Cystatin C and carotid intima-media thickness in asymptomatic adults: the Multi-Ethnic Study of Atherosclerosis (MESA)

Associations of childhood adiposity with adult intima-media thickness and inflammation: a 20-year longitudinal population-based cohort

BACKGROUND

The associations between childhood adiposity and adult increased carotid intima-media thickness (cIMT) have been well established, which might be corroborated by the association between adiposity in children and inflammation in adults. However, longitudinal data regarding biological pathways associated with childhood adiposity are lacking.

METHODS

The current study included participants from the STANISLAS cohort who had adiposity measurements at age 5-18 years [ N  = 519, mean (SD) age, 13.0 (2.9) years; 46.4% male], and who were measured with cIMT, vascular-related and metabolic-related proteins at a median follow-up of 19 ± 2 years. BMI, waist-to-height ratio and waist circumference were converted to age-specific and sex-specific z -scores.

RESULTS

A minority of children were overweight/obese (16.2% overweight-BMI z -score >1; 1.3% obesity- z -score >2). Higher BMI, waist-height ratio and waist circumference in children were significantly associated with greater adult cIMT in univariable analysis, although not after adjusting for C-reactive protein. These associations were more pronounced in those with consistently high adiposity status from childhood to middle adulthood. Participants with higher adiposity during childhood (BMI or waist-height ratio) had higher levels of insulin-like growth factor-binding protein-1, protein-2, matrix metalloproteinase-3, osteopontin, hemoglobin and C-reactive protein in adulthood. Network analysis showed that IL-6, insulin-like growth factor-1 and fibronectin were the key proteins associated with childhood adiposity.

CONCLUSION

In a population-based cohort followed for 20 years, higher BMI or waist-to-height ratio in childhood was significantly associated with greater cIMT and enhanced levels of proteins reflective of inflammation, supporting the importance of inflammation as progressive atherosclerosis in childhood adiposity.

Association of Estimated GFR Calculated Using Race-Free Equations With Kidney Failure and Mortality by Black vs Non-Black Race

Importance

At a given estimated glomerular filtration rate (eGFR), individuals who are Black have higher rates of mortality and kidney failure with replacement therapy (KFRT) compared with those who are non-Black. Whether the recently adopted eGFR equations without race preserve racial differences in risk of mortality and KFRT at a given eGFR is unknown.

Objective

To assess whether eGFR equations with and without race and cystatin C document racial differences in risk of KFRT and mortality in populations including Black and non-Black participants.

Design, Setting, and Participants

Retrospective individual-level data analysis of 62 011 participants from 5 general population and 3 chronic kidney disease (CKD) US-based cohorts with serum creatinine, cystatin C, and follow-up for KFRT and mortality from 1988 to 2018.

Exposures

Chronic Kidney Disease Epidemiology Collaboration equation with serum creatinine (eGFRcr with and without race), cystatin C (eGFRcys without race), or both markers (eGFRcr-cys without race).

Main Outcomes and Measures

The prevalence of decreased eGFR at baseline and hazard ratios of KFRT and mortality in Black vs non-Black participants were calculated, adjusted for age and sex. Analyses were performed within each cohort and with random-effect meta-analyses of the models.

Results

Among 62 011 participants (20 773 Black and 41 238 non-Black; mean age, 63 years; 53% women), the prevalence ratio (95% CI; percent prevalences) of eGFR less than 60 mL/min/1.73 m2 comparing Black with non-Black participants was 0.98 (95% CI, 0.93-1.03; 11% vs 12%) for eGFRcr with race, 0.95 (95% CI, 0.91-0.98; 17% vs 18%) for eGFRcys, and 1.2 (95% CI, 1.2-1.3; 13% vs 11%) for eGFRcr-cys but was 1.8 (95% CI, 1.7-1.8; 15% vs 9%) for eGFRcr without race. During a mean follow-up of 13 years, 8% and 4% of Black and non-Black participants experienced KFRT and 34% and 39% died, respectively. Decreased eGFR was associated with significantly greater risk of both outcomes for all equations. At an eGFR of 60 mL/min/1.73 m2, the hazard ratios for KFRT comparing Black with non-Black participants were 2.8 (95% CI, 1.6-4.9) for eGFRcr with race, 3.0 (95% CI, 1.5-5.8) for eGFRcys, and 2.8 (95% CI, 1.4-5.4) for eGFRcr-cys vs 1.3 (95% CI, 0.8-2.1) for eGFRcr without race. The 5-year absolute risk differences for KFRT comparing Black with non-Black participants were 1.4% (95% CI, 0.2%-2.6%) for eGFRcr with race, 1.1% (95% CI, 0.2%-1.9%) for eGFRcys, and 1.3% (95% CI, 0%-2.6%) for eGFRcr-cys vs 0.37% (95% CI, -0.32% to 1.05%) for eGFRcr without race. Similar patterns were observed for mortality.

Conclusions and Relevance

In this retrospective analysis of 8 US cohorts including Black and non-Black individuals, the eGFR equation without race that included creatinine and cystatin C, but not the eGFR equation without race that included creatinine without cystatin C, demonstrated racial differences in the risk of KFRT and mortality throughout the range of eGFR. The eGFRcr-cys equation may be preferable to the eGFRcr equation without race for assessing racial differences in the risk of KFRT and mortality associated with low eGFR.

Elevated Serum Cystatin C and Decreased Cathepsin S/Cystatin C Ratio Are Associated with Severe Peripheral Arterial Disease and Polyvascular Involvement

Peripheral arterial disease (PAD) is frequently associated with atherosclerotic manifestations of the carotids and coronaries. Polyvascular involvement and low ankle−brachial index predict major cardiovascular events and high mortality. Cathepsin S (Cat S) promotes the inflammatory pathways of the arterial wall, while Cystatin C (Cys C) functions as its inhibitor; therefore, Cys C was proposed to be a biomarker of progression in PAD. In a single-center observational study, we investigated the correlations of serum Cys C and Cat S/Cys C ratio in a group of 90 PAD patients, predominantly with polyvascular involvement. Cys C and Cat S/Cys C were associated with ankle−brachial index (ABI) scores <0.4 in univariate and multiple regression models. Furthermore, both markers correlated positively with the plasma Von Willebrand Factor Antigen (VWF: Ag) and Von Willebrand Factor collagen-binding activity (VWF: CB). In addition, Cat S/Cys C was significantly decreased, whereas Cys C increased in subjects with three-bed atherosclerotic involvement. According to our results, high serum Cys C and low Cat S/Cys C ratios may indicate severe peripheral arterial disease and polyvascular atherosclerotic involvement.

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Independent associations of urinary albumin-to-creatinine ratio and serum cystatin C with carotid intima-media thickness in community-living Taiwanese adults

Background

Renal function is a key factor of cardiovascular disease. Carotid intima-media thickness (IMT) has been widely used as a marker of early subclinical atherosclerosis. The determinants of cystatin C, a novel marker of renal function, have not been extensively studied in the Asian population. This study aimed to assess the determinants of cystatin C and explore whether carotid thickening was associated with urinary albumin-creatinine ratio and cystatin C in community-living Taiwanese adults.

Methods

A cross-sectional study was conducted on participants from Taichung City, Taiwan. All the participants underwent carotid ultrasonography. Carotid IMT-mean and IMT-maximum were derived. Kidney biomarkers were measured on the basis of urinary albumin-to-creatinine ratio (ACR) and cystatin C. Multiple linear regression analysis was used.

Results

A total of 1032 individuals were recruited, and 469 (45.44%) of them were men. An increased cystatin C level was significantly associated with older age, male gender, lack of physical activity, low HDL cholesterol, abdominal obesity, high hs-CRP, and high ACR. The multivariate-adjusted mean carotid IMT-mean and IMT-maximum values significantly increased by 80.49 and 195.23 μm for every one unit of increase in cystatin C level and by 0.07 and 0.14 μm for every one unit of increase in ACR, respectively (all p < 0.001 except ACR on IMT-maximum with p < 0.01). Lack of physical activity, low HDL, abdominal obesity, high hs-CRP, and high ACR were the determinants of cystatin C.

