Microalbuminuria in the US population: third National Health and Nutrition Examination Survey

Evidence of chronic kidney disease in veterans with incident diabetes mellitus

While chronic kidney disease (CKD) is regularly evaluated among patients with diabetes, kidney function may be significantly impaired before diabetes is diagnosed. Moreover, disparities in the severity of CKD in such a population are likely. This study evaluated the extent of CKD in a national cohort of 36,764 US veterans first diagnosed with diabetes between 2003 and 2013 and prior to initiating oral antidiabetic therapy. Evidence of CKD (any stage) at the time of diabetes diagnosis was determined using eGFR and urine-albumin-creatinine ratios, the odds of which were assessed using logistic regression controlling for patient characteristics. CKD was evident in 31.6% of veterans prior to being diagnosed with diabetes (age and gender standardized rates: 241.8 per 1,000 adults [overall] and 247.7 per 1,000 adult males), over half of whom had at least moderate kidney disease (stage 3 or higher). The odds of CKD tended to increase with age (OR: 1.88; 95% CI: 1.82-1.93), hemoglobin A1C (OR: 1.05; 95% CI: 1.04-1.06), systolic blood pressure (OR: 1.04; 95% CI: 1.027-1.043), and BMI (OR: 1.016; 95% CI: 1.011-1.020). Both Asian Americans (OR: 1.53; 95% CI: 1.15-2.04) and African Americans (OR: 1.11; 95% CI: 1.03-1.20) had higher adjusted odds of CKD compared to whites, and prevalence was highest in the Upper Midwest and parts of the Mid-South. Results suggest that evidence of CKD is common among veterans before a diabetes diagnosis, and certain populations throughout the country, such as minorities, may be afflicted at higher rates.

Ambulatory blood pressure in the dash diet trial: Effects of race and albuminuria

We evaluated whether low-grade albuminuria or black race modulates ambulatory blood pressure (BP) or nocturnal BP response to the DASH diet. Among 202 adults enrolled in the DASH multicenter trial who were fed the DASH or control diet for 8 weeks, reductions in 24-hour daytime and nighttime SBP and DBP were significantly larger for DASH compared to control. Median changes in nocturnal BP dipping were not significant. Compared to urine albumin excretion of <7 mg/d, ≥7 mg/d was associated with larger significant median reductions in 24-hour SBP (-7.3 vs -3.1 mm Hg), all measures of DBP (24-hour: -5.9 vs -1.8 mm Hg; daytime: -9.9 vs -4.0 mm Hg; nighttime -9.0 vs -2.0 mm Hg), and with increased nocturnal SBP dipping (2.3% vs -0.5%). Black race was associated with larger median reduction in 24-hour SBP only (-5.5 vs -2.4 mm Hg). This analysis suggests greater effect of DASH on ambulatory BP in the presence of low-grade albuminuria.

Early Markers of Sickle Nephropathy in Children With Sickle Cell Anemia Are Associated With Red Cell Cation Transport Activity

The early stages of sickle cell nephropathy (SCN) manifest in children with sickle cell anemia (SCA) as hyperfiltration and proteinuria. The physiological conditions of the renovascular system are among the most conducive to hemoglobin S polymerization in the body and will magnify small changes in red cell volume thus crucially modulating intracellular concentrations of hemoglobin S. This large cross-sectional study of children with sickle cell anemia measured glomerular filtration rates and microalbuminuria to report prevalence, clinical correlates and uniquely, association with key red cell cation transport mechanisms. One hundred and twelve patients (mean age 10.7 ± 4.1) were recruited. The prevalence of hyperfiltration and microalbuminuria was 98% and 15.1%, respectively. Glomerular filtration rates did not vary with age, but proteinuria became more prevalent with increasing age. Both features associated with markers of hemolysis, while elevated hemoglobin F was protective, but no association was seen with systolic or diastolic blood pressure. In multivariate analysis, both Gardos channel (β = 0.476, P < 0.001) and KCl co-transporter (KCC; β = -0.216, P = 0.009) activity, alongside age (β = 0.237, P = 0.004), remained independently predictive for microalbuminuria. Increased activity of Gardos channel and P_sickle positively associated with microalbuminuria, while increased KCC activity associated with a reduction in microalbuminuria. This study demonstrates a direct link between the abnormally active red cell cation transport systems in sickle cell disease and sickle organopathy. Small variations in the activity of these transport mechanisms predict for SCN and measurement of them may help identify those at risk, while pharmaceutical manipulation of these excessively active systems may ameliorate their risk.

Association between shift work and microalbuminuria: data from KNHANES(2012-2014)

Background

Shift work disturbs workers’ biological clocks and this condition can cause various health problems including cardiovascular disease. The elevated albuminuria level has been significantly associated with the risk of the cardiovascular disease even within a normal reference range. Therefore, this study aimed to investigate the association between shift work and microalbuminuria.

Methods

Workers aged over 20 years from the fifth and sixth Korea National Health and Nutrition Examination Survey(KNHANES 2012–2014; n = 3000) were included in this analysis. The multiple logistic regression analysis was performed to determine the association between shift work and microalbuminuria stratified by gender.

Results

The prevalence of microalbuminuria in male subjects was higher among day workers, but the difference was not significant. However, the prevalence of microalbuminuria among females was higher in shift workers with statistical significance. For female, the Odds ratio of microalbuminuria in shift workers was significantly higher with 1.86 (95% CI 1.02–3.39) compared with day workers. After dividing into 5 subgroups of the shift work pattern, the odds ratio of microalbuminuria for fixed night shift was significantly higher at 4.68 (95% CI 1.29–17.00) compared with day workers.

Conclusions

This study showed that shift work was associated with microalbuminuria in female workers. Especially we found out the association between fixed night shift and microalbuminuria in female workers.

A multicenter cohort study of primary hypertension in Korea: study design and interim analysis of the Korean registry of target organ damage in hypertension (KorHR)

BACKGROUND

The Korean Registry of Target Organ Damage in Hypertension aims to evaluate the clinical characteristics and prevalence of subclinical target organ damage in Korean hypertensive patients.

METHOD

This is a prospective, observational, multicenter cohort study in which 23 university hospitals participated. Since May 2013, we have enrolled 1,318 consecutive hypertensive patients without known cardiovascular disease who met the following inclusion criteria: 1) age older than 30 years and 2) the first visit to the participating hospitals was within the last 5 years.

RESULTS

The mean age was 52 ± 12 years; 62.1% were male, and 41.3% were incident hypertensives. Patients with diabetes mellitus accounted for 7.8% of the population and 43.8% had hyperlipidemia or were on statins at baseline. The mean office blood pressures were 152 ± 20/96 ± 14 mmHg for incident hypertensive patients and 129 ± 13/78 ± 10 mmHg for patients on treatment. Patients with electrocardiographic and echocardiographic left ventricular hypertrophy accounted for 18.9 and 25.6%, respectively. The mean brachial-ankle pulse wave velocity (PWV) was 1564 ± 293 m/s and 19.5% had PWV values of more than 1750 cm/s. Patients with microalbuminuria and chronic kidney disease accounted for 21 and 4%, respectively. The first prescribed class of antihypertensive medications was angiotensin converting enzyme inhibitors in 2.9%, angiotensin receptor blockers (ARBs) in 57.5%, diuretics in 7.6%, calcium channel blockers (CCBs) in 61.0%, beta blockers in 17.3%, and fixed dose combination pill in 27.8%.

CONCLUSION

Our interim analysis shows that subclinical target organ damage in hypertension is considerably present for incident or treated hypertensive patients. CCBs and ARBs were the most commonly prescribed classes of antihypertensive medications and fixed dose combination pills were actively used in Korea.

TRIAL REGISTRATION

NCT01861080. Registered 16 May 2013.

Rapid decline in lung function in healthy adults predicts incident excess urinary albumin excretion later in life

Introduction

Chronic lung disease, often characterised by rapid decline in lung function, is associated with vascular endothelial dysfunction (characterised by moderate to severe excess urinary albumin excretion (eUAE) but their longitudinal relationship is inadequately studied. In a bidirectional longitudinal examination of healthy adults, we analysed the following two hypotheses: (1) rapid decline (ie, highest tertile of lung function decline) predicts eUAE and (2) eUAE predicts rapid decline.

Methods

We performed a secondary data analysis from 3052 eligible participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. For analysis 1, the predictor was rapid decline in lung function between the peak value (attained at or before CARDIA visit year 10 or Y10 at a mean age of 35 years) and Y20; and the outcome was incident eUAE at Y20 and/or Y25. For analysis 2, the predictor was eUAE at Y10 and the outcome was rapid decline between Y10 and Y20.

