Risk factor profile for chronic kidney disease is similar to risk factor profile for small artery disease

Relationship between chronic kidney disease and cerebral white matter hyperintensities: a systematic review

Background

This systematic review summarizes available evidence on the relationship between white matter hyperintensities (WMH) volumetric quantification on brain MRI scans and chronic kidney disease (CKD).

Methods

The literature search was performed in March 2022 using MEDLINE PubMed Central, Scopus and Web of Science - Publons as search engines. Relevant articles investigating, with a quantitative volumetric approach, the link between WMH and CKD patients were selected.

Results

The database search strategy found 987 articles, after excluding duplicates, the titles and abstracts of the remaining 320 articles were examined. Subsequently 276 articles were excluded as they were not relevant to the topic. Of the 44 articles evaluated for eligibility, 36 were excluded because the quantitative analysis of WMH was not volumetric. Finally, 8 articles were included in this systematic review.

Conclusions

Literature on this topic is extremely heterogeneous in terms of methodology and samples. However, evidence shows that there is a relationship between CKD and WMH volume of the brain. We recommend that quantifiable biomarkers such as estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (UACR) should be included in studies dealing with cerebrovascular disease. The biological and molecular mechanisms underlying cerebrovascular damage in patients with chronic renal failure deserve to be further explored.

Association of urinary angiotensinogen with renal arteriolar remodeling in chronic kidney disease

OBJECTIVE

Renin-angiotensin system (RAS) might be associated with arteriolar remodeling. The present study aimed to explore the hitherto unknown relationship between renal RAS and renal arteriolar remodeling and to elucidate whether altered renal RAS subsequently affects renal function in patients with chronic kidney disease (CKD).

METHODS

In this retrospective study, patients with various CKDs not using RAS inhibitors who underwent renal biopsy were included in cross-sectional and longitudinal analyses. Urinary angiotensinogen (UAGT) levels and wall/lumen ratio (WLR) were determined to evaluate renal RAS and renal arteriolar remodeling, respectively. The association between ln(UAGT) and ln(WLR) was cross-sectionally examined using a liner regression model. Furthermore, the association of ln(UAGT) with subsequent changes in estimated glomerular filtration rate (eGFR) per year were longitudinally examined in the largest subgroup of patients who were diagnosed with IgA nephropathy.

RESULTS

In the overall cohort (n = 54), the median age, blood pressures, eGFR, and WLR were 37 years, 120/73 mmHg, 85 ml/min per 1.73 m2, and 0.93, respectively. Ln(UAGT) was significantly and positively associated with ln(WLR) even after adjusting for classical and nonclassical clinical renal risk factors. In patients with IgA nephropathy, higher ln(UAGT) was associated with higher ln(WLR). Ln(UAGT) also tended to be associated with a greater decline in eGFR per year over a median period of 8.7 years, even after adjusting for potential confounding factors.

CONCLUSION

In patients with CKD, renal RAS might be associated with renal arteriolar remodeling and future decline in eGFR, independent of potential risk factors.

Interactions Between Kidney Function and Cerebrovascular Disease: Vessel Pathology That Fires Together Wires Together

