Very Low Levels of Microalbuminuria Are Associated With Increased Risk of Coronary Heart Disease and Death Independently of Renal Function, Hypertension, and Diabetes

Soluble receptor for advanced glycation end-products positively correlated to kidney injury with coronary heart disease

AIMS

Coronary heart disease (CHD) patients with changed serum soluble receptor for advanced glycation end products (sRAGE) will experience microalbuminuria and even kidney dysfunction. However, the role of sRAGE for microalbuminuria in CHD is still not established. This study aimed to evaluate the association between sRAGE and early kidney dysfunction in CHD patients.

MATERIALS AND METHODS

In this cross-sectional study, sRAGE and urinary albumin-to-creatinine ratio (uACR) were measured in hospitalized CHD patients who have undergone coronary arteriography to evaluate the distinction and correlation between sRAGE and uACR.

RESULTS

There were 127 CHD patients (mean age: 63.06 ± 10.93 years, 93 males) in the study, whose sRAGE were 1.83 ± 0.64 μg/L. The sRAGE level was higher in kidney injury group (uACR ≥ 30 mg/g) compared with no kidney injury group (uACR < 30 mg/g) [(2.08 ± 0.70 vs. 1.75 ± 0.61) μg/L, P < 0.05]. Moreover, the positive correlation between serum sRAGE and uACR was significant in CHD patients (r = 0.196, P < 0.05). Binary logistic regression suggests sRAGE as a predictor for microalbuminuria in CHD patients [Odd Ratio = 2.62 (1.12-6.15), P < 0.05)]. The area under the receiver operating characteristic curve (AUC) of sRAGE is higher than that of the traditional indicators of renal function such as creatinine and estimated glomerular filtration rate, indicating sRAGE might have a good performance in evaluating early kidney injury in CHD patients [AUC is 0.660 (0.543-0.778), P < 0.01)].

CONCLUSIONS

Serum sRAGE was positively correlated to uACR and might serve as a potential marker to predict early kidney injury in CHD patients.

Endothelial dysfunction markers syndecan-1 and thrombomodulin are associated with higher albuminuria levels in type 2 diabetes with no history of clinical cardiovascular disease

INTRODUCTION

Individuals with type 2 diabetes and increased albuminuria, a well-established marker of microvascular complications, are at a higher risk for cardiovascular disease (CVD) and premature mortality. Therefore, a better understanding of the underlying pathophysiology is needed to improve risk stratification and tailor prevention and intervention.

METHODS

We conducted a cross-sectional study including 463 individuals with type 2 diabetes, various degrees of albuminuria and without CVD. We analysed the association between albuminuria and markers of endothelial function (thrombomodulin and syndecan-1), thrombin generation (thrombin-antithrombin complex, prothrombin fragment 1 + 2), fibrinogen, platelet function (activation using soluble plasma selectin and aggregation using Multiplate® Analyzer) using regression models.

RESULTS

In the study cohort 33 % were women, the mean ± SD age was 65 ± 9 years, and median [IQR] diabetes duration was 15 [9-20] years. In total, 344 (74 %) individuals had normal albuminuria, 87 (19 %) moderately- and 32 (7 %) severely increased albuminuria levels. Higher markers of endothelial function and fibrinogen were independently associated with higher albuminuria levels (p < 0.01). No association between albuminuria and markers of thrombin generation and platelet was demonstrated.

CONCLUSION

We demonstrated an independent association between albuminuria and markers of endothelial function and fibrinogen in individuals with type 2 diabetes and no history of CVD.

Normoalbuminuria-is it normal? The association of urinary albumin within the 'normoalbuminuric' range with adverse cardiovascular and mortality outcomes: A systematic review and meta-analysis

AIM

To assess the association between urinary albumin-to-creatinine ratio (UACR) categories within the normal range with mortality and adverse cardiovascular outcomes.

MATERIALS AND METHODS

PubMed and Embase were systematically searched for real-world evidence studies. Studies were manually evaluated according to predefined eligibility criteria. We included prospective and retrospective cohort studies of the association between UACR categories <30 mg/g and cardiovascular outcomes or mortality. Published information regarding study design, participants, UACR categorization, statistical methods, and results was manually collected. Two UACR categorization approaches were defined: a two-category (UACR <10 mg/g vs. 10-30 mg/g) and a three-category division (UACR <5 mg/g vs. 5-10 and 10-30 mg/g). A random effects meta-analysis was performed on studies eligible for the meta-analysis.

RESULTS

In total, 22 manuscripts were identified for the systematic review, 15 of which were eligible for the meta-analysis. The results suggest an association between elevated UACR within the normal to mildly increased range and higher risks of all-cause mortality, cardiovascular death, and coronary heart disease, particularly in the range of 10-30 mg/g. Compared with UACR <10 mg/g, the hazard ratio [HR (95% confidence interval, CI)] for UACR between 10 and 30 mg/g was 1.41 (1.15, 1.74) for all-cause mortality and 1.56 (1.23, 1.98) for coronary heart disease. Compared with UACR <5 mg/g, the risk of cardiovascular mortality for UACR between 10 and 30 mg/g was more than twofold [HR (95% CI): 2.12 (1.61, 2.80)]. Intermediate UACR (5-10 mg/g) was also associated with a higher risk of all-cause mortality [HR (95% CI): 1.14 (1.05, 1.24)] and cardiovascular mortality [HR (95% CI): 1.50 (1.14, 1.99)].

CONCLUSIONS

We propose considering higher UACR within the normoalbuminuric range as a prognostic factor for cardiovascular morbidity and mortality. Our findings underscore the clinical significance of even mild increases in albuminuria.

Routine cardiac biomarkers for the prediction of incident major adverse cardiac events in patients with glomerulonephritis: a real-world analysis using a global federated database

RATIONALE & OBJECTIVE

Glomerulonephritis (GN) is a leading cause of chronic kidney disease (CKD). Major adverse cardiovascular events (MACE) are prolific in CKD. The risk of MACE in GN cohorts is multifactorial. We investigated the prognostic significance of routine cardiac biomarkers, Troponin I and N-terminal pro-BNP (NT-proBNP) in predicting MACE within 5 years of GN diagnosis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Data were obtained from TriNetX, a global federated health research network of electronic health records (EHR).

EXPOSURE OR PREDICTOR

Biomarker thresholds: Troponin I: 18 ng/L, NT-proBNP: 400 pg/mL.

OUTCOMES

Primary outcome: Incidence of major adverse cardiovascular events (MACE).

SECONDARY OUTCOME

was the risk for each individual component of the composite outcome.

ANALYTICAL APPROACH

1:1 propensity score matching using logistic regression. Cox proportional hazard models were used to assess the association of cardiac biomarkers with the primary and secondary outcomes, reported as Hazard Ratio (HR) and 95% confidence intervals (CI). Survival analysis was performed which estimates the probability of an outcome over a 5-year follow-up from the index event.

RESULTS

Following PSM, 34,974 and 18,218 patients were analysed in the Troponin I and NTproBNP cohorts, respectively. In the Troponin I all cause GN cohort, 3,222 (9%) developed composite MACE outcome HR 1.79; (95% CI, 1.70, 1.88, p < 0.0001). In the NTproBNP GN cohort, 1,686 (9%) developed composite MACE outcome HR 1.99; (95% CI, 1.86, 2.14, p < 0.0001).

LIMITATIONS

The data are derived from EHR for administrative purposes; therefore, there is the potential for data errors or missing data.

CONCLUSIONS

In GN, routinely available cardiac biomarkers can predict incident MACE. The results suggest the clinical need for cardiovascular and mortality risk profiling in glomerular disease using a combination of clinical and laboratory variables.

Cardiovascular and Kidney Outcomes of Non-Diabetic CKD by Albuminuria Severity: Findings From the CRIC Study

RATIONALE & OBJECTIVE

The clinical trajectory of normoalbuminuric chronic kidney disease (CKD), particularly in the absence of diabetes, has not yet been well-studied. This study evaluated the association of kidney and cardiovascular outcomes with levels of albuminuria in a cohort of patients with nondiabetic CKD.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

1,463 adults with nondiabetic CKD without known glomerulonephritis and diagnosed with hypertensive nephrosclerosis or unknown cause of CKD participating in the Chronic Renal Insufficiency Cohort (CRIC) Study.

EXPOSURE

Albuminuria stage at study entry.

OUTCOME

Primary outcome: Composite kidney (halving of estimated glomerular filtration rate [eGFR], kidney transplantation, or dialysis), Secondary outcomes: (1) eGFR slope, (2) composite cardiovascular disease events (hospitalization for heart failure, myocardial infarction, stroke, or all-cause death), (3) all-cause death.

ANALYTICAL APPROACH

Linear mixed effects and Cox proportional hazards regression analyses.

RESULTS

Lower levels of albuminuria were associated with female sex and older age. For the primary outcome, compared with normoalbuminuria, those with moderate and severe albuminuria had higher rates of kidney outcomes (adjusted hazard ratio [AHR], 3.3 [95% CI, 2.4-4.6], and AHR, 8.6 [95% CI, 6.0-12.0], respectively) and cardiovascular outcomes (AHR, 1.5 [95% CI, 1.2-1.9], and AHR, 1.5 [95% CI, 1.1-2.0], respectively). Those with normoalbuminuria (<30μg/mg; n=863) had a slower decline in eGFR (-0.46mL/min/1.73m2 per year) compared with those with moderate (30-300μg/mg, n=372; 1.41mL/min/1.73m2 per year) or severe albuminuria (>300μg/mg, n=274; 2.63mL/min/1.73m2 per year). In adjusted analyses, kidney outcomes occurred, on average, sooner among those with moderate (8.6 years) and severe (7.3 years) albuminuria compared with those with normoalbuminuria (9.3 years) whereas the average times to cardiovascular outcomes were similar across albuminuria groups (8.2, 8.1, and 8.6 years, respectively).

LIMITATIONS

Self-report of CKD etiology without confirmatory kidney biopsies; residual confounding.

CONCLUSIONS

Participants with normoalbuminuric nondiabetic CKD experienced substantially slower CKD progression but only modestly lower cardiovascular risk than those with high levels of albuminuria. These findings inform the design of future studies investigating interventions among individuals with lower levels of albuminuria.

PLAIN-LANGUAGE SUMMARY

Diabetes and hypertension are the leading causes of chronic kidney disease (CKD). Urine albumin levels are associated with cardiovascular and kidney disease outcomes among individuals with CKD. However, previous studies of long-term clinical outcomes in CKD largely included patients with diabetes. As well, few studies have evaluated long-term outcomes across different levels of urine albumin among people without diabetes. In this study, we found individuals with nondiabetic CKD and low urine albumin had much slower decline of kidney function but only a modestly lower risk of a cardiovascular events compared with those with high levels of urine albumin. Individuals with low urine albumin were much more likely to have a cardiovascular event than progression of their kidney disease. These findings inform the design of future studies investigating treatments among individuals with lower levels of albuminuria.