Results

After adjustment for covariates in analysis 1, rapid decline in FEV₁ or FVC between peak and Y20 predicted incident eUAE at Y20 and/or Y25 (OR 1.51 and 1.44, respectively; p≤0.05 for both analyses). In analysis 2, eUAE at Y10 did not predict subsequent rapid decline.

Conclusions

Healthy adults with rapid decline in lung function are at risk for developing vascular endothelial dysfunction, as assessed by incident eUAE, later in life.

Eicosapentaenoic and Docosahexaenoic Acids Attenuate Progression of Albuminuria in Patients With Type 2 Diabetes Mellitus and Coronary Artery Disease

Background

Albuminuria is a marker of inflammation and an independent predictor of cardiovascular morbidity and mortality. The current study evaluated whether eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation attenuates progression of albuminuria in subjects with coronary artery disease.

Methods and Results

Two‐hundred sixty‐two subjects with stable coronary artery disease were randomized to either Lovaza (1.86 g of EPA and 1.5 g of DHA daily) or no Lovaza (control) for 1 year. Percent change in urine albumin‐to‐creatinine ratio (ACR) was compared. Mean (SD) age was 63.3 (7.6) years; 17% were women and 30% had type 2 diabetes mellitus. In nondiabetic subjects, no change in urine ACR occurred in either the Lovaza or control groups. In contrast, ACR increased 72.3% (P<0.001) in diabetic subjects not receiving Lovaza, whereas those receiving Lovaza had no change. In diabetic subjects on an angiotensin‐converting enzyme‐inhibitor or angiotensin‐receptor blocker, those receiving Lovaza had no change in urine ACR, whereas those not receiving Lovaza had a 64.2% increase (P<0.001). Change in ACR was directly correlated with change in systolic blood pressure (r=0.394, P=0.01).

Conclusions

EPA and DHA supplementation attenuated progression of albuminuria in subjects with type 2 diabetes mellitus and coronary artery disease, most of whom were on an angiotensin‐converting enzyme‐inhibitor or angiotensin‐receptor blocker. Thus, EPA and DHA supplementation should be considered as additional therapy to an angiotensin‐converting enzyme‐inhibitor or angiotensin‐receptor blocker in subjects with type 2 diabetes mellitus and coronary artery disease.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01624727.

Virus-Enabled Biosensor for Human Serum Albumin

The label-free detection of human serum albumin (HSA) in aqueous buffer is demonstrated using a simple, monolithic, two-electrode electrochemical biosensor. In this device, both millimeter-scale electrodes are coated with a thin layer of a composite containing M13 virus particles and the electronically conductive polymer poly(3,4-ethylenedioxy thiophene) or PEDOT. These virus particles, engineered to selectively bind HSA, serve as receptors in this biosensor. The resistance component of the electrical impedance, Zre, measured between these two electrodes provides electrical transduction of HSA binding to the virus-PEDOT film. The analysis of sample volumes as small as 50 μL is made possible using a microfluidic cell. Upon exposure to HSA, virus-PEDOT films show a prompt increase in Zre within 5 s and a stable Zre signal within 15 min. HSA concentrations in the range from 100 nM to 5 μM are detectable. Sensor-to-sensor reproducibility of the HSA measurement is characterized by a coefficient-of-variance (COV) ranging from 2% to 8% across this entire concentration range. In addition, virus-PEDOT sensors successfully detected HSA in synthetic urine solutions.

Beginning the trajectory to ESKD in adult life: albuminuria in Australian aboriginal children and adolescents

BACKGROUND

Globally, disadvantaged populations suffer a high burden of chronic kidney disease (CKD). The trajectory to CKD during childhood and adolescence remains unclear due to a paucity of longitudinal studies.

METHODS

This was a prospective, population-based cohort study in which since 2002 we have followed 3418 children (1469 non-Aboriginal and 1949 Aboriginal) attending participating schools across New South Wales (NSW), Australia. The albumin:creatinine ratio was measured by dipstick every 2 years together with the body mass index (BMI) and blood pressure. We used multivariable logistic generalised estimating equation models to examine whether Aboriginal children had a higher prevalence of albuminuria compared with non-Aboriginal children with increasing age and to identify potential risk factors.

RESULTS

The mean age at enrolment was 10.6 years, at which time 14.2 % of the children were obese and 16.0 % overweight, with 11.5 % found to have albuminuria. Over 8 years (11,387 participant-years) of follow-up the prevalence of albuminuria increased to 18.5 %, overweight to 16.1 % and obesity to 17.2 %. The BMI standard deviation score (SDS) was found to have a differential effect on the risk of albuminuria in Aboriginal and non-Aboriginal children (P interaction < 0.01). The prevalence of albuminuria decreased as the BMI SDS increased in both groups of children, but it increased more in non-Aboriginal children, leading to a 2.5 % higher prevalence of albuminuria in overweight Aboriginal children (95 % confidence interval 1.0-4.2 %).

CONCLUSION

Compared with non-Aboriginal children, Aboriginal children are of higher risk of albuminuria when overweight or obese. We hypothesise that overweight and obesity are key contributors to the development of adult onset CKD among Aboriginal Australians, which needs further exploration in future studies.

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.

Suggestions on how to make suboptimal kidney transplantation an ethically viable option

To overcome kidney donation, the pool of potentially eligible donors has been widened by using suboptimal organs harvested from living donors or cadavers. These organs may engender health complications as age, risk factors, and pathologies of donors fail to meet the standard donor criteria. After examining a wide array of literature on suboptimal kidney transplants, we evidenced two major issues: the lack of standardized terminology and the lack of longterm data on the health outcomes of both suboptimal living donors and recipients. Consequently, surgeons are still unable to provide patients with thorough information to obtain a well-informed consent. Suboptimal kidney transplantation still remains in its experimental stage, thereby raising many ethical and medico-legal concerns. We suggest that one possible solution to overcome some of the ethical shortcomings of suboptimal kidney donations is to provide living donors and recipients honest, accurate, and thorough information about its health risks. To this aim, we advocate adopting a widely standardized terminology that would embrace the whole concept of suboptimal kidney transplantation, increasing the number of future publications on the health outcomes of living donors and recipients, spurring ethical reflection to improve the experience of suboptimal kidney transplantation and reduce the waiting-list for kidney transplantation.

African Ancestry-Specific Alleles and Kidney Disease Risk in Hispanics/Latinos

African ancestry alleles may contribute to CKD among Hispanics/Latinos, but whether associations differ by Hispanic/Latino background remains unknown. We examined the association of CKD measures with African ancestry-specific APOL1 alleles that were directly genotyped and sickle cell trait (hemoglobin subunit β gene [HBB] variant) on the basis of imputation in 12,226 adult Hispanics/Latinos grouped according to Caribbean or Mainland background. We also performed an unbiased genome-wide association scan of urine albumin-to-creatinine ratios. Overall, 41.4% of participants were male, 44.6% of participants had a Caribbean background, and the mean age of all participants was 46.1 years. The Caribbean background group, compared with the Mainland background group, had a higher frequency of two APOL1 alleles (1.0% versus 0.1%) and the HBB variant (2.0% versus 0.7%). In the Caribbean background group, presence of APOL1 alleles (2 versus 0/1 copies) or the HBB variant (1 versus 0 copies) were significantly associated with albuminuria (odds ratio [OR], 3.2; 95% confidence interval [95% CI], 1.7 to 6.1; and OR, 2.6; 95% CI, 1.8 to 3.8, respectively) and albuminuria and/or eGFR<60 ml/min per 1.73 m² (OR, 2.9; 95% CI, 1.5 to 5.4; and OR, 2.4; 95% CI, 1.7 to 3.5, respectively). The urine albumin-to-creatinine ratio genome-wide association scan identified associations with the HBB variant among all participants, with the strongest association in the Caribbean background group (P=3.1×10^-10 versus P=9.3×10^-3 for the Mainland background group). In conclusion, African-specific alleles associate with CKD in Hispanics/Latinos, but allele frequency varies by Hispanic/Latino background/ancestry.

Microalbuminuria, cardiovascular risk factors and cardiovascular morbidity in a British population: The EPIC-Norfolk Population-based Study

BACKGROUND

Microalbuminuria is independently associated with increased cardiovascular risk and renal function deterioration in diabetes and hypertension, but the clinical relevance of raised albuminuria in the general population is less certain. We examined the prevalence of microalbuminuria and its relationship to cardiovascular risk factors and cardiovascular morbidity in the UK general population.