The kidney and the brain, as high-flow end organs relying on autoregulatory mechanisms, have unique anatomic and physiological hemodynamic properties. Similarly, the two organs share a common pattern of microvascular dysfunction as a result of aging and exposure to vascular risk factors (e.g., hypertension, diabetes and smoking) and therefore progress in parallel into a systemic condition known as small vessel disease (SVD). Many epidemiological studies have shown that even mild renal dysfunction is robustly associated with acute and chronic forms of cerebrovascular disease. Beyond ischemic SVD, kidney impairment increases the risk of acute cerebrovascular events related to different underlying pathologies, notably large artery stroke and intracerebral hemorrhage. Other chronic cerebral manifestations of SVD are variably associated with kidney disease. Observational data have suggested the hypothesis that kidney function influences cerebrovascular disease independently and adjunctively to the effect of known vascular risk factors, which affect both renal and cerebral microvasculature. In addition to confirming this independent association, recent large-scale human genetic studies have contributed to disentangling potentially causal associations from shared genetic predisposition and resolving the uncertainty around the direction of causality between kidney and cerebrovascular disease. Accelerated atherosclerosis, impaired cerebral autoregulation, remodeling of the cerebral vasculature, chronic inflammation and endothelial dysfunction can be proposed to explain the additive mechanisms through which renal dysfunction leads to cerebral SVD and other cerebrovascular events. Genetic epidemiology also can help identify new pathological pathways which wire kidney dysfunction and cerebral vascular pathology together. The need for identifying additional pathological mechanisms underlying kidney and cerebrovascular disease is attested to by the limited effect of current therapeutic options in preventing cerebrovascular disease in patients with kidney impairment.

Association of Albuminuria With White Matter Hyperintensities Volume on Brain Magnetic Resonance Imaging in Elderly Japanese - The Hisayama Study

BACKGROUND

Both chronic kidney disease and brain white matter hyperintensities (WMH) are known to be risk factors of dementia and mortality.Methods and Results:In 2012, 1,214 community-dwelling Japanese subjects aged ≥65 years underwent brain magnetic resonance imaging (MRI) scans and a comprehensive health examination. This study investigated associations of the urinary albumin : creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) with the WMH volume to intracranial volume (WMHV : ICV) ratio, and the association of the combination of UACR and the WMHV : ICV ratio with cognitive decline and mortality risk. The geometric mean of the WMHV : ICV ratio was 0.223% in the entire study population, and increased significantly with higher UACR levels after adjusting for potential confounding factors (0.213% for normoalbuminuria, 0.248% for microalbuminuria, and 0.332% for macroalbuminuria; P_trend=0.01). In contrast, there was no clear association between eGFR and the WMHV : ICV ratio. Compared with subjects with normoalbuminuria and a smaller WMHV : ICV ratio (<0.257% [median]), subjects with albuminuria and a larger WMHV : ICV ratio (≥0.257%) had higher probabilities of cognitive decline at baseline and all-cause death during the follow-up.

CONCLUSIONS

This study suggests that subjects with albuminuria have a greater risk of WMH enlargement and that the combination of albuminuria and WMH enlargement increases the risk of cognitive decline and all-cause mortality in an elderly Japanese population.

Assessment of Renal Function and Risk Factors for Chronic Kidney Disease in Patients With Peripheral Arterial Disease

Chronic kidney disease (CKD) and peripheral arterial disease (PAD) share common risk factors. We assessed renal function and the prevalence of CKD in patients with PAD and investigated the characteristics of the risk factors for CKD in this population. Renal function of 421 patients with PAD was evaluated. Among the participants, 194 (46.1%) patients had decreased estimated glomerular filtration rate (eGFR). The prevalence of CKD was much higher among patients with PAD. Hypertension (odds ratios [ORs] 2.156, 95% confidence interval [CI] 1.413-3.289, P < .001), serum uric acid (OR 3.794, 95% CI 2.220-6.450, P < .001), and dyslipidemia (OR 1.755, 95% CI 1.123-2.745, P = .014) were significantly associated with CKD and the independent risk factors for CKD in patients with PAD. CKD is common and has a high prevalence in a population with PAD. Patients with PAD may be considered as a high-risk population for CKD. Recognition and modification of risk factors for CKD might beneficially decrease CKD incidence and improve prognosis in patients with PAD.

Decreased kidney function relates to progression of cerebral microbleeds in lacunar stroke patients

BACKGROUND

It is hypothesized that impaired kidney function and cerebral microbleeds represent microvascular damage in different organs. Several cross-sectional studies found impaired kidney function to be associated with the presence of cerebral microbleeds.

