Albuminuria is strongly associated with arterial stiffness, especially in diabetic or hypertensive subjects--a population-based study (Taichung Community Health Study, TCHS)

High Urine Albumin-to-Creatinine Ratio is Associated with Increased Arterial Stiffness in Diabetes: A Chinese Cross-Sectional Study

Purpose

Elevated urine albumin-to-creatinine ratio (UACR) is an established risk factor for microvascular disease in the general population. However, it is unclear whether UACR is associated with arterial stiffness in diabetes. We aimed to assess the relationship between UACR levels and the risk of arterial stiffness in patients with diabetes.

Methods

From July 2021 to February 2023, a total of 1039 participants were assessed for the risk of arterial stiffness, which was evaluated by brachial-ankle pulse wave velocity (baPWV). The value of UACR≥30 mg/g was defined as high UACR. The UACR level had an abnormal distribution and was log2-transformed for analyses to reduce skewness and volatility. High baPWV was evaluated as categorical variables divided by the highest quartile of the values by sex. The relationship between UACR and arterial stiffness was analyzed by linear curve fitting analyses. Multiple logistic regression models were used to analyze the crude and adjusted odds ratio (OR) of UACR for high baPWV with 95% confidence interval (CI). In addition to applying non-adjusted and multivariate-adjusted models, interaction and stratified analyses were also carried out.

Results

The baPWV level was significantly higher in the high UACR group compared with that in the normal UACR group (1861.84 ± 439.12 cm/s vs 1723.13 ± 399.63 cm/s, p<0.001). Adjusted smoothed plots suggested that there are linear relationships between log2-transformed UACR and high baPWV, and Spearman correlation coefficient was 0.226 (0.176-0.276, p<0.001). The OR (95% CI) between log2-transformed UACR and high baPWV were 1.26 (1.19-1.33, p<0.001), and 1.16 (1.08-1.25, p<0.001) respectively in diabetic patients before and after adjusting for potential confounders.

Conclusion

The elevated UACR was associated with arterial stiffness in Chinese patients with diabetes.

Synergistic effect of albuminuria on atherosclerosis in patients with primary aldosteronism

Background

Primary aldosteronism (PA) has been associated with atherosclerosis beyond the extent of essential hypertension, but the impact of albuminuria remains unknown.

Objective

To investigate the effect of concomitant albuminuria on arterial stiffness in PA.

Design

Prospective cohort study.

Methods

A prospective cohort study was conducted to evaluate the association of albuminuria (>30 mg/g in morning spot urine) with arterial stiffness, as measured non-invasively by pulse wave velocity (PWV) in patients with PA. Propensity score matching (PSM) with age, sex, diabetes, systolic and diastolic blood pressure, creatinine, potassium, number of antihypertensive medications, and hypertension history was used to balance baseline characteristics. The effects of albuminuria on PWV before and 1 year after treatment were analyzed.

Results

A total of 840 patients with PA were enrolled, of whom 243 had concomitant albuminuria. After PSM, there were no significant differences in baseline demographic parameters except alpha-blocker and spironolactone use. PWV was greater in the presence of albuminuria (p = 0.012) and positively correlated with urine albumin-creatinine ratio. Multivariable regression analysis identified albuminuria, age, body weight, systolic blood pressure, and calcium channel blocker use as independent predictors of PWV. As for treatment response, only PA patients with albuminuria showed significant improvements in PWV after PSM (p = 0.001). The magnitude of improvement in PWV increased with urine albumin-creatinine ratio and reached plateau when it exceeded 100 mg/g according to restricted cubic spline analysis.

Conclusion

Concomitant albuminuria in PA was associated with greater arterial stiffness and more substantial improvement after targeted treatment. Both the baseline and the improved extent of PWV increased in correlation with rising urine albumin-creatinine ratio levels, reaching a plateau when the urine albumin-creatinine ratio surpassed 100 mg/g.

Non-albumin proteinuria marks tubular involvement and is associated with arterial stiffness in subjects affected by severe obesity

INTRODUCTION

Obesity is a well-established risk factor for kidney disease, and tubular damage can play a pivotal role in the development of obesity-related kidney damage. This study aimed to investigate the pathophysiological pathways involved in the development of non-albumin proteinuria (NAP), a marker of tubular involvement, in a cohort of subjects with severe obesity and preserved kidney function.

METHODS

A total of 106 subjects with BMI ≥ 35 kg/m2 in waiting list for bariatric surgery underwent blood chemistry analysis including metabolic and lipid profile, vascular tests for cardiovascular risk stratification and a comprehensive assessment of kidney function, including renal resistive index (RRI) and NAP measurement.

RESULTS

Nineteen patients with ACR ≥ 30 mg/g regardless of NAP values (ALB+), nineteen with NAP≥ 150 mg/g and albuminuria < 30 mg/g (iNAP) and sixty-eight without proteinuria (No-P) were found. Both ALB+ and iNAP groups exhibited a higher prevalence of hypertension and anti-hypertensive treatment compared to No-P, while the prevalence of diabetes was similar between groups. Concerning lipid profile, no differences in total, HDL and LDL cholesterol were found, while ALB+ patients had higher serum triglyceride levels than the other two groups. RRI and carotid-femoral pulse wave velocity (cf-PWV) was significantly higher in ALB+ and iNAP groups compared to No-P. Remarkably, cf-PWV remained still significant after adjustment for age, sex and MBP (p = 0.0004). In overall population, a multiple regression analysis showed that cf-PWV was an independent determinant of NAP in a model including age, sex, glycated hemoglobin, systolic and mean blood pressure (R2 =0.17, p = 0.031).

CONCLUSION

iNAP subjects showed increased arterial stiffness comparable to that observed in ALB+ group, suggesting that they may represent a subgroup at higher cardiovascular risk, often unrecognized in clinical practice.

Traditional Chinese medicine body constitution predicts new-onset diabetic albuminuria in patients with type 2 diabetes: Taichung diabetic body constitution prospective cohort study

This prospective cohort study explored whether body constitution (BC) independently predicts new-onset albuminuria in persons with type 2 diabetes mellitus (T2DM) enrolled in the diabetes care management program (DCMP) of a medical center, providing evidence of integrating traditional Chinese medicine into DCMP for improving care quality. Persons with T2DM (n = 426) originally without albuminuria enrolled in DCMP were recruited in 2010 and were then followed up to 2015 for detecting new-onset albuminuria. The participants received urinalysis and blood test annually. Albuminuria was determined by an elevated urinary albumin/creatinine ratio (≥ 30 µg/mg), and poor glucose control was defined as Glycosylated hemoglobin above or equal to 7%. BC type (Yin deficiency, Yang deficiency, and phlegm stasis) was assessed using a well-validated body constitution questionnaire at baseline. Risk factors for albuminuria (sociodemographic factors, diabetes history, lifestyle behaviors, lipid profile, blood pressure, and kidney function) were also recorded. Hazard ratios (HR) of albuminuria for BC were estimated using multivariate Cox proportional hazards model. During the 4-year follow-up period, albuminuria occurred in 30.5% of participants (n = 130). The HR indicated that Yin deficiency was significantly associated with an increased risk of new-onset albuminuria in persons with T2DM and good glucose control after adjustment for other risk factors (HR = 2.09; 95% confidence interval = 1.05-4.17, P = .04), but not in those with poor glucose control. In persons with T2DM and poor glucose control, phlegm stasis was also significantly associated with a higher risk of albuminuria (2.26; 1.03-4.94, P = .04) after multivariate adjustment, but not in those with good glucose control. In addition to already-known risk factors, BC is an independent and significant factor associated with new-onset albuminuria in persons with T2DM. Our results imply Yin deficiency and phlegm stasis interacting with glucose control status may affect new-onset albuminuria in persons with T2DM.