Chronic Kidney Disease Stage and Cardiovascular and Mortality Events Among Older Adults: The SPRINT Trial

Rationale & Objective

The risk implications of the Kidney Disease: Improving Global Outcomes (KDIGO) chronic kidney disease classification in older adults are controversial. We evaluated the risk of adverse outcomes in this population across categories of estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR).

Study Design

Prospective cohort.

Settings & Participants

In total, 2,509 participants aged ≥75 years in the Systolic Blood Pressure Intervention Trial (SPRINT).

Exposure

KDIGO eGFR and UACR categories. We combined KDIGO categories G1 and G2, G3b and G4, as well as A2 and A3.

Outcomes

Primary SPRINT outcome (composite of myocardial infarction, other acute coronary syndromes, stroke, heart failure, or death from cardiovascular causes), and all-cause death.

Analytical Approach

Multivariable Cox proportional hazard models.

Results

Mean age was 79.8 years, and 37.4% were female. The mean eGFR was 64.0 mL/min/1.73 m2, and the median UACR was 13.1 mg/g. In multivariable Cox proportional hazard analysis, compared with participants with eGFR ≥ 60 mL/min/1.73 m2 and UACR < 30 mg/g, there was no statistically significant difference in the risk of the primary outcome among participants with eGFR 45-59 or 15-44 mL/min/1.73 m2 and UACR < 30 mg/g. However, those with eGFR 45-59 or 15-44 mL/min/1.73 m2 and UACR ≥ 30 mg/g had higher risk of the primary outcome (HR [95% CI], 1.97 [1.27-3.04] and 3.32 [2.23-4.93], respectively). The risk for all-cause death was higher for each category of abnormal eGFR and UACR, with the highest risk observed among those with eGFR 15-44 mL/min/1.73 m2 and UACR ≥ 30 mg/g (3.34 [2.05-5.44]).

Limitations

Individuals with diabetes and urine protein >1 g/day were excluded from SPRINT.

Conclusion

Among older adults SPRINT participants, low eGFR without albuminuria was associated with higher mortality but not with increased risk of cardiovascular events. Additional studies are needed to evaluate an adapted chronic kidney disease stage-based risk stratification for older adults.

The Early Diagnosis and Treatment of Chronic Renal Insufficiency

BACKGROUND

Chronic renal insufficiency (CRI) is becoming more common and has an increasing impact on public health. In Germany, approximately one in ten adults has CRI. Its most serious consequence is generally not the development of end-stage renal failure, but rather the markedly increased cardiovascular risk as kidney function declines.

METHODS

This review is based on the findings of a selective search in PubMed for literature about the treatment options for CRI, and on our overview of the existing guideline recommendations on diagnostic testing. .

RESULTS

Patients with diabetes mellitus and arterial hypertension are at especially high risk of developing CRI. For these patients, some of the guidelines recommend regular testing for albuminuria and measurement of the glomerular filtration rate (GFR), though sometimes only when specific risk constellations are present. The treatment of CRI has evolved in recent years. At first, aside from general measures, only RAS inhibitors were available as a specific therapy for CRI. With the extension of the approval of SGLT-2 inhibitors to non-diabetic CRI patients, the options for treatment have become wider. Two randomized controlled trials have revealed the benefit of SGLT-2 inhibitors with respect to their primary combined endpoints: time to a specified eGFR reduction and renal/cardiovascular death (HR 0.61 [0.51; 0.72] and 0.72 [0.64; 0.82]). The potential side effects and contraindications of SGLT-2 inhibitors must be taken into account. A further treatment option for diabetics with CRI has become available with the approval of the non-steroidal mineralocorticoid receptor antagonist finerenone.

CONCLUSION

In patients with risk factors, renal function should be regularly tested.

The Urinary Glycopeptide Profile Differentiates Early Cardiorenal Risk in Subjects Not Meeting Criteria for Chronic Kidney Disease

Early diagnosis and treatment of chronic kidney disease (CKD) is a worldwide challenge. Subjects with albumin-to-creatinine ratio (ACR) ≥ 30 mg/g and preserved renal function are considered to be at no cardiorenal risk in clinical practice, but prospective clinical studies evidence increased risk, even at the high-normal (HN) ACR range (10-30 mg/g), supporting the need to identify other molecular indicators for early assessment of patients at higher risk. Following our previous studies, here we aim to stratify the normoalbuminuria range according to cardiorenal risk and identify the glycoproteins and N-glycosylation sites associated with kidney damage in subclinical CKD. Glycoproteins were analyzed in urine from hypertensive patients within the HN ACR range compared to control group (C; ACR < 10 mg/g) by mass spectrometry. A different cohort was analyzed for confirmation (ELISA) and sex perspective was evaluated. Patients' follow-up for 8 years since basal urine collection revealed higher renal function decline and ACR progression for HN patients. Differential N-glycopeptides and their N -glycosylation sites were also identified, together with their pathogenicity. N-glycosylation may condition pathological protein deregulation, and a panel of 62 glycoproteins evidenced alteration in normoalbuminuric subjects within the HN range. Haptoglobin-related protein, haptoglobin, afamin, transferrin, and immunoglobulin heavy constant gamma 1 (IGHG1) and 2 (IGHG2) showed increased levels in HN patients, pointing to disturbed iron metabolism and tubular reabsorption and supporting the tubule as a target of interest in the early progression of CKD. When analyzed separately, haptoglobin, afamin, transferrin, and IGHG2 remained significant in HN, in both women and men. At the peptide level, 172 N-glycopeptides showed differential abundance in HN patients, and 26 showed high pathogenicity, 10 of them belonging to glycoproteins that do not show variation between HN and C groups. This study highlights the value of glycosylation in subjects not meeting KDIGO criteria for CKD. The identified N-glycopeptides and glycosylation sites showed novel targets, for both the early assessment of individual cardiorenal risk and for intervention aimed at anticipating CKD progression.

The relationship between low levels of albuminuria and mortality among adults without major cardiovascular risk factors

AIMS

The determine if elevated levels of albuminuria within the low range (urinary albumin-to-creatinine ratio, UACR <30 mg/g) are linked to cardiovascular death in adults lacking major cardiovascular risk factors.

METHODS

The association between UACR and cardiovascular mortality was investigated among 12,835 participants in the 1999-2014 National Health and Nutrition Examination Survey using Cox proportional hazard models and confounder-adjusted survival curves. We excluded participants with baseline cardiovascular disease, hypertension, diabetes, pre-diabetes, estimated glomerular filtration rate (eGFR) <60ml/min/1.73m2, currently pregnant, and those who had received dialysis in the last year.

RESULTS

Over a median follow-up of 12.3 years, 110 and 621 participants experienced cardiovascular and all-cause mortality. In multivariable-adjusted models, each doubling of UACR was associated with a 36% higher risk of cardiovascular death [HR 1.36 (95% confidence interval (CI) 1.02-1.82)] and a 24% higher risk of all-cause mortality [HR 1.24 (95% CI 1.10-1.39)]. The 15-year adjusted cumulative incidences of cardiovascular mortality were 0.91%, 0.99%, and 2.1% for UACR levels of <4.18 mg/g, 4.18 to <6.91 mg/g, and ≥6.91 mg/g, respectively. The 15-year adjusted cumulative incidences of all-cause mortality were 5.1%, 6.1%, and 7.4% for UACR levels of <4.18 mg/g, 4.18 to <6.91 mg/g, and ≥6.91 mg/g, respectively.

CONCLUSIONS

Adults with elevated levels of albuminuria within the low range (UACR <30 mg/g) and no major cardiovascular risk factors had elevated risks of cardiovascular and all-cause mortality. The risks increased linearly with higher albuminuria levels. This emphasizes a risk gradient across all albuminuria levels, even within the supposedly normal range, adding to the existing evidence.

Association of Albuminuria With Chronic Kidney Disease Progression in Persons With Chronic Kidney Disease and Normoalbuminuria : A Cohort Study

BACKGROUND

Albuminuria is a major risk factor for chronic kidney disease (CKD) progression, especially when categorized as moderate (30 to 300 mg/g) or severe (>300 mg/g). However, there are limited data on the prognostic value of albuminuria within the normoalbuminuric range (<30 mg/g) in persons with CKD.

OBJECTIVE

To estimate the increase in the cumulative incidence of CKD progression with greater baseline levels of albuminuria among persons with CKD who had normoalbuminuria (<30 mg/g).

DESIGN

Multicenter prospective cohort study.

SETTING

7 U.S. clinical centers.

PARTICIPANTS

1629 participants meeting criteria from the CRIC (Chronic Renal Insufficiency Cohort) study with CKD (estimated glomerular filtration rate [eGFR], 20 to 70 mL/min/1.73 m2) and urine albumin-creatinine ratio (UACR) less than 30 mg/g.

MEASUREMENTS

Baseline spot urine albumin divided by spot urine creatinine to calculate UACR as the exposure variable. The 10-year adjusted cumulative incidences of CKD progression (composite of 50% eGFR decline or kidney failure [dialysis or kidney transplantation]) from confounder adjusted survival curves using the G-formula.

RESULTS

Over a median follow-up of 9.8 years, 182 of 1629 participants experienced CKD progression. The 10-year adjusted cumulative incidences of CKD progression were 8.7% (95% CI, 5.9% to 11.6%), 11.5% (CI, 8.8% to 14.3%), and 19.5% (CI, 15.4% to 23.5%) for UACR levels of 0 to less than 5 mg/g, 5 to less than 15 mg/g, and 15 mg/g or more, respectively. Comparing persons with UACR 15 mg/g or more to those with UACR 5 to less than 15 mg/g and 0 to less than 5 mg/g, the absolute risk differences were 7.9% (CI, 3.0% to 12.7%) and 10.7% (CI, 5.8% to 15.6%), respectively. The 10-year adjusted cumulative incidence increased linearly based on baseline UACR levels.

LIMITATION

UACR was measured once.

CONCLUSION

Persons with CKD and normoalbuminuria (<30 mg/g) had excess risk for CKD progression, which increased in a linear fashion with higher levels of albuminuria.

PRIMARY FUNDING SOURCE

None.

Higher Arterial Stiffness Predicts Chronic Kidney Disease in Adults: The ELSA-Brasil Cohort Study

BACKGROUND

Central Illustration : Higher Arterial Stiffness Predicts Chronic Kidney Disease in Adults: The ELSA-Brasil Cohort Study.

BACKGROUND

Arterial stiffening can directly affect the kidneys, which are passively perfused by a high flow. However, whether the relation between arterial stiffness and renal function depends on diabetes and hypertension conditions, is a matter of debate.

OBJECTIVE

To investigate the relationship between arterial stiffening by carotid-to-femoral pulse wave velocity (cfPWV) and chronic kidney disease (CKD) incidence in individuals and verify whether this association is present in individuals without hypertension and diabetes.

METHODS

A longitudinal study of 11,647 participants of the ELSA-Brasil followed up for four years (2008/10-2012/14). Baseline cfPWV was grouped per quartile, according to sex-specific cut-offs. Presence of CKD was ascertained by glomerular filtration rate (eGFR-CKD-EPI) < 60 ml/min/1.73 m2 and/or albumin-to-creatinine ratio ≥ 30 mg/g. Logistic regression models were run for the whole cohort and a subsample free from hypertension and diabetes at baseline, after adjustment for age, sex, race, schooling, smoking, cholesterol/HDL ratio, body mass index, diabetes, use of antihypertensive, systolic blood pressure, heart rate, and cardiovascular disease. Statistical significance was set at 5%.