METHODS

Cross-sectional population-based study of 23,964 individuals, aged 40-79 years recruited in 1993-1997 for the EPIC-Norfolk Study. Smoking status, prevalent physician diagnosed diabetes, hypertension, cardiovascular disease and cancer were derived from a health and lifestyle questionnaire. Albumin-to-creatinine ratios were estimated from random spot urine specimens collected at the survey visit, and using these ratios participants were categorized into normoalbuminuria, microalbuminuria (2.5-25 mg/mmol), and macroalbuminuria.

RESULTS

The prevalence of microalbuminuria and macroalbuminuria was 11.8% and 0.9% respectively in the total population and significantly higher in women (14.4%) compared with men (8.9%) (P<0.001). Independent determinants of microalbuminuria were age, sex, systolic blood pressure and current smoking. Microalbuminuria was independently associated with cardiovascular morbidity, after adjusting for known cardiovascular risk factors, with odds ratio (95% confidence interval) for prevalent cardiovascular disease of 1.30 (1.12-1.51) in all men and women.

CONCLUSION

Microalbuminuria was present in approximately 12% of this population. It was independently associated with cardiovascular risk factors and prevalent cardiovascular disease. Microalbuminuria may be a useful indicator of high absolute cardiovascular risk in the community but prospective data are needed to establish its independent predictive value for future events.

Association of albuminuria with all-cause and cardiovascular disease mortality in diabetes: the Strong Heart Study

Objectives — To estimate the relative risks of albuminuria with all-cause and cardiovascular disease (CVD) mortality in a large cohort of American Indians with diabetes. Methods — A total of 1,953 diabetic participants in the Strong Heart Study were evaluated based on albuminuria categories at baseline examination. The Cox proportional hazards model was used to examine associations. Results — Of the 1,953 participants, 605 (31%) and 410 (21%) had microalbuminuria and macroalbuminuria, respectively, at baseline examination. Microalbuminuria (HR=1.42, 95% CI 1.15—1.77 for all-cause, and HR=1.48, CI 1.01—2.17 for CVD), and macroalbuminuria (HR=3.39, CI 2.71—4.25 for all-cause, and HR=3.74, CI 2.56—5.47 for CVD) were significant predictors for all-cause and CVD mortality after adjustment for other CVD risk factors. Conclusions — Results from the present study suggest that albuminuria is a strong independent predictor of all-cause and CVD Mortality in American Indians with diabetes.

All Components of Metabolic Syndrome Are Associated with Microalbuminuria in a Chinese Population

BACKGROUND AND AIM

Albuminuria is a well-known predictor of poor renal and cardiovascular outcomes and associated with increased risk of all-cause mortality. The study aimed to evaluate the associations between metabolic characteristics and the presence of albuminuria.

METHODS

This cross-sectional study included 18,384 adult Chinese who participated in health examinations during 2013-2014. Differences in clinical characteristics were compared for microalbuminuria (MAU) and albuminuria, and between genders. Potential risk factors associated with the risk of developing MAU and albuminuria were analyzed using univariate logistic regression. Multiple logistic regression was applied to further identify the independent associations between different levels of risk factors and the presence of MAU and albuminuria. The area under the ROC curve (AUC) was used to determine the discriminatory ability of metabolic risk factors in detecting albuminuria.

RESULTS

There were significant gender differences in clinical characteristics according to albuminuria status. Risk for the presence of albuminuria was significantly associated with age, male gender, waist circumference (WC), waist-to-height ratio (WHtR), hypertension, fasting plasma glucose (FPG), and triglycerides to high-density lipoprotein cholesterol ratio (TG/HDL-C) in univariate logistic regression. Multiple logistic regression analysis indicated that the factors significantly associated with the presence of MAU were WC > 90cm, WHtR at 0.6-0.7, hypertension, FPG > 6.1 mmole/L, and TG/HDL-C ratio > 1.6. The optimal cutoffs for risk factors of metabolic syndrome (MetS) to predict albuminuria in males and females were: WC, 90.8 vs. 80.0 cm; WHtR, 0.53 vs. 0.52; MAP, 97.9 vs. 91.9 mmHg; FPG, 5.40 vs. 5.28 mmole/L; and TG/HDL-C, 1.13 vs. 1.08.

CONCLUSION

MetS and all its components were associated with the presence of MAU in a health check-up population in China. Gender specific and optimal cutoffs for MetS components associated with the presence of MAU were determined.

CKD Progression and Mortality among Hispanics and Non-Hispanics

Although recommended approaches to CKD management are achieved less often in Hispanics than in non-Hispanics, whether long-term outcomes differ between these groups is unclear. In a prospective longitudinal analysis of participants enrolled into the Chronic Renal Insufficiency Cohort (CRIC) and Hispanic-CRIC Studies, we used Cox proportional hazards models to determine the association between race/ethnicity, CKD progression (50% eGFR loss or incident ESRD), incident ESRD, and all-cause mortality, and linear mixed-effects models to assess differences in eGFR slope. Among 3785 participants, 13% were Hispanic, 43% were non-Hispanic white (NHW), and 44% were non-Hispanic black (NHB). Over a median follow-up of 5.1 years for Hispanics and 6.8 years for non-Hispanics, 27.6% of all participants had CKD progression, 21.3% reached incident ESRD, and 18.3% died. Hispanics had significantly higher rates of CKD progression, incident ESRD, and mean annual decline in eGFR than did NHW (P<0.05) but not NHB. Hispanics had a mortality rate similar to that of NHW but lower than that of NHB (P<0.05). In adjusted analyses, the risk of CKD progression did not differ between Hispanics and NHW or NHB. However, among nondiabetic participants, compared with NHB, Hispanics had a lower risk of CKD progression (hazard ratio, 0.61; 95% confidence interval, 0.39 to 0.95) and incident ESRD (hazard ratio, 0.50; 95% confidence interval, 0.30 to 0.84). At higher levels of urine protein, Hispanics had a significantly lower risk of mortality than did non-Hispanics (P<0.05). Thus, important differences in CKD progression and mortality exist between Hispanics and non-Hispanics and may be affected by proteinuria and diabetes.

Association between Body Mass Index, Waist Circumference and Prevalence of Microalbuminuria in Korean Adults of Age 30 Years and Older without Diabetes, Hypertension, Renal Failure, or Overt Proteinuria: The 2013 Korean National Health and Nutrition Examination Survey

Background

Microalbuminuria and obesity markers are known risk factors for cardiovascular or renal disease. This study aimed to evaluate the prevalence of microalbuminuria according to body mass index (BMI) and abdominal obesity criteria.

Methods

The study subjects included 3,979 individuals aged 30 years or older who did not have diabetes, hypertension, renal failure, or overt proteinuria, from among those who participated in The Korean National Health and Nutrition Examination Survey in 2013, a cross-sectional, nationally representative, stratified survey. Microalbuminuria was defined as a urinary albumin to creatinine ratio of 30 to 300 mg/g. BMI and waist circumference were classified according to the Asia-Pacific criteria.

Results

The prevalence of microalbuminuria was found to be 5.1%. In the normoalbuminuria group, 3.4%, 41.7%, 24%, 27.6%, and 3.2% of participants were included in the underweight, normal, overweight, obesity 1, and obesity 2 groups, respectively. These percentages in the microalbuminuria group were 7.1%, 34.5%, 19.2%, 28.6%, and 10.6%, respectively (P<0.001). The waist circumference in men was 21.4% in the normoalbuminuria group and 36.5% in the microalbuminuria group (P=0.004). Logistic regression analyses were performed to evaluate the relationship between the presence of microalbuminuria and BMI or waist circumference groups. The risk of microalbuminuria was significant only in the underweight group (odds ratio, 13.22; 95% confidence interval, 2.55–68.63; P=0.002) after adjusting for confounding factors, abdominal obesity was not significantly associated with microalbuminuria.

Conclusion

The prevalence of microalbuminuria in a general population in Korea was associated with underweight in men and was not associated with waist circumference in either men or women.

Identifying the determinants of microalbuminuria in obese patients in primary care units: the effects of blood pressure, random plasma glucose and other risk factors

OBJECTIVE

The objective of this study is to evaluate the demographic characteristics, blood pressure and blood glucose and the other related factors that affect the microalbuminuria levels in the obese patients aged 40 and above who applied to the primary care for medical evaluation.