Kidney disease parameters, metabolic goal achievement, and arterial stiffness risk in Chinese adult people with type 2 diabetes

BACKGROUND

To investigate the arterial stiffness (AS) risk within urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) categories and the joint effect between kidney disease parameters and metabolic goal achievement on AS risk in adult people with type 2 diabetes (T2D).

METHODS

A total of 27 439 Chinese participants with T2D from 10 National Metabolic Management Centers (MMC) were categorized into four albuminuria/decreased eGFR groups. The criteria for decreased eGFR and AS were eGFR <90 ml/min/1.73 m² and brachial-ankle pulse wave velocity value >the 75th percentile (1770.0 cm/s). Three metabolic goals were defined as glycated hemoglobin <7%, BP <130/80 mmHg, andlow-density lipoprotein cholesterol <2.6 mmol/L.

RESULTS

After full adjustment, odds ratios (ORs) for AS were highest for albuminuria and decreased eGFR (2.23 [1.98-2.52]) and were higher for albuminuria and normal eGFR (1.52 [1.39-1.67]) than for those with nonalbuminuria and decreased eGFR (1.17 [1.04-1.32]). Both UACR and eGFR in the subgroup or overall population independently correlated with AS risk. The achievement of ≥2 metabolic goals counteracted the association between albuminuria and AS risk (OR: 0.93; 95% CI: 0.80-1.07; p = .311). When the metabolic goals added up to ≥2 for patients with decreased eGFR, they showed significantly lower AS risk (OR: 0.65; 95% CI: 0.56-0.74; p < .001).

CONCLUSIONS

Both higher UACR and lower eGFR are determinants of AS risk, with UACR more strongly related to AS than eGFR in adults with T2D. The correlation between albuminuria/decreased eGFR and AS was modified by the achievement of multiple metabolic elements.

The relationship between urinary albumin to creatinine ratio and all-cause mortality in the elderly population in the Chinese community: a 10-year follow-up study

BACKGROUND

In patients with diabetes and hypertension, proteinuria is independently associated with all-cause death. However, in the general population, urinary albumin to creatinine ratio (UACR) is less used to predict all-cause mortality. When the urinary albumin to creatinine ratio is within the normal range (UACR< 30 mg/g), the clinical relevance of an increased urinary albumin excretion rate is still debated. We studied the relationship between UACR and all-cause mortality in community populations, and compared UACR groups within the normal range.

METHODS

The participants were the inhabitants from the Wanshoulu community in Beijing, China. The average age is 71.48 years, and the proportion of women is 60.1%. A total of 2148 people completed random urine samples to determine the urinary albumin to creatinine ratio (UACR). The subjects were divided into three groups according to UACR: Group 1 (UACR< 10 mg/g), Group 2 (10 mg/g < UACR< 30 mg/g), Group 3 (UACR> 30 mg/g). We used Kaplan-Meier survival analysis and Cox regression model to verify the relationship between UACR and all-cause mortality.

RESULTS

At an average follow-up of 9.87 years (718,407.3 years), the total mortality rate were 183.4/1000. In the Cox proportional hazards model, after adjusting for possible confounders, those with normal high-value UACR (group 2) showed a higher all-cause mortality than those with normal low-value UACR (group 1) [hazard ratio (HR) 1.289, 95% confidence interval (CI) 1.002 ~ 1.659 for all-cause mortality]. Those with proteinuria (group 3) showed a higher all-cause mortality than those with normal low-value UACR (group 1) [hazard ratio (HR) 1.394, 95% confidence interval (CI) 1.020 ~ 1.905 for all-cause mortality].

CONCLUSION

Urinary albumin to creatinine ratio is an important risk factor for all-cause death in community population. Even if it is within the normal range (UACR< 30 mg/g), it occurs in people with high normal value (10 mg/g < UACR< 30 mg/g), the risk of all-cause death will also increase.

Renal Function, Albumin-Creatinine Ratio and Pulse Wave Velocity Predict Silent Coronary Artery Disease and Renal Outcome in Type 2 Diabetic and Prediabetic Subjects

INTRODUCTION

Silent coronary heart disease is frequently undetected in type 2 diabetes mellitus (DM2) and pre-diabetes determined by glucose intolerance (GI). Pulse wave velocity (PWV) and albumin-creatinine ratio (ACR) have been considered markers of cardiovascular mortality, coronary heart disease and chronic renal failure.

AIM

To evaluate the incidence of coronary artery disease (CAD) and the relationship between urinary albumin-creatinine ratio, glomerular filtration rate (GFR) and PWV in type 2 DM with silent CAD.

METHODS

We analyzed 92 individuals (44 male), 49 (60±7y) type 2 DM non-insulin dependents and 43 prediabetics (43±4y), with Grade I-II hypertension and no symptoms of CAD. All type 2 DM patients were under antidiabetic treatment with A1C hemoglobin between 5.5 and 6.5%. Every patient underwent a myocardial perfusion SPECT scan. In those subjects with ischemic patterns, coronary angiography was performed. In addition, PWV, glomerular filtration rate, and ACR were evaluated.

STATISTICS

mean±SEM, and ANOVA among groups.

RESULTS

48.59% of DM2 and 25.58% of GI patients had silent coronary artery had silent coronary artery disease and higher ACR, PWV and reduced GFR. Higher ACR and PWV and reduced GFR. DM2 and GI showed a negative relationship between GFR and ACR. Moreover, this relation was also observed in different levels of GFR (>60 ml/min and <60ml.min (p<0.05) in patients with CAD, suggesting a cardio-renal interaction in DM2.

CONCLUSION

Higher PWV, lower GFR and ACR predict the incidence of CAD in DM2. Dysglycemic individuals also represent a group of higher risk for coronary artery disease with similar predictors as in DM2. Diabetic and prediabetics still develop renal microalbuminuria. Thus, PWV seems to represent a reliable marker of renal impairment and coronary artery disease.

Brachial-ankle pulse wave velocity is independently associated with urine albumin-to-creatinine ratio in a Chinese community-based cohort

PURPOSE

Arterial stiffness is important in the development of albuminuria. The brachial-ankle pulse wave velocity (baPWV) acts as an indicator of arterial stiffness and may be associated with cardiovascular disease morbidity and mortality. The urine albumin-to-creatinine ratio (UACR) is a metric used to diagnose albuminuria and has also been shown to be associated with cardiovascular disease. Here, we aim to elucidate the relationship between the baPWV and UACR in the Chinese community.