AIM

To further confirm the association between both small vessel diseases, we aimed to determine whether kidney function is related to progression of cerebral microbleeds in a longitudinal study design.

METHODS

In 89 lacunar stroke patients, baseline brain magnetic resonance imaging (including gradient-echo images), baseline estimated glomerular filtration rate (eGFR), blood pressure measurements, and follow-up brain magnetic resonance imaging after two years were available. Presence of cerebral microbleeds on baseline and follow-up magnetic resonance imaging was scored visually. Cerebral microbleeds progression was defined as the presence of any new microbleed on follow-up magnetic resonance imaging. The association between cerebral microbleeds progression (dependent variable) and eGFR (independent variable) was assessed by logistic regression analysis.

RESULTS

Cerebral microbleeds progression was present in 17 patients (19.1%). Lower eGFR was associated with cerebral microbleeds progression (OR 1.55 per 10 ml/min/1.73 m(2) decrease, 95% CI 1.05-2.30, with correction for sex and age). After additional correction for baseline presence of cerebral microbleeds or correction for cardiovascular risk factors, including blood pressure, this result remained significant.

CONCLUSIONS

In this longitudinal study, we found an independent association between lower eGFR and cerebral microbleeds progression. Cerebral microbleeds and impaired kidney function are both seen as manifestations of microvascular organ damage and our findings further strengthen the association between both small vessel pathologies and also the assumption that small vessel disease could be considered a multisystem disorder.

Cerebral small vessel disease and renal function: systematic review and meta-analysis

Background

The small vessel disease (SVD) that appears in the brain may be part of a multisystem disorder affecting other vascular beds such as the kidney and retina. Because renal failure is associated with both stroke and white matter hyperintensities we hypothesised that small vessel (lacunar) stroke would be more strongly associated with renal failure than cortical stroke. Therefore, we performed a systematic review and meta-analysis to establish first if lacunar stroke was associated with the renal function, and second, if cerebral small vessel disease seen on the MRI of patients without stroke was more common in patients with renal failure.

Methods

We searched Medline and EMBASE for studies in adults with cerebral SVD (lacunar stroke or white matter hyper intensities (WMH) on Magnetic Resonance Imaging (MRI)), in which renal function was assessed (estimated glomerular filtration rate (eGFR) or proteinuria). We extracted data on SVD diagnosis, renal function, demographics and comorbidities. We performed two meta-analyses: first, we calculated the odds of renal impairment in lacunar (small vessel) ischaemic stroke compared to other ischaemic stroke subtypes (non-small vessel disease); and second, we calculated the odds of renal impairment in non-stroke individuals with WMH on MRI compared to individuals without WMH. We then performed a sensitivity analysis by excluding studies with certain characteristics and repeating the meta-analysis calculation.

Results

After screening 11,001 potentially suitable titles, we included 37 papers reporting 32 studies of 20,379 subjects: 15 of stroke patients and 17 of SVD features in non-stroke patients. To diagnose lacunar stroke, 13/15 of the studies used risk factor-based classification (none used diffusion-weighted MRI). 394/1,119 (35%) of patients with lacunar stroke had renal impairment compared with 1,443/4,217 (34%) of patients with non-lacunar stroke, OR 0.88, (95% CI 0.6-1.30). In individuals without stroke the presence of SVD was associated with an increased risk of renal impairment (whether proteinuria or reduced eGFR) OR 2.33 (95% CI 1.80-3.01), when compared to those without SVD. After adjustment for age and hypertension, 15/21 studies still reported a significant association between renal impairment and SVD.

Conclusion

We found no specific association between renal impairment and lacunar stroke, but we did find that in individuals who had not had a stroke, having more SVD features on imaging was associated with a worse renal function, which remained significant after controlling for hypertension. However, this finding does not exclude a powerful co-associate effect of age or vascular risk factor exposure. Future research should subtype lacunar stroke sensitively and control for major risk factors.