MATERIALS AND METHODS

The population of the research, which was a cross-sectional type, comprised obese patients aged 40 and above who had applied to the community health centers in the center of Malatya. A total of 422 obese patients consisting of 116 males and 306 females were included in the research. The anthropometric measurements of the participants were determined, their blood pressures and their random blood glucoses were evaluated, as well. A microalbuminuria measurement was performed in the urine samples taken from the patients using "Nycocard Reader II" device.

FINDINGS

The incidence of microalbuminuria in patients was found as 31.5%, whereas the incidence of macroalbuminuria was 6.6%. The incidence of microalbuminuria in female patients was 32.7%, while it was 28.4% in male patients; on the other hand, the incidence of macroalbuminuria in female patients was found as 6.8%, whereas this percentage was determined as 7.8 in male patients (p > 0.05). The probability of the incidence of microalbuminuria increased 2.8 times more in those with the diastolic blood pressure of 90 mmHg and above when compared to those without it (GA: 1.79-4.56), whereas the incidence increased 3.2 times more in those with the random blood glucose of 200 mg/l and above (GA: 1.32-7.84) (p < 0.001). In our study, among the variables predicting the microalbuminuria in obese patients; the cutoff values of the diastolic and systolic blood pressures, the waist circumference were found as >85 mmHg; >130 mmHg; >141 mg/dl, respectively, in male patients and found as >85 mmHg, >114 cm, and 109 cm, respectively, in female patients. The sensitivity and specificity of the tests indicating the cutoff values showed significance (p < 0.05). There was no statistically significant relevance between the microalbumin levels of the obese patients via the anthropometric criteria, except for their waist circumference (p > 0.05).

RESULT

In this study, the blood pressure and blood glucose levels of the patients along with their waist circumference that indicated a central obesity were specified as the determinants of microalbuminuria. While the obese patients are being evaluated in terms of proteinuria, the cutoff values of these variables can be taken into consideration.

Prevalence and distribution of (micro)albuminuria in toddlers

BACKGROUND

Microalbuminuria is common in the general adult population, with a prevalence of ∼7%, and is an independent indicator of renal and cardiovascular risks. Whether albuminuria is acquired during life (as a result of hypertension/diabetes) or is congenital and already present at birth is unknown. We studied the prevalence of microalbuminuria in toddlers and compared the distribution of albuminuria with that of the general adult population. In addition, we looked for possible associations between microalbuminuria and antenatal, postnatal and maternal factors.

METHODS

The urinary albumin concentration (UAC) was measured in 1352 children and the urinary albumin:creatinine ratio (UACR) in 1288 children from the Groningen Expert Center for Kids with Obesity (GECKO) Drenthe cohort (age range 20-40 months). Albuminuria distribution was compared with the albuminuria distribution in 40 854 participants of the general adult cohort of the Prevention of Renal and Vascular End stage Disease (PREVEND) study. Associations between albuminuria (expressed as UAC and UACR) and antenatal, postnatal and maternal factors were tested with linear regression analysis.

RESULTS

The median UAC in the GECKO study was 2.3 mg/L (5th-95th percentiles: 2.1-25.5) and in the PREVEND study it was 6.0 mg/L (2.3-28.6) (P distribution comparison 0.053). The prevalence of UAC ≥ 20 mg/L was 6.9% in the GECKO study and 7.8% in the PREVEND study (P = 0.195). The prevalence of UACR ≥ 30 mg/g in the GECKO study was 23.4%. UAC and UACR were lower in boys. UAC was not associated with other determinants, but UACR was associated with age and gestational diabetes.

CONCLUSIONS

The distribution of UAC and the prevalence of UAC > 20 mg/L in toddlers and in the young general adult population are comparable. These findings suggest that microalbuminuria is a congenital condition that may predispose to a higher cardiovascular risk later in life.

Early stage of vascular disease and diabetic kidney disease: an under-recognized entity

Early stage of vascular disease and diabetic kidney disease (DKD stages 1 and 2) has been under-recognized, under common practice worldwide. The lack of sensitive diagnostic marker leads to late diagnosis and a progression of underlying vascular disease associated with chronic renal ischemia, which eventually intensifies the magnitude of DKD damage. Treatment at this late stage fails to correct the renal ischemia, or restore renal function, due to the altered vascular homeostasis associated with an impaired nitric oxide production. In contrast to the above information, early recognition of vascular disease and DKD with sensitive diagnostic markers would be able to implement an effective prevention of progression of vascular disease and DKD. Treatment at early stage under environment favorable for adequate vascular homeostasis is able to correct the renal ischemia and improve the renal function.

Proteinuria and clinical outcome in CHD patients

INTRODUCTION

CHD patients, especially those with associated hypoxaemia, usually have some level of renal function impairment, even though they are relatively young. The aim of the study was to evaluate those clinical and analytical factors that may contribute to microalbuminuria and determine the association of 24-hour proteinuria with thrombotic events and mortality.

METHODS

A total of 251 CHD patients were studied and demographic characteristics, blood test, and 24-hour urinalysis were analysed.

RESULTS

Of the patients, 221 were non-hypoxaemic, and 30 were hypoxaemic (oxygen saturation of 84.3±5.9%). Of the non-hypoxaemic patients, 30 (13.6%), and of the hypoxaemic patients 9 (30%), showed proteinuria (>0.15 g/24 hours) (p=0.028). Hypoxaemic CHD patients also showed higher haematocrit (%) (50.7 (34.6; 72.1) versus 42.8 (34.6; 48.9), p<0.001), serum creatinine (mg/dl) (1.07±0.2 versus 0.96±1.9, p=0.004), microalbuminuria (mg/dl/24 hours) (1.2 (0.0; 261.5) versus 0.5 (0.0; 4.37), p<0.001), proteinuria (gr/24 hours) (1.0 (0.4; 3.1) versus 0.08 (0.04; 0.52), p=0.043), and N-terminal pro-B-type natriuretic peptide (pg/ml) (417.8 (35.7; 8534.0) versus 44.9 (0.0; 670.5), p<0.001) concentrations than non-hypoxaemic CHD patients. During a median follow-up of 26.0 (16.9; 57.7) months, five patients died - one patient had 24-hour proteinuria and four patients did not (p=0.581) - and three patients had some type of thrombosis - two patients had 24-hour proteinuria and one patient did not (p=0.014). Kaplan-Meier survival analysis showed no significant difference between CHD patients with and without 24-hour proteinuria (p=0.631).

CONCLUSION

CHD patients with proteinuria have significantly more thrombosis and more hypoxaemia than those patients without proteinuria.

Association of Glomerular Filtration Rate with Inflammation in Polycystic Ovary Syndrome

Background

We aimed to estimate the glomerular filtration rate (GFR) in women with polycystic ovary syndrome (PCOS) and to determine the relationship between GFR with C-reactive protein (CRP) and uric acid.

Materials and Methods

In this cross-sectional study, one-hundred and forty PCOS women and 60 healthy subjects were evaluated. The study was carried out at Endocrinol- ogy Outpatient Clinic, Erzurum Training and Research Hospital, Erzurum, Turkey, from December 2010 to January 2011. GFRs were estimated by Modification of Diet in Renal Disease (MDRD) formula. CRP, urinary albumin excretion (UAE) and uric acid levels were also measured.

Results

GFRs were significantly higher in PCOS group than control (135.24 ± 25.62 vs. 114.92 ± 24.07 ml/min per 1.73 m²). CRP levels were significantly higher in PCOS patients (4.4 ± 3.4 vs. 2.12 ± 1.5 mg/l). The PCOS group had significantly higher serum uric acid levels (4.36 ± 1.3 mg/dl vs. 3.2 ± 0.73 mg/dl). There was also significantly higher proteinuria level in PCOS patients.

Conclusion

Even though PCOS patients had higher GFR, serum uric acid and UAE val- ues than control patients, the renal function was within normal limits. Increased GFR in PCOS women positively correlates with elevated serum CRP and uric acid.

Urinalysis in children and adolescents

BACKGROUND

Urinalysis is the most commonly performed biochemical test in infancy and early childhood. The urine sample should be correctly obtained, age-specific aspects should be considered, and age-dependent reference values should be used.

METHOD

This review is based on a selective literature search in electronic databases, textbooks, and guidelines from Germany and abroad on the acquisition of urine samples and the performance of urinalysis in infancy and early childhood.