METHODS

A community-based cohort of 3669 subjects was selected for the analysis. The BaPWV and UACR were measured from each subject. UACR ≥ 30 mg/g was defined as pathological albuminuria.

RESULTS

The mean baPWV was 1536.59 ± 305.89 cm/s, and the median UACR value was 6.11 mg/g (interquartile range 4.17, 10.68). A threshold-effect analysis was conducted, and the results showed that the cut-off value for the baPWV was 1269 cm/s. In subjects with baPWV values lower than 1269 cm/s, the prevalence of microalbuminuria and macroalbuminuria was not significantly associated with the baPWV (odds ratio 0.77, 95% confidence interval 0.57-1.03, P = 0.08). However, in participants with baPWV ≥ 1269 cm/s, the prevalence of microalbuminuria and macroalbuminuria increased with increasing baPWV 100 cm/s (odds ratio 1.16, 95% confidence interval 1.11-1.22, P < 0.001).

CONCLUSIONS

These findings suggest that, in this Chinese community-based cohort, elevated baPWV is independently associated with pathological albuminuria with a cut-off value of 1269 cm/s as determined by threshold-effect analysis.

Measuring the Interaction Between the Macro- and Micro-Vasculature

Structural and functional dysfunction in both the macro- and microvasculature are a feature of essential hypertension. In a healthy cardiovascular system, the elastic properties of the large arteries ensure that pulsations in pressure and flow generated by cyclic left ventricular contraction are dampened, so that less pulsatile pressure and flow are delivered at the microvascular level. However, in response to aging, hypertension, and other disease states, arterial stiffening limits the buffering capacity of the elastic arteries, thus exposing the microvasculature to increased pulsatile stress. This is thought to be particularly pertinent to high flow/low resistance organs such as the brain and kidney, which may be sensitive to excess pressure and flow pulsatility, damaging capillary networks, and resulting in target organ damage. In this review, we describe the clinical relevance of the pulsatile interaction between the macro- and microvasculature and summarize current methods for measuring the transmission of pulsatility between the two sites.

Association between Brachial-Ankle Pulse Wave Velocity and Microalbuminuria and to Predict the Risk for the Development of Microalbuminuria Using Brachial-Ankle Pulse Wave Velocity Measurement in Type 2 Diabetes Mellitus Patients

Brachial-ankle pulse wave velocity (baPWV) provides a useful means of assessing cardiovascular events and diabetic complications. However, the nature of associations between baPWV and microalbuminuria (MAU) and its presence in Type 2 diabetes mellitus (Type 2 DM) have rarely been investigated. This study aimed to examine the association between baPWV and MAU coupled with prediction of MAU using baPWV measurement among Type 2 DM patients. In this cross-sectional study, we enrolled 424 Type 2 DM patients who visited the cardiology and endocrinology department at a tertiary level health care facility, Republic of Korea between 1 January 2006 to 31 December 2008. Clinical and laboratory data were collected, and risk factors associated with MAU and prediction of risk for the development of MAU using baPWV measurement. The association between MAU and baPWV was examined using multivariable logistic regression analysis and predicted MAU by using receiver operating characteristic (ROC) curve analysis. Of the 424 Type 2 DM patients, 93 (21.9%) had MAU (20-200 μg/min). baPWV (cm/sec) was found to be significantly correlated with MAU levels (ug/min) (r = 0.791, p < 0.001). Further, baPWV was significantly associated MAU with higher odds ratio (adjusted odds ratio (AOR) 10.899; 95% confidence interval (CI) (4.518-26.292)). Similarly, smoking (AOR 10.899; 95% CI (4.518-26.292)), and low-density lipoprotein (LDL)-cholesterol (mg/dL) (AOR 1.017; 95% CI (1.001-1.033)) were also significantly associated with MAU. The appropriate cut-off value for baPWV to predict MAU 20 μg/min in our study was 1700 cm/sec (area under ROC curve = 0.976). This study shows that baPWV, cigarette smoking, and LDL-cholesterol are associated with MAU in Type 2 DM patients and suggests that a baPWV cut-off of 1700 cm/sec could be used to predict the presence of MAU (20 μg/min) in Type 2 DM patients in the Korean community.

Application of a decision tree to establish factors associated with a nomogram of aortic stiffness

Aortic stiffness is a marker of vascular aging and may reflect occurrence of cardiovascular (CV) diseases. Aortic pulse wave velocity (PWV), a marker of aortic stiffness, can be measured by applanation tonometry. A nomogram of aortic stiffness was evaluated by the calculation of PWV index. Theoretical PWV can be calculated according to age, gender, mean blood pressure, and heart rate, allowing to form an individual PWV index [(measured PWV - theoretical PWV)/theoretical PWV]. The purpose of the present cross-sectional study was to investigate the determinants of the PWV index, by applying a decision tree. A cross-sectional study was conducted from 2012 to 2017, and 597 individuals were included. A training decision tree was constructed based on seventy percent of these subjects (N = 428). The remaining 30% (N = 169) were used as the testing dataset to evaluate the performance of the decision trees. The input variables for the models were clinical and biochemical parameters. The different input variables remained in the model were diabetes, tobacco status, carotid plaque, albuminuria, C-reactive protein, total cholesterol, BMI, and previous CV diseases. For the validation decision model, the sensitivity, specificity, and accuracy values for identifying the related risk factors of PWV index were 70%, 78%, and 0.73. Since determinants of PWV index were all well-accepted CV risk factors, a nomogram of aortic stiffness could be considered as an integrator of CV risk factors on their duration of exposure and could be utilized to develop future programs for CV risk assessment and reduction strategies.

Greater aortic stiffness is associated with renal dysfunction in participants of the ELSA-Brasil cohort with and without hypertension and diabetes

Background

Arterial stiffness has been associated with renal dysfunction and its progression, but the pathophysiological relation underlying this association has not been fully established, particularly among individuals without hypertension and diabetes. We investigated the cross-sectional associations between arterial stiffness and renal function in adults without cardiovascular disease, and whether this association remained among subjects without hypertension and diabetes.

Methods

All eligible participants from ELSA-Brasil (2008–2010), aged 35 to 74 years (N = 13,586) were included, of whom 7,979 were free from hypertension and diabetes. The response variables were: 1) low glomerular filtration rate (eGFR<60ml/min/1.73m²) estimated by CKD-EPI; 2) increased albumin/creatinine ratio (ACR ≥30mg/g); and 3) chronic kidney disease (CKD). Arterial stiffness was ascertained by the carotid-femoral pulse wave velocity (PWV). The covariates were sex, age, race/color, level of schooling, smoking, body mass index, total cholesterol/HDL-c glycated hemoglobin, diabetes, systolic blood pressure, heart rate and use of antihypertensive drugs. Logistic regression was used to examine the associations.

Results

After all adjustments, 1 m/s increase in PWV was associated with ORs equal to 1.10 (95%CI: 1.04–1.16), 1.10 (95%CI: 1.05–1.16) and 1.12 (95%CI: 1.08–1.17) of low eGFR, high ACR, and CKD, respectively. In subjects without hypertension and diabetes, these ORs were 1.19 (95%CI: 1.07–1.33), 1.20 (95%CI: 1.07–1.32) and 1.21 (95%CI: 1.11–1.30), respectively.