Low ankle-brachial index is associated with early-stage chronic kidney disease in type 2 diabetic patients independent of albuminuria

Aims

The role of low ankle-brachial index (ABI) in early-stage chronic kidney disease (CKD) is not fully known. This study was designed to investigate the prevalence of low ABI in early-stage CKD defined as an estimated glomerular filtration rate (eGFR) between 60–89 ml/min/1.73 m² of type 2 diabetic patients without albuminuria and to determine the association between the low ABI and mildly decreased eGFR.

Methods

The cross-sectional study enrolled 448 type 2 diabetic patients with normoalbuminuria. The patients were stratified into two groups according to the CKD-EPI eGFR level: the normal group with eGFR level ≥90 mL/min/1.73 m² and the lower group with eGFR of 60–89. ABI was categorized as normal (1.0–1.39), low-normal (0.9–0.99), and low (<0.9). Both stepwise forward multiple linear regression and binary logistic regression analyses were performed to examine the association between ABI categories and eGFR levels and to assess the relation of low ABI and early-stage CKD.

Results

The prevalence of low ABI in early-stage CKD of type 2 diabetic patients without albuminuria was 39.5%. Low ABI was associated with an approximate 3-fold greater risk of early-stage CKD in bivariate logistic regression analysis, and remained significantly associated with a 2.2 fold risk (95% confidence interval: 1.188–4.077; P = 0.012) after adjusting traditional chronic kidney disease risk factors.

Conclusions

There was a high prevalence of low ABI in early-stage CKD patients of type 2 diabetes with normoalbuminuria and a close relation between low ABI and early-stage CKD, suggesting that we should pay much more attention to the patients who have only mildly decreased eGFR and normoalbuminuria but have already had a low ABI in clinic work and consider the preventive therapy in early stage.

Validation of the Montreal cognitive assessment versus mini-mental state examination against hypertension and hypertensive arteriopathy after transient ischemic attack or minor stroke

BACKGROUND AND PURPOSE

Lack of reduced cognitive impairment with blood pressure (BP) lowering in trials may reflect use of the Mini-Mental State Examination (MMSE), which is insensitive to mild cognitive impairment after cerebrovascular events compared with the Montreal Cognitive Assessment. We determined relationships between impairment on MMSE versus Montreal Cognitive Assessment (MoCA) with the major physiological determinant of vascular cognitive impairment: hypertension and hypertensive arteriopathy.

METHODS

Cognitive impairment in consecutive patients 6 months after transient ischemic attack or minor stroke was defined as significant, mild, or none (MMSE<23, 23-26, ≥27; MoCA<20, 20-24, ≥25) and related to 20 premorbid systolic BP readings, home BP measurement (3 measurements, 3×daily for 1 month), and hypertensive arteriopathy (creatinine, stroke versus transient ischemic attack, leukoaraiosis) by ordinal regression.

RESULTS

Of 463 patients, 45% versus 28% had at least mild cognitive impairment on the MoCA versus MMSE (P<0.001). Hypertensive arteriopathy was more strongly associated with cognitive impairment on the MoCA than MMSE (creatinine: odds ratio=3.99; 95% confidence interval, 2.06-7.73 versus 2.16, 1.08-4.33; event: 1.53, 1.06-2.19 versus 1.23, 0.81-1.85; leukoaraiosis: 2.09, 1.42-3.06 versus 1.34, 0.87-2.07). Premorbid and home BP measurement systolic BP were more strongly associated with impairment on vascular subdomains of the MoCA than MMSE (odds ratio/10 mm Hg: visuospatial 1.29 versus 1.05; attention 1.18 versus 1.07; language 1.22 versus 0.91; naming 1.07 versus 0.86).

CONCLUSIONS

The stronger relationship between impairment on the MoCA with hypertensive arteriopathy, independent of age, indicates a greater sensitivity for vascular-origin cognitive impairment. Use of MoCA should improve sensitivity for cognitive impairment and treatment effects in future studies.

