was significantly associated with renal function decline in patients with CKD. A higher CI-DVP may have independent prognostic value in slower renal function decline and better composite renal and cardiovascular outcomes in CKD patients.

Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness

BACKGROUND

Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness in obese children and adolescents.

METHODS

Ninety-two obese patients aged 10-18 years were compared with 49 healthy control individuals. Insulin resistance was measured as the homeostatic assessment model (HOMA), and arterial stiffness was measured as carotid-femoral pulse wave velocity (cfPWV).

RESULTS

Mean ± SD daytime systolic BP (SBP) (obese: 125±8.3mm Hg; control: 121±10.1mm Hg; P = 0.03) and nighttime SBP (obese: 108±10.7mm Hg; control: 102±8.2mm Hg; P = 0.0001) were higher in the obese group when compared with the control group. No difference was found in daytime diastolic BP (DBP), whereas nighttime DBP (obese: 60±6.6mm Hg; control: 57±4.8mm Hg; P = 0.001) and night-to-day BP ratios were higher in the obese group. Nighttime SBP was related to BMI z score (β = 6.0; 95% confidence interval (CI) = 2.9-9.1; P = 0.0002) and waist/height ratio (β = 36.7; 95% CI = 5.6-67.9; P = 0.02) in the obese group. HOMA index (obese: median = 3.7, interquartile range (IQR) = 2.3-6.0; control: median = 2.6, IQR = 1.8-3.4; P = 0.002) was higher, whereas cfPWV (obese: 4.8±0.8 m/s; control: 5.1±0.6 m/s; P = 0.03) was lower in the obese group. CfPWV was not related to logHOMA index. In multiple regression analyses, the higher nighttime BP in the obese group was independent of logHOMA and cfPWV.

CONCLUSIONS

Obese children had a higher nighttime BP when compared with the control group independently of insulin resistance and arterial stiffness. No relationship was found between insulin resistance and arterial stiffness. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov identifier NCT01310088.

The utility of microalbuminuria measurements in pediatric burn injuries in critical care

PURPOSE

Microalbuminuria, as measured by urinary albumin-creatinine ratios (ACRs), has been shown to be a marker of systemic inflammation and an indicator of the potential severity of trauma and critical illness. Severe pediatric burns represent the best model in which to investigate the clinical utility of microalbuminuria. This study aims to ascertain whether ACR measurements have any role in predicting the severity or the intensive care requirements in the critically unwell pediatric burn population.

MATERIALS AND METHODS

A retrospective observational study was undertaken within a regional burn center with a dedicated 8-bed burn intensive care unit (ICU). This looked at 8 years of consecutive pediatric burns requiring intensive care support-a total of 63 patients after exclusions. Daily urinary ACR measurements were acquired from all patients.

RESULTS

All patients had greater than or equal to 1 ACR measurement out with the reference range, and only 8% (5/63) presented to the ICU with a normal ACR. The median day for the peak ACR measurement was day 4. The relative lack of mortalities (3/63) precluded adequate correlations between ACR and outcomes. Peak and mean ACR values correlate well with length of ICU stay, and the peak ACR also correlates with total length of hospital stay and severity of burn injury as measured by total body surface area burnt and number of organ systems requiring support. No significant differences were found when the patients were stratified by age. The peak ACR measurement was found to be independently predictive of the length of the ICU stay. As such, we have created a predictive model to prove that an ACR that remains less than 12 mg/mmol is predicative of an ICU stay of less than or equal to 7 days.

CONCLUSIONS

The clinical utilities of ACR measurements are demonstrated by their correlation with the severity of injury, length of ICU stay, and requirements for multiple organ support. Albumin-creatinine ratios raised over certain thresholds highlight to the clinician the need for closer observation and the potential deterioration of patients.