RESULTS

The chance of CKD was 42% (CI 95%: 1.05;1.92) greater among individuals in the upper quartile of cfPWV. Among normotensive, non-diabetic participants, individuals in the 2nd, 3rd, and 4th quartiles of cfPWV presented greater chances of developing CKD, as compared to those in the lower quartile, and the magnitude of this association was the greatest for those in the upper quartile (OR: 1.81 CI 95%: 1.14;2.86).

CONCLUSION

Higher cfPWV increased the chances of CKD and suggests that this effect is even greater in individuals without diabetes and hypertension.

Screening, identifying, and treating chronic kidney disease: why, who, when, how, and what?

1 in 7 American adults have chronic kidney disease (CKD); a disease that increases risk for CKD progression, cardiovascular events, and mortality. Currently, the US Preventative Services Task Force does not have a screening recommendation, though evidence suggests that screening can prevent progression and is cost-effective. Populations at risk for CKD, such as those with hypertension, diabetes, and age greater than 50 years should be targeted for screening. CKD is diagnosed and risk stratified with estimated glomerular filtration rate utilizing serum creatinine and measuring urine albumin-to-creatinine ratio. Once identified, CKD is staged according to C-G-A classification, and managed with lifestyle modification, interdisciplinary care and the recently expanding repertoire of pharmacotherapy which includes angiotensin converting enzyme inhibitors or angiotensin-II receptor blockers, sodium-glucose-cotransporter-2 inhibitors, and mineralocorticorticoid receptor antagonists. In this paper, we present the why, who, when, how, and what of CKD screening.

Association of urinary albumin-to-creatinine ratio with cardiometabolic risk markers and pre-diabetes in adults with normoglycemia, normoalbuminuria, and normotension with parental type 2 diabetes

INTRODUCTION

This is a post hoc analysis of urinary albumin-to-creatinine ratio (uACR) within the normoalbuminuric range in relation to cardiometabolic risk factors among initially normoglycemic, normotensive participants in the Pathobiology of Prediabetes in a Biracial Cohort (POP-ABC) Study.

RESEARCH DESIGN AND METHODS

308 healthy African American (AA) and European American (EA) participants in the POP-ABC Study underwent baseline assessments, including oral glucose tolerance test, anthropometry, urinary albumin-to-creatinine ratio (uACR), lipids, adipocytokines, insulin sensitivity and secretion. Participants were followed quarterly for 5.5 years (mean 2.62 years) for the primary outcome of incident pre-diabetes.

RESULTS

The cohort's mean fasting glucose was 92.1±6.90 mg/dL, 2-hour plasma glucose was 123±25.0 mg/dL, systolic blood pressure was 123±15.9 mm Hg, and diastolic blood pressure was 74±8.80 mm Hg. Baseline uACR levels (range 1-29 mg/g) were similar in AA versus EA participants (6.40 mg/g±4.80 vs 6.80±5.40 mg/g, p=0.52), higher in women than men (7.30 mg/g±5.30 vs 4.60±3.90 mg/g, p<0.0001), and showed significant associations with cardiometabolic risk factors, including age, insulin sensitivity, high-density lipoprotein cholesterol, and adiponectin levels (p=0.03-0.004). During 5.5 years of follow-up, 104 participants developed pre-diabetes and 204 maintained normoglycemia. Baseline uACR quartiles were associated with incident pre-diabetes (r=0.19, p=0.0011).

CONCLUSIONS

Baseline uACR levels were associated with cardiometabolic risk markers and incident pre-diabetes risk among adults with normoglycemia, normoalbuminuria and normotension with parental diabetes.

The relationship between low levels of albuminuria and cardiovascular mortality among apparently healthy adults

Background

Albuminuria is associated with cardiovascular events among adults with underlying cardiovascular disease and diabetes, even at low levels of urinary albumin excretion. We hypothesized that low levels of albuminuria in the 'normal' range (urinary albumin-to-creatine ratio (UACR) <30 mg/g) are associated with cardiovascular death among apparently healthy adults.

Methods

We studied adults who participated in the 1999-2014 National Health and Nutrition Examination Survey. We excluded participants with baseline cardiovascular disease, hypertension, diabetes, estimated glomerular filtration rate (eGFR) <60ml/min/1.73m2, those who were currently pregnant, and those who had received dialysis in the last year. After excluding these conditions, only 5.0% of the remaining population had UACR ≥30 mg/g (N=873) and were excluded. The final sample size was 16,247. We assessed the relationship between UACR and cardiovascular and all-cause mortality using multivariable-adjusted Cox proportional hazards models. Models were adjusted for age, sex, race or ethnicity, smoking status, systolic blood pressure, hemoglobin A1c, total cholesterol, health insurance, food insecurity, serum albumin, body mass index, use of statins, and eGFR.

Results

Mean age was 38.9 years (SD 13.6) and 53.7% were women. The median length of follow-up was 12.2 years. In multivariable-adjusted models, each doubling of UACR (within the <30 mg/g range) was associated with a 36% higher risk of cardiovascular death [HR 1.36 (95% confidence interval (CI) 1.11-1.65)] and a 28% higher risk of all-cause mortality [HR 1.28 (95%CI 1.17-1.41)]. The highest tertile of UACR (7.1-29.9 mg/g) was associated with an 87% higher risk of cardiovascular death [HR 1.87 (95%CI 1.20-2.92)] and 59% higher risk of all-cause mortality [HR 1.59 (95%CI 1.28-1.96)], compared with the lowest tertile (< 4.3 mg/g).

Conclusions

In a nationally representative sample of relatively healthy community-dwelling adults, higher levels of albuminuria in the conventionally "normal" range <30 mg/g in healthy individuals are associated with greater mortality. Overall, our findings contribute to the growing body of evidence on the existence of a risk gradient across all levels of albuminuria, even in the so-called normal range.

Microalbuminuria and Its Correlation with the Severity of Coronary Artery Disease: A Cross-sectional Study in a Rural Area of Central India

Microalbuminuria is a well-established, strong, and independent risk factor of cardiovascular disease. Patients with microalbuminuria are also said to have a higher atherosclerotic load in the form of multivessel coronary artery disease (CAD) than those who do not. In this study, we tried to correlate microalbuminuria with the severity of CAD. In this cross-sectional study, 100 patients with CAD diagnosed on the basis of coronary angiography were enrolled from August 2019 to August 2021. Triple-vessel CAD was observed in 79.4% of cases with the presence of microalbuminuria compared with 3% of cases without microalbuminuria. The association of microalbuminuria with the severity of disease was statistically significant (P <0.01). A significant correlation was observed between microalbuminuria and the Framingham risk score in cases of CAD (P <0.01), which was a measure of the 10-year risk of cardiovascular disease.

Association of kidney disease index with all-cause and cardiovascular mortality among individuals with hypertension

BACKGROUND

This study aimed to investigate the association between a novel kidney disease index (KDI), which combines information from both estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (uACR), and all-cause and cardiovascular disease (CVD) mortality among individuals with hypertension.

METHODS

We analyzed data from 19 988 adults with hypertension who participated in the National Health and Nutrition Examination Survey from 1999 to 2018. Mortality outcomes were determined by linking to National Death Index records through December 31, 2019. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for all-cause and CVD mortality.

RESULTS

Baseline KDI levels were positively associated with glucose, insulin resistance, hemoglobin A1c, triglycerides, and C-reactive protein (p value for trend <.05). During a follow-up period of 179 859 person-years, a total of 5069 deaths were documented, including 1741 from cardiovascular causes. After multivariable adjustment, each standard deviation increment in KDI level was associated with a 27% increased risk of all-cause mortality and a 31% increased risk of cardiovascular deaths (both p < .05). Further analysis showed a J-shaped association between KDI and mortality, with the risk increasing dramatically when KDI exceeded 0.27.

CONCLUSION

Elevated KDI levels were significantly associated with increased mortality from all causes and CVD among individuals with hypertension. We recommend routine testing of eGFR and uACR in hypertensive patients, and using KDI as a tool to identify individuals who are most likely to benefit from preventive therapies.

Albuminuria-Related Genetic Biomarkers: Replication and Predictive Evaluation in Individuals with and without Diabetes from the UK Biobank

Increased albuminuria indicates underlying glomerular pathology and is associated with worse renal disease outcomes, especially in diabetic kidney disease. Many single nucleotide polymorphisms (SNPs), associated with albuminuria, could be potentially useful to construct polygenic risk scores (PRSs) for kidney disease. We investigated the diagnostic accuracy of SNPs, previously associated with albuminuria-related traits, on albuminuria and renal injury in the UK Biobank population, with a particular interest in diabetes. Multivariable logistic regression was used to evaluate the influence of 91 SNPs on urine albumin-to-creatinine ratio (UACR)-related traits and kidney damage (any pathology indicating renal injury), stratifying by diabetes. Weighted PRSs for microalbuminuria and UACR from previous studies were used to calculate the area under the receiver operating characteristic curve (AUROC). CUBN-rs1801239 and DDR1-rs116772905 were associated with all the UACR-derived phenotypes, in both the overall and non-diabetic cohorts, but not with kidney damage. Several SNPs demonstrated different effects in individuals with diabetes compared to those without. SNPs did not improve the AUROC over currently used clinical variables. Many SNPs are associated with UACR or renal injury, suggesting a role in kidney dysfunction, dependent on the presence of diabetes in some cases. However, individual SNPs or PRSs did not improve the diagnostic accuracy for albuminuria or renal injury compared to standard clinical variables.

Correlation of Mid-Trimester Spot Urinary Albumin: Creatinine Ratio With the Adverse Pregnancy Outcome

Background Urinary albumin creatinine ratio (ACR) is a known method of measurement of microalbuminuria. Microalbuminuria may be an early marker of endothelial dysfunction which can lead to various complications during the course of pregnancy. The objective of our study was to evaluate the correlation of mid-trimester spot urinary ACR with the pregnancy outcome. Material and methods We performed a prospective cohort study in the department of Obstetrics & Gynaecology, All India Institute of Medical Sciences, Bhopal, for a period of one year. We studied 130 antenatal women between 14 and 28 weeks of gestation after obtaining written informed consent. The patients with ongoing urinary tract infection (UTI), pre-existing hypertension, or diabetes were excluded. Urinary samples were examined for spot ACR, and the women were followed until delivery. Primary maternal outcomes were development of gestational hypertension, pre-eclampsia, gestational diabetes mellitus (GDM), and preterm labour. Neonatal outcome was assessed in terms of birth weight, the APGAR (Appearance, Pulse, Grimace, Activity, Respiration) scores, and neonatal intensive care unit (NICU) admission. Results  In our study, mean urinary ACR was 19.07±12.94 mcg/mg and median urinary ACR (IQR) was 18 (9.43-25.25) mcg/mg. Prevalence of microalbuminuria in our study was 19.2%. It was observed that urinary ACR level was significantly higher in women with maternal complications like GDM, gestational hypertension, preeclampsia, and preterm labour. Also, mean urinary ACR of women who developed preeclampsia was higher (37.53±31.85) compared to women who developed gestational hypertension (27.40±9.71). Urinary ACR level was significantly higher in babies with low APGAR scores and in babies who needed NICU admission (p value < 0.05). The sensitivity and specificity of spot urinary ACR to predict GDM and preeclampsia were found to be good as calculated from the receiver operating curve. Conclusion We found definite correlation of higher values of mid-trimester urinary ACR with the adverse pregnancy outcome.