Conclusion

The increase in PWV was associated with all renal dysfunction markers, even in individuals without hypertension and diabetes, suggesting a relation that is not completely mediated by the presence of these conditions.

Arterial stiffness is associated with target organ damage in subjects with pre-hypertension

INTRODUCTION

Present study was to evaluate whether increased arterial stiffness was associated with target organ damage in pre-hypertensive subjects.

MATERIAL AND METHODS

Pre-hypertensive subjects enrolled and echocardiography was used to evaluate left ventricular hypertrophy (LVH) and the first morning urine was collected to evaluate albumin and creatinine ratio (ALB/Cr ratio). Carotid-femoral pulse wave velocity (cf-PWV) was measured.

RESULTS

A total of 420 subjects were recruited and mean age was 42.6 years. Mean systolic/diastolic blood pressure (SBP/DBP) were 130 ±9 mm Hg and 85 ±4 mm Hg. The prevalence of albuminuria and left ventricular hypertrophy was 8.6 % and 11.7 %. Mean cf-PWV was 9.2 ±1.0 m/s, with arterial stiffness prevalence was 8.8%. Subjects with arterial stiffness had higher cf-PWV value (10.6 ±0.4 m/s vs. 8.7 ±0.6 m/s, p < 0.05), and ALB/Cr ratio (28.3 ±13.2 µg/mg vs. 23.1 ± 11.4 µg/mg, p < 0.05). Overall, with multivariate regression analysis, aging and arterial stiffness were significantly associated with pre-hypertension. With stepwise adjusted for potential covariates including age, male gender, fasting plasma glucose, presence of current cigarette smoking, dyslipidemia, statins and SBP, increased cf-PWV remained independently associated with left ventricular hypertrophy and albuminuria, with an increased odds of 41 % and 24 % (p < 0.05), respectively.

CONCLUSIONS

In pre-hypertensive subjects, arterial stiffness is independently associated with LVH and albuminuria and cf-PWV may be a useful marker to identify target organ damage in pre-hypertensive subjects.

Amiloride Improves Endothelial Function and Reduces Vascular Stiffness in Female Mice Fed a Western Diet

Obese premenopausal women lose their sex related cardiovascular disease protection and develop greater arterial stiffening than age matched men. In female mice, we have shown that consumption of a Western diet (WD), high in fat and refined sugars, is associated with endothelial dysfunction and vascular stiffening, which occur via activation of mineralocorticoid receptors and associated increases in epithelial Na⁺ channel (ENaC) activity on endothelial cells (EnNaC). Herein our aim was to determine the effect that reducing EnNaC activity with a very-low-dose of amiloride would have on decreasing endothelial and arterial stiffness in young female mice consuming a WD. To this end, we fed female mice either a WD or control diet and treated them with or without a very-low-dose of the ENaC-inhibitor amiloride (1 mg/kg/day) in the drinking water for 20 weeks beginning at 4 weeks of age. Mice consuming a WD were heavier and had greater percent body fat, proteinuria, and aortic stiffness as assessed by pulse-wave velocity than those fed control diet. Treatment with amiloride did not affect body weight, body composition, blood pressure, urinary sodium excretion, or insulin sensitivity, but significantly reduced the development of endothelial and aortic stiffness, aortic fibrosis, aortic oxidative stress, and mesenteric resistance artery EnNaC abundance and proteinuria in WD-fed mice. Amiloride also improved endothelial-dependent vasodilatory responses in the resistance arteries of WD-fed mice. These results indicate that a very-low-dose of amiloride, not affecting blood pressure, is sufficient to improve endothelial function and reduce aortic stiffness in female mice fed a WD, and suggest that EnNaC-inhibition may be sufficient to ameliorate the pathological vascular stiffening effects of WD-induced obesity in females.

Aortic stiffness and change in glomerular filtration rate and albuminuria in older people

Background

Aortic stiffness increases with age and increases pulsatile stress in the microcirculation. Abnormalities in kidney microvascular structure and function may contribute to development or progression of chronic kidney disease in older people.

Methods

We performed a longitudinal analysis of 629 community-dwelling elderly Icelandic adults from the Age, Gene/Environment Susceptibility-Reykjavik Study with two visits over a mean follow-up of 5.3 years. We evaluated the associations of carotid-femoral pulse wave velocity (CFPWV), carotid pulse pressure (CPP) and augmentation index (AI), with the change in estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) assessed as annual change and dichotomized as large changes. Models were adjusted for age, sex, height, heart rate, traditional cardiovascular disease risk factors and baseline kidney measures.

Results

When eGFR was analyzed as a continuous variable, higher baseline CFPWV and CPP, but not AI, were significantly associated with a larger annual decline in eGFR in models adjusted for age, sex, height, heart rate and baseline eGFR, but not after additional adjustment for the mean arterial pressure. When eGFR was analyzed as a categorical variable, higher CFPWV was significantly associated with a decrease in eGFR of ≥3 mL/min/1.73 m 2 /year [odds ratio (OR) 1.53, 95% confidence interval (CI) 1.11-2.13] and higher AI was associated with 30% eGFR decline during follow-up (OR 1.44 and 95% CI 1.03-2.00) in fully adjusted models. None of the tonometry measures was associated with change in UACR.

Conclusions

Abnormalities in vascular health may play a role in large declines in eGFR beyond the traditional cardiovascular disease risks in this older Icelandic cohort.

Arterial Stiffness Is More Associated with Albuminuria than Decreased Glomerular Filtration Rate in Patients with Type 2 Diabetes Mellitus: The REBOUND Study

AIM

The aim of this study was to evaluate the association between arterial stiffness and albuminuria and glomerular filtration rate (GFR) in patients with type 2 diabetes mellitus.

METHODS

This multicenter cohort study analyzed 2613 patients with type 2 diabetes. Brachial-ankle pulse wave velocity (baPWV) was used as a noninvasive marker of arterial stiffness. Additionally, the patients were categorized into four groups according to their albumin-to-creatinine ratio (ACR, normoalbuminuria versus albuminuria) and estimated GFR (eGFR, <60 mL/min/1.73 m² versus ≥60 mL/min/1.73 m²).

RESULTS

A univariate analysis revealed that maximal baPWV was significantly associated with both the ACR (r = 0.297, P < 0.001) and eGFR (r = -0.220, P < 0.001). A multivariate analysis adjusted for significant clinical variables and eGFR showed that baPWV remained significantly correlated with the ACR (r = 0.150, P < 0.001). Also, baPWV was correlated positively with the ACR in patients with an eGFR ≥ 60 mL/min/1.73 m² (r = 0.146, P < 0.001). However, baPWV was not correlated with eGFR after adjustment for significant clinical variables.

CONCLUSIONS

The present findings indicate that arterial stiffness is more associated with albuminuria than a decrease in GFR in patients with type 2 diabetes mellitus.

Ankle-brachial index and brachial-ankle pulse wave velocity are associated with albuminuria in community-based Han Chinese

BACKGROUND/OBJECTIVES

Our study aimed to explore whether the ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) were associated with albuminuria in community-based Han Chinese.