Poor lung function has inverse relationship with microalbuminuria, an early surrogate marker of kidney damage and atherosclerosis: the 5th Korea National Health and Nutrition Examination Survey

Background

Despite epidemiological evidences of relationship between poor lung function and atherosclerosis, the relationship between poor lung function and microalbuminuria (MAU), an early surrogate marker of both kidney damage and atherosclerosis, is not well understood. Hence, we plan to investigate the relationship between poor lung function and MAU using multivariate models to adjust for other atherogenic risk factors.

Methods

We used data from the 5^th Korean National Health and Nutrition Examination Survey. Poor lung function is determined by spirometric measurement, primarily through estimation of the forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Declines in the percent predicted FVC (<80%) and in the FEV₁/FVC ratio (<0.7) are defined as restrictive and obstructive patterns, respectively. Urine albumin to urine creatinine levels ratio (UACR) were measured in spot urine samples. MAU was defined as UACR >30 mg/g.

Results

Inverse relationship was observed between lung function and UACR. In an age-adjusted regression model, the regression coefficient (B) of 10% lower FVC was 11.09 in men (P = 0.002), which remained significant after adjustment for SBP, FBG, triglyceride level, BMI, smoking history, and heavy alcohol consumption (B = 7.52, P = 0.043). When the restrictive pattern was compared to the normal pattern, the odds ratios (OR) (95% confidence interval, 95%CI) for MAU were 1.90 (1.32–2.72) in men, after adjustment for age, hypertension, diabetes mellitus, triglyceride level, obesity, smoking history, physical activity, and heavy alcohol consumption.

Conclusions

Our study, the first investigation in Asia, demonstrated that the restrictive pattern is related to MAU in men. Furthermore, there was linear relationship between lower FVC and UACR. Thus, our current study suggests that poor lung function, particularly the restrictive pattern, is related to kidney damage as well as atherosclerosis.

Association of low-grade albuminuria with adverse cardiac mechanics: findings from the hypertension genetic epidemiology network (HyperGEN) study

BACKGROUND

Albuminuria is a marker of endothelial dysfunction and has been associated with adverse cardiovascular outcomes. The reasons for this association are unclear but may be attributable to the relationship between endothelial dysfunction and intrinsic myocardial dysfunction.

METHODS AND RESULTS

In the Hypertension Genetic Epidemiology Network (HyperGEN) Study, a population- and family-based study of hypertension, we examined the relationship between urine albumin-to-creatinine ratio (UACR) and cardiac mechanics (n=1894, all of whom had normal left ventricular ejection fraction and wall motion). We performed speckle-tracking echocardiographic analysis to quantify global longitudinal, circumferential, and radial strain, and early diastolic (e') tissue velocities. We used E/e' ratio as a marker of increased left ventricular filling pressures. We used multivariable-adjusted linear mixed effect models to determine independent associations between UACR and cardiac mechanics. The mean age was 50±14 years, 59% were female, and 46% were black. Comorbidities were increasingly prevalent among higher UACR quartiles. Albuminuria was associated with global longitudinal strain, global circumferential strain, global radial strain, e' velocity, and E/e' ratio on unadjusted analyses. After adjustment for covariates, UACR was independently associated with lower absolute global longitudinal strain (multivariable-adjusted mean global longitudinal strain [95% confidence interval] for UACR Quartile 1 = 15.3 [15.0-15.5]% versus UACR Q4 = 14.6 [14.3-14.9]%, P for trend <0.001) and increased E/e' ratio (Q1 = 25.3 [23.5-27.1] versus Q4 = 29.0 [27.0-31.0], P=0.003). The association between UACR and global longitudinal strain was present even in participants with UACR < 30 mg/g (P<0.001 after multivariable adjustment).

CONCLUSIONS

Albuminuria, even at low levels, is associated with adverse cardiac mechanics and higher E/e' ratio.