Application of nanoparticles in the diagnosis and treatment of chronic kidney disease

With the development of nanotechnology, nanoparticles have been used in various industries. In medicine, nanoparticles have been used in the diagnosis and treatment of diseases. The kidney is an important organ for waste excretion and maintaining the balance of the internal environment; it filters various metabolic wastes. Kidney dysfunction may result in the accumulation of excess water and various toxins in the body without being discharged, leading to complications and life-threatening conditions. Based on their physical and chemical properties, nanoparticles can enter cells and cross biological barriers to reach the kidneys and therefore, can be used in the diagnosis and treatment of chronic kidney disease (CKD). In the first search, we used the English terms "Renal Insufficiency, Chronic" [Mesh] as the subject word and terms such as "Chronic Renal Insufficiencies," "Chronic Renal Insufficiency," "Chronic Kidney Diseases," "Kidney Disease, Chronic," "Renal Disease, Chronic" as free words. In the second search, we used "Nanoparticles" [Mesh] as the subject word and "Nanocrystalline Materials," "Materials, Nanocrystalline," "Nanocrystals," and others as free words. The relevant literature was searched and read. Moreover, we analyzed and summarized the application and mechanism of nanoparticles in the diagnosis of CKD, application of nanoparticles in the diagnosis and treatment of renal fibrosis and vascular calcification (VC), and their clinical application in patients undergoing dialysis. Specifically, we found that nanoparticles can detect CKD in the early stages in a variety of ways, such as via breath sensors that detect gases and biosensors that detect urine and can be used as a contrast agent to avoid kidney damage. In addition, nanoparticles can be used to treat and reverse renal fibrosis, as well as detect and treat VC in patients with early CKD. Simultaneously, nanoparticles can improve safety and convenience for patients undergoing dialysis. Finally, we summarize the current advantages and limitations of nanoparticles applied to CKD as well as their future prospects.

The Risk of Cardiovascular Events in Individuals With Primary Glomerular Diseases

RATIONALE & OBJECTIVE

Little is known about the risk of cardiovascular disease (CVD) in patients with various primary glomerular diseases. In a population-level cohort of adults with primary glomerular disease, we sought to describe the risk of CVD compared with the general population and the impact of traditional and kidney-related risk factors on CVD risk.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Adults with membranous nephropathy (n = 387), minimal change disease (n = 226), IgA nephropathy (n = 759), and focal segmental glomerulosclerosis (n = 540) from a centralized pathology registry in British Columbia, Canada (2000-2012).

EXPOSURE

Traditional CVD risk factors (diabetes, age, sex, dyslipidemia, hypertension, smoking, prior CVD) and kidney-related risk factors (type of glomerular disease, estimated glomerular filtration rate [eGFR], proteinuria).

OUTCOME

A composite CVD outcome of coronary artery, cerebrovascular, and peripheral vascular events, and death due to myocardial infarction or stroke.

ANALYTICAL APPROACH

Subdistribution hazards models to evaluate the outcome risk with non-CVD death treated as a competing event. Standardized incidence rates (SIR) calculated based on the age- and sex-matched general population.

RESULTS

During a median 6.8 years of follow-up, 212 patients (11.1%) experienced the CVD outcome (10-year risk, 14.7% [95% CI, 12.8%-16.8%]). The incidence rate was high for the overall cohort (24.7 per 1,000 person-years) and for each disease type (range, 12.2-46.1 per 1,000 person-years), and was higher than that observed in the general population both overall (SIR, 2.46 [95% CI, 2.12-2.82]) and for each disease type (SIR range, 1.38-3.98). Disease type, baseline eGFR, and proteinuria were associated with a higher risk of CVD and, when added to a model with traditional risk factors, led to improvements in model fit (R² of 14.3% vs 12.7%), risk discrimination (C-statistic of 0.81 vs 0.78; difference, 0.02 [95% CI, 0.01-0.04]), and continuous net reclassification improvement (0.4 [95% CI, 0.2-0.6]).

LIMITATIONS

Ascertainment of outcomes and comorbidities using administrative data.

CONCLUSIONS

Patients with primary glomerular disease have a high absolute risk of CVD that is approximately 2.5 times that of the general population. Consideration of eGFR, proteinuria, and type of glomerular disease may improve risk stratification of CVD risk in these individuals.

PLAIN-LANGUAGE SUMMARY

Patients with chronic kidney disease are known to be at high risk of cardiovascular disease. Cardiovascular risk in patients with primary glomerular diseases is poorly understood because these conditions are rare and require a kidney biopsy for diagnosis. In this study of 1,912 Canadian patients with biopsy-proven IgA nephropathy, minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy, the rate of cardiovascular events was 2.5 times higher than in the general population and was high for each disease type. Consideration of disease type, kidney function, and proteinuria improved the prediction of cardiovascular events. In summary, our population-level study showed that patients with primary glomerular diseases have a high cardiovascular risk, and that inclusion of kidney-specific risk factors may improve risk stratification.

Hypertension-mediated organ damage and established cardiovascular disease in patients with hypertension: the China Hypertension Survey, 2012-2015

Hypertension is a major health burden worldwide. However, there is limited data on the status of hypertension-mediated organ damage (HMOD) and established cardiovascular (CV) disease in Chinese hypertensive patients. The aim of this study is to determine the prevalence of HMOD and established CV disease in a nationally representative population in China. A stratified multistage random sampling method was used in the China Hypertension Survey and 21,243 participants aged 35 or older were eligible for analysis in this study. For each participant, the demographic information and a self-reported medical history were acquired. Blood pressure was measured with the electronic device 3 times on the right arm, supported at heart level, after the participant was sitting at rest for 5 min. Samples of blood and urine were tested. 2-D and Doppler echocardiography were used to assess the heart's function and structures. Sampling weights were calculated based on the 2010 China population census data. Overall, the weighted prevalence of asymptomatic HMOD was 22.1%, 28.9%, 23.1%, 6.4%, and 6.2% for wide pulse pressure, left ventricular hypertrophy, microalbuminuria, chronic kidney disease, and abnormal ankle-brachial index, respectively. For the established CV disease, the weighted prevalence was 1.8%, 1.3%, 2.0%, and 1.1% for stroke, coronary artery disease, heart failure, and atrial fibrillation, respectively. The prevalence of asymptomatic HMOD and established CV disease was greater with higher blood pressure level (P < 0.05), rather than ankle-brachial index. Compared to those with uncontrolled hypertension, the prevalence of asymptomatic HMOD was lower in patients with controlled hypertension. In summary, the prevalence of HMOD in Chinese people aged 35 or older was very common, indicating a substantial future burden of both morbidity and mortality from hypertension in China. Clinical trial registration number: ChiCTR-ECS-14004641.

Oxidative stress contributes to reductions in microvascular endothelial- and nitric oxide-dependent dilation in women with a history of gestational diabetes

Women with a history of gestational diabetes mellitus (GDM) are twice as likely to develop cardiovascular disease and ~7x as likely to develop type II diabetes as their age-matched counterparts. However, the mechanism(s) mediating these associations remain unclear. We hypothesized that endothelium- and NO-dependent dilation would be attenuated through oxidant stress mechanisms in the microvasculature of women with a history of GDM compared to control women with a history of uncomplicated pregnancy (HC). Ten HC (35±4yrs) and 10 GDM (34±4yrs) underwent a standard local heating protocol (42°C; 0.1°C·s^-1). Two intradermal microdialysis fibers were placed in the ventral forearm for local delivery of lactated Ringer's (control), or 5mM L-ascorbate. After full expression of the local heating response, 15mM N^G-nitro-L-arginine methyl ester NO synthase-inhibition) was perfused. Red cell flux was measured continuously by laser-Doppler flowmetry and cutaneous vascular conductance (CVC=flux/MAP) was standardized to maximum (%CVCmax; 28mM SNP + 43°C). Urine albumin:creatinine ratio (ACR) was measured. GDM had attenuated endothelium-dependent (GDM: 67±7 vs. HC: 90±4%CVCmax; p<0.001) and NO-dependent (GDM: 54±7 vs. HC: 71±3%; p=0.001) dilation at the control site and tended to have higher urine ACR (p=0.06). Both endothelium-dependent (r²=0.53, p=0.02) and NO-dependent (r²=0.56, p=0.01) dilation were related to urine ACR in GDM. L-ascorbate perfusion improved endothelium-dependent (82±5%CVCmax; p=0.03 vs. control) and NO-dependent (68±5%; p=0.02 vs. control) dilation in GDM but had no effect in HC (p>0.05). Otherwise healthy women with a history of GDM have attenuated microvascular endothelial function and this dysfunction is mediated, in part, by oxidative stress.

The Lower Limit of Reference of Urinary Albumin/Creatinine Ratio and the Risk of Chronic Kidney Disease Progression in Patients With Type 2 Diabetes Mellitus

A urine albumin/creatinine ratio (UACR) <30 mg/g is considered to be normal, while increased risk of incident hypertension and cardiovascular disease mortality in subjects with high normal UACR level had been observed. However, a mild elevated but normal UACR level was associated with the risk of initiating chronic kidney disease (CKD) is uncertain. We investigated whether higher normal UACR is associated with the risk of developing CKD. A total of 4821 subjects with type 2 diabetes mellitus (T2DM), an estimated glomerular filtration rate >60 ml/min/1.73 m2 and UACR <30 mg/g enrolled in a diabetes disease management program between 2006 and 2020 were studied. The optimal cutoff point for baseline UACR as a predictor for progression to CKD according to the 2012 KDIGO definition was calculated using receiving operating characteristic curve analysis. After a mean of 4.9 years follow-up, the CKD risk progression increased in parallel with the quartiles of baseline UACR <30 mg/g (p for trend <0.0001). UACR cutoff points of 8.44 mg/g overall, 10.59 mg/g in males and 8.15 mg/g in females were associated with the risk of CKD progression. In multivariate Cox regression analysis, the hazard ratios for the association between UACR (>8.44 mg/g, >10.9 mg/g, >8.15 mg/g in overall, male, and female patients, respectively) and the risk of CKD progression were significant. This study demonstrated that a cutoff UACR value of >10 mg/g could significantly predict the cumulative incidence and progression of CKD in patients with T2DM.

Ten-Year Risk-Prediction Equations for Incident Heart Failure Hospitalizations in Chronic Kidney Disease: Findings from the Chronic Renal Insufficiency Cohort Study and the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Heart failure (HF) is a leading contributor to cardiovascular morbidity and mortality in the population with chronic kidney disease (CKD). HF risk prediction tools that use readily available clinical parameters to risk-stratify individuals with CKD are needed.