RESULTS

The timing and mode of acquisition of the urine sample affect the assessment of hematuria, proteinuria, leukocyturia, nitrituria, and the uropathogenic bacterial colony count in the urine culture. Dipstick tests can be used for targeted screening for these features. The test results should be interpreted together with the findings of urine microscopy, the medical history, and the physical examination. Proteinuria should be quantified and differentiated; both of these things can be done either from collected urine or (especially in infants and young children) from a spontaneously voided urine sample, by determination of the protein/creatinine quotient. Orthostatic proteinuria in an adolescent requires no further evaluation or treatment. Hematuria should be characterized as either glomerular or non-glomerular erythrocyturia. Asymptomatic, isolated microhematuria in childhood is not uncommon and often transient; in the absence of a family history, it usually does not require an extensive work-up. Proteinuria combined with hematuria should arouse the suspicion of glomerulonephritis.

CONCLUSION

Urinalysis in infancy and early childhood is a simple and informative diagnostic test as long as the urine sample has been obtained properly and the results are interpreted appropriately for this age group.

Presence of Cardiometabolic Risk Factors Is Not Associated with Microalbuminuria in 14-to-20-Years Old Slovak Adolescents: A Cross-Sectional, Population Study

Introduction

In adults, microalbuminuria indicates generalized endothelial dysfunction, and is an independent risk factor for cardiovascular and all cause mortality. Slovak adults present one of the highest cardiovascular mortality rates in Europe. Thus Slovak adolescents are on a high-risk to develop cardiovascular afflictions early, and screening for microalbuminuria might be useful in early assessment of their cardiovascular risk. We aimed to study the prevalence of microalbuminuria in Slovak adolescents, and the association of urinary albumin-to-creatinine ratio (ACR) to cardiovascular risk factors.

Subjects and methods

Anthropometric data, blood pressure, blood count, glucose homeostasis, lipid profile, renal function, inflammatory status, concentrations of homocysteine and uric acid were determined and associated with ACR in 2 666 adolescents (49.4% boys, 51.6% girls) aged 14-to-20 years. Microalbuminuria was classified as ACR 2.5–25.0 mg/mmol in boys and 3.5–35.0 mg/mmol in girls.

Results

Prevalence of microalbuminuria in both genders reached 3.3%, and did not differ significantly between lean and centrally obese subjects. Girls presented higher ACR than boys (normoalbuminuric: 0.6±0.5 mg/mmol vs. 0.5±0.4 mg/mmol, p>0.001; microalbuminuric: 9.3±7.3 mg/mmol vs. 5.0±3.8 mg/mmol; p>0.001). Microalbuminuric adolescents and those presenting normoalbuminuria within the upper ACR quartile were slimmer than their normoalbuminuric counterparts or adolescents with normoalbuminuria within the lower quartile, respectively. No association between microalbuminuria and cardiovascular risk markers was revealed.

Conclusion

Results obtained in this study do not support our assumption that ACR associates with cardiometabolic risk factors in apparently healthy adolescents. Follow-up studies until adulthood are needed to estimate the potential cardiometabolic risk of apparently healthy microalbuminuric adolescents.

Comparison of longer-term outcomes after kidney transplantation between Hispanic and non-Hispanic whites in the United States

Little is known about the longer-term kidney transplant outcomes in the rapidly growing Hispanic population. Using the United States Renal Data System, we identified 105 250 Caucasian patients who received a first kidney transplant between January 1, 1996 and December 31, 2010. We tested for differences between Hispanic and non-Hispanic patients in the outcomes of (1) mortality, (2) all-cause graft failure, and (3) graft failure excluding death with a functioning graft. We used Cox regression to estimate (with 95% confidence intervals) multivariable-adjusted cause-specific hazard ratios (aHRCS ) for mortality and all-cause graft failure and subdistribution hazard ratios (aHRSD ) accounting for death as a competing risk for graft failure excluding death with a functioning graft. Both mortality [aHRCS  = 0.69 (0.65-0.73)] and all-cause graft failure [aHRCS  = 0.79 (0.75-0.83)] were lower in Hispanics. The association between Hispanic ethnicity and graft failure excluding death was modified by age (p < 0.003). Compared with non-Hispanic whites, graft failure excluding death with a functioning graft did not differ in Hispanics aged 18-39 years [aHRSD  = 0.96 (0.89-1.05)] or aged 40-59 years [aHRSD  = 1.08 (1.00-1.16)], but was 13% lower in those aged ≥60 years [aHRSD  = 0.87 (0.78-0.98)]. In conclusion, once accounting for differences in overall survival, better graft survival was found in older Hispanic patients, but among not those aged <60 years.

Kidney disease among children in sub-Saharan Africa: systematic review

The global burden of kidney disease is increasing, and several etiologies first begin in childhood. Risk factors for pediatric kidney disease are common in Africa, but data regarding its prevalence are lacking. We completed a systematic review of community-based studies describing the prevalence of proteinuria, hematuria, abnormal imaging, or kidney dysfunction among children in sub-Saharan Africa (SSA). Medline and Embase were searched. Five hundred twenty-three references were reviewed. Thirty-two references from nine countries in SSA were included in the qualitative synthesis. The degree of kidney damage and abnormal imaging varied widely: proteinuria 32.5% (2.2-56.0%), hematuria 31.1% (0.6-67.0%), hydronephrosis 11.3% (0.0-38.0%), hydroureter 7.5% (0.0-26.4%), and major kidney abnormalities 0.1% (0.0-0.8%). Serum creatinine was reported in four studies with insufficient detail to identify the prevalence renal dysfunction. A majority of the studies were performed in Schistosoma haematobium endemic areas. A lower prevalence of kidney disease was observed in the few studies from nonendemic areas. Published data on pediatric kidney disease in SSA are highly variable and dependent on S. haematobium prevalence. More community-based studies are needed to describe the burden of pediatric kidney disease, particularly in regions where S. haematobium infection is nonendemic.

Urinary albumin excretion is increased in patients with rheumatoid arthritis and associated with arterial stiffness

OBJECTIVE

Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular disease (CVD). High urinary albumin excretion is a risk factor for CVD in the general population, but its role in atherosclerosis in patients with RA is not well defined.

METHODS

We determined the urine albumin to creatinine ratio (UACR) in 136 patients with RA and 79 controls. Individuals with diabetes or a clinical history of CVD were excluded. We measured coronary artery calcium (CAC) with electron beam computer tomography and augmentation index (AIx) using pulse wave analysis. In patients with RA, erythrocyte sedimentation rate and concentrations of vascular cell adhesion protein-1 (VCAM-1), interleukin 10 (IL-10), C-reactive protein, IL-6, tumor necrosis factor-α, and cystatin-C were measured and results correlated with UACR.

RESULTS

Patients with RA had higher UACR [median (interquartile range): 7.6 (4.0-15.5) mg/g] than control subjects: 5.6 (3.3-9.0) mg/g; p = 0.02. The presence of CAC was not associated with UACR in RA or control subjects. In patients with RA, UACR was significantly correlated with AIx (rho = 0.24, p = 0.01), higher levels of VCAM-1 (rho = 0.2, p = 0.01), and lower levels of IL-10 (rho = -0.2, p = 0.02). The association between AIx and higher UACR remained significant in multivariate analysis [β coefficient of 1.5 (95% CI 0.1-2.8), p = 0.03 that adjusted for age, sex, and race].

CONCLUSION

Urinary albumin excretion was higher in patients with RA than controls and correlated with increased arterial stiffness, higher VCAM-1, and lower IL-10 concentrations.

A Family History of Diabetes Modifies the Association between Elevated Urine Albumin Concentration and Hyperglycemia in Nondiabetic Mexican Adolescents

We examined the frequency of elevated urine albumin concentration (UAC) and its association with metabolic syndrome (MetS) and metabolic markers in 515 nondiabetic Mexican adolescents stratified by family history of diabetes (FHD). UAC was measured in a first morning urine sample and considered elevated when excretion was ≥20 mg/mL. MetS was defined using International Diabetes Federation criteria. Fasting insulin, insulin resistance, and lipids were evaluated. Multivariate logistic regression was performed. Elevated UAC was present in 12.4% and MetS was present in 8.9% of the adolescents. No association was found between elevated UAC and MetS. Among adolescents with FHD, 18.4% were overweight and 20.7% were obese, whereas, among those without a FHD, 15.9% were overweight and 7.5% were obese. Hyperglycemia was higher in those with elevated UAC than in those without (44.4% versus 5.1%, p = 0.003). Hyperglycemia (OR = 9.8, 95% CI 1.6-59.4) and number of MetS components (OR = 4.5, 95% CI 1.5-13.3) were independently associated with elevated UAC. Among female participants, abdominal obesity was associated with elevated UAC (OR = 4.5, 95% CI 1.2-16.9). Conclusion. Elevated UAC was associated neither with MetS nor with any metabolic markers in nondiabetic adolescents. However, FHD modified the association of elevated UAC with hyperglycemia and the number of MetS components.