Microalbuminuria as a risk predictor in diabetes: the continuing saga

OBJECTIVE The rationale for this study was to review the data on microalbuminuria (MA), an amount of albumin in the urine of 30-299 mg/day, in patients with diabetes in the context of cardiovascular risk and development of kidney disease. The objective was to review the pathophysiology of MA in patients with diabetes and review the data from trials regarding MA in the context of risk for cardiovascular events or kidney disease progression. RESEARCH DESIGN AND METHODS Data sources were all PubMed-referenced articles in English-language peer-reviewed journals since 1964. Studies selected had to have a minimum 1-year follow-up and be either a randomized trial linking MA to cardiovascular or kidney disease outcome, a meta-analysis/systematic review, or a large observational cohort study. RESULTS The data suggest that MA is a risk marker for cardiovascular events and possibly for kidney disease development. Its presence alone, however, does not indicate established kidney disease, especially if the estimated glomerular filtration rate is >60 mL/min/1.73 m(2). An increase in MA, when blood pressure and other risk factors are controlled, portends a poor prognosis for kidney outcomes over time. Early in the course of diabetes, aggressive risk factor management focused on glycemic and blood pressure goals is important to delay kidney disease development and reduce cardiovascular risk. CONCLUSIONS MA is a marker of cardiovascular disease risk and should be monitored per guidelines once or twice a year for progression to macroalbuminuria and kidney disease development, especially if plasma glucose, lipids, and blood pressure are at guideline goals.

Significance of microalbuminuria in relation to subclinical coronary atherosclerosis in asymptomatic nonhypertensive, nondiabetic subjects

We aimed to investigate the significance of microalbuminuria and its relationship with subclinical atherosclerosis in nonhypertensive and nondiabetic patients, by using coronary artery computed tomography (CT). A total of 1,318 nonhypertensive and nondiabetic subjects who had taken coronary artery CT and measured spot urine albumin to creatinine ratio (UACR) were evaluated. The atherosclerotic changes of coronary arteries were greater in subjects with microalbuminuria, reflected by coronary artery calcium score (CACS) and significant coronary artery stenosis (CACS ≥ 100 in 15.3% vs 7.6% and stenosis ≥ 50% in 11.5% vs 4.9% of patients with vs without microalbuminuria, P = 0.008 and P = 0.011, respectively). Among various parameters that are known as a risk factor or possible biomarkers of coronary artery disease, presence of microalbuminuria, age and Framingham risk score were significantly related to coronary artery stenosis. Among them the presence of microalbuminuria showed stronger correlation than others to the coronary artery stenosis detected by CT, even after adjusting confounding factors (OR 3.397, 95% confidence interval 1.138 to 10.140, P = 0.028). The presence of microalbuminuria by UACR was significantly associated with presence of coronary artery stenosis ≥ 50% in asymptomatic, nonhypertensive and nondiabetic general population. Our study suggests that the presence of microalbuminuria may imply subclinical coronary artery disease, even in asymptomatic population.

Male erectile dysfunction and microalbuminuria in adult nigerians with essential hypertension

BACKGROUND

Microalbuminuria has been described as a marker of generalized vascular damage.

AIMS

The aim of the present study was to determine the prevalence of erectile dysfunction (ED) and microalbuminuria in adult male Nigerians with newly diagnosed hypertension. We also evaluated the relations between ED and microalbuminuria, electrocardiographic left ventricular hypertrophy, serum lipids, and cigarette smoking.

MATERIALS AND METHODS

A total of 81 male adult Nigerians with newly diagnosed hypertension were recruited into the study. There were also 75 age- and sex-matched healthy normotensive controls. ED was evaluated using a standardized questionnaire of the International Index of Erectile Function and microalbuminuria was determined using the Micra Test strips (Boehringer Manneheim GMBh, Mannheim, Germany).

RESULTS

Eighty-one hypertensive patients and 75 normotensive controls were studied. Mean age of the patients and the controls was 53.8 ± 5.6 and 51.2 ± 7.1 respectively. ED was found in 32.1% of the hypertensive patients and 16% of normotensive controls (P < 0.001). The prevalence of microalbuminuria was significantly higher in patients with ED than in those without it (65.4% vs. 23.6%, P < 0.0001).