METHODS

We included Black and White participants aged 30-79 years with CKD stages 2-4 who were enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study and were without self-reported cardiovascular disease. We assessed model performance of the Pooled Cohort Equations to Prevent Heart Failure (PCP-HF) to predict incident hospitalizations due to HF and refit the PCP-HF in the population with CKD by using CRIC data-derived coefficients and survival from CRIC study participants in the CKD population (PCP-HFCKD). We investigated the improvement in HF prediction with inclusion of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) into the PCP-HFCKD equations by change in C-statistic, net reclassification improvement (NRI), and integrated discrimination improvement index (IDI). We validated the PCP-HFCKD with and without eGFR and UACR in Multi-Ethnic Study of Atherosclerosis (MESA) participants with CKD.

RESULTS

Among 2328 CRIC Study participants, 340 incident HF hospitalizations occurred over a mean follow-up of 9.5 years. The PCP-HF equations did not perform well in most participants with CKD and had inadequate discrimination and insufficient calibration (C-statistic 0.64-0.71, Greenwood-Nam-D'Agostino (GND) chi-square statistic P value < 0.05), with modest improvement and good calibration after being refit (PCP-HFCKD: C-statistic 0.61-0.78), GND chi-square statistic P value > 0.05). Addition of UACR, but not eGFR, to the refit PCP-HFCKD improved model performance in all race-sex groups (C-statistic [0.73-0.81], GND chi-square statistic P value > 0.05, delta C-statistic ranging from 0.03-0.11 and NRI and IDI P values < 0.01). External validation of the PCP-HFCKD in MESA demonstrated good discrimination and calibration.

CONCLUSIONS

Routinely available clinical data that include UACR in patients with CKD can reliably identify individuals at risk of HF hospitalizations.

Hypertension-mediated organ damage in masked hypertension

OBJECTIVES

Masked hypertension - a blood pressure (BP) phenotype characterized by a clinic BP in the normal range but elevated BP outside the office - is associated with early hypertension-mediated organ damage. This study examined early target organ manifestations of masked hypertension diagnosed by home (HBPM) and ambulatory (ABPM) BP monitoring.

METHODS

Left ventricular (LV) structure and diastolic function measured by echocardiography, microalbuminuria, and coronary artery calcification were evaluated in 420 patients with high clinic BP (SBP 120-150 mmHg or DBP 80-95 mmHg). Evidence of hypertension-mediated organ damage was compared in patients with sustained normotension, masked hypertension, and sustained hypertension based on measurements by HBPM, daytime ABPM, and 24-h ABPM.

RESULTS

The 420 participants averaged 48 (12) [mean (SD)] years of age; the average clinic BP was 130 (13)/81 (8) mmHg. In individuals with masked hypertension diagnosed by HBPM, indexed LV mass, relative wall thickness, and e' and E/e' (indices of LV relaxation), were generally intermediate between values observed in normotensives and sustained hypertensive patients, and were significantly greater in masked hypertension than normotensives. Similar trends were observed when masked hypertension was diagnosed by ABPM but a diagnosis of masked hypertension was not as reliably associated with LV remodeling or impaired LV relaxation in comparison to normotensives. There were trends towards greater likelihoods of detectable urinary microalbumin and coronary calcification in masked hypertension than in normotensives.

CONCLUSION

These results support previous studies demonstrating early hypertension-mediated organ damage in patients with masked hypertension, and suggest that HBPM may be superior to ABPM in identifying patients with masked hypertension who have early LV remodeling and diastolic LV dysfunction.

Urinary C-megalin as a novel biomarker of progression to microalbuminuria: A cohort study based on the diabetes Distress and Care Registry at Tenri (DDCRT 22)

AIMS

Megalin is a multiligand receptor expressed in proximal tubular cells that reabsorbs filtered albumin and correlates cross-sectionally with albuminuria. We investigated the association between urinary C-megalin levels and the incidence of microalbuminuria in patients with diabetes mellitus.

METHODS

This cohort study included 752 patients with type 1 or 2 diabetes mellitus and a urinary albumin-to-creatinine (Cr) ratio (UACR) within the normoalbuminuric range (<30 mg/g Cr). The association between urinary C-megalin and persistent microalbuminuria, accounting for the possible interaction between baseline UACR and urinary C-megalin, was estimated using a Cox proportional hazards model.

RESULTS

During a median follow-up period of 1.99 years, 179 cases of persistent microalbuminuria were observed. The association between urinary C-megalin and persistent microalbuminuria was UACR-dependent (P for interaction < 0.001), with the highest association observed in the absence of UACR (per 100 fM/gCr of urinary C-megalin: adjusted hazard ratio, 1.13; 95% CI 1.07-1.19), gradually decreasing as UACR increased to 30 mg/g Cr. UACR dependence was confirmed by sensitivity analyses according to low-normal (<10 mg/gCr) or high-normal (10-<30 mg/gCr) UACR.

CONCLUSIONS

Urinary C-megalin is associated with progression to microalbuminuria, especially in those with low-normal UACR levels, and its usefulness to identify high risk patients requires further investigation.

Polymorphism rs10105606 of LPL as a Novel Risk Factor for Microalbuminuria

Introduction

An important clinical feature of metabolic syndrome is abdominal obesity. Microalbuminuria is important in predicting the risk of cardiovascular and renal complications in abdominal obesity patients. However, the association between microalbuminuria polymorphism and abdominal obesity has not been conducted. The objective of this study is to analyze the genetic polymorphism of microalbuminuria in participants with metabolically unhealthy obesity (MUO).

Methods

Among 1325 MUO participants, we identified genomic loci underlying those with microalbuminuria, compared to those without microalbuminuria. Single nucleotide polymorphisms (SNPs) were selected with P < 1 × 10⁻⁵ from the Manhattan plot. Multivariable linear regression and analysis of variance were used to analyze the association between different SNP genotypes and microalbuminuria.

Results

The analysis showed homozygous participants for the risk allele A of rs10105606 and Affx-31885823 had 1.978-fold risk and 1.921-fold increased risk of microalbuminuria, respectively. Heterozygous distribution of rs117180252, rs10105606, and Affx-31885823 also increased the risk of microalbuminuria compared to the wild type. Further analysis showed Lipoprotein lipase (LPL), RN7SL87P, and RPL30P9 were the candidate genes associated with lipid metabolism and abdominal obesity.

Conclusion

In conclusion, LPL, RN7SL87P, and RPL30P9 minor allele carriers with abdominal obesity are more susceptible to microalbuminuria, explaining the inter-individual differences of microalbuminuria in MUO patients.

Investigating the global prevalence and consequences of undiagnosed stage 3 chronic kidney disease: methods and rationale for the REVEAL-CKD study

Background

Timely diagnosis and treatment of stage 3 chronic kidney disease (CKD) can prevent further loss of kidney function and progression to kidney failure. However, contemporary data on the global prevalence of undiagnosed stage 3 CKD are scarce. REVEAL-CKD is a multinational, multifocal and observational study aiming to provide insights into undiagnosed stage 3 CKD in a large population.

Methods

Patients (aged ≥18 years) with data in selected secondary databases from 11 countries will be included if they have at least two estimated glomerular filtration rate (eGFR) measurements from 2015 onwards that are ≥30 and <60 mL/min/1.73 m², recorded >90 and ≤730 days apart. Undiagnosed cases are those without an International Classification of Diseases 9/10 diagnosis code for CKD (any stage) any time before and up to 6 months after the second qualifying eGFR measurement. Time to diagnosis will be assessed using a Kaplan–Meier approach; patient characteristics associated with undiagnosed CKD will be assessed using adjusted logistical regression analyses.

Results

REVEAL-CKD will assess the point prevalence of undiagnosed stage 3 CKD and time to CKD diagnosis in initially undiagnosed cases overall and in individual countries. Trends in undiagnosed CKD prevalence by calendar year will be assessed. Patient characteristics, healthcare resource utilization, adverse clinical outcomes, and CKD management and monitoring practices in patients with versus without a CKD diagnosis will be compared.

Conclusions

REVEAL-CKD will increase awareness of the global clinical and economic burden of undiagnosed stage 3 CKD and provide valuable insights to inform clinical practice and policy changes.

Abnormalities in Cardiac Structure and Function among Individuals with CKD: The COMBINE Trial

Background

Individuals with CKD have a high burden of cardiovascular disease (CVD). Abnormalities in cardiac structure and function represent subclinical CVD and can be assessed by cardiac magnetic resonance imaging (cMRI).

Methods

We investigated differences in cMRI parameters in 140 individuals with CKD stages 3b-4 who participated in the CKD Optimal Management with BInders and NicotinamidE (COMBINE) trial and in 24 age- and sex-matched healthy volunteers. Among COMBINE participants, we examined the associations of eGFR, urine albumin-creatinine ratio (UACR), phosphate, fibroblast growth factor 23 (FGF23), and parathyroid hormone (PTH) with baseline (N=140) and 12-month change (N=112) in cMRI parameters.

Results

Mean (SD) ages of the COMBINE participants and healthy volunteers were 64.9 (11.9) and 60.4 (7.3) years, respectively. The mean (SD) baseline eGFR values in COMBINE participants were 32.1 (8.0) and 85.9 (16.0) ml/min per 1.73 m² in healthy volunteers. The median (interquartile range [IQR]) UACR in COMBINE participants was 154 (20.3-540.0) mg/g. Individuals with CKD had lower mitral valve E/A ratio compared with healthy volunteers (for CKD versus non-CKD, β estimate, -0.13; 95% CI, -0.24 to -0.012). Among COMBINE participants, multivariable linear regression analyses showed that higher UACR was significantly associated with lower mitral valve E/A ratio (β estimate per 1 unit increase in natural-log UACR, -0.06; 95% CI, -0.09 to -0.03). This finding was preserved among individuals without baseline CVD. UACR was not associated with 12-month change in any cMRI parameter. eGFR, phosphate, FGF23, and PTH were not associated with any cMRI parameter in cross-sectional or change analyses.

Conclusions

Individuals with CKD stages 3b-4 have evidence of cMRI abnormalities. Albuminuria was independently associated with diastolic dysfunction, as assessed by mitral valve E/A ratio, in individuals with CKD with and without clinical CVD. Albuminuria was not associated with change in any cMRI parameter.

Early renal and vascular damage within the normoalbuminuria condition

OBJECTIVE

A continuous association between albuminuria and cardiorenal risk exists further below moderately increased albuminuria ranges. If only based in albumin to creatinine ratio (ACR) higher than 30 mg/g, a significant percentage of individuals may be out of the scope for therapeutic management. Despite epidemiological outcomes, the identification of biochemical changes linked to early albuminuria is underexplored, and normoalbuminuric individuals are usually considered at no risk in clinical practice. Here, we aimed to identify early molecular alterations behind albuminuria development.