Diabetic kidney disease in children and adolescents

Diabetes, more frequently type 1, but increasingly also type 2, commonly occurs in childhood. While more advanced diabetic kidney disease (DKD), e.g., loss of glomerular filtration rate (GFR), does not occur until adulthood, kidney biopsies show DKD structural changes as early as 1.5-5 years after the onset of type 1 diabetes. Earliest clinical sign of DKD, increased urine albumin excretion, commonly appears during childhood and adolescence and presents an important opportunity to detect and intervene in early DKD, perhaps more successfully than later in the disease course. Longitudinal studies of type 1 diabetes have enriched our understanding of the DKD natural history and modifiable risk factors for DKD progression. These studies have also shown that the presence of DKD marks a subset of people with diabetes who are at the highest risk of early mortality, supporting an enhanced focus on DKD detection, prevention, and treatment. Early studies suggest that youth-onset type 2 diabetes is associated with a higher prevalence of comorbidities and risk factors and follows a more aggressive natural history. A deeper understanding of the natural history, risk factors, underlying mechanisms and therapeutic options for DKD in young-onset type 2 diabetes awaits further studies.

Kidney function in severely obese adolescents undergoing bariatric surgery

OBJECTIVE

Determine objective measures of kidney function and analyze factors associated with kidney dysfunction in severely obese adolescents undergoing weight loss surgery were described.

METHODS

Cross-sectional data from 242 adolescent participants in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study before weight loss surgery were analyzed. Kidney status was assessed by measuring urine albumin creatinine ratio to determine microalbuminuria and by calculating serum cystatin C-based estimated glomerular filtration rate (eGFR) to assess kidney function.

RESULTS

Mean age and median body mass index (BMI) were 17.1 years and 50.5 kg/m(2) , respectively; 76% were females and 65% were non-Hispanic white race. Fourteen percent of the cohort had microalbuminuria, and 3% had macroalbuminuria; 3% had eGFR < 60 ml/min/1.73 m(2) , and 7.1% had eGFR > 150 ml/min/1.73 m(2) . In adjusted analyses, female gender and increasing ferritin levels were significantly associated with the presence of microalbuminuria/macroalbuminuria. Increasing BMI and homeostasis model assessment of insulin resistance values were significantly associated with lower eGFR.

CONCLUSIONS

A significant number of severely obese adolescents undergoing weight loss surgery have evidence of early kidney dysfunction. Longitudinal studies following weight loss surgery in these individuals are needed to determine whether these kidney abnormalities are reversible following weight loss therapy.

Association of the estimated 24-h urinary sodium excretion with albuminuria in adult koreans: the 2011 Korea National Health and Nutrition Examination Survey

BACKGROUND

Sodium intake and albuminuria have important roles in blood pressure and renal progression. Although their relationship has been reported, the results have not been consistent and all studies have examined small populations.

OBJECTIVE

This study investigated the role of the estimated 24-h urinary sodium excretion as a marker of sodium intake and albuminuria.

DESIGN

This investigation included 5,187 individuals age 19 years and older from a cross-sectional, nationally representative, stratified survey: The Korea National Health and Nutrition Examination Survey (KNHANES V-2), in 2011. Albuminuria was defined as a urinary albumin/creatinine ratio ≥30 mg/g. The 24-h urinary sodium excretion was estimated from a spot urine.

RESULTS

On classifying our participants into quartiles based on the estimated 24-h urinary sodium excretion, the prevalence of albuminuria increased with the 24-h urinary sodium excretion (5.3, 5.7, 7.5, and 11.8% in the first through fourth quartiles, respectively, p for trend <0.001). Even after adjusting for age, sex, diabetes, obesity, and hypertension, the significance persisted. In a multiple logistic regression analysis, the second and third quartiles of the estimated 24-h urinary sodium excretion were not associated with the presence of albuminuria with the first quartile as a control. However, the fourth quartile was significantly associated with the presence of albuminuria (odds ratio 1.61 [95% confidence interval 1.71-2.21], p = 0.003) after adjusting for age, sex, diabetes, obesity, and hypertension.

CONCLUSIONS

These findings suggest that salt intake is associated with the presence of albuminuria in the general Korean adult population.

Maternal supplementation with vitamin A or β-carotene and cardiovascular risk factors among pre-adolescent children in rural Nepal

Vitamin A plays an important role in fetal renal and cardiovascular development, yet there has been little research on its effects on cardiovascular risk factors later in childhood. To examine this question, we followed the children of women who had been participants in a cluster-randomized, double blind, placebo-controlled trial of weekly supplementation with 7000 μg retinol equivalents of preformed vitamin A or 42 mg of β-carotene from 1994 to 1997 in rural Nepal. Women received their assigned supplements before, during and after pregnancy. Over a study period of 3 years, 17,531 infants were born to women enrolled in the trial. In 2006-2008, we revisited and assessed 13,118 children aged 9-13 years to examine the impact of maternal supplementation on early biomarkers of chronic disease. Blood pressure was measured in the entire sample of children. In a subsample of 1390 children, venous blood was collected for plasma glucose, Hb1Ac and lipids and a morning urine specimen was collected to measure the ratio of microalbumin/creatinine. Detailed anthropometry was also conducted in the subsample. The mean ± s.d. systolic and diastolic blood pressure was 97.2 ± 8.2 and 64.6 ± 8.5 mm Hg, respectively, and about 5.0% had high-blood pressure (⩾120/80 mm Hg). The prevalence of microalbuminuria (⩾30 mg/g creatinine) was also low at 4.8%. There were no differences in blood pressure or the risk of microalbuminuria between supplement groups. There were also no group differences in fasting glucose, glycated hemoglobin, triglycerides or cholesterol. Maternal supplementation with vitamin A or β-carotene had no overall impact on cardiovascular risk factors in this population at pre-adolescent age in rural Nepal.

Biomarkers in cardiorenal syndromes

Cardiac and renal diseases often coexist and patients with cardiac and renal failure have high morbidity and mortality. Cardiorenal syndromes (CRSs) are disorders of the heart and kidneys whereby dysfunction in one organ may induce dysfunction in the other organ. Five subtypes of CRSs have been defined by the Acute Dialysis Quality Initiative Consensus Group. There is a need for early detection and monitoring of patients with CRSs. Biomarkers play a key role in the diagnosis and monitoring of acute myocardial infarction, chronic heart failure, and chronic kidney disease. In recent years, new biomarkers have been identified that may play a role in the early diagnosis of acute kidney injury. Herein, we review the use of serum and urine biomarkers in the diagnosis and management of CRSs. The established cardiac and renal biomarkers such as the cardiac troponins, natriuretic peptides, urine albumin, and creatinine, as well as the new renal biomarkers cystatin C and neutrophil gelatinase-associated lipocalin are reviewed in detail. The recent advances in assay methods, clinical studies, and recommendations in clinical guidelines are discussed. With advances in biomarker research, in future, perhaps a multimarker approach will become feasible to stratify the diagnosis of CRS for individualized treatment and prognosis.

Impact of albuminuria on the incidence of periprocedural myocardial injury in patients undergoing elective coronary stent implantation

Albuminuria has traditionally been associated with an elevated risk of cardiovascular events. However, few studies have examined the potential relation between albuminuria and periprocedural risk in percutaneous coronary intervention (PCI). The aim of this study was to evaluate the impact of albuminuria on the incidence of periprocedural myocardial injury (PMI) in patients who underwent PCI. The study included 252 consecutive patients who underwent PCI. The incidence of PMI was significantly higher in patients with albuminuria than in those with normoalbuminuria (31.9% vs 43.3%, respectively, p = 0.014). Even after adjustment for confounders, the presence of albuminuria predicted PMI (odds ratio 2.07, 95% confidence interval 1.08 to 3.97, p = 0.029). Furthermore, patients with albuminuria and preserved estimated glomerular filtration rate had a 4.2-fold higher risk for PMI than did patients with normoalbuminuria and preserved estimated glomerular filtration rate. In conclusion, albuminuria was a strong predictor of PMI in patients who underwent PCI.