CONCLUSION

The study shows that ED and microalbuminuria are common in male adult Nigerians with hypertension. It also demonstrates that male ED is associated with an increased risk of cardiovascular disease.

Peritoneal protein leakage, systemic inflammation, and peritonitis risk in patients on peritoneal dialysis

BACKGROUND

Whether peritoneal protein leakage predicts risk for peritonitis in patients on peritoneal dialysis (PD) is unknown. In this observational cohort study, we aimed to determine that association and, further, to explore if it might be explained by systemic inflammation. ♢

METHODS

We prospectively followed 305 incident PD patients to first-episode peritonitis, censoring, or the end of the study. Demographics, comorbidity score, biochemistry, and peritoneal protein clearance (PrC) were collected at baseline. The predictors of first-episode peritonitis were analyzed prospectively. ♢

RESULTS

During follow-up, 14 868 patient months and 251 episodes of peritonitis were observed. The baseline PrC was 73.2 mL/day (range: 53.2 - 102 mL/day). Patients with a high PrC were prone to be older and malnourished. They also had a higher comorbidity score and higher C-reactive protein values. In 132 first episodes of peritonitis, baseline PrC was shown to be a significant independent predictor after adjustment for age, sex, body mass index, diabetes, residual renal function, hemoglobin, and peritoneal transport rate. Systemic inflammatory markers such as serum albumin, C-reactive protein, and interleukin-6 could not explain the association of PrC and high risk for peritonitis. ♢

CONCLUSIONS

Baseline peritoneal protein leakage was able to independently predict risk for peritonitis, which is not explained by systemic inflammation. The underlying mechanisms should be explored in future.

Cardiovascular disease in chronic kidney disease: untying the Gordian knot

Chronic kidney disease (CKD) affects around 10-13% of the general population, with only a small proportion in end stage renal disease (ESRD), either on dialysis or awaiting renal transplantation. It is well documented that CKD patients have an extremely high risk of developing cardiovascular disease (CVD) compared with the general population, so much so that in the early stages of CKD patients are more likely to develop CVD than they are to progress to ESRD. Various pathophysiological pathways and explanations have been advanced and suggested to account for this, including endothelial dysfunction, dyslipidaemia, inflammation, left ventricular hypertrophy and cardiac autonomic dysfunction. In this review, we try to understand and further explore the link between CKD and CVD, as well as offering interventional advice where available, while exposing the current lack of RCT-based research and trial evidence in this area. We also suggest pragmatic Interim measures we could take while we wait for definitive RCTs.

Loss of the endothelial glycocalyx links albuminuria and vascular dysfunction

Patients with albuminuria and CKD frequently have vascular dysfunction but the underlying mechanisms remain unclear. Because the endothelial surface layer, a meshwork of surface-bound and loosely adherent glycosaminoglycans and proteoglycans, modulates vascular function, its loss could contribute to both renal and systemic vascular dysfunction in proteinuric CKD. Using Munich-Wistar-Fromter (MWF) rats as a model of spontaneous albuminuric CKD, multiphoton fluorescence imaging and single-vessel physiology measurements revealed that old MWF rats exhibited widespread loss of the endothelial surface layer in parallel with defects in microvascular permeability to both water and albumin, in both continuous mesenteric microvessels and fenestrated glomerular microvessels. In contrast to young MWF rats, enzymatic disruption of the endothelial surface layer in old MWF rats resulted in neither additional loss of the layer nor additional changes in permeability. Intravenous injection of wheat germ agglutinin lectin and its adsorption onto the endothelial surface layer significantly improved glomerular albumin permeability. Taken together, these results suggest that widespread loss of the endothelial surface layer links albuminuric kidney disease with systemic vascular dysfunction, providing a potential therapeutic target for proteinuric kidney disease.