METHODS

Hypertensive patients under renin-angiotensin system (RAS) suppression were classified as control, (ACR < 10 mg/g) or high-normal (ACR = 10-30 mg/g). Urinary protein alterations were quantified and confirmed by untargeted and targeted mass spectrometry. Coordinated protein responses with biological significance in albuminuria development were investigated. Immunohistochemistry assays were performed in human kidney and arterial tissue to in situ evaluate the associated damage.

RESULTS

A total of 2663 identified proteins reflect inflammation, immune response, ion transport and lipids metabolism (P value ≤ 0.01). A1AT, VTDB and KNG1 varied in high-normal individuals (P value < 0.05), correlated with ACR and associated with the high-normal condition (odds ratio of 20.76, 6.00 and 7.04 were found, respectively (P value < 0.001)). After 12 months, protein variations persist and aggravate in progressors to moderately increased albuminuria. At tissue level, differential protein expression was found in kidney from individuals with moderately increased albuminuria and atherosclerotic aortas for the three proteins, confirming their capacity to reflect subclinical organ damage.

CONCLUSION

Early renal and vascular damage is molecularly evidenced within the normoalbuminuria condition.

Framing Cause-Effect Relationship of Acute Coronary Syndrome in Patients with Chronic Kidney Disease

The main causes of death in patients with chronic kidney disease (CKD) are of cardiovascular nature. The interaction between traditional cardiovascular risk factors (CVRF) and non-traditional risk factors (RF) triggers various complex pathophysiological mechanisms that will lead to accelerated atherosclerosis in the context of decreased renal function. In terms of mortality, CKD should be considered equivalent to ischemic coronary artery disease (CAD) and properly monitored. Vascular calcification, endothelial dysfunction, oxidative stress, anemia, and inflammatory syndrome represents the main uremic RF triggered by accumulation of the uremic toxins in CKD subjects. Proteinuria that appears due to kidney function decline may initiate an inflammatory status and alteration of the coagulation—fibrinolysis systems, favorizing acute coronary syndromes (ACS) occurrence. All these factors represent potential targets for future therapy that may improve CKD patient’s survival and prevention of CV events. Once installed, the CAD in CKD population is associated with negative outcome and increased mortality rate, that is the reason why discovering the complex pathophysiological connections between the two conditions and a proper control of the uremic RF are crucial and may represent the solutions for influencing the prognostic. Exclusion of CKD subjects from the important trials dealing with ACS and improper use of the therapeutical options because of the declined kidney functioned are issues that need to be surpassed. New ongoing trials with CKD subjects and platelets reactivity studies offers new perspectives for a better clinical approach and the expected results will clarify many aspects.

Is there a relationship between sleep apnoea and microalbuminuria?

Introduction

Obstructive sleep apnoea (OSA) is a cause of hypoxia, and the correlation between hypoxia and microvascular complications is well known. Microalbuminuria (MAU) is a marker for endovascular dysfunction and an indicator of cardiovascular events and all-cause mortality in the general population. The aim of this study was to investigate the relationship between microvascular damage and the metabolic complications of OSA based on the presence of MAU.

Material and method

Urinary albumin/creatinine ratio (ACR) and microalbumin level were examined in patients with an apnoea-hypopnoea index (AHI) greater than 5/h (study group) and in patients with an AHI less than 5/h (control group). The exclusion criteria were other possible causes of MAU (hypertension, nephropathy, coronary artery disease, and severe thyroid dysfunction).

Results

Of 103 patients enrolled, 80 formed the group with OSA and 23 served as controls. According to the AHI values, the patients were divided into four groups as normal, mild, moderate and severe. There was no significant difference between the four groups in terms of the microalbumin level and urinary albumin/creatinine ratio.

Conclusion

In this study, no significant relationship was found between MAU and sleep apnoea.

Albuminuria Testing in Hypertension and Diabetes: An Individual-Participant Data Meta-Analysis in a Global Consortium

Albuminuria is an under-recognized component of chronic kidney disease definition, staging, and prognosis. Guidelines, particularly for hypertension, conflict on recommendations for urine albumin-to-creatinine ratio (ACR) measurement. Separately among 1 344 594 adults with diabetes and 2 334 461 nondiabetic adults with hypertension from the chronic kidney disease Prognosis Consortium, we assessed ACR testing, estimated the prevalence and incidence of ACR ≥30 mg/g and developed risk models for ACR ≥30 mg/g. The ACR screening rate (cohort range) was 35.1% (12.3%-74.5%) in diabetes and 4.1% (1.3%-20.7%) in hypertension. Screening was largely unrelated to the predicted risk of prevalent albuminuria. The median prevalence of ACR ≥30 mg/g across cohorts was 32.1% in diabetes and 21.8% in hypertension. Higher systolic blood pressure was associated with a higher prevalence of albuminuria (odds ratio [95% CI] per 20 mm Hg in diabetes, 1.50 [1.42-1.60]; in hypertension, 1.36 [1.28-1.45]). The ratio of undetected (due to lack of screening) to detected ACR ≥30 mg/g was estimated at 1.8 in diabetes and 19.5 in hypertension. Among those with ACR <30 mg/g, the median 5-year incidence of ACR ≥30 mg/g across cohorts was 23.9% in diabetes and 21.7% in hypertension. Incident albuminuria was associated with initiation of renin-angiotensin-aldosterone system inhibitors (incidence-rate ratio [95% CI], diabetes 3.09 [2.71-3.53]; hypertension 2.87 [2.29-3.59]). In conclusion, despite similar risk of albuminuria to those with diabetes, ACR screening in patients with hypertension was low. Our findings suggest that regular albuminuria screening should be emphasized to enable early detection of chronic kidney disease and initiation of treatment with cardiovascular and renal benefits.

Introduction to Nephrocardiology

The interaction between nephrology and cardiovascular medicine is much broader than the cardiorenal syndrome. Many different aspects of cardiovascular medicine are interconnected with and substantially influenced by the conditions that fall into the realm of nephrology, and vice versa. Those aspects include pathophysiology, risk factors, epidemiology, prognosis, prevention, diagnosis, monitoring, and therapy. Discovery of the interconnected areas and development of appropriate knowledge and skill to optimally approach those circumstances can improve the quality of care and outcome of a large population of patients. Therefore, establishment of the distinct subspeciality of nephrocardiology is imperative.

Albuminuria Is Associated with Hepatic Iron Load in Patients with Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome

Background: Increased albuminuria is associated with increased serum ferritin, insulin resistance, and non-alcoholic fatty liver disease (NAFLD). Liver iron accumulation is also related to hyperferritinemia, insulin resistance, and NAFLD; however, there is no evidence on its relationship with albuminuria. Aims: To assess the relationship between hepatic iron load and urine albumin-to-creatinine ratio (UACR) in patients with metabolic syndrome (MetS) and NAFLD. Methods: In total, 75 MetS and NAFLD patients (aged 40–60 years, BMI 27–40 kg/m²) were selected from a cohort according to available data on hepatic iron load (HepFe) by magnetic resonance imaging (MRI). Subjects underwent anthropometric measurements, biochemistry testing, and liver MRI. Increased albuminuria was defined by UACR. Results: UACR correlated with NAFLD, HepFe, triglycerides, serum ferritin, fasting insulin, insulin resistance (calculated using the homeostatic model assessment for insulin resistance—HOMA-IR- formula), and platelets (p < 0.05). Multiple regression analysis adjusted for gender, age, eGFR, HbA1c, T2DM, and stages of NAFLD, found that HepFe (p = 0.02), serum ferritin (p = 0.04), fasting insulin (p = 0.049), and platelets (p = 0.009) were associated with UACR (R² = 0.370; p = 0.007). UACR, liver fat accumulation, serum ferritin, and HOMA-IR increased across stages of HepFe (p < 0.05). Patients with severe NAFLD presented higher HepFe, fasting insulin, HOMA-IR, and systolic blood pressure as compared to patients in NAFLD stage 1 (p < 0.05). Conclusion: Hepatic iron load, serum ferritin, fasting insulin, and platelets were independently associated with albuminuria. In the context of MetS, increased stages of NAFLD presented higher levels of HepFe. Higher levels of HepFe were accompanied by increased serum ferritin, insulin resistance, and UACR. The association between iron accumulation, MetS, and NAFLD may represent a risk factor for the development of increased albuminuria.

Liver fat content is independently associated with microalbuminuria in a normotensive, euglycaemic Chinese population: a community-based, cross-sectional study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is associated with microalbuminuria (MA) in patients with diabetes/pre-diabetes. Whether this association is mediated by blood glucose and blood pressure (BP) remains unclear. This study investigated whether liver fat content (LFC) was associated with MA in a normotensive and non-diabetic population.

DESIGN

A cross-sectional substudy.

SETTINGS

LFC was determined from the hepatic/renal echogenicity ratio at ultrasound. MA was defined as an albumin-to-creatinine ratio (ACR) of 30-300 µg/mg (early- morning urine sample). Multivariable logistic regression and receiver operating characteristic (ROC) curve analyses were used to evaluate LFC as a predictor of MA.

PARTICIPANTS

Between May 2010 and June 2011, this cross-sectional, community-based study enrolled residents from Shanghai (China), aged ≥40 years and with normal glucose tolerance and BP.

RESULTS

A total of 550 residents (median age, 57 years; 174 men) were enrolled and stratified according to LFC quartiles. ACR (p<0.001) and MA prevalence (p=0.012) increased across the LFC quartiles. Multivariable logistic regression showed that the OR for MA (per SD increase in LFC) was 1.840 (95% CI 1.173 to 2.887, p=0.008) after adjustment for potential confounders including age, gender, waist-hip ratio, blood urea nitrogen, systolic and diastolic BP, fasting blood glucose, postprandial glucose, low-density lipoprotein-cholesterol, triglycerides, high-density lipoprotein-cholesterol, total cholesterol, estimated glomerular filtration rate and lipid-lowering drugs. The ROC analysis revealed that the optimal LFC cut-off value for predicting MA was 6.82%.

CONCLUSION

LFC is independently associated with MA in normotensive, euglycaemic middle-aged and elderly Chinese individuals. Screening for MA in people with NAFLD might facilitate early intervention to minimise kidney disease risk.

Association between nonalcoholic fatty liver and increased low-level albuminuria in postmenopausal women in China: A cross-sectional study

BACKGROUND

Several studies have suggested that nonalcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD). The excretion of low-level albuminuria (LLA) elevates as the prevalence of CVD increases. However, few studies have explored the association between NAFLD and LLA.

METHODS

This cross-sectional study included 31 147 Chinese adults (7664 men and 23 483 women). The "normal" level of albuminuria as determined by the urinary albumin to creatinine ratio (UACR) was below 30 mg/g. LLA was defined as a higher level within the "normal" albuminuria range (5.54 mg/g < LLA≤29.9 mg/g). The participants with NAFLD were defined as having a fatty liver index (FLI) ≥ 60. The FLI was calculated using the Bedogni equation.