Factors associated with cerebral white matter hyperintensities in haemodialysis patients

AIM

Cerebral white matter hyperintensities (WMHs), comprising periventricular hyperintensity (PVH) and deep and subcortical white matter hyperintensity (DSWMH) on magnetic resonance imaging (MRI), have been reported to be markers of ischaemic cerebral small-vessel disease and risk factors for future stroke, cognitive impairment and dementia in the general population. However, there have been only a few reports describing WMHs in haemodialysis (HD) patients and these previous studies have been relatively small population studies with little investigation on prevalence and risk factors according to the regional subtypes of WMHs.

METHODS

Cranial MRI was performed on 179 HD patients and 58 healthy control subjects and we investigated the prevalence of WMHs (PVH and/or DSWMH) and the clinical factors associated with the presence of WMHs.

RESULTS

The prevalence of WMHs was significantly higher in the HD patients than in the healthy subjects. In the HD patients, multiple logistic regression analysis showed that independent and significant factors associated with the presence of PVH were age, female gender and systolic blood pressure and those associated with the presence of DSWMH were age, female gender, systolic blood pressure and body mass index.

CONCLUSIONS

These findings indicated a high prevalence of WMHs in HD patients. Older age, female gender and high blood pressure were strong factors associated with the presence of both PVH and DSWMH. Moreover, excess body weight was a significant factor associated with the presence of DSWMH only, indicating that there may be differences in risk factors according to the subtype of WMHs.

Low ankle-brachial index and the development of rapid estimated GFR decline and CKD

BACKGROUND

Low ankle-brachial index (ABI) is associated with increases in serum creatinine level. Whether low ABI is associated with the development of rapid estimated glomerular filtration rate (eGFR) decline, stage 3 chronic kidney disease (CKD), or microalbuminuria is uncertain.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Framingham Offspring cohort participants who attended the sixth (1995-1998) and eighth (2005-2008) examinations.

PREDICTOR

ABI, categorized as normal (>1.1 to <1.4), low-normal (>0.9 to 1.1), and low (≤0.9).

OUTCOMES

Rapid eGFR decline (eGFR decline ≥3 mL/min/1.73 m(2) per year), incident stage 3 CKD (eGFR <60 mL/min/1.73 m(2)), incident microalbuminuria.

MEASUREMENTS

GFR was estimated using the serum creatinine-based CKD-EPI (CKD Epidemiology Collaboration) equation. Urinary albumin-creatinine ratio (UACR) was determined based on spot urine samples.

RESULTS

During 9.5 years, 9.0% (232 of 2,592) experienced rapid eGFR decline and 11.1% (270 of 2,426) developed stage 3 CKD. Compared to normal ABI, low ABI was associated with 5.73-fold increased odds of rapid eGFR decline (95% CI, 2.77-11.85; P<0.001) after age, sex, and baseline eGFR adjustment; this persisted after multivariable adjustment for standard CKD risk factors (OR, 3.60; 95% CI, 1.65-7.87; P = 0.001). After adjustment for age, sex, and baseline eGFR, low ABI was associated with a 2.51-fold increased odds of stage 3 CKD (OR, 2.51; 95% CI, 1.16-5.44; P = 0.02), although this was attenuated after multivariable adjustment (OR, 1.68; 95% CI, 0.75-3.76; P = 0.2). In 1,902 free of baseline microalbuminuria, low ABI was associated with increased odds of microalbuminuria after adjustment for age, sex, and baseline UACR (OR, 2.81; 95% CI, 1.07-7.37; P = 0.04), with attenuation upon further adjustment (OR, 1.88; P = 0.1).

LIMITATIONS

Limited number of events with low ABI. Outcomes based on single serum creatinine and UACR measurements at each examination.

CONCLUSIONS

Low ABI is associated with an increased risk of rapid eGFR decline, suggesting that systemic atherosclerosis predicts a decrease in kidney function.