Conclusion

Cystatin C and ACR were strongly and linearly associated with carotid thickening, a marker of subclinical atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-020-02123-x.

Association between kidney disease measures and intracranial atherosclerosis: The ARIC study

OBJECTIVE

To test the association between reduced kidney function (assessed by estimated glomerular filtration rate [eGFR] and cystatin C [CysC]) and kidney damage (assessed by urinary albumin-to-creatinine ratio [ACR]) and intracranial atherosclerotic disease (ICAD) by high-resolution vessel wall MRI (VWMRI) in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS).

METHODS

We conducted a cross-sectional analysis of ARIC participants with data on kidney measures and VWMRI in 2011 to 2013. The main outcomes were presence of intracranial plaques and luminal stenosis. Multivariable models were adjusted for demographics, cardiovascular risk factors, and use of antithrombotic medications.

RESULTS

A total of 1,762 participants (mean ± SD age, 76.3 ± 5.3) were included. eGFR based on CysC (eGFRcysc) <60 mL/min/1.73 m2 (vs ≥60 mL/min/1.73 m2) was associated with plaque presence (adjusted odds ratio [OR] 1.29, 95% confidence interval [CI] 1.04-1.60), any detectable stenosis (adjusted OR 1.31, 95% CI 1.04-1.63), and >70% stenosis or occlusion (adjusted OR 2.15, 95% CI 1.32-3.50). Neither ACR nor CysC showed statistically significant associations with ICAD features in adjusted models. In adjusted multinomial models, participants with eGFRcysc <60 mL/min/1.73 m2 (vs ≥60 mL/min/1.73 m2) had an increased OR of 1.41 (95% CI 1.06-1.87) for having 1 plaque (vs none) but no significant increase for multiple plaques; ACR ≥30 was associated with moderate (50%-70%) stenosis (OR 2.01, 95% CI 1.14-3.55) vs absent or less than 50% stenosis.

CONCLUSION

In community-dwelling older adults, reduced kidney function or elevated kidney damage was associated with ICAD measured by VWMRI. This finding may help to better identify a population at high risk for ICAD.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.

Post-Stroke Depression and Estimated Glomerular Filtration Rate: A Prospective Stroke Cohort

PURPOSE

Post-stroke depression (PSD) is a frequent comorbidity in patients presenting with acute ischemic stroke. Impaired kidney function has been associated with depression in non-stroke subjects. We would like to evaluate whether the estimated glomerular filtration rate (eGFR) on admission is associated with the development of PSD.

PATIENTS AND METHODS

Total of 268 patients with acute ischemic stroke were recruited and completed 1-month follow-up visit. eGFR was calculated from the serum creatinine value, race, age, and sex by using the chronic kidney disease epidemiology collaboration equation (CKD-EPI creatinine equation). The 17-item Hamilton Depression Scale was used to evaluate depression symptoms. Patients with a depression score of ≥7 were evaluated using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for diagnosing post-stroke depression at 1 month. Meanwhile, 114 normal control subjects were also recruited.

RESULTS

Ninety-three (34.7%) patients were diagnosed as having PSD at 1 month. There was a significant intergroup difference in eGFR levels within 24 hrs after admission (F=13.608, p<0.001). The levels of eGFR within 24 hrs after admission were significantly lower in both non-PSD patients and PSD patients than in normal controls. In logistic regression, the level of eGFR (<82mL/min/1.73m²) was independently associated with increased risk of PSD even after adjusting for confounders (OR=2.328, 95% CI:1.092-4.965, p=0.029).

CONCLUSION

Reduced eGFR was found to be correlated with the development of PSD and it suggests the need for greater attentions and potential interventions for depression in patients with stroke and with reduced eGFR.

Serum Cystatin C and Arterial Stiffness in Middle-Aged and Elderly Adults without Chronic Kidney Disease: A Population-Based Study

BACKGROUND Cystatin C is a protease inhibitor that is increased in the serum of patients with chronic kidney disease (CKD) and is associated with an increased risk of developing cardiovascular disease (CVD). This study aimed to evaluate the association between serum levels of cystatin C and arterial stiffness, associated with dyslipidemia, obesity, and increased pulse pressure, in middle-aged and elderly individuals without CKD in a population in China. MATERIAL AND METHODS A cross-sectional population-based study included 1,138 patients aged ≥40 years without CKD, defined as an estimated glomerular filtration rate measured by serum creatinine (eGFRSCr) ≥60 ml/min/1.73 m². Study participants provided clinical details, including height and weight, and blood samples for serum measurements of cystatin C and lipid profiles and completed a clinical questionnaire. Pulse pressure was calculated as the mean systolic pressure (SBP) minus the diastolic pressure (DBP). Data underwent multivariate logistic regression analysis. RESULTS An increase in serum levels of cystatin C was associated with an increased risk of arterial stiffness. Each standard deviation in the increase of cystatin C resulted in a 22% increased risk of dyslipidemia, a 27% increased risk of obesity, and a 24% increased risk of increased pulse pressure, after adjusting for confounders. These associations were further confirmed in a sensitivity analysis by excluding participants with hypertension, diabetes, and patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). CONCLUSIONS In middle-aged and elderly individuals without CKD, arterial stiffness determined by obesity, dyslipidemia and increased pulse pressure, was significantly associated with increased serum levels of cystatin C.

Association between renal damage markers and carotid atherosclerosis in Afro-descendants with hypertension belonging to a minority ethnic group from Brazil

Ethnicity appears to play an important role in the prevalence and severity of hypertension, renal disease, and atherosclerosis. A cross-sectional study was conducted, including 206 Afro-descendants with hypertension, living in the remaining quilombo communities. These subjects underwent a carotid intima-media thickness (CIMT) assessment. The presence of renal injury was assessed by: (1) The glomerular filtration rate (GFR) estimated by the formula CKD-EPI using creatinine and cystatin C and (2) Albuminuria (ACR ≥30 mg/g). The Poisson distribution model was set with robust variance to identify factors associated with carotid atherosclerosis. The statistical analysis was performed using the Stata 12.0 software, adopting a significance level of 5%. Most subjects were women (61.65%); the average age was 61.32 (±12.44) years. Subjects (12.62%) were identified with GFR <60 mL/min/1.73 m2 and 22.8% with albuminuria. Patients (59.22%) presented with a high CIMT. In the adjusted regression model, age ≥60 years (PR: 1.232 [CI 95%:1.091-1.390], p value = .001), ACR ≥30 mg/g (PR: 1.176 [CI 95%: 1.007-1.373], p = .040), and GFR/CKD-EPI using cystatin C (PR: 1.250 [CI 95%: 1.004-1.557], p = .045) were independently associated with carotid atherosclerosis. The occurrence of atherosclerotic lesions was high in the studied group. Age, albuminuria, and GFR (estimated by the formula CKD-EPI using cystatin C) influenced the prevalence of carotid atherosclerosis.

Decreased Estimated Glomerular Filtration Rate (eGFR), Not Proteinuria, Is Associated with Asymptomatic Intracranial Arterial Stenosis in Chinese General Population

The relationship between chronic kidney disease (CKD), which is defined by declined estimated glomerular filtration rate (eGFR) and/or proteinuria, and asymptomatic intracranial arterial stenosis (ICAS) is largely unknown. We conducted a population-based, cross-sectional study by recruiting 5209 participants free of previous stroke, transient ischemic attack and coronary heart disease. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and proteinuria was estimated with urine dipstick. The presence of ICAS was assessed by transcranial color-coded Doppler (TCD). Out of the whole population, 684 (13.1%) participants suffered ICAS. After adjusting for the confounding factors, eGFR < 45 ml/min/m² was an independent risk factor of asymptomatic ICAS (odds ratio [OR], 3.29, 95% confidence interval [CI], 1.67–6.51), but the trend was different between the two groups stratified by the age of 60 (P = 0.01). However, the association between proteinuria and asymptomatic ICAS was not statistically significant. In conclusion, declined eGFR, not proteinuria, is associated with asymptomatic ICAS in Chinese general population, especially in people over 60 years old.