METHODS

Total 2127 subjects (860 men and 1267 women) aged 60 years and over were recruited in Beijing. Albuminuria was assessed by the urinary albumin-to-creatinine ratio (UACR) of ≥30 mg/g. BaPWV was divided by quartile. The logistic regression was used to determine the odds ratio (OR) and 95% confidence intervals (CIs) of ABI and baPWV with albuminuria.

RESULTS

ABI was associated with albuminuria in the interaction model (OR 0.89, 95% CI 0.81-0.99 by every 0.1 unit increase of ABI), especially in hypertension (OR 0.82, 95% CI 0.73-0.92) and diabetes (OR 0.83, 95% CI 0.68-0.98) groups. BaPWV groups were also significantly associated with albuminuria, ORs of having albuminuria for baPWV quartile II, III, and IV were 1.02(0.65-1.52), 1.05(0.72-1.61), and 1.18(1.04-1.47) in the interaction model. For hypertension and diabetes patients, only the baPWV quartile IV group had higher OR.

CONCLUSIONS

ABI and baPWV were associated with albuminuria after adjusting for other risk factors in Chinese community-based elderly Han population. The association of ABI with albuminuria was stronger in hypertension and diabetes patients.

Age and gender differences in the influences of eNOS T-786C polymorphism on arteriosclerotic parameters in general population in Japan

OBJECTIVE

The influence of T-786C polymorphism in the promoter region of endothelial nitric oxide synthase (eNOS) on arteriosclerotic parameters by age and gender were examined.

METHODS

Brachial-ankle pulse wave velocity (baPWV), heart-rate adjusted augmentation index (AIx@75), pulse pressure (PP) and albumin-creatinine ratio (ACR) were assessed as arteriosclerotic parameters in addition to non-high-density lipoprotein cholesterol (non-HDL-C) to HDL-C (non-HDL-C/HDL-C) ratio in 1499 participants. T-786C polymorphism (rs2070744) was screened using a TaqMan allelic discrimination assay. Analyses of covariance were carried.

RESULTS

Women with the non-C allele showed significantly lower AIx@75 in participants aged <65 years and baPWV in participants aged ≥65 years than those with C allele. In contrast, men with the non-C allele showed significantly higher PP in participants aged <65 years, and higher ACR and non-HDL-C/HDL-C ratio in participants aged ≥65 years. In men on cholesterol-lowering medication, the non-C allele carriers showed significantly higher non-HDL-C compared to those in the C allele carriers.

CONCLUSIONS

eNOS T-786C polymorphism is significantly associated with arteriosclerotic parameters accompanied with age and gender differences, possibly involving antioxidative and/or endothelial signaling other than inflammatory signaling.

Arterial Stiffness: A Novel Risk Factor for Kidney Injury Progression?

Arterial stiffness is typical feature of vascular remodeling in chronic kidney disease (CKD). Increased arterial stiffness raises flow and pressure pulsatility and is considered the principle pathogenic mechanism of isolated systolic hypertension, left ventricular hypertrophy, and congestive heart failure. Apart from the impact of arterial stiffness on left ventricular afterload, downstream transmission of pressure pulsatility to the level of microcirculation is suggested to promote injury of other susceptible organs. This may be of particular importance for kidney injury progression, since passive renal perfusion along with low resistance and input impedance in renal microvessels make kidneys particularly vulnerable to the damaging effect of systemic pulsatile pressure. Recent studies have provided evidence that arterial stiffness culminates in elevated pulsatility and resistance in renal microvasculature, promoting structural damage of small intra-renal arterioles. Further, prospective observational studies have shown that reduced aortic compliance is closely associated with the annual rate of renal function decline and represents independent predictor of kidney injury progression to end-stage renal disease among patients with CKD. This article provides insights into the cross-talk between macrocirculation and renal microcirculation and summarizes the currently available clinical evidence linking increased arterial stiffness with kidney disease progression.

Plasma pro-inflammatory cytokines, IgM-uria and cardiovascular events in patients with chest pain: A comparative study

BACKGROUND

Risk stratification of patients presenting with acute chest pain is crucial for immediate and long-term management. Traditional predictors are suboptimal; therefore inflammatory biomarkers are studied for clinical assessment of patients at risk. Recently, we reported the association of IgM-uria with worse cardiovascular outcome in patients with acute chest pain. In this study, in the same cohort of patients with chest pain, we compared the value of IgM-uria to pro-inflammatory cytokines in predicting the occurrence of subsequent cardiovascular events.

METHODS

A total of 178 consecutive patients presenting with acute chest pain to the emergency department at the University Hospital of Lund, were recruited. Twenty-seven of 57 patients with acute coronary syndrome (ACS), and 18 of 118 patients with non-specific chest pain at baseline developed a subsequent major cardiovascular event during the 18 months follow-up. Urinary proteins (IgM-uria and Microalbuminuria) and plasma inflammatory markers (IL-6, Il-8, IL-10, IFN-γ and TNF-α) were measured at time of admission.

RESULTS

Using the receiver operating characteristic curves, the area under the curve for predicting cardiovascular events was 0.71 (95%CI 0.61-0.81) for IgM-uria, 0.61 (95%CI 0.51-0.71) for IL-6, 0.63 (95%CI 0.53-0.72) for IL-8, 0.65 (95%CI 0.56-0.74) for IL-10, and 0.64 (95% CI 0.54-0.74) for TNF-α. In multivariate Cox-regression analysis adjusted for age, microalbuminuria, IgM-uria, IL-10, TNF-α, troponin T, hsCRP and ACS at baseline; IgM-uria was the only biomarker that remained an independent predictor of outcome (HR = 4.2, 95%CI 2.2-7.8, p < 0.001).

CONCLUSION

In patients with chest pain with or without acute coronary syndrome, IgM-uria could better predict the occurrence of cardiovascular events than plasma pro-inflammatory cytokines.

Arterial stiffness, pulse pressure, and the kidney

Classical studies indicate that the contribution of kidneys to hypertension is almost exclusively related to the association between mean arterial pressure (MAP) and vascular resistance. Recent reports including estimates of glomerular filtration rate (GFR) have shown that pulse pressure (PP) and pulse wave velocity, 2 major indices of arterial stiffness, now emerge as significant predictors of cardiovascular risk and age-associated decline in GFR. Such findings are mainly observed in patients with hypertension and renal failure and in atherosclerotic subjects undergoing coronary angiography. In such patients, amplification of PP between ascending and terminal aorta at the renal site is constantly increased over 10mm Hg (P < 0.001), whereas MAP level remains continuously unmodified. This PP amplification is significantly associated with presence of proteinuria. Furthermore, increases in plasma creatinine and aortic stiffness are independently and positively correlated (P < 0.001) both in cross-sectional and longitudinal studies. All these relationships associating PP, arterial stiffness, and renal function are mainly observed in patients 60 years of age or older. Furthermore, in renal transplant patients and their donors, subjects have been recruited for evaluations of arterial stiffness and posttransplant decline in GFR. Determinants of GFR decline were evaluated 1 and 9 years after transplantation. The first year GFR decline was related to smoking and acute rejection, whereas the later was significantly and exclusively associated with donor age and aortic stiffness. Thus, in hypertensive humans, the observed association between PP and GFR suggests that the 2 parameters are substantially mediated by arterial stiffness, not exclusively by vascular resistance.