RESULTS

A positive association was found between UACR and FLI through multivariate linear regression analyses (nonstandardized β ± SE: .047 ± 0.004, P <.001). The logistic regression analyses revealed that NAFLD had adjusted odds ratios (ORs) showing a significant relationship with LLA in models 1 to 4 (all subjects: OR, 1.207; 95% CI, 1.098-1.326; women: OR, 1.43; 95% CI, 1.26-1.63; all P <.001); however, we did not find significant adjusted ORs among the men. In the stratified analyses, the relationship between NAFLD and LLA was significant among postmenopausal women with a body mass index ≥24 but <28 kg/m² , fasting plasma glucose ≥5.6 but <7.0 mmol/L, or postprandial plasma glucose ≥7.8 but <11.1 mmol/L and those aged below 60 years without moderate-intensity exercise.

CONCLUSIONS

A noteworthy association between NAFLD and LLA was found among postmenopausal women who had borderline blood glucose values, were overweight, and did not engage in moderate-intensity physical activity.

Effect of continuous positive airway pressure on albuminuria in patients with obstructive sleep apnea: a meta-analysis

PURPOSE

A relationship between albuminuria and obstructive sleep apnea (OSA) has been documented in previous studies. Nevertheless, the impact of continuous positive airway pressure (CPAP) treatment on albuminuria in subjects with OSA is debated. This meta-analysis was carried out to investigate whether or not CPAP treatment affected urinary albumin-to-creatinine ratio (UACR) in subjects with OSA.

METHODS

A comprehensive literature search was conducted on Web of Science, Embase, and PubMed from January 1990 to December 2020. Information on patients' characteristics, features of the studies, and UACR of pre- and post-CPAP treatment was collected. For estimation of the pooled effects, standardized mean difference (SMD) was applied.

RESULTS

This meta-analysis included 6 articles and 211 subjects. The pooled analysis suggested that CPAP therapy exerted a favorable effect on the decrease of UACR in subjects with OSA (SMD = 0.415, 95% CI = 0.026 to 0.804, z = 2.09, p = 0.037). Subgroup analyses revealed that the CPAP treatment effect was not influenced by sample size, BMI, age, or AHI.

CONCLUSION

The present meta-analysis indicated that UACR was significantly reduced by CPAP therapy in subjects with OSA. Further well-designed randomized controlled trials with large sample size are required to confirm the benefits.

Real-time point-of-care total protein measurement with a miniaturized optoelectronic biosensor and fast fluorescence-based assay

Measurement of total protein in urine is key to monitoring kidney health in diabetes. However, most total protein assays are performed using large, expensive laboratory chemistry analyzers that are not amenable to point-of-care analysis or home monitoring and cannot provide real-time readouts. We developed a miniaturized optoelectronic biosensor using a vertical cavity surface-emitting laser (VCSEL), coupled with a fast protein assay based on protein-induced fluorescence enhancement (PIFE), that can dynamically measure protein concentrations in protein-spiked buffer, serum, and urine in seconds with excellent sensitivity (urine LOD = 0.023 g/L, LOQ = 0.075 g/L) and over a broad range of physiologically relevant concentrations. Comparison with gold standard clinical assays and standard fluorimetry tools showed that the sensor can accurately and reliably quantitate total protein in clinical urine samples from patients with diabetes. Our VCSEL biosensor is amenable to integration with miniaturized electronics, which could afford a portable, low-cost, easy-to-use device for sensitive, accurate, and real-time total protein measurements from small biofluid volumes.

Podocentric view of glomerular proteinuria: Focused on cytoskeletal changes and toward promising targeted therapies and challenges

Among renal cells, podocytes (glomerular epithelial cells) are the most critical to prevent plasma proteins from excessive loss by forming their sophisticated foot processes (FP) and slit diaphragms (SD). A general finding in the glomeruli of patients with nephrotic syndrome is the foot processes "effacement" resulted from dysregulated actin cytoskeleton reorganization. Ultrastructural analysis in patients with nephrotic syndrome has demonstrated that such changes tend to be dynamic and can sometimes be reversible. In a more molecular sense, injured podocytes can no longer maintain their tight regulation and "retract" their FP, but not "efface" them. Past studies have revealed multiple exquisite mechanisms and arrays of proteins participating in the regulation of cytoskeletal rearrangement, and these mechanisms serve as potential targets to treat. A major challenge to develop specific therapies is the targeted mechanism has to be crucial and specific enough for podocyte-oriented kidney diseases, and it would be even better to manifest in most of the glomerulonephritis. Studies have shown many approaches targeting different mechanisms, but none of them has been proved to be effective in clinical medicine. Up to the present, Abatacept (Orencia) is the first (and the only) clinical targeted therapy demonstrating limited success. It inhibits the co-stimulatory response of B7-1 (CD80) induced in various types of glomerulonephritis. Future clinical studies have to be expanded to substantiate this highly specific targeted therapy because the Abatacept effect is not generally accepted even within the nephrology community. Nevertheless, there are ongoing searches for specific treatment targeting podocytes through various approaches.

Diagnostic accuracy of semiquantitative point of care urine albumin to creatinine ratio and urine dipstick analysis in a primary care resource limited setting in South Africa

Background

The prevalence of chronic kidney disease (CKD) is predicted to rise over the next few decades. In resource-limited settings access to central laboratory services is limited. Point-of-care (POC) urine dipstick testing offers the potential to detect markers of kidney damage (albuminuria) as well as markers of other disease processes. We evaluated the diagnostic accuracy of the semi-quantitative albumin-creatinine ratio (ACR) Sysmex UC-1000 POC urine dipstick system as well as the extent of other abnormal dipstick findings in urine.

Methods

700 participants from a rural area in South Africa were screened for albuminuria. A spot urine sample was used to measure POC and central laboratory ACR. We determined the sensitivity, specificity, positive predictive value and negative predictive value of the POC ACR, and recorded dipstick parameters.

Results

The prevalence of albuminuria was 11.6% (95%CI; 9.3–14.2). Those with albuminuria had higher mean diastolic (82 vs 79 mmHg, p = 0.019) and systolic (133 vs 128 mmHg, p = 0.002) blood pressures and a higher proportion of diabetes mellitus (17.6 vs 4.9%, p < 0.001). The sensitivity of the POC ACR system was 0.79, specificity 0.84, positive predictive value 0.39 and negative predictive value 0.97. The sensitivity improved to 0.80, 0.85, 0.85 and 0.89 in those with elevated blood pressure, diabetes mellitus, HIV positive status, and those 65 years and older, respectively. Abnormalities other than albuminuria were detected in 240 (34.3%) of the samples; 88 (12.6%) were positive for haematuria, 113 (16.1%) for leucocytes, 66 (9.4%) for nitrites and 27 (3.9%) for glycosuria.

Conclusion

Our study shows that POC ACR has good negative predictive value and could be used to rule out albuminuria when screening for CKD. Additionally, a high proportion of participants had other urine abnormalities detected with dipsticks which may reflect kidney disease or co-morbid untreated genitourinary pathology such as urinary tract infections or endemic schistosomiasis with important implications for CKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02290-5.

Renal Replacement Modality Affects Uremic Toxins and Oxidative Stress

Nowadays, the high prevalence of kidney diseases and their related complications, including endothelial dysfunction and cardiovascular disease, represents one of the leading causes of death in patients with chronic kidney diseases. Renal failure leads to accumulation of uremic toxins, which are the main cause of oxidative stress development. The renal replacement therapy appears to be the best way to lower uremic toxin levels in patients with end-stage renal disease and reduce oxidative stress. At this moment, despite the increasing number of recognized toxins and their mechanisms of action, it is impossible to determine which of them are the most important and which cause the greatest complications. There are many different types of renal replacement therapy, but the best treatment has not been identified yet. Patients treated with diffusion methods have satisfactory clearance of small molecules, but the clearance of medium molecules appears to be insufficient, but treatment with convection methods cleans medium molecules better than small molecules. Hence, there is an urgent need of new more validated, appropriate, and reliable information not only on toxins and their role in metabolic disorders, including oxidative stress, but also on the best artificial renal replacement therapy to reduce complications and prolong the life of patients with chronic kidney disease.

Association of metabolic syndrome with the incidence of low-grade albuminuria: a cohort study in middle-aged and elderly Chinese adults

Background: Individuals with metabolic syndrome have elevated risks of micro- and macro-albuminuria as well as chronic kidney disease (CKD).

Objective: To assess the influence of metabolic abnormalities on the presence of low-grade albuminuria (below the threshold for microalbuminuria).

Design, participants, and main outcome measures: This community-based cohort study included 3,935 eligible individuals aged 40 years or older. The presence of low-grade albuminuria was detected in those without micro- or macro-albuminuria and analyzed according to the highest quartile of the baseline urinary albumin-to-creatinine ratio (ACR ≥11.13 mg/g). CKD was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m² or the new presence of albuminuria (ACR ≥30 mg/g).

Results: Overall, 577 (14.7%) participants developed low-grade albuminuria and 164 (4.2%) participants developed CKD during a mean follow-up period of 3.6 years. Compared with participants without metabolic syndrome, those with metabolic syndrome had greater risks of low-grade albuminuria [adjusted odd ratio (OR) and 95% confidence interval (95% CI): 1.30 (1.05–1.61)] and CKD [1.71 (1.20–2.44)]. Moreover, the incidence rates of low-grade albuminuria and CKD increased as the number of metabolic syndrome components increased (P for trend <0.0001).

Conclusions: The presence of metabolic syndrome is associated with increased incidence rates of low-grade albuminuria and CKD the middle-aged and elderly Chinese populations.

Prediction of microalbuminuria from proteinuria in chronic kidney disease due to non-diabetic lifestyle-related diseases: comparison with diabetes

BACKGROUND

To suppress increases in kidney failure and cardiovascular disease due to lifestyle-related diseases other than diabetes, early intervention is desirable. We examined whether microalbuminuria could be predicted from proteinuria.

METHODS

The participants consisted of adults who exhibited a urinary protein-to-creatinine ratio (uPCR) of < 0.5 g/gCr and an eGFR of ≥ 15 ml/min/1.73 m² in their spot urine at their first examination for lifestyle-related disease. Urine was tested three times for each case, with microalbuminuria defined as a urinary albumin-to-creatinine ratio (uACR) of 30-299 mg/gCr, at least twice on three measurements. Youden's Index was used as an index of the cut-off value (CO) according to the ROC curve.

RESULTS

A single uPCR was useful for differentiating normoalbuminuria and micro- and macroalbuminuria in patients with non-diabetic lifestyle-related diseases. Regarding the GFR categories, the CO of the second uPCR was 0.09 g/gCr (AUC 0.89, sensitivity 0.76, specificity 0.89) in G1-4 (n = 197) and 0.07 g/gCr (AUC 0.92, sensitivity 0.85, specificity 0.88) in G1-3a (n = 125). Using the sum of two or three uPCR measurements was more useful than a single uPCR for differentiating microalbuminuria in non-diabetic lifestyle disease [CO, 0.16 g/gCr (AUC 0.91, sensitivity 0.85, specificity 0.87) and 0.23 g/gCr (AUC 0.92, sensitivity 0.88, specificity 0.84), respectively].

CONCLUSION

Microalbuminuria in Japanese individuals with non-diabetic lifestyle-related diseases can be predicted from the uPCR, wherein the CO of the uPCR that differentiates normoalbuminuria and micro- and macroalbuminuria was 0.07 g/gCr for G1-3a, while that in G3b-4 was 0.09 g/gCr.