Cystatin C, vascular biomarkers and measured glomerular filtration rate in patients with unresponsive hypertensive phenotype: a pilot study

Background: Biomarkers are commonly used to estimate the presence of subclinical cardiovascular disease (CVD) in patients with essential arterial hypertension (HT). In addition to known association between cystatin C and glomerular filtration rate (GFR), elucidating the association between cystatin C and vascular biomarkers (intima-media thickness of common carotid arteries (CCIMT), carotid plaque and renal artery resistance index (RRI)) in patients with unresponsive hypertensive phenotype could be of significant clinical interest.

Methods: Participants (n = 200, median age 58 (52–64) years, 49% female) under treatment with antihypertensive drugs were stratified into two subgroups based on their blood pressure level as having responsive hypertension (RHT – compliant and responsive to treatment, n = 100), or nonresponsive (URHT – compliant but nonresponsive to treatment, n = 100). GFR was measured by isotopic (slope-intercept) method (99m Tc diethylene triamine penta-acetic acid – mGFR).

Results: The URHT group had significantly higher median cystatin C serum concentration (p = 0.02) and CCIMT (p = 0.00) compared to the RHT group, with no significant difference in RRI (p = 0.51) and mGFR among subgroups [69.9 ± 28.2 vs 76.74 ± 23.61 ml/min/1.73m², p = 0.27]. In the URHT group, cystatin C was found to be associated with CCIMT (p = 0.02), hsCRP (p = 0.01) and duration of HT (p = 0.02), independently of mGFR and age. Independent predictors of URHT phenotype were CCIMT (p= 0.02) and hsCRP (p= 0.04).

Conclusion: In addition to GFR, cystatin C serum concentration is positively and independently associated with CCIMT in patient with URHT phenotype and subclinical CVD. Prospective larger studies should further investigate the clinical importance of this relationship.

[Chronic kidney failure and carotid atherosclerosis in diabetic patient]

INTRODUCTION

Chronic kidney failure is an independent risk factor of cardiovascular disease. Its association with carotid atherosclerosis remains controversial. The purpose of our study was to assess the factors associated with carotid atherosclerosis specially the components of chronic kidney disease.

METHODS

In a cross-sectional study, we enrolled type 1 or type 2 diabetic patients from the endocrinology an diabetology department of the military hospital of Rabat assigned in two groups according to the presence or absence of carotid atherosclerosis. Kidney function was assessed based on albuminuria and the estimated glomerular filtration rate calculated using the "modification of diet in renal disease" equation. A multiple logistic regression analysis was performed to identify independent factors associated with carotid atherosclerosis.

RESULTS

One hundred and six diabetic patients were enrolled including 96 type 2 diabetic patients. Age (P<0.001), diabetes duration (P=0.04), hypertension (P=0.002), peripheral arterial disease (P<0.001) and chronic kidney failure (P=0.001) were significantly associated with carotid atherosclerosis. After adjusting for age, hypertension, diabetes duration and peripheral arterial disease, chronic kidney failure was an independent factor associated with carotid atherosclerosis (OR: 5.46; 95%IC: 1.29-23.01; P=0.021).

CONCLUSION

Our data suggest that chronic kidney failure is associated with carotid atherosclerosis in diabetic patients independently of the common cardiovascular risk factors.

Differential Association of Psychosocial Comorbidities With Subclinical Atherosclerosis in Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with an elevated risk of cardiovascular disease (CVD) events and subclinical atherosclerosis, but the reasons for the excess risk are unclear. We explored whether psychosocial comorbidities, which may be associated with CVD in the general population, are differentially associated with subclinical atherosclerosis in RA compared to controls.

METHODS

Data were from a longitudinal cohort study of 195 RA patients and 1,073 non-RA controls. Using validated scales, heterogeneity in the associations of psychosocial measures (depression, stress, anxiety/anger, support, discrimination/hassles) with measures of subclinical atherosclerosis (coronary artery calcium [CAC] and carotid intima-media thickness [IMT]/plaque) were compared in RA and non-RA groups using multivariable generalized linear models. Computed tomography and ultrasound were used to identify CAC and IMT/plaque, respectively. CAC >100 units was used to define moderate/severe CAC.

RESULTS

In RA, per-unit higher anxiety scores (odds ratio [OR] 1.10, P = 0.029), anger scores (OR 1.14, P = 0.037), depressive symptoms (OR 3.41, P = 0.032), and caregiver stress (OR 2.86, P = 0.014) were associated with increased odds of CAC >100 units after adjustment for relevant covariates. These findings persisted despite adjustment for markers of inflammation (C-reactive protein and interleukin-6 levels) and were seen only in RA, not in controls (adjusted multiplicative interaction P = 0.001-0.077). In RA, job stress was associated with an increased risk of carotid plaque (adjusted OR = 3.21, P = 0.019), and increasing social support was associated with lower internal carotid IMT (adjusted P = 0.024).

CONCLUSION

Depressive symptoms, stress, anger/anxiety, and social support may preferentially affect CVD risk in RA, and screening/treatment for psychosocial morbidities in RA may help ameliorate the additional CVD burden.

Variations in glomerular filtration rate are associated with subclinical atherosclerosis in healthy postmenopausal women

OBJECTIVE

This study aims to evaluate the potential effects of renal function variations on vascular structure before the development of hypertension.

METHODS

This pilot study included 141 postmenopausal women without evidence of renal dysfunction or hypertension. Markers of renal function and levels of glomerular filtration rate (GFR)--using standard calculations (GFR based on levels of creatinine [GFR(epi)]) and newer creatinine and/or cystatin calculations (GFR based on levels of creatinine and cystatin [GFR(cr cystatin)] and GFR based on levels of cystatin [GFR(cystatin)])--were associated with hemodynamic parameters and markers of vascular structure (intima-media thickness [IMT] and presence of atheromatous plaques in carotid and femoral arteries).

RESULTS

Levels of GFR(epi), GFR(cr cystatin), and GFR(cystatin) exhibited a significant negative correlation with femoral artery IMT, whereas levels of GFR(epi) correlated significantly with mean carotid bulb (CB) IMT. Multivariate analysis showed that CB-IMT was predicted by GFR(epi) levels and age (β-coefficient = -0.212, P = 0.020), whereas femoral artery IMT was predicted by GFR(epi) levels (β-coefficient = -0.293, P = 0.001). GFR(epi) levels lower than the 25th percentile were associated with higher CB-IMT (P = 0.009), femoral artery IMT (P = 0.001), and combined IMT (P = 0.035) compared with higher GFR(epi) levels. Moreover, GFR(epi) levels greater than the 25th percentile were associated with lower odds for the presence of atherosclerotic plaques at the CB and carotid arteries combined (CB: odds ratio, 0.146; P = 0.006; combined: odds ratio, 0.249; P = 0.043) compared with lower GFR(epi) levels.

CONCLUSIONS

A mild decrease in renal function within normal limits of GFR is independently associated with the presence of subclinical atherosclerosis in a sample of apparently healthy young postmenopausal women. Assessment of GFR using creatinine (vs cystatin C) levels is a more sensitive marker of its association with IMT and atherosclerotic plaques in this postmenopausal population.

Correlation between Carotid Intima-Media Thickness and Early-Stage Chronic Kidney Disease: Results from Asymptomatic Polyvascular Abnormalities in Community Study

OBJECTIVE

Chronic kidney disease (CKD) might be a potential independent risk factor for increased carotid intima-media thickness (IMT). Our aim is to determine whether mild to moderate kidney dysfunction is associated with increased carotid IMT.