Association between pulse wave velocity and a marker of renal tubular damage (N-acetyl-β-D-glucosaminidase) in patients without diabetes

The authors assessed the association between the ratio of urinary activity of N-acetyl-β-D-glucosaminidase (NAG) to creatinine and the brachial-ankle pulse wave velocity (baPWV) in patients without overt diabetes mellitus (DM). This was a cross-sectional study of 233 patients who had an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m(2) and no history of kidney disease. Patients were divided into two groups: high NAG group (>5.8 U/g creatinine) and low NAG group (≤5.8 U/g creatinine). Mean baPWVs of the high NAG group were significantly higher than those of the low NAG group in both the eGFR ≥30 and <60 tertiles and the eGFR ≥60 and <90 tertiles. The baPWV was positively correlated with NAG in all patients (r=0.341, P<.001). Stepwise multivariate regression analysis showed that the baPWV was significantly related with NAG, age, and systolic blood pressure. Elevated NAG is related to elevated arterial stiffness in patients without DM.

Association of albumin-creatinine ratio and cystatin C with change in ankle-brachial index: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Low ankle-brachial index (ABI) is a reflection of atherosclerotic disease, and high ABI is an indicator of calcified vessels. The associations of albuminuria and cystatin C level with incidence of either low or high ABI are unknown.

STUDY DESIGN

Prospective longitudinal cohort study.

SETTING & PARTICIPANTS

MESA (Multi-Ethnic Study of Atherosclerosis) enrolled community-dwelling adults (N=6,814) aged 45-84 years who were free of clinical cardiovascular disease at baseline.

PREDICTORS

Baseline albumin-creatinine ratio (ACR) and serum cystatin C level.

OUTCOMES

Development of low (<0.90), and high (>1.40) ABI using multinomial regression among persons with ABI of 0.90-1.40 at baseline.

RESULTS

During 9.8 years of follow-up, 221 and 89 participants progressed to low and high ABIs, respectively. Baseline ACR and cystatin C level were higher among progressors compared with nonprogressors. In multivariable analyses, doubling of ACR was associated with increased risk of progression to low (OR, 1.08; 95% CI, 0.99-1.20) and high (OR, 1.16; 95% CI, 1.01-1.32) ABIs. Compared to the lowest quintile, the highest quintile of ACR had a significantly increased risk of progression to low (OR, 1.79; 95% CI, 1.03-3.12) and high (OR, 2.76; 95% CI, 1.32-5.77) ABIs. Higher cystatin C levels were associated with progression to low (OR per 1-SD greater, 1.12; 95% CI, 1.00-1.26) but not high (OR per 1-SD greater, 1.01; 95% CI, 0.81-1.25) ABI, but the highest quintile of cystatin C was not associated independently with either outcome.

LIMITATIONS

Single measure of albuminuria and low number of progressors to high ABI.

CONCLUSIONS

In adults free of clinical cardiovascular disease, albuminuria was a strong independent risk factor for the development of both high and low ABIs, important and different measures of peripheral artery disease.

Elevated brachial-ankle pulse wave velocity is independently associated with microalbuminuria in a rural population

Microalbuminuria is a marker of generalized endothelial dysfunction resulting from arterial stiffness or insulin resistance, and brachial-ankle pulse wave velocity (baPWV) is a good measure of arterial stiffness. We aimed to investigate whether elevated baPWV is independently associated with microalbuminuria. This study included 1,648 individuals aged over 40 who participated in the baseline Multi-Rural Cohort Study conducted in Korean rural communities between 2005 and 2006. Participants were classified into less than 30 mg/g as normoalbuminuria or 30-300 mg/g as microalbuminuriausing urinary albumin creatinine ratio (UACR). The median and Q1-Q3 baPWV values were significantly higher in the microalbuminuric group both in men (1,538, 1,370-1,777 cm/s vs. 1,776, 1,552-2,027 cm/s, P < 0.001) and women (1,461, 1,271-1,687 cm/s vs. 1,645, 1,473-1,915 cm/s, P < 0.001). BaPWV was independently associated with microalbuminuria in both genders after adjusting for pulse rate; fasting blood glucose; triglyceride; homeostatic model assessment insulin resistance (HOMAIR) and, history of hypertension and diabetes. Fasting blood sugar and HOMAIR were judged as having nothing to do with multicolinearity (r = 0.532, P < 0.001). Elevated baPWV was independently associated with microalbuminuria regardless of insulin resistance among rural subjects over 40 yr.

Urinary albumin excretion from spot urine samples predict all-cause and stroke mortality in Africans

BACKGROUND

Increased urinary albumin excretion reflects general vascular damage and predicts adverse cardiovascular and renal outcomes. Albuminuria can be determined from easily collected spot urine samples, especially in low-resource settings. However, no prognostic evidence exists for Africans.

METHODS

We followed clinical outcomes in 1,061 randomly selected non diabetic, human immunodeficiency virus (HIV)-negative Africans (mean age: 51.5 years; 62.0% women). Baseline urinary albumin-to-creatinine ratio was assessed from spot urine samples.

RESULTS

Over a median follow-up of 4.52 years, 132 deaths occurred, of which 47 were cardiovascular related. The urinary albumin-to-creatinine ratio averaged 6.1 μg/mg (5th to 95th percentile interval; 1.2-70.0). In multivariable-adjusted analyses, urinary albumin excretion predicted all-cause mortality (hazard ratio (HR), 1.26; 95% confidence interval (CI), 1.07-1.48; P = 0.006), and a tendency existed for cardiovascular mortality (HR, 1.26; 95% CI, 0.97-1.63; P = 0.087), which seemed to be driven by fatal stroke (HR, 1.72; 95% CI, 1.17-2.54; P = 0.006) rather than cardiac mortality (HR, 0.67; 95% CI, 0.41-1.07; P = 0.094). The predictive value remained in 528 hypertensives for both all-cause (HR, 1.38; 95% CI, 1.13-1.69; P = 0.001) and cardiovascular (HR, 1.45; 95% CI, 1.07-1.96; P = 0.017) mortality, again driven by stroke. Our findings also remained significant after we excluded participants with macroalbuminuria, those on antihypertensive treatment, as well as participants who died within 1 year after enrollment.

CONCLUSION

In nondiabetic HIV-negative Africans, albuminuria predicts all-cause and stroke mortality.

Risks of decreased renal function and increased albuminuria for glycemic status and metabolic syndrome components: Taichung Community Health study

BACKGROUND

The objective of this study was to assess the association of glycemic status and decreased renal function as determined by estimated glomerular filtration rate (eGFR) and albuminuria in an adult Taiwanese metropolitan population.

METHODS

We did a cross-sectional survey in a representative sample of 2,350 Taiwanese adults aged 40 years and over living in a metropolitan city in Taiwan from 2004 to 2005. Glycemic status was classified as normal glycemia, hyperglycemia, and type 2 diabetes (T2D). Renal function was assessed with eGFR using modified Modification of Diet in Renal Disease Study equation for Chinese. Albuminuria was determined by the urinary albumin-creatinine ratio. Decreased renal function was defined as eGFR <60 mL/min/1.73 m(2) and albuminuria as the albumin-creatinine ratio >30 mg g(-1) creatinine.