Increased urinary protein excretion in the "normal" range is associated with increased renin-angiotensin system activity

Increased levels of albuminuria and proteinuria, both linked to augmented renin-angiotensin system (RAS) activity, are associated with adverse kidney and cardiovascular events. However, the relationship between variations in urinary albumin excretion (UAE) and total protein excretion (UTPE) in the normal range and RAS activity is unclear. We examined the association between UAE and UTPE and the hemodynamic response to angiotensin II (ANG II) challenge, a well-accepted indirect measure of RAS activity, in healthy individuals with normal UAE and UTPE. Forty subjects (15 men, 25 women; age 38 ± 2 yr; UAE, 3.32 ± 0.55 mg/day; UTPE, 56.8 ± 3.6 mg/day) were studied in high-salt balance. Blood pressure (BP), arterial stiffness determined by applanation tonometry, and circulating RAS components were measured at baseline and in response to graded ANG II infusion. The primary outcome was the BP response to ANG II challenge at 30 and 60 min. UAE was associated with a blunted diastolic BP response to ANG II infusion (30 min, P = 0.005; 60 min, P = 0.17), a relationship which remained even after adjustment (30 min, P < 0.001; 60 min, P = 0.035). Similar results were observed with UTPE (30 min, P = 0.031; 60 min, P = 0.001), even after multivariate analysis (30 min, P = 0.008; 60 min, P = 0.001). Neither UAE nor UTPE was associated with systolic BP, circulating RAS components, or arterial stiffness responses to ANG II challenge. Among healthy individuals with UAE and UTPE in the normal range, increased levels of these measures were independently associated with a blunted diastolic BP response to ANG II, indicating increased vascular RAS activity, which is known to be deleterious to both renal and cardiac function.

Increased B-type natriuretic peptide and decreased proteinuria might reflect decreased capillary leakage and is associated with a better outcome in patients with severe burns

Introduction

It is difficult to adjust fluid balance adequately in patients with severe burns due to various physical changes. B-type natriuretic peptide (BNP) is emerging as a potential marker of hydration state. Proteinuria is used as a predictor of outcome in severe illness and might correlate to systemic capillary leakage. This study investigates whether combining BNP and proteinuria can be used as a guide for individualized resuscitation and as a predictor of outcome in patients with severe burns.

Methods

From 2006 to 2009, 38 consecutive patients (age 47 ± 15 years, 74% male) with severe burns were included and followed for 20 days. All had normal kidney function at admission. BNP and proteinuria were routinely measured. Ordered and actually administered fluid resuscitation volumes were recorded. The Sequential Organ Failure Assessment (SOFA) score was used as the measure of outcome.

Results

BNP increased during follow-up, reaching a plateau level at Day 3. Based on median BNP levels at Day 3, patients were divided into those with low BNP and those with high BNP levels. Both groups had comparable initial SOFA scores. Patients with high BNP received less fluid from Days 3 to 10. Furthermore, patients with a high BNP at Day 3 had less morbidity, reflected by lower SOFA scores on the following days. To minimize effects of biological variability, proteinuria on Days 1 and 2 was averaged. By dividing the patients based on median BNP at Day 3 and median proteinuria, patients with high BNP and low proteinuria had significantly lower SOFA scores during the entire follow-up period compared to those patients with low BNP and high proteinuria.

Conclusions

Patients with higher BNP levels received less fluid. This might be explained by a lower capillary leakage in these patients, resulting in more intravascular fluid and consequently an increase in BNP. In combination with low proteinuria, possibly reflecting minimal systemic capillary leakage, a high BNP level was associated with a better outcome. BNP and proteinuria have prognostic potential in severely burned patients and may be used to adjust individual resuscitation.

Reduction in basal nitric oxide activity causes albuminuria

OBJECTIVE

The barrier function of the glomerular filter has been studied for decades. Albuminuria reflects a malfunction of this barrier, and in animals dysfunctional endothelial nitric-oxide (NO) synthase results in albuminuria. We aimed to analyze the importance of NO for the glomerular barrier function in humans.