METHODS

We employed 3629 subjects free from clinical cardiovascular diseases at the baseline visit of the Asymptomatic Polyvascular Abnormalities in Community Study. Kidney function was evaluated in terms of estimated glomerular filtration rate (eGFR) calculated by the Chronic Kidney Disease Epidemiology Collaboration China equation. The mean of the maximal internal and common carotid IMT was measured by means of high-resolution B-mode ultrasound. Univariable linear regressions and multivariate logistic regressions were used to evaluate the independent association between kidney function and carotid IMT.

RESULTS

In the unadjusted linear analysis, carotid IMT showed a significant negative correlation with eGFR in both male (r = -.346, P < .001) and female (r = -.253, P < .001) subjects. After adjustment for age, traditional vascular risk factors (smoking, diabetes, systolic blood pressure, diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, and antihypertensive drug use), and nontraditional risk factors (C-reactive protein and homocysteine), the association remained significant. The odds ratio for increased IMT was 1.299 (95% confidence interval [CI], 1.062-1.588) in the group with an eGFR of 60-89 mL/minute/1.73 m(2) and 1.789 (95% CI, 1.203-2.660) in the group with an eGFR of 30-59 mL/minute/1.73 m(2).

CONCLUSIONS

Increased IMT is associated with early-stage CKD. This association is independent of traditional and nontraditional cardiovascular risk factors. Early detection of kidney dysfunction is important to improve risk stratification of atherosclerotic disease.

Association of carotid intima-media thickness with cardiovascular risk factors and patient outcomes in advanced chronic kidney disease: the RRI-CKD study

Background: Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and an increased risk of adverse cardiovascular disease (CVD) outcomes. The relationships of intima-media thickness (IMT), a measure of subclinical atherosclerosis, with traditional and nontraditional risk factors and with adverse outcomes in CKD patients are not well-established. Methods: IMT, clinical characteristics, cardiovascular risk factors, and clinical outcomes were measured in 198 subjects from the Renal Research Institute (RRI) CKD study, a four-center prospective cohort of patients with estimated glomerular filtration rate (eGFR) ≤ 50 mL/min/1.73 m² not requiring renal replacement therapy. Results: The patients averaged 61 ± 14 years of age; the mean eGFR was 29 ± 12 mL/min/1.73 m². Maximum IMT was more closely associated with traditional cardiovascular risk factors, including age, diabetes, dyslipidemia, and systolic blood pressure, than with nontraditional risk factors or with eGFR. Higher values of maximum IMT were also independently associated with clinical CVD and with other markers of subclinical CVD. Maximum IMT ≥ 2.6 mm was predictive of the composite endpoint of CVD events and death (hazard ratio (HR): 5.47 (95% confidence interval (CI): 2.97 – 10.07, p < 0.0001)) but was not related to progression to end-stage renal disease (HR: 1.67 (95% CI: 0.74 – 3.76, p = 0.21)). Conclusion: In patients with advanced pre-dialysis CKD, higher maximum IMT was associated with traditional cardiovascular risk factors, CVD, and other markers of subclinical CVD and was an independent predictor of cardiovascular events and death. Additional research is needed to examine the clinical utility of IMT in the risk stratification and clinical management of patients with CKD.

Impact of cystatin-C level on the prevalence and angiographic characteristics of vasospastic angina in Korean patients

Cystatin-C, a marker of mild renal dysfunction, has been reported to be associated with cardiovascular diseases including vasospastic angina (VSA). We aimed to investigate the impact of cystatin-C level on the prevalence and angiographic characteristics of VSA in Korean patients.A total of 549 patients in the VA-KOREA (Vasospastic Angina in KOREA) registry who underwent ergonovine provocation tests were consecutively enrolled. Estimated glomerular filtration rate (eGFR) and levels of serum creatinine (Cr) and cystatin-C were assessed before angiography.The patients were classified into two groups: the VSA group (n = 149, 27.1%) and the non-VSA group (n = 400). Although eGFR and Cr levels were similar between the two groups, the VSA group had a significantly higher level of cystatin-C (P < 0.05). A high level of cystatin-C (second tertile, hazard ratio 1.432; 95% confidence interval [1.1491.805]; P = 0.026, third tertile, 1.947 [1.132-2.719]; P = 0.003) and current smoking (2.710 [1.415-4.098]; P < 0.001) were independently associated with the prevalence of VSA. Furthermore, the highest level of cystatin-C (> 0.96 ng/mL) had a significant impact on the incidence of multivessel spasm (2.608 [1.061-4.596]; P = 0.037).A high level of cystatin-C was independently associated with the prevalence of VSA and with a high-risk type of VSA in Korean patients, suggesting that proactive investigation of VSA should be considered for patients with mild renal dysfunction indicated by elevated cystatin-C.

Relative risks of chronic kidney disease for mortality and end-stage renal disease across races are similar

Some suggest race-specific cutpoints for kidney measures to define and stage chronic kidney disease (CKD), but evidence for race-specific clinical impact is limited. To address this issue, we compared hazard ratios of estimated glomerular filtration rates (eGFR) and albuminuria across races using meta-regression in 1.1 million adults (75% Asians, 21% Whites, and 4% Blacks) from 45 cohorts. Results came mainly from 25 general population cohorts comprising 0.9 million individuals. The associations of lower eGFR and higher albuminuria with mortality and end-stage renal disease (ESRD) were largely similar across races. For example, in Asians, Whites, and Blacks, the adjusted hazard ratios (95% confidence interval) for eGFR 45-59 versus 90-104 ml/min per 1.73 m(2) were 1.3 (1.2-1.3), 1.1 (1.0-1.2), and 1.3 (1.1-1.7) for all-cause mortality, 1.6 (1.5-1.7), 1.4 (1.2-1.7), and 1.4 (0.7-2.9) for cardiovascular mortality, and 27.6 (11.1-68.7), 11.2 (6.0-20.9), and 4.1 (2.2-7.5) for ESRD, respectively. The corresponding hazard ratios for urine albumin-to-creatinine ratio 30-299 mg/g or dipstick 1+ versus an albumin-to-creatinine ratio under 10 or dipstick negative were 1.6 (1.4-1.8), 1.7 (1.5-1.9), and 1.8 (1.7-2.1) for all-cause mortality, 1.7 (1.4-2.0), 1.8 (1.5-2.1), and 2.8 (2.2-3.6) for cardiovascular mortality, and 7.4 (2.0-27.6), 4.0 (2.8-5.9), and 5.6 (3.4-9.2) for ESRD, respectively. Thus, the relative mortality or ESRD risks of lower eGFR and higher albuminuria were largely similar among three major races, supporting similar clinical approach to CKD definition and staging, across races.

Association of kidney disease measures with ischemic versus hemorrhagic strokes: pooled analyses of 4 prospective community-based cohorts

BACKGROUND AND PURPOSE

Although low glomerular filtration rate (GFR) and albuminuria are associated with increased risk of stroke, few studies compared their contribution to risk of ischemic versus hemorrhagic stroke separately. We contrasted the association of these kidney measures with ischemic versus hemorrhagic stroke.

METHODS

We pooled individual participant data from 4 community-based cohorts: 3 from the United States and 1 from The Netherlands. GFR was estimated using both creatinine and cystatin C, and albuminuria was quantified by urinary albumin-to-creatinine ratio (ACR). Associations of estimated GFR and ACR were compared for each stroke type (ischemic versus intraparenchymal hemorrhagic) using study-stratified Cox regression.

RESULTS

Among 29,595 participants (mean age, 61 [SD 12.5] years; 46% men; 17% black), 1261 developed stroke (12% hemorrhagic) during 280,549 person-years. Low estimated GFR was significantly associated with increased risk of ischemic stroke, but not hemorrhagic stroke, whereas high ACR was associated with both stroke types. Adjusted hazard ratios for ischemic and hemorrhagic stroke at estimated GFR of 45 (versus 95) mL/min per 1.73 m2 were 1.30 (95% confidence interval, 1.01-1.68) and 0.92 (0.47-1.81), respectively. In contrast, the corresponding hazard ratios for ACR of 300 (versus 5) mg/g were 1.62 (1.27-2.07) for ischemic and 2.57 (1.37-4.83) for hemorrhagic stroke, with significantly stronger association with hemorrhagic stroke (P=0.04). For hemorrhagic stroke, the association of elevated ACR was of similar magnitude as that of elevated systolic blood pressure.