Diabetes and age-related demographic differences in risk factor control

Disparate vascular outcomes in diabetes by race and/or ethnicity may reflect differential risk factor control, especially pre-Medicare. Assess concurrent target attainment for glycohemoglobin <7%, non-high density lipoprotein-cholesterol <130 mg/dL, and blood pressure <140/<90 mm Hg in white, black, and Hispanic diabetics <65 years and ≥65 years of age. The National Health and Nutrition Examination Surveys 1999-2010 data were analyzed on diagnosed and undiagnosed diabetics ≥18 years old. Concurrent target attainment was higher in whites (18.7%) than blacks (13.4% [P = .02] and Hispanics [10.3%, P < .001] <65 years but not ≥65 years of age; 20.0% vs. 15.9% [P = .13], 19.5% [P = .88]). Disparities in health care insurance among younger whites, blacks, and Hispanics, respectively, (87.4% vs. 81.1%, P < .01; 68.0%, P < .001) and infrequent health care (0-1 visits/y; 14.3% vs. 15.0%, P = not significant; 32.0%, P < .001) declined with age. Cholesterol treatment predicted concurrent control in both age groups (multivariable odds ratio >2, P < .001). Risk factor awareness and treatment were lower in Hispanics than whites. When treated, diabetes and hypertension control were greater in whites than blacks or Hispanics. Concurrent risk factor control is low in all diabetics and could improve with greater statin use. Insuring younger adults, especially Hispanic, could raise risk factor awareness and treatment. Improving treatment effectiveness in younger black and Hispanic diabetics could promote equitable risk factor control.

Closing the gap in hypertension control between younger and older adults: National Health and Nutrition Examination Survey (NHANES) 1988 to 2010

BACKGROUND

Joint National Committee goal blood pressure for all adults was <140/<90 mm Hg or lower from 1984 to 2013. Adults aged ≥60 years (older) have mainly isolated systolic hypertension, with major trials attaining systolic blood pressure <150 but not <140 mm Hg. The main objective was to assess changes in hypertension control to <140/<90 mm Hg in younger (aged <60 years) and older adults and <150/<90 mm Hg in the latter.

METHODS AND RESULTS

National Health and Nutrition Examination Surveys (NHANES) 1988 to 1994, 1999 to 2004, and 2005 to 2010 were analyzed in adults aged ≥18 years. From 1988 to 1994 to 2005 to 2010, hypertension control to <140/<90 mm Hg improved in older (31.6% to 53.1%; P<0.001) and younger (45.7% to 55.9%; P<0.001) patients. The age gap in control declined from 14.1% (P<0.01) in 1988 to 1994 to 2.8% (P=0.13) in 2005 to 2010. Better hypertension control reflected increased percentages of older (55.6% to 77.5%) and younger (34.6% to 54.7%) patients on treatment and treated older (45.7% to 64.9%) and younger (56.8% to 73.4%) patients controlled (all P<0.001). Control to <150/<90 mm Hg rose from 48.8% to 69.9% in older adults. Antihypertensive medication number and percentages on ≥3 medications increased in both age groups but increased more in older patients (P<0.01). Blood pressure control was higher in both age groups with ≥2 healthcare visits per year and on statin therapy.

CONCLUSIONS

The age gap in hypertension control to <140/<90 mm Hg was virtually eliminated in 2005 to 2010 as clinicians intensified therapy, especially in older patients in whom isolated systolic hypertension predominates, controlling 70% to <150/<90 mm Hg. More frequent healthcare visits and the use of statin therapy may improve hypertension control in all adults.

Accumulation of microvascular target organ damage in newly diagnosed hypertensive patients

Early identification of hypertensive target organ damage (TOD) emerges as important for global cardiovascular risk assessment. Retinal vascular alterations, capillary rarefaction, and microalbuminuria represent different forms of microvascular TOD. However, data regarding their concomitant presence in the early stages of hypertension, the association of the number of affected organs with cardiovascular risk, and aldosterone effect on multiple TOD are lacking. We studied naïve, never-treated patients with recent duration of hypertension and healthy volunteers. Innovative software was developed to estimate retinal vascular diameters and capillary density. Biochemical parameters including microalbuminuria and serum aldosterone were derived. Framingham Risk Score was used to determine cardiovascular risk. In total 103 subjects, 66 hypertensives and 37 normotensives, were included. Hypertensive patients exhibited a greater number of affected target organs compared with normotensives (P = .014), with retinopathy and capillary rarefaction (40.9%) representing the most common TOD among hypertensives. The number of affected organs was linearly correlated with increased Framingham score and serum aldosterone, analyzed with univariate (P < .001 and P = .002) and multivariate analysis (P = .025 and P = .004), respectively. Physicians dealing with hypertensive patients should be aware of the possibility of diffuse microvascular impairment and seek multiple TOD even in the early stages of hypertension.

Urinary albumin concentration and long-term cardiovascular risk in acute coronary syndrome patients: a PROVE IT-TIMI 22 substudy

Albuminuria has been shown to be associated with mortality and cardiovascular events, independent of traditional cardiovascular risk factors. This suggests that albuminuria may not just represent glomerular damage, but may be a marker of more diffuse endothelial dysfunction. We investigated the relationship between urinary albumin levels after an acute coronary syndrome and cardiovascular outcomes in statin treated subjects after acute coronary syndromes (ACS). Furthermore we assessed the effect of intensive statin treatment on albuminuria among patients in the PROVE IT-TIMI 22 trial, in which patients who had been hospitalized with ACS were randomized to pravastatin 40 mg (standard therapy) or atorvastatin 80 mg daily (intensive therapy). In univariate analyses, increasing urine albumin concentration was associated with increased risk of myocardial infarction, stroke, heart failure, and composite of death, myocardial infarction and stroke at 2 years. However, in a multivariable model containing traditional cardiovascular risk factors, albuminuria was not an independent predictor of the primary PROVE IT endpoint of death, myocardial infarction, unstable angina, revascularization and stroke, and was only an independent predictor of all-cause mortality at urinary albumin concentration >300 mcg/ml. There was no significant change in urinary albumin concentration from enrolment to end of study in either the standard or intensive statin therapy groups, and no significant difference between treatment groups. Our results suggest that after an acute coronary syndrome in statin treated patients, microalbuminuria may reflect traditional cardiovascular risk factor burden and offer little prognostic information independent of those factors.

Free triiodothyronine concentrations are inversely associated with microalbuminuria

Thyroid function and microalbuminuria are both associated with vascular disease and endothelial damage. However, whether thyroid function is associated with microalbuminuria is not well established. The objective was to explore the relationship between thyroid hormones and microalbuminuria in Chinese population. A community-based cross-sectional study was performed among 3,346 Chinese adults (aged ≥ 40 years). Serum free triiodothyronine (FT3), free thyroxine (FT4), and TSH (thyroid stimulating hormone) were determined by chemiluminescent microparticle immunoassay. A single-void first morning urine sample was obtained for urinary albumin-creatinine ratio measurement. The prevalence of microalbuminuria decreased according to FT3 quartiles (13.2, 9.5, 8.6, and 8.2%, P for trend = 0.0005). A fully adjusted logistic regression analysis showed that high FT3 levels were associated with low prevalent microalbuminuria. The adjusted odds ratios for microalbuminuria were 0.61 (95% CI, 0.43-0.87, P = 0.007) when comparing the highest with the lowest quartile of FT3. The exclusion of participants with abnormal FT3 did not appreciably change the results (OR = 0.69, 95% CI, 0.49-0.98, P = 0.02). We concluded that serum FT3 levels, even within the normal range, were inversely associated with microalbuminuria in middle-aged and elderly Chinese adults. FT3 concentrations might play a role in the pathogenesis of microalbuminuria.

Prevalence of and factors associated with albuminuria in the Korean adult population: the 2011 Korea National Health and Nutrition Examination Survey

BACKGROUND

Microalbuminuria is associated with increased risk of renal disease and cardiovascular diseases even in non-diabetic subjects. High incidence rates of microalbuminuria have been found in a number of population-based studies. However, the prevalence and risk factors associated with microalbuminuria in the general population in Korea are unclear.

OBJECTIVES

The present study was performed to estimate the prevalence of microalbuminuria and investigate the associated risk factors in the general adult population using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2) data from 2011.

METHODS

A total of 5,202 participants (mean age, 45.6 years; men, 2,337; women, 2,865) were included in the analysis. Microalbuminuria was evaluated in participants of KNHANES V-2 based on the urine albumin-creatinine ratio. Estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease study equation.