RESEARCH DESIGN AND METHODS

To assess the effect of endothelial dysfunction on albuminuria, we measured the urine albumin-to-creatinine ratio (UACR) both before and after the blockade of NO synthases (NOSs) with systemic infusion of N(G)-monomethyl-L-arginine (L-NMMA) in two distinct study populations. In population A, 62 hypertensive patients with type 2 diabetes and, in population B, 22 patients with hypercholesterolemia but without hypertension or type 2 diabetes were examined. All subjects had normal renal function.

RESULTS

There was a significant increase in the UACR in response to NOS inhibition with L-NMMA in hypertensive patients with type 2 diabetes (study population A) and in patients with hypercholesterolemia (study population B). Linear regression analyses revealed that the change in mean arterial presssure in response to L-NMMA was not related to the increase in the UACR in response to L-NMMA in either population, even after adjusting for filtration fraction.

CONCLUSIONS

NOS inhibition provokes albuminuria that is unrelated to changes in blood pressure. It is noteworthy that this finding was evident in patient groups prone to endothelial dysfunction and albuminuria. Thus, acute deterioration of endothelial function by reducing NO activity causes an increase in albuminuria.

Are ACEI/ARBs associated with the decreased peritoneal protein clearance in long-term PD patients?

Objective. Peritoneal protein clearance (PrC) is recognized as a new marker of systemic endothelial dysfunction and predictor of mortality in patients on peritoneal dialysis (PD). Given that angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARBs) could improve endothelial dysfunction in the general population, we aim to explore whether this benefit is present in the PD population.

METHODS

We analysed data from a PD cohort with data prospectively collected. The PrC, defined daily doses (DDDs) of ACEI/ARBs, as well as other clinical variables were recorded at baseline and then repeatedly measured at 3- to 6-month intervals till to death or censoring. A total of 156 patients were treated with ACEI/ARBs with 0.60 of median time-averaged DDDs, the untreated group consisted of 149 patients who received none of the above drugs during the follow-up.

RESULTS

The baseline and time-averaged PrC were 69.9 ± 34.7 mL/day and 75.2 ± 28.3 mL/day, respectively. Time-averaged PrC was an independent predictor of mortality adjusted for recognized confounders in a multivariate Cox regression model (P = 0.037). There were no significant differences in the time course of PrC (P = 0.82) and peritoneal protein loss (P = 0.83) between the ACEI/ARBs group and the untreated group after adjustment for age, gender, diabetes, baseline C-reactive protein, mean blood pressure and baseline PrC or baseline peritoneal protein loss in the generalized linear mixed model.

CONCLUSIONS

We conclude that ACEI/ARBs did not correlate with a decreased PrC in this observational study. The effect of higher doses of ACEI/ARBs needs to be determined in future interventional studys.

Urine Albumin Creatinine Ratio is Associated with Carotid Atherosclerosis in a Community Based Cohort: Atherosclerosis Risk of Rural Area in Korean General Population Study

BACKGROUND

Albuminuria is a surrogate marker of endothelial dysfunction and a predictor of cardiovascular events. Data are limited with regard to the relationship between albuminuria and subclinical atherosclerosis in a community-based cohort. We determined the association between albuminuria measured by the urine albumin creatinine ratio (UACR) and carotid intima media thickness (CIMT) in a Korean rural population.

METHODS

We enrolled 1,369 healthy subjects older than 40 years (857 males and 518 females) with normal renal function and measured the CIMT. We excluded subjects with overt proteinuria (> 300 mg/day) or with treatment of diabetes mellitus, hypertension, dyslipidemia, and any cardiovascular disease. The subjects were stratified into the quartile value of the UACR (lowest quartile: UACR < 4.8 and highest quartile: UACR > 17.7). And we evaluate the relationship between UACR and CIMT by linear regression and logistic regression analysis.