RESULTS

593 (25.23%) had hyperglycemia and 287 (12.21%) had T2D. As glycemia level increased, the prevalence of albuminuria and decreased eGFR increased. After adjustment, T2D was associated with an OR of 2.93 (95% CI: 2.11-4.07) for albuminuria, and an OR of 2.05 (95% CI: 1.18-3.58) for decreased eGFR.

CONCLUSIONS

In a representative sample from a metropolitan city in Taiwan, T2D was associated with albuminuria and decreased eGFR.

Increased urinary IgM excretion in patients with chest pain due to coronary artery disease

BACKGROUND

Micro-albuminuria is a recognized predictor of cardiovascular morbidity and mortality in patients with coronary artery disease. We have previously reported, in diabetic and non-diabetic patients, that an increased urinary excretion of IgM is associated with higher cardiovascular mortality. The purpose of this study was to investigate the pattern of urinary IgM excretion in patients with acute coronary syndrome (ACS) and its correlation to cardiovascular outcome.

METHODS

Urine albumin, and IgM to creatinine concentration ratios were determined in 178 consecutive patients presenting with chest pain to the Department of Emergency Medicine (ED) at the University Hospital of Lund. Fifty eight (23 female) patients had ACS, 55 (19 female) patients had stable angina (SA), and 65 (35 female) patients were diagnosed as non-specific chest pain (NS).

RESULTS

Urine albumin and IgM excretions were significantly higher in patients with ACS (p = 0.001, and p = 0.029, respectively) compared to patients with NS-chest pain. During the 2 years follow-up time, 40 (19 female) patients suffered a new major cardiovascular event (ACS, acute heart failure, stroke) and 5 (4 male/1 female) patients died of cardiovascular cause. A high degree of albuminuria and IgM-uria significantly predicted cardiovascular mortality and morbidity (HR = 2.89, 95% CI: 1.48 - 5.66, p = 0.002). Microalbuminuric patients (≥3 mg/mmol) with high IgM-uria (≥0.005 mg/mmol) had a 3-fold higher risk for cardiovascular new events compared to patients with low IgM-uria (RR = 3.3, 95% CI: 1.1 - 9.9, p = 0.001).

CONCLUSION

In patients with chest pain, an increased urine IgM excretion, is associated with coronary artery disease and long-term cardiovascular complications. Measuring urine IgM concentration could have a clinical value in risk stratification of patients with ACS.

Target renal damage: the microvascular associations of increased aortic stiffness in patients with COPD

Background

Although renal impairment has been described in COPD, there is opportunity to evaluate further to determine nature and consider optimal management. Increased aortic stiffness, as seen in COPD, leads to reduced buffering of pulsatile flow. We hypothesised that urinary albumin creatinine ratio (UACR) would reflect glomerular damage related to aortic stiffness.

Methods

Patients with COPD and controls underwent spirometry, blood pressure, arterial stiffness - aortic pulse wave velocity (PWV) and provided a spot urine sample for UACR, with other renal biomarkers measured.

Results

The UACR was increased in patients (n = 52): 0.80 mg/mmol compared to controls (n = 34): 0.46 mg/mmol, p < 0.05. Aortic PWV was related to log₁₀ UACR in all subjects (r = 0.426, p < 0.001) and COPD patients alone. Aortic PWV was a significant variable for UACR with oxygen saturations, after accounting for potential confounders. Eight subjects (7 patients) reached a defined clinical microalbuminuria threshold, with aortic PWV greater in these patients compared to those patients without, although albuminuria is a continuum. Proximal tubular damage biomarkers, unlike the glomerular marker, were not different between patients and controls.

Conclusions

There is glomerular damage in patients with COPD evidenced by increased UACR, related to increased aortic stiffness. Besides the macrovascular prognostic implications of increased aortic stiffness, the microvascular state in COPD management should be considered.

Central obesity and albuminuria: both cross-sectional and longitudinal studies in Chinese

Background

Albuminuria is recognized as a marker of vascular dysfunction. Central obesity increases the risk of cardiovascular disease. Little is known about the association between albuminuria and central obesity in Chinese. We aimed to assess the association between central obesity and prevalence and incidence of albuminuria in a middle-aged population-based cohort study.

Methods

This is a cross-sectional and longitudinal cohort study. A total of 2350 subjects aged ≥40 years were recruited in 2004 in Taiwan for cross-sectional analysis. Longitudinal analysis included 1432 baseline normoalbuminuria subjects with a mean 2.8 years follow-up, 67 of whom exhibited incident albuminuria. Albuminuria was defined as urinary albumin-to-creatinine ratio ≥30 mg/g creatinine. Multiple logistic regression analyses were used to evaluate the relationship between central obesity and prevalence and incidence of albuminuria after adjustment for age, gender, body mass index, blood pressure, renal function, glucose, high sensitivity c-reactive protein, smoking, betel nut chewing, alcohol drinking, and physical activity.

Results

At baseline, albuminuria is significantly associated with central obesity. The adjusted odds ratio of having albuminuria among subjects with central obesity was 1.73(95% confidence interval (CI): 1.04–2.85), compared to the subjects without central obesity. In multivariable models, participants with central obesity at baseline had a 112% increase in risk of incident albuminuria (adjusted incidence rate ratio (95% CI): 2.12(1.01–4.44)) compared with participants with non-central obesity.

Conclusions

Abdominal adiposity was independently associated with increased prevalence and incidence of albuminuria in Chinese. The mechanisms linking adiposity and albuminuria need to be addressed.

Determining the optimal cut-off value of the urinary albumin-to-creatinine ratio to detect atherosclerotic vascular diseases

BACKGROUND

We examined whether low-grade albuminuria, below the conventional cut-off value for microalbuminuria, was associated with atherosclerotic vascular diseases in 8897 community-dwelling Koreans aged ≥50 years.

METHODS

The urinary albumin-to-creatinine ratio (UACR) was calculated using random spot urine. Common carotid artery (CCA) intimamedia thickness (IMT) and CCA internal diameter were measured using high-resolution B-mode ultrasonography, and carotid plaque was evaluated. Brachial-ankle pulse wave velocity (BaPWV) and the ankle-brachial index (ABI) were examined, and peripheral arterial disease was defined as ABI <0.9.

RESULTS

Youden's indices, predicting abnormal atherosclerotic conditions, were greatest at a UACR cut-off value of ∼15 mg/g, below the threshold conventionally used to define microalbuminuria. Compared with low normoalbuminuria (UACR <15.0 mg/g), CCA IMT, CCA diameter, and BaPWV were significantly greater in individuals with high normoalbuminuria (UACR 15.0-29.9 mg/g), who also had a significantly higher risk of carotid plaque than did those with low normoalbuminuria.

CONCLUSIONS

Subclinical atherosclerotic vascular diseases developed at lower UACRs, below the conventional classification of microalbuminuria. Further longitudinal studies are needed to investigate the relationship between microalbuminuria and the development of subclinical atherosclerosis.