CONCLUSIONS

Whereas albuminuria showed significant association with both stroke types, the association of decreased estimated GFR was only significant for ischemic stroke. The strong association of albuminuria with both stroke types warrants clinical attention and further investigations.

Subclinical cardiovascular disease is associated with a high glomerular filtration rate in the nondiabetic general population

A reduced glomerular filtration rate (GFR) in chronic kidney disease is a risk factor for cardiovascular disease. However, evidence indicates that a high GFR may also be a cardiovascular risk factor. This issue remains unresolved due to a lack of longitudinal studies of manifest cardiovascular disease with precise GFR measurements. Here, we performed a cross-sectional study of the relationship between high GFR measured as iohexol clearance and subclinical cardiovascular disease in the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6), a representative sample of the middle-aged general population. A total of 1521 persons without cardiovascular disease, chronic kidney disease, diabetes, or micro- or macroalbuminuria were examined with carotid ultrasonography and electrocardiography. The GFR in the highest quartile was associated with an increased odds ratio of having total carotid plaque area greater than the median of non-zero values (odds ratio 1.56, 95% confidence interval 1.02-2.39) or electrocardiographic signs of left ventricular hypertrophy (odds ratio 1.62, 95% confidence interval 1.10-2.38) compared to the lowest quartile. The analyses were adjusted for cardiovascular risk factors, urinary albumin excretion, and fasting serum glucose. Thus, high GFR is associated with carotid atherosclerosis and left ventricular hypertrophy and should be investigated as a possible risk factor for manifest cardiovascular disease in longitudinal studies.

Impact of Chronic Kidney Disease on Carotid Atherosclerosis According to Blood Pressure Category

Background and Purpose—

We aimed to clarify the association of chronic kidney disease (CKD) with carotid atherosclerosis and the impact of CKD on carotid atherosclerosis according to blood pressure categories in an urban general population.

Methods—

We studied 3466 Japanese individuals (35–93 years old) in the Suita Study. Carotid atherosclerosis was expressed as the maximum carotid intima-media thickness and the presence of stenosis (>25%). The estimated glomerular filtration rate was calculated using the equations recommended by the Japanese Society of Nephrology. CKD was defined as estimated glomerular filtration rate <60 mL/min per 1.73 m 2 . Blood pressure categories were defined by the European Society of Hypertension and European Society of Cardiology 2007 criteria.

Results—

The multivariable-adjusted maximum carotid intima-media thickness and odds ratio for stenosis in subjects with estimated glomerular filtration rate <50 mL/min per 1.73 m 2 were greater than those in subjects with estimated glomerular filtration rate ≥90 mL/min per 1.73 m 2 . When subjects were stratified according to blood pressure categories, the multivariable-adjusted maximum carotid intima-media thickness was significantly greater in CKD subjects than in non-CKD subjects only in subjects with hypertension. Similarly, the impact of CKD on stenosis was evident only in subjects with hypertension (multivariable-adjusted odds ratios for stenosis [95% confidence interval] were 2.21 [1.53–3.19] in non-CKD/hypertension and 3.16 [2.05–4.88] in CKD/hypertension compared with non-CKD/optimal blood pressure).

Conclusions—

In a general population, the association of CKD with carotid atherosclerosis was modest, but CKD was independently associated with carotid atherosclerosis in subjects with hypertension.

Cystatin C versus creatinine in determining risk based on kidney function

BACKGROUND

Adding the measurement of cystatin C to that of serum creatinine to determine the estimated glomerular filtration rate (eGFR) improves accuracy, but the effect on detection, staging, and risk classification of chronic kidney disease across diverse populations has not been determined.

METHODS

We performed a meta-analysis of 11 general-population studies (with 90,750 participants) and 5 studies of cohorts with chronic kidney disease (2960 participants) for whom standardized measurements of serum creatinine and cystatin C were available. We compared the association of the eGFR, as calculated by the measurement of creatinine or cystatin C alone or in combination with creatinine, with the rates of death (13,202 deaths in 15 cohorts), death from cardiovascular causes (3471 in 12 cohorts), and end-stage renal disease (1654 cases in 7 cohorts) and assessed improvement in reclassification with the use of cystatin C.

RESULTS

In the general-population cohorts, the prevalence of an eGFR of less than 60 ml per minute per 1.73 m(2) of body-surface area was higher with the cystatin C-based eGFR than with the creatinine-based eGFR (13.7% vs. 9.7%). Across all eGFR categories, the reclassification of the eGFR to a higher value with the measurement of cystatin C, as compared with creatinine, was associated with a reduced risk of all three study outcomes, and reclassification to a lower eGFR was associated with an increased risk. The net reclassification improvement with the measurement of cystatin C, as compared with creatinine, was 0.23 (95% confidence interval [CI], 0.18 to 0.28) for death and 0.10 (95% CI, 0.00 to 0.21) for end-stage renal disease. Results were generally similar for the five cohorts with chronic kidney disease and when both creatinine and cystatin C were used to calculate the eGFR.

CONCLUSIONS

The use of cystatin C alone or in combination with creatinine strengthens the association between the eGFR and the risks of death and end-stage renal disease across diverse populations. (Funded by the National Kidney Foundation and others.).

Cystatin C versus creatinine in determining risk based on kidney function

BACKGROUND

Adding the measurement of cystatin C to that of serum creatinine to determine the estimated glomerular filtration rate (eGFR) improves accuracy, but the effect on detection, staging, and risk classification of chronic kidney disease across diverse populations has not been determined.

METHODS

We performed a meta-analysis of 11 general-population studies (with 90,750 participants) and 5 studies of cohorts with chronic kidney disease (2960 participants) for whom standardized measurements of serum creatinine and cystatin C were available. We compared the association of the eGFR, as calculated by the measurement of creatinine or cystatin C alone or in combination with creatinine, with the rates of death (13,202 deaths in 15 cohorts), death from cardiovascular causes (3471 in 12 cohorts), and end-stage renal disease (1654 cases in 7 cohorts) and assessed improvement in reclassification with the use of cystatin C.

RESULTS

In the general-population cohorts, the prevalence of an eGFR of less than 60 ml per minute per 1.73 m(2) of body-surface area was higher with the cystatin C-based eGFR than with the creatinine-based eGFR (13.7% vs. 9.7%). Across all eGFR categories, the reclassification of the eGFR to a higher value with the measurement of cystatin C, as compared with creatinine, was associated with a reduced risk of all three study outcomes, and reclassification to a lower eGFR was associated with an increased risk. The net reclassification improvement with the measurement of cystatin C, as compared with creatinine, was 0.23 (95% confidence interval [CI], 0.18 to 0.28) for death and 0.10 (95% CI, 0.00 to 0.21) for end-stage renal disease. Results were generally similar for the five cohorts with chronic kidney disease and when both creatinine and cystatin C were used to calculate the eGFR.

CONCLUSIONS

The use of cystatin C alone or in combination with creatinine strengthens the association between the eGFR and the risks of death and end-stage renal disease across diverse populations. (Funded by the National Kidney Foundation and others.).

Association between cystatin C and arteriosclerosis in the absence of chronic kidney disease

AIM

Chronic kidney disease (CKD) is a known risk factor for cardiovascular disease (CVD). Cystatin C was recently reported to be an endogenous surrogate of kidney function, and a high level of cystatin C is reported to be a strong predictor of CVD; however, the association between cystatin C and arteriosclerosis in a non-CKD population is unclear. This study aimed to clarify the association between cystatin C and arteriosclerosis in a non-CKD population.