Study of the effect of chronic kidney disease on the incidence of cardiovascular events in a native Spanish population

AIMS

To evaluate the relationship between chronic kidney disease and the patient's cardiovascular risk measured through the incidence of major adverse cardiovascular events in a sample of Spanish population.

DESIGN AND METHODS

The sample consisted of 2,668 subjects. Mean age was 50.6±14.5 years and 54.6% were female. In all, 3.5% of subjects had a glomerular filtration rate (GFR) below 60ml/min and 4.3% a urinary albumin excretion (UAE) above 30mg/g. GFR was estimated from serum creatinine using the CKD-EPI equation. UAE was measured in first morning urine sample as mg/g of creatinine. We examined the multivariable association between the estimated GFR and the risks of cardiovascular events and death. The median follow-up was 81 (75-89) months.

RESULTS

In CKD patients the hazard ratio (HR) was 1.36 (95% CI 0.97-1.91) (P=.079) for cardiovascular events and 1.62 (95% CI 0.53-4.91) (P=.396) for cardiovascular mortality. Increased UAE was also associated with higher cardiovascular risk (HR 2.38; 95% CI 1.51-3.74; P<.001) as well as increased cardiovascular mortality (HR 4.78; 95% CI 2.50-9.11; P<.001). For patients with UAE between 30 and 300mg/g HR for cardiovascular events was 2.09 (95% CI 1.34-3.50; P=.005) and 3.80 (95% CI 1.81-7.96; P<.001) for cardiovascular mortality.

CONCLUSIONS

An independent association was found between reduced GFR and cardiovascular event incidence and mortality. Increased UAE showed a higher prognostic value than decreased GFR. Our findings highlight the clinical and public health importance of routinely measuring UAE.

Increased epicardial adipose tissue thickness is associated with microalbuminuria in hypertensive patients with left ventricular hypertrophy

OBJECTIVE

Epicardial adipose tissue (EAT) is a cardiometabolic risk factor, and its possible relationship with hypertension has been previously reported. Microalbuminuria (MA) is associated with target-organ damage, especially in patients with hypertension with left ventricular hypertrophy (LVH) and suggest endothelial dysfunction. This study aimed to investigate the relationship between echocardiographic EAT thickness and presence of MA in patients with hypertension.

METHODS

A total of 297 newly diagnosed hypertension patients who applied to the outpatient clinic were enrolled consecutively in this study. Patients were divided into two groups regarding the presence of LVH in echocardiography. An age and gender matched control group was set including 156 healthy patients without HT. All subjects underwent transthoracic echocardiography for the measurement of EAT thickness. Spot urine samples were collected for the assessment of MA.

RESULTS

In hypertensive patients with LVH, the EAT thicknesses (6.6 ± 1.8 vs 5.3 ± 1.5 vs 5.1 ± 1.3, p < .001; respectively) and prevalence of MA (41.2 vs 20.1 vs 3.2%; p < .001 respectively) were significantly higher than the other two groups. In hypertensive patiens without LVH, no relationship was found between the presence of MA and EAT thickness. In multivariate regression analyses, EAT thickness (OR: 3.141, 95%CI: 2.425-6.123, p < .001) and left ventricular mass index (OR: 1.339, 95%CI: 1.145-2.143, p = .003) were determined as independent predictors for MA development in hypertensive patients with LVH.

CONCLUSION

Measurement of EAT thickness may help to identify high-risk hypertensive patients for target-organ damage especially among patients with LVH.

A study on the correlation between remnant cholesterol and urinary albumin to creatinine ratio in Chinese community adults: A report from the REACTION study

BACKGROUND

The correlation between remnant cholesterol (RC) and urinary albumin to creatinine ratio (UACR) has not been illustrated. The present study aims to explore the correlation between RC levels and UACR in Chinese community adults.

METHODS

This study included 35 848 participants from a cohort study (REACTION). The UACR data were divided into three groups: UACR <10 mg/g, 10 ≤UACR<30 mg/g, and UACR ≥30 mg/g groups. RC was divided into two groups, according to the 75th percentile: <75% group and ≥75% group. Multiple logistic regression analysis was used to evaluate the correlation between RC and UACR.

RESULTS

The RC exhibited an adjusted odds ratio that was significant in models 1-5. Although all confounders were corrected in model 5, RC and UACR were still significantly correlated， and the correlation was more significant in females，when compared to males (odds ratio [OR]: 1.117, 95% CI: 1.063-1.176, P < 0.001 for all subjects; OR: 1.092, 95% CI: 1.128-1.161, P = 0.004 for females; and OR: 1.085, 95% CI: 0.998-1.194, P = 0.088 for males). The RC was significantly correlated with UACR for subjects with 5.6 ≤ fasting blood glucose < 7.0 or 7.8 ≤ post-load blood glucose < 11.1 mmol/L, 24 ≤ body mass index (BMI) < 28 kg/m² , 120 ≤ systolic blood pressure < 140 and/or 80 ≤ diastolic blood pressure < 90 mm Hg.

CONCLUSIONS

In the Chinese community, RC is highly correlated with UACR, and the correlation is more significant in females compared with males. At higher RC levels, patients with critical values of blood pressure, BMI and blood glucose have a more significant correlation between RC and UACR.

Associations of Cardiac, Kidney, and Diabetes Biomarkers With Peripheral Neuropathy among Older Adults in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The aim of this study was to assess the association of high-sensitivity cardiac troponin (hs-cTnT) and other cardiac, kidney, hyperglycemia, and inflammatory biomarkers with peripheral neuropathy (PN) in a community-based population.

METHODS

We conducted a cross-sectional analysis of 3056 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study who underwent standardized monofilament PN testing and had measures of cardiac function (hs-cTnT, N-terminal pro-B-type natriuretic peptide [NT-proBNP], and growth differentiation factor 15 [GDF15]), kidney function (serum creatinine, cystatin C, β-2 microglobulin, urine albumin-to-creatinine ratio), hyperglycemia (fasting glucose, hemoglobin A1c [Hb A1c], fructosamine, glycated albumin, 1,5-anhydroglucitol), and inflammation (C-reactive protein) assessed at visit 6 (2016-2017; age 71-94 years). We used logistic regression to assess the associations of these biomarkers (modeled in diabetes-specific tertiles) with PN in older adults with and without diabetes after adjusting for traditional risk factors.

RESULTS

In total, 33.5% of participants had PN (37.3% with diabetes and 31.9% without diabetes). There was an independent association of hs-cTnT with PN regardless of diabetes status (diabetes T3 vs. T1: odds ratio [OR], 2.15 [95% CI, 1.44-3.22]; no diabetes: OR, 2.31 [95%CI, 1.76-3.03]; P = 0.72 for interaction). Among participants without diabetes, there were also significant associations of NT-proBNP (OR, 1.40 [95% CI, 1.08-1.81]) and urine albumin-to-creatinine ratio (OR, 1.55 [95% CI, 1.22-1.97]) with PN. Associations of hyperglycemia biomarkers including Hb A1c (OR, 1.76 [95% CI, 1.22-2.54]), fructosamine (OR, 1.71 [95% CI, 1.19-2.46]), and glycated albumin (OR, 1.45 [95% CI, 1.03-2.03]) with PN were significant only among participants with diabetes.

CONCLUSIONS

Overall, hs-cTnT appears to be a global marker of end organ damage, including PN. Laboratory biomarkers may be able to help us identify those individuals with PN.

Kidney Disease Biomarkers Improve Heart Failure Risk Prediction in the General Population

BACKGROUND

The kidneys play an important role in heart failure (HF), but it is unclear if renal biomarkers improve HF risk prediction beyond established risk factors. We aimed to assess whether adding biomarkers of kidney disease to conventional risk factors improved 10-year risk prediction for incident HF in a contemporary community sample.

METHODS

We included 450 212 participants in the UK Biobank aged 39 to 70 years without HF who had been assessed in 2006 to 2010 with the urine albumin-to-creatinine ratio and estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C. There were 1701 incident cases of HF during up to 10.3 years of follow-up (mean 8.2±0.7 years). We used the Atherosclerosis Risk in Communities study heart failure risk score excluding natriuretic peptides as the base model to which we added eGFR and urine albumin-to-creatinine ratio. Harrell's C-statistic of ARIC-HF was 0.845 (95% CI, 0.831-0.859).

RESULTS

Each combination of added kidney measures (creat-eGFR, cysC-eGFR, and urine albumin-to-creatinine ratio) led to significant improvement in risk discrimination, calibration, and reclassification. The optimal pair of added kidney measures was cysC-eGFR and urine albumin-to-creatinine ratio (ΔC=0.019 [95% CI, 0.015-0.022]). Addition of cysC-eGFR made the largest contribution to reclassification improvement (continuous net reclassification improvement 0.323 [95% CI, 0.278-0.360]).

CONCLUSIONS

In a large community sample, the addition of kidney disease markers to conventional risk factors improved prediction of 10-year HF risk. Our results support including kidney disease markers in the identification of persons at highest risk of HF and demonstrate a possible role of impaired kidney function in HF development in asymptomatic persons.

Patterns of urinary albumin and IgM associate with markers of vascular ageing in young to middle-aged individuals in the Malmö offspring study

BACKGROUND

Increased urinary excretion of IgM and low-grade albuminuria are associated with increased risk of cardiovascular morbidity and mortality. The objective of this study was to investigate the association between urinary IgM, albuminuria, and vascular parameters reflecting arterial structure and function.

METHODS

Subjects of the present study were from the Malmö Offspring study (MOS) cohort, and included 1531 offspring (children and grand-children) to first-generation subjects that participated in the Malmö Diet Cancer-Cardiovascular Arm study cohort. At baseline, technical measurements of arterial stiffness (carotid-femoral pulse wave velocity; c-f PWV), carotid arterial morphology, 24-h ambulatory blood pressure recordings, ankle-brachial-index (ABI), and evaluation of endothelial function (reactive hyperemia index, RHI) were performed. Urinary (U) IgM, U-albumin, and U-creatinine were measured. Multivariate adjusted logistic regression was used to test whether U-IgM excretion and increasing urinary albumin excretion were related to vascular parameters.

RESULTS

Detectable U-IgM was independently associated with higher systolic blood pressure, odds ratio (OR) 1.021, 95% confidence interval (CI, 1.003-1.039), p = 0.025 and lower ABI; ABI dx: OR 0.026, 95% CI (0.002-0.381), p = 0.008, ABI sin: OR 0.040, 95% CI (0.003-0.496), p = 0.012. Low-grade albuminuria was independently associated with systolic and diastolic blood pressure, aortic blood pressure, the c-f PWV and the number of carotid intima plaques (p < 0.05).

CONCLUSIONS

In young to middle-aged, mostly healthy individuals, increased U-IgM excretion and low-grade albuminuria are associated with adverse vascular parameters. Increased U-IgM excretion may reflect subclinical peripheral atherosclerosis, whereas increased U-albumin excretion is associated with a wide range of cardiovascular abnormalities. This may reflect different pathophysiological mechanisms.