RESULTS

Increasing quartile of the UACR had a stepwise increase in body mass index, blood pressure, cholesterol profile [low density lipoprotein (LDL)-cholesterol and triglyceride], glucose, homeostratic model assessment of insulin resistance (HOMA-IR), and C-reactive protein (all p values < 0.001). Maximal CIMT from the 1(st) to the 4(th) quartile values of the UACR were 0.74 ± 0.17, 0.77 ± 0.18, 0.78 ± 0.18, and 0.82 ± 0.21 mm, respectively (p < 0.001). In a multivariate regression model adjusted for age, sex, systolic blood pressure, triglyceride, LDL-cholesterol, fasting blood sugar, waist circumference, adiponectin, HOMA-IR, high sensitive C-reactive protein, smoking, UACR showed a significant association with maximal CIMT (B = 0.014, R(2) = 0.145, p = 0.002).

CONCLUSION

Albuminuria measured by the UACR was significantly associated with both CIMT and traditional risk factors of atherosclerosis except for smoking in healthy Koreans.

The importance of renin-angiotensin blockade in patients with cardio-renal disease

The existence of the renin-angiotensin-aldosterone system was first postulated over 100 years ago. Following the identification of all the major components, came the discovery of their potential pathogenicity in cardiovascular and renal disease. The introduction of drugs that inhibit the synthesis or actions of this system has prompted a number of trials that have largely shaped how cardiovascular and renal disease is managed today. The continued discovery of yet more components of this system promises to further our understanding of its influence on disease processes and herald the development of more highly selective drugs, ensuring that the renin-angiotensin-aldosterone system will continue to be a key area of interest for many years to come.

Microalbuminuria: An inexpensive, non invasive bedside tool to predict outcome in critically ill patients

This study was conducted to evaluate whether microalbuminuria on admission and after 24 hrs of admission to intensive care unit (ICU) predicts outcome as well as the Acute Physiology and Chronic Health Evaluation (APACHE) II severity illness score, the current accepted method of doing so. The study was carried out in a 20 bed mixed medical-surgical ICU of a tertiary care hospital. Of 525 consecutive adult patients with ICU stay of more than 24 hrs, 238 were included for the study. Patients with pregnancy, menstruation, anuria, macroscopic hematuria, urinary tract infection, marked proteinuria due to renal and post-renal structural diseases, were excluded. Spot urine samples were collected on admission to ICU and 24 hrs thereafter. Urine albumincreatinine ratio (ACR) was measured on ICU admission (ACR1) and after 24 hrs (ACR2) and expressed in mg/g. Patient demographics were noted on admission. For disease severity scoring, APACHE II scores were calculated. Each patient was followed up throughout their ICU stay for a maximum of 28 days and the following outcome data were obtained: ICU length of stay and ICU mortality. Of the 238 patients, 196 survived while 42 patients died in the ICU. Non-survivors had a significantly higher median ACR2 [162.7 mg/g (IQR 69.5-344.3)] in comparison to the survivors who had a median ACR2 = 54.4 mg/g (IQR 19.0-129.1) (P< 0.0001). The median ACR1 [161.0 mg/g (IQR 29.0-369.3)] of non-survivors was higher than the median ACR1 [80.4 mg/g (IQR 35.1-167.6)] of survivors but failed to reach statistical significance (P= 0.0948). In a receiver operating characteristic curve (ROC) analysis, ACR2 emerged as the best indicator of mortality [(area under curve (AUC) of ACR2 = 0.71 > AUC (ACR1) =0.58 > AUC (ΔACR) =0.55] similar to the currently used APACHE II scores (AUC = 0.78) (P=0.3). At a cutoff of 101 mg/g, ACR2 had a sensitivity of 69%, specificity of 67%, positive predictive value of 31% and a negative predictive value of 91% for predicting mortality in the critically ill patients. Absence of significant microalbuminuria at 24 hrs of ICU admission may help to predict survival in the ICU.