METHODS

Of the 637 Japanese adults (264 men, 373 women) enrolled, we analyzed 446 participants with an estimated glomerular filtration rate (eGFR) >60 mL/min and no proteinuria (177 men, 269 women) without a history of CVD. Kidney function was evaluated according to serum cystatin C levels and eGFR. Arteriosclerosis was evaluated on the basis of the cardio-ankle vascular index (CAVI) and carotid intima-media thickness (CIMT).

RESULTS

The mean age of our subjects was 67.0±10.0 years. No variables showed any significant differences according to gender. The results of multiple linear regression analysis showed a significant correlation between serum cystatin C and CAVI only in women, but not CIMT.

CONCLUSION

We observed a significant correlation between cystatin C and CAVI, which is a marker of early-stage arteriosclerosis, in women in a non-CKD population with no proteinuria and eGFR>60 mL/min.

Mild renal dysfunction and metabolites tied to low HDL cholesterol are associated with monocytosis and atherosclerosis

BACKGROUND

The number of circulating blood monocytes impacts atherosclerotic lesion size, and in mouse models, elevated levels of high-density lipoprotein cholesterol suppress blood monocyte counts and atherosclerosis. We hypothesized that individuals with mild renal dysfunction at increased cardiovascular risk would have reduced high-density lipoprotein levels, high blood monocyte counts, and accelerated atherosclerosis.

METHODS AND RESULTS

To test whether mild renal dysfunction is associated with an increase in a leukocyte subpopulation rich in monocytes that has a known association with future coronary events, we divided individuals from the Malmö Diet and Cancer study (MDC) into baseline cystatin C quintiles (n=4757). Lower levels of renal function were accompanied by higher monocyte counts, and monocytes were independently associated with carotid bulb intima-media thickness cross-sectionally (P=0.02). Cystatin C levels were positively and plasma high-density lipoprotein cholesterol levels negatively associated with monocyte counts at baseline, after adjustment for traditional risk factors. Several amino acid metabolites tied to low levels of high-density lipoprotein cholesterol and insulin resistance measured in a subset of individuals (n=752) by use of liquid chromatography-mass spectrometry were independently associated with a 22% to 34% increased risk of being in the top quartile of monocytes (P<0.05).

CONCLUSIONS

A low high-density lipoprotein cholesterol, insulin resistance phenotype occurs in subjects with mild renal dysfunction and is associated with elevated monocytes and atherosclerosis. High blood monocyte counts may represent a previously unrecognized mechanism underlying the strong relationship between cystatin C and cardiovascular risk.

Chronic kidney disease, plasma lipoproteins, and coronary artery calcium incidence: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To determine the association of chronic kidney disease and coronary artery calcium (CAC) incidence, and the distribution of lipoproteins across categories of kidney function and their association with CAC risk.

METHODS AND RESULTS

We analyzed data from 2795 participants in the Multi-Ethnic Study of Atherosclerosis with no CAC (calcium score=0) at baseline enrolled at the first Multi-Ethnic Study of Atherosclerosis visit between the years 2000 and 2002. During a median follow-up of 2.4 years, incident calcium (calcium score>0 at follow-up) developed in 12%, 19%, and 27% of participants with a cystatin-c estimated glomerular filtration rate (mL/min per 1.73 m)(2) of ≥90, 60 to 89, and 30 to 59 (P for difference <0.001), respectively. Compared with those with normal kidney function (estimated glomerular filtration rate≥90), adjusted CAC incidence risk ratios, and 95% confidence intervals (CIs) were as follows: 1.26 (95% CI, 1.04-1.52), and 1.56 (95% CI, 1.11-2.20; P(trend)=0.014) in those with estimated glomerular filtration rate of 60 to 89 and 30 to 59, respectively. These associations were attenuated after adjusting for a characteristic and strongly interrelated lipid phenotype (principal component 1), which was more common in those with chronic kidney disease and characterized by a predominance of triglyceride-rich lipoproteins: CAC incidence risk ratios=1.21 (95% CI, 1.00-1.46) and 1.44 (95% CI, 1.02-2.04; P(trend)=0.06) in those with estimated glomerular filtration rate 60 to 89 and 30 to 59, respectively, after adjusting for principal component 1.

CONCLUSIONS

Chronic kidney disease is strongly associated with CAC incidence. Part of this association is mediated through a characteristic lipid phenotype comprising elevations in triglyceride-rich lipoproteins.

The association between renal function biomarkers and subclinical cardiovascular measures in African Caribbean families

BACKGROUND

Risk of cardiovascular disease (CVD) and mortality are increased in people with subclinical CVD. The impact of ethnicity and race on subclinical CVD is substantial. Previous studies assessed the heritability of several renal function biomarkers and their relationship with subclinical CVD among populations of European ancestries, but, to our knowledge, no such data are available in African ancestry populations.

OBJECTIVE

Our aim was to investigate the relationships between renal function biomarkers and subclinical CVD among Afro-Caribbeans residing on the island of Tobago.

DESIGN AND METHODS

402 participants, aged 18 to 103 years, from seven large, multi-generation pedigrees (average family size: 50; range: 19 to 96; -3500 relative pairs) were included in this study. Subclinical cardiovascular disease (SCVD) was assessed by brachial-ankle pulse wave velocity (baPWV) and carotid intima-media thickness (IMT). Serum cystatin C, creatinine, and eGFR based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation were used to assess kidney function. The variance component approach, implemented in Sequential Oligogenic Linkage Analysis Routines (SOLAR), was used to assess heritability of these traits, and association with SCVD.

RESULTS

Heritability of renal function biomarkers ranged from .19-.32 (all P < .001), and was highest for cystatin C (h2 = .32, P < .0001). Serum cystatin C was independently associated with arterial stiffness (P = .04). This association was not found with other renal function biomarkers. No significant association between renal function and IMT was found.

CONCLUSION

Our data suggest that cystatin C is significantly heritable and associated with arterial stiffness among Afro-Caribbeans.

Age and association of kidney measures with mortality and end-stage renal disease

CONTEXT

Chronic kidney disease (CKD) is prevalent in older individuals, but the risk implications of low estimated glomerular filtration rate (eGFR) and high albuminuria across the full age range are controversial.

OBJECTIVE

To evaluate possible effect modification (interaction) by age of the association of eGFR and albuminuria with clinical risk, examining both relative and absolute risks.

DESIGN, SETTING, AND PARTICIPANTS

Individual-level meta-analysis including 2,051,244 participants from 33 general population or high-risk (of vascular disease) cohorts and 13 CKD cohorts from Asia, Australasia, Europe, and North/South America, conducted in 1972-2011 with a mean follow-up time of 5.8 years (range, 0-31 years).

MAIN OUTCOME MEASURES

Hazard ratios (HRs) of mortality and end-stage renal disease (ESRD) according to eGFR and albuminuria were meta-analyzed across age categories after adjusting for sex, race, cardiovascular disease, diabetes, systolic blood pressure, cholesterol, body mass index, and smoking. Absolute risks were estimated using HRs and average incidence rates.

RESULTS

Mortality (112,325 deaths) and ESRD (8411 events) risks were higher at lower eGFR and higher albuminuria in every age category. In general and high-risk cohorts, relative mortality risk for reduced eGFR decreased with increasing age; eg, adjusted HRs at an eGFR of 45 mL/min/1.73 m2 vs 80 mL/min/1.73 m2 were 3.50 (95% CI, 2.55-4.81), 2.21 (95% CI, 2.02-2.41), 1.59 (95% CI, 1.42-1.77), and 1.35 (95% CI, 1.23-1.48) in age categories 18-54, 55-64, 65-74, and ≥75 years, respectively (P <.05 for age interaction). Absolute risk differences for the same comparisons were higher at older age (9.0 [95% CI, 6.0-12.8], 12.2 [95% CI, 10.3-14.3], 13.3 [95% CI, 9.0-18.6], and 27.2 [95% CI, 13.5-45.5] excess deaths per 1000 person-years, respectively). For increased albuminuria, reduction of relative risk with increasing age was less evident, while differences in absolute risk were higher in older age categories (7.5 [95% CI, 4.3-11.9], 12.2 [95% CI, 7.9-17.6], 22.7 [95% CI, 15.3-31.6], and 34.3 [95% CI, 19.5-52.4] excess deaths per 1000 person-years, respectively by age category, at an albumin-creatinine ratio of 300 mg/g vs 10 mg/g). In CKD cohorts, adjusted relative hazards of mortality did not decrease with age. In all cohorts, ESRD relative risks and absolute risk differences at lower eGFR or higher albuminuria were comparable across age categories.