Arterial stiffness is associated with incident albuminuria and decreased glomerular filtration rate in type 2 diabetic patients

OBJECTIVE

To investigate the association between aortic stiffness and incident albuminuria and the decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We investigated 461 Japanese type 2 diabetic patients, comprising 199 women and 262 men, with a mean age of 59 ± 11 years. Patients were divided into two groups according to the median value of carotid-femoral pulse wave velocity (cf-PWV), which was used to evaluate aortic stiffness. The end point was defined as the transition from normo- to microalbuminuria or micro- to macroalbuminuria. The Cox proportional hazard model was used to calculate the hazard ratio (HR) and 95% CI. The correlation between cf-PWV and rate of change in eGFR was also determined by linear regression analysis.

RESULTS

The baseline mean (± SD) cf-PWV was 9.6 ± 2.4 m/s. During a median follow-up period of 5.9 years (range 0.3-8.6), progression of albuminuria was observed in 85 patients. The 5-year cumulative incidence of the end point in patients with cf-PWV below and above the median was 8.5 and 19.4%, respectively (P = 0.002, log-rank test). cf-PWV was significantly associated with incident albuminuria (HR 1.23, 95% CI 1.13-1.33, P < 0.001) by multivariate Cox regression analysis. A significant association between cf-PWV and annual change in eGFR was also suggested by multiple linear regression analysis (standardized estimate -0.095, P = 0.031).

CONCLUSIONS

Aortic stiffness is associated with incident albuminuria and the rate of decline in glomerular filtration rate in type 2 diabetic patients.

Aortic pulse wave velocity is associated with measures of subclinical target organ damage

OBJECTIVES

Our goal was to evaluate the associations of central arterial stiffness, measured by aortic pulse wave velocity (aPWV), with subclinical target organ damage in the coronary, peripheral arterial, cerebral, and renal arterial beds.

BACKGROUND

Arterial stiffness is associated with adverse cardiovascular outcomes. We hypothesized that aPWV is associated with subclinical measures of atherosclerosis-coronary artery calcification (CAC) and ankle-brachial index (ABI) and arteriolosclerosis-brain white matter hyperintensity (WMH) and urine albumin-creatinine ratio (UACR).

METHODS

Participants (n = 812; mean age 58 years; 58% women, 71% hypertensive) belonged to hypertensive sibships and had no history of myocardial infarction or stroke. aPWV was measured by applanation tonometry, CAC by electron beam computed tomography, ABI using a standard protocol, WMH volume by brain magnetic resonance, and UACR by standard methods. WMH was log-transformed, whereas CAC and UACR were log-transformed after adding 1 to reduce skewness. The associations of aPWV with CAC, ABI, WMH, and UACR were assessed by multivariable linear regression using generalized estimating equations to account for the presence of sibships. Covariates included in the models were age, sex, body mass index, history of smoking, hypertension and diabetes, total and high-density lipoprotein cholesterol, estimated glomerular filtration rate, use of aspirin and statins, and pulse pressure.

RESULTS

The mean ± SD aPWV was 9.8 ± 2.8 m/s. After adjustment for age, sex, conventional cardiovascular risk factors, and pulse pressure, higher aPWV (1 m/s increase) was significantly associated with higher log (CAC + 1) (β ± SE = 0.14 ± 0.04; p = 0.0003), lower ABI (β ± SE = -0.005 ± 0.002; p = 0.02), and greater log (WMH) (β ± SE = 0.03 ± 0.009; p = 0.002), but not with log (UACR + 1) (p = 0.66).

CONCLUSIONS

Higher aPWV was independently associated with greater burden of subclinical disease in coronary, lower extremity, and cerebral arterial beds, highlighting target organ damage as a potential mechanism underlying the association of arterial stiffness with adverse cardiovascular outcomes.

Implications of proteinuria: CKD progression and cardiovascular outcomes

In this review, we summarize the evidence for the associations of proteinuria with incident CKD, progression of kidney disease, development of kidney failure, as well as the association with surrogates of cardiovascular disease (CVD), clinical cardiovascular outcomes, and all-cause mortality. Results reveal that proteinuria is a powerful and independent risk factor for kidney and cardiovascular outcomes, and that these relationships are independent of the level of glomerular filtration rate. Furthermore, these associations are true in populations at high, medium, and low risk for kidney disease progression and development of CVD. We show data which demonstrate that the associations with CVD are present even at levels of proteinuria below current cutoffs for microalbuminuria, and that changes in proteinuria may be a useful predictor of future outcomes. Finally, we provide some theories as to why proteinuria may be a risk factor for development of CVD.

Arterial stiffness in chronic kidney disease: the usefulness of a marker of vascular damage

Increased arterial stiffness is a marker of vasculopathy in chronic kidney disease (CKD) patients, suggesting a significant cardiovascular damage. Detection of arterial stiffness provides physicians with useful prognostic information independent of traditional cardiovascular (CV) risk factors. In addition, this knowledge may help guide appropriate therapeutic choices and monitor the effectiveness of antihypertensive therapies. We review the relationship between arterial stiffness and CKD, as well as the prognostic implications of increased arterial stiffness and the potential therapeutic strategies to ameliorate arterial compliance and outcome in CKD.

Arterial stiffness is strongly associated with insulin resistance in Chinese--a population-based study (Taichung Community Health Study, TCHS)

AIM

Few studies have investigated the association between insulin resistance and arterial stiffness in Chinese. We aimed to investigate this relationship in a population-based study of middle-aged Chinese.

METHODS

A total of 2,188 subjects aged 40 years and older were recruited in 2004 in Taiwan. The association between arterial stiffness (measured by brachial-ankle pulse wave velocity (baPWV)) and insulin resistance (represented by homeostasis model assessment (HOMA-IR) and fasting glucose levels) was studied by multiple logistic and linear regression analyses.

RESULTS

The respective prevalence of diabetes and impaired fasting glucose (IFG) was 13.9% and 30.6% in males and 10.4% and 20.8% in females. Using multiple linear regression analyses, we found baPWV to be strongly associated with age, gender, body mass index (BMI), waist circumference (WC), systolic blood pressure (BP), diastolic BP, fasting glucose, and triglycerides. Compared to the lowest HOMA-IR tertile I and adjusting for age, BMI, WC, gender, triglycerides, systolic BP, diastolic BP, smoking, alcohol drinking, betel nut chewing, and physical activity, the odds ratios (95% confidence interval) of arterial stiffness for the higher HOMA-IR tertiles II and III were 1.15 (0.77-1.71) and 1.60 (1.05-2.46), respectively. Using a general linear model with adjustment for age, systolic BP, diastolic BP, BMI, WC, and triglycerides, baPWV was significantly lower in the diabetic group by 90.3 cm/sec in males and 100.5 cm/sec in females compared to the IFG group. When comparing the IFG group to the normal glucose group, baPWV was 28.5 cm/sec lower in males and 14.4 cm/sec lower in females.

CONCLUSIONS

Arterial stiffness is independently associated with insulin resistance in Chinese middle-aged adults. Subjects with diabetes or IFG have higher baPWV than normoglycemic subjects.