RESULTS

The weighted prevalence of microalbuminuria was 5.2% (95% CI, 4.4-6.1) in the general population. The prevalence of albuminuria is increased with age. After adjustment for age and sex, the presence of albuminuria was associated with increased waist circumference, systolic and diastolic blood pressure, aspartate aminotransferase, triglyceride, fasting plasma glucose, and the presence of hypertension and diabetes. In logistic regression analyses, older age, female sex, diabetes, hypertension, and serum aspartate aminotransferase were independently associated with the presence of albuminuria.

CONCLUSION

The prevalence of microalbuminuria was found to be 5.2%, and conventional risk factors for cardiovascular diseases are closely related to the presence of microalbuminuria in Korea. Microalbuminuria may be a useful marker to identify individuals with increased risk of cardiovascular disease.

Prevalence of microalbuminuria among middle-aged population of China: a multiple center cardiovascular epidemiological study

We assessed the prevalence of microalbuminuria (MAU) and the relationships with other cardiovascular (CV) risk factors among a middle-aged Chinese population. Data from 10 313 participants were included in our cross-sectional survey. Microalbuminuria was defined as the urine albumin to creatinine ratio of 30:300 mg/g from a single-spot morning urine sample. Microalbuminuria was found to be common in males and females (15.04% vs 10.09%) aged 35 to 64 years in this Chinese general population, especially in those with obesity, hypertension, and diabetes. Multivariate analysis found that body mass index, triglyceride, high-sensitivity C-reactive protein, alcohol consumption, hypertension, and diabetes were independently associated with MAU. Microalbuminuria may be a useful indicator for risk of CV disease in general populations.

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

OBJECTIVE

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

DESIGN

Cross-sectional study of prevalence of MAU.

SETTING

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

PARTICIPANTS

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

PRIMARY AND SECONDARY OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Association between Salt Intake and Albuminuria in Normotensive and Hypertensive Individuals

Background. There is a little published data regarding the association between salt intake and albuminuria as an important alarm for progression of cardiovascular and renal dysfunction. We aimed to assess this relationship to emphasize the major role of restricting salt intake to minimize albuminuria and prevent these life-threatening events. Methods. The study population comprised 820 individuals. Participants were assigned to groups as follows: normal albuminuria, slight albuminuria, and clinical albuminuria. Daily salt intake was assessed on the basis of 24-hour urinary sodium excretion, since urinary sodium excretion largely equals sodium intake. Results. In normotensive participants, the mean level of urine albumin was higher in those who had higher amounts of salt intake with a significantly upward trend (the mean urinary albumin level in low-salt-diet group, in medium-salt-intake group, and in high-salt-intake group was 42.70 ± 36.42, 46.89 ± 38.91, and 53.38 ± 48.23, resp., (P = 0.017)). There was a significant positive correlation between 24-hour urinary sodium secretion and the level of urine albumin (beta = 0.130, P < 0.001). The amount of salt intake was significantly associated with urine albumin concentration (beta = 3.969, SE = 1.671, P = 0.018). Conclusion. High salt intake was shown to be associated with higher level of microalbuminuria even adjusted for potential underlying risk factors.

Differences in progression to ESRD between black and white patients receiving predialysis care in a universal health care system

BACKGROUND AND OBJECTIVES

Studies performed in the United States showed that blacks progress from CKD to ESRD faster than do whites. Possible explanations are differences in health care system factors. This study investigated whether progression is also faster in a universal health care system, where all patients receive comparable care.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the PREdialysis PAtient REcord study, a multicenter follow-up study of patients with CKD who started predialysis care in The Netherlands (1999-2011), were analyzed. Time-dependent Cox proportional hazards models were used to estimate the hazard ratio (HR) for starting renal replacement therapy (RRT), and linear mixed models were used to compare renal function decline (RFD) between blacks and whites. To explore possible mechanisms, analyses were adjusted for patient characteristics.

RESULTS

At initiation of predialysis care, blacks (n=49) were younger and had more diabetes mellitus, higher proteinuria levels, and a higher estimated GFR than whites (n=946). Median follow-up time in months was similar (blacks: 13.9 [boundaries of interquartile range (IQR), 5.3 to 19.5]; whites: 13.1 [IQR, 5.1 to 24.0]). For blacks compared with whites, the crude HR for starting RRT within the first 15 months was 0.86 (95% confidence interval [CI], 0.55 to 1.34) and from 15 months onward, 1.93 (95% CI, 1.02 to 3.68), which increased after adjustment. RFD was faster by 0.18 (95% CI, 0.05 to 0.32) ml/min per 1.73 m(2) per month in blacks compared with whites.

CONCLUSION

Blacks receiving predialysis care in a universal health care system have faster disease progression than whites, suggesting that health care system factors have a less influential role than had been thought in explaining black-white differences.

Factors associated with microalbuminuria in 7,549 children and adolescents with type 1 diabetes in the T1D Exchange clinic registry

OBJECTIVE

To examine factors associated with clinical microalbuminuria (MA) diagnosis in children and adolescents in the T1D Exchange clinic registry.

RESEARCH DESIGN AND METHODS

T1D Exchange participants <20 years of age with type 1 diabetes ≥ 1 year and urinary albumin-to-creatinine ratio (ACR) measured within the prior 2 years were included in the analysis. MA diagnosis required all of the following: 1) a clinical diagnosis of sustained MA or macroalbuminuria, 2) confirmation of MA diagnosis by either the most recent ACR being ≥ 30 mg/g or current treatment with an ACE inhibitor (ACEI) or angiotensin receptor blocker (ARB), and 3) no known cause for nephropathy other than diabetes. Logistic regression was used to assess factors associated with MA.

RESULTS

MA was present in 329 of 7,549 (4.4%) participants, with a higher frequency associated with longer diabetes duration, higher mean glycosylated hemoglobin (HbA1c) level, older age, female sex, higher diastolic blood pressure (BP), and lower BMI (P ≤ 0.01 for each in multivariate analysis). Older age was most strongly associated with MA among participants with HbA1c ≥ 9.5% (≥ 80 mmol/mol). MA was uncommon (<2%) among participants with HbA1c <7.5% (<58 mmol/mol). Of those with MA, only 36% were receiving ACEI/ARB treatment.

CONCLUSIONS

Our results emphasize the importance of good glycemic and BP control, particularly as diabetes duration increases, in order to reduce the risk of nephropathy. Since age and diabetes duration are important nonmodifiable factors associated with MA, the importance of routine screening is underscored to ensure early diagnosis and timely treatment of MA.

Expanded Criteria Donors in Kidney Transplantation: The Role of Older Donors in a Setting of Older Recipients

Kidney transplantation (KT) is the therapy of choice for end-stage renal disease (ESRD). The ESRD population is aging and so are patients waiting for KT. New strategies have been made for increasing the donor and recipient pools, and as a consequence kidneys from older donors or donors with significant comorbidities, the so-called “expanded criteria donor” (ECD) kidneys, are used for transplantation. Although good outcomes have been achieved from ECD, several issues are still waiting for clarification and need to be discussed. The concept of age matching is accepted as a method to ameliorate utilization of these allografts, but an optimal and widely accepted strategy is still not defined. The development of machine perfusion and the dual kidney transplantation are techniques which further improve the outcome of transplants from ECD, but the described experiences are scarce or coming from small single institutional reports. Also due to age-related immune dysfunction and associated comorbidities, the elderly recipients are more susceptible to immunosuppression related complications (e.g., infections and malignancy), although a widely accepted and validated immunosuppressive regimen is still lacking. In this paper, we review the issues related to KT employing allografts from marginal donors with a particular interest for the elderly patients.

Albuminuria is associated with too few glomeruli and too much testosterone

Normally, the glomerular filtration barrier almost completely excludes circulating albumin from entering the urine. Genetic variation and both pre- and postnatal environmental factors may affect albuminuria in humans. Here we determine whether glomerular gene expression in mouse strains with naturally occurring variations in albuminuria would allow identification of proteins deregulated in relatively 'leaky' glomeruli. Albuminuria increased in female B6 to male B6 to female FVB/N to male FVB/N mice, whereas the number of glomeruli/kidney was the exact opposite. Testosterone administration led to increased albuminuria in female B6 but not female FVB/N mice. A common set of 39 genes, many expressed in podocytes, were significantly differentially expressed in each of the four comparisons: male versus female B6 mice, male versus female FVB/N mice, male FVB/N versus male B6 mice, and female FVB/N versus female B6 mice. The transcripts encoded proteins involved in oxidation/reduction reactions, ion transport, and enzymes involved in detoxification. These proteins may represent novel biomarkers and even therapeutic targets for early kidney and cardiovascular disease.