CONCLUSIONS

Both low eGFR and high albuminuria were independently associated with mortality and ESRD regardless of age across a wide range of populations. Mortality showed lower relative risk but higher absolute risk differences at older age.

A study of atherosclerosis in patients with chronic renal failure with special reference to carotid artery intima media thickness

Objectives:

Cardiovascular disease is the leading cause of morbidity and mortality in patients with chronic renal failure (CRF). This study attempts to identify the factors responsible for atherosclerosis in CRF patients using carotid artery intima media thickness (CAIMT) as a surrogate marker of atherosclerosis.

Materials and Methods:

CAIMT was measured by high-resolution B-mode ultrasonography in 100 CRF patients and 50 age- and sex-matched healthy controls. Data were analyzed by software SPSS (17^th version) for Windows.

Results:

CRF patients had a significantly higher CAIMT (1026.83 ± 17.19 micron, mean ± SE, P < 0.001) than age- and sex-matched healthy controls (722.46 ± 7.61 micron). There was inverse correlation between CAIMT and glomerular filtration rate (GFR) (P < 0.001) independent of traditional risk factors. There was also significant positive correlation between CAIMT and traditional risk factors of atherosclerosis. Ischemic heart disease (IHD) also showed positive correlation with CAIMT (P = 0.007) and inverse correlation with GFR (P = 0.005).

Conclusions:

There is high prevalence of atherosclerosis in CRF patients. CAIMT can be used to detect and predict future incidence of IHD in CRF patients.

Age, sex, and hypertension-related remodeling influences left ventricular torsion assessed by tagged cardiac magnetic resonance in asymptomatic individuals: the multi-ethnic study of atherosclerosis

BACKGROUND

The aim of the present study was to evaluate how torsion is influenced by left ventricular (LV) remodeling associated with age, sex, and hypertension in a large community-based population.

METHODS AND RESULTS

Myocardial shortening and torsion were assessed by tagged cardiac magnetic resonance in 1478 participants without clinically apparent cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis (MESA). Torsion was defined as the difference between apical and basal rotation divided by slice distance. In multivariable linear regression models, older age was associated with lower stroke volume (-3.6 mL per decade; P<0.001) and higher LV mass-to-volume ratio (0.03 g/mL per decade; P<0.001), along with lower circumferential shortening (-0.17% per decade; P<0.05). Torsion, however, was greater at older ages (0.14° per decade; P<0.001) and in women (0.37°/cm versus men; P<0.001). Hypertensive participants had higher LV mass and LV mass-to-volume ratio (15.5 g and 0.07 g/mL, respectively; P<0.001 for both). Circumferential shortening was lower in hypertensive (-0.42%; P<0.01), whereas torsion was higher after adjustment for age and sex (0.17°/cm; P<0.05).

CONCLUSIONS

Older age is associated with lower LV volumes and greater relative wall thickness and is accompanied by lower circumferential myocardial shortening, whereas torsion is greater with older age. Hypertensive individuals have greater LV volumes and relative wall thickness and lower circumferential shortening. Torsion, however, is greater in hypertension independently of age and sex. Torsion may therefore represent a compensatory mechanism to maintain an adequate stroke volume and cardiac output in the face of the progressively reduced LV volumes and myocardial shortening associated with hypertension and aging.

Comparison of risk prediction using the CKD-EPI equation and the MDRD study equation for estimated glomerular filtration rate

CONTEXT

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation more accurately estimates glomerular filtration rate (GFR) than the Modification of Diet in Renal Disease (MDRD) Study equation using the same variables, especially at higher GFR, but definitive evidence of its risk implications in diverse settings is lacking.

OBJECTIVE

To evaluate risk implications of estimated GFR using the CKD-EPI equation compared with the MDRD Study equation in populations with a broad range of demographic and clinical characteristics.

DESIGN, SETTING, AND PARTICIPANTS

A meta-analysis of data from 1.1 million adults (aged ≥ 18 years) from 25 general population cohorts, 7 high-risk cohorts (of vascular disease), and 13 CKD cohorts. Data transfer and analyses were conducted between March 2011 and March 2012.

MAIN OUTCOME MEASURES

All-cause mortality (84,482 deaths from 40 cohorts), cardiovascular mortality (22,176 events from 28 cohorts), and end-stage renal disease (ESRD) (7644 events from 21 cohorts) during 9.4 million person-years of follow-up; the median of mean follow-up time across cohorts was 7.4 years (interquartile range, 4.2-10.5 years).

RESULTS

Estimated GFR was classified into 6 categories (≥90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m(2)) by both equations. Compared with the MDRD Study equation, 24.4% and 0.6% of participants from general population cohorts were reclassified to a higher and lower estimated GFR category, respectively, by the CKD-EPI equation, and the prevalence of CKD stages 3 to 5 (estimated GFR <60 mL/min/1.73 m(2)) was reduced from 8.7% to 6.3%. In estimated GFR of 45 to 59 mL/min/1.73 m(2) by the MDRD Study equation, 34.7% of participants were reclassified to estimated GFR of 60 to 89 mL/min/1.73 m(2) by the CKD-EPI equation and had lower incidence rates (per 1000 person-years) for the outcomes of interest (9.9 vs 34.5 for all-cause mortality, 2.7 vs 13.0 for cardiovascular mortality, and 0.5 vs 0.8 for ESRD) compared with those not reclassified. The corresponding adjusted hazard ratios were 0.80 (95% CI, 0.74-0.86) for all-cause mortality, 0.73 (95% CI, 0.65-0.82) for cardiovascular mortality, and 0.49 (95% CI, 0.27-0.88) for ESRD. Similar findings were observed in other estimated GFR categories by the MDRD Study equation. Net reclassification improvement based on estimated GFR categories was significantly positive for all outcomes (range, 0.06-0.13; all P < .001). Net reclassification improvement was similarly positive in most subgroups defined by age (<65 years and ≥65 years), sex, race/ethnicity (white, Asian, and black), and presence or absence of diabetes and hypertension. The results in the high-risk and CKD cohorts were largely consistent with the general population cohorts.

CONCLUSION

The CKD-EPI equation classified fewer individuals as having CKD and more accurately categorized the risk for mortality and ESRD than did the MDRD Study equation across a broad range of populations.

Subclinical atherosclerotic changes related to chronic kidney disease in asymptomatic black and white young adults: the Bogalusa heart study

PURPOSE

Chronic kidney disease (CKD) remains asymptomatic until its late stage, and also significantly increases the risk of cardiovascular (CV) disease morbidity and mortality. However, information in scant on the prevalence of CKD, and its association with subclinical atherosclerosis as depicted by carotid intima media thickness (IMT) in younger adults.

METHODS

This cross-sectional study included 1193 participants (43% males, 30% blacks) aged 23 to 43 years, residing in the semi-rural biracial (black-white) community of Bogalusa, Louisiana. The measured variables include estimated glomerular filtration rate (eGFR) to determine functional renal changes and urine album creatinine ratio to diagnose albuminuria, along with CV risk factor variables, and both segmental and composite carotid IMT.

RESULTS

Ninety-nine (8.5%) subjects had CKD, with blacks showing higher prevalence than whites (p = .01). Subjects with albuminuria had significantly greater internal carotid IMT (p = .03), common carotid IMT (p = .005), and composite carotid IMT (p = .04) than those without. In the multivariate logistic regression model, albuminuria was associated with black race (odds ratio [OR], 1.92; p = .005), female gender (OR, 2.24; p = .002), diabetes (OR, 6.26; p < .001), hypertension (OR, 2.36; p < .001), obesity (OR, 1.73; p = 0.02), and composite carotid IMT (OR, 1.83; p = .02), after adjusting for age. However, reduction in eGFR did not show significant independent association with carotid IMT.

CONCLUSION

Among asymptomatic young adults, subclinical atherosclerosis and structural renal damage depicted by albuminuria coexist, which has implications for early prevention and control.

Lower estimated GFR and higher albuminuria are associated with adverse kidney outcomes. A collaborative meta-analysis of general and high-risk population cohorts

Both a low estimated glomerular filtration rate (eGFR) and albuminuria are known risk factors for end-stage renal disease (ESRD). To determine their joint contribution to ESRD and other kidney outcomes, we performed a meta-analysis of nine general population cohorts with 845,125 participants and an additional eight cohorts with 173,892 patients, the latter selected because of their high risk for chronic kidney disease (CKD). In the general population, the risk for ESRD was unrelated to eGFR at values between 75 and 105 ml/min per 1.73 m(2) but increased exponentially at lower levels. Hazard ratios for eGFRs averaging 60, 45, and 15 were 4, 29, and 454, respectively, compared with an eGFR of 95, after adjustment for albuminuria and cardiovascular risk factors. Log albuminuria was linearly associated with log ESRD risk without thresholds. Adjusted hazard ratios at albumin-to-creatinine ratios of 30, 300, and 1000 mg/g were 5, 13, and 28, respectively, compared with an albumin-to-creatinine ratio of 5. Albuminuria and eGFR were associated with ESRD, without evidence for multiplicative interaction. Similar associations were found for acute kidney injury and progressive CKD. In high-risk cohorts, the findings were generally comparable. Thus, lower eGFR and higher albuminuria are risk factors for ESRD, acute kidney injury and progressive CKD in both general and high-risk populations, independent of each other and of cardiovascular risk factors.

Reduced kidney function and preclinical atherosclerosis in HIV-infected individuals: the study of fat redistribution and metabolic change in HIV infection (FRAM)

BACKGROUND/AIMS

Reduced kidney function and albuminuria are associated with higher risk for cardiovascular disease (CVD) and mortality in HIV-infected individuals. We investigated whether reduced estimated glomerular filtration rate (eGFR) and albuminuria are associated with subclinical vascular disease, as assessed by carotid intima-medial thickness (cIMT).

METHODS

Cross-sectional analysis of 476 HIV-infected individuals without clinical evidence of CVD enrolled in the Fat Redistribution and Metabolic Change in HIV infection (FRAM) study, using multivariable linear regression. eGFR(Cys) and eGFR(Cr) were calculated from cystatin C and creatinine levels. Albuminuria was defined as a positive urine dipstick (≥ 1+) or urine albumin-to-creatinine ratio ≥ 30 mg/g. Common and internal cIMT were measured by high-resolution B-mode ultrasound.

RESULTS

In unadjusted analyses, eGFR(Cys) and eGFR(Cr) were strongly associated with com- mon and internal cIMT. Each 10 ml/min/1.73 m2 decrease in eGFR(Cys) and eGFR(cr) was associated with a 0.008 mm higher common cIMT (p = 0.003, p = 0.01) and a 0.024 and 0.029 mm higher internal cIMT (p = 0.003), respectively. These associations were eliminated after adjustment for age, gender, and race. Albuminuria showed little association with common or internal cIMT in all models.

CONCLUSIONS

In HIV-infected individuals without prior CVD, reduced kidney function and albuminuria were not independently associated with subclinical vascular disease, as assessed by cIMT. These results suggest that research should focus on searching for novel mechanisms by which kidney disease confers cardiovascular risk in HIV-infected individuals.

Association of estimated glomerular filtration rate and albuminuria with all-cause and cardiovascular mortality in general population cohorts: a collaborative meta-analysis

BACKGROUND

Substantial controversy surrounds the use of estimated glomerular filtration rate (eGFR) and albuminuria to define chronic kidney disease and assign its stages. We undertook a meta-analysis to assess the independent and combined associations of eGFR and albuminuria with mortality.

METHODS

In this collaborative meta-analysis of general population cohorts, we pooled standardised data for all-cause and cardiovascular mortality from studies containing at least 1000 participants and baseline information about eGFR and urine albumin concentrations. Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause and cardiovascular mortality associated with eGFR and albuminuria, adjusted for potential confounders.

FINDINGS

The analysis included 105,872 participants (730,577 person-years) from 14 studies with urine albumin-to-creatinine ratio (ACR) measurements and 1,128,310 participants (4,732,110 person-years) from seven studies with urine protein dipstick measurements. In studies with ACR measurements, risk of mortality was unrelated to eGFR between 75 mL/min/1.73 m(2) and 105 mL/min/1.73 m(2) and increased at lower eGFRs. Compared with eGFR 95 mL/min/1.73 m(2), adjusted HRs for all-cause mortality were 1.18 (95% CI 1.05-1.32) for eGFR 60 mL/min/1.73 m(2), 1.57 (1.39-1.78) for 45 mL/min/1.73 m(2), and 3.14 (2.39-4.13) for 15 mL/min/1.73 m(2). ACR was associated with risk of mortality linearly on the log-log scale without threshold effects. Compared with ACR 0.6 mg/mmol, adjusted HRs for all-cause mortality were 1.20 (1.15-1.26) for ACR 1.1 mg/mmol, 1.63 (1.50-1.77) for 3.4 mg/mmol, and 2.22 (1.97-2.51) for 33.9 mg/mmol. eGFR and ACR were multiplicatively associated with risk of mortality without evidence of interaction. Similar findings were recorded for cardiovascular mortality and in studies with dipstick measurements.

INTERPRETATION

eGFR less than 60 mL/min/1.73 m(2) and ACR 1.1 mg/mmol (10 mg/g) or more are independent predictors of mortality risk in the general population. This study provides quantitative data for use of both kidney measures for risk assessment and definition and staging of chronic kidney disease.

FUNDING

Kidney Disease: Improving Global Outcomes (KDIGO), US National Kidney Foundation, and Dutch Kidney Foundation.

Increased prevalence of carotid artery atherosclerosis in rheumatoid arthritis is artery-specific

OBJECTIVE

Cardiovascular (CV) morbidity and mortality are increased in rheumatoid arthritis (RA). Prior investigations of the association of RA with measures of carotid atherosclerosis have yielded conflicting results. We compared carotid intima-media thickness (IMT) of both the common carotid (CCA) and proximal internal carotid (bulb-ICA) arteries, and plaque prevalence, between RA and non-RA participants.

METHODS

Subjects with RA were participants in a cohort study of subclinical CV disease in RA. Non-RA controls were selected from the Multi-Ethnic Study of Atherosclerosis. Both groups underwent B-mode ultrasonography of the right and left CCA and bulb-ICA. Linear regression was used to model the association of RA status with CCA and bulb-ICA-IMT, and logistic regression for the association of RA status with plaque.

RESULTS

We compared 195 RA patients to 198 non-RA controls. CV risk factors were similarly distributed, except for a higher prevalence of hypertension in the RA group. Mean adjusted bulb-ICA-IMT was higher in RA patients than controls (1.16 vs 1.02 mm, respectively; p < 0.001), while mean adjusted CCA-IMT did not differ significantly. After adjusting for CV risk factors, the odds of plaque were significantly increased in RA participants compared to controls (OR 2.41, 95% CI 1.26-4.61). The association of gender, age, smoking, and hypertension with bulb-ICA-IMT and plaque did not significantly differ by RA status. Interleukin 6 was strongly associated with bulb-ICA-IMT and plaque in controls but not in RA patients. In the RA group, shared epitope was associated with an increased prevalence of plaque.

CONCLUSION

Compared to controls, RA was associated with a higher prevalence and higher severity of atherosclerosis in the bulb-ICA but not the CCA. Our data suggest that future studies in RA that utilize carotid artery measurements should include assessment of the bulb-ICA.