Different Relevance of Peripheral, Central or Nighttime Blood Pressure Measurements in the Prediction of Chronic Kidney Disease Progression in Patients with Mild or No-Proteinuria

Prediction of CKD Progression and Cardiovascular Events Using Albuminuria and Pulse Wave Velocity

INTRODUCTION

Chronic kidney disease (CKD) is associated with cardiovascular disease (CVD) and death. Albuminuria is an established risk factor, but additional biomarkers predicting CKD progression or CVD are needed. Arterial stiffness is an easily measurable parameter that has been associated with CVD and mortality. We evaluated the ability of carotid-femoral pulse wave velocity (PWV) and urine albumin-creatinine (UAC) ratio to predict CKD progression, cardiovascular events, and mortality in a cohort of CKD patients.

METHODS

In CKD stage 3-5 patients, PWV and UAC were measured at baseline. CKD progression was defined as 50% decline in estimated glomerular filtration rate (eGFR), initiation of dialysis, or renal transplantation. A composite endpoint was defined as CKD progression, myocardial infarction, stroke, or death. Endpoints were analyzed using Cox regression analysis adjusted for possible confounders.

RESULTS

We included 181 patients (median age 69 [interquartile range 60-75] years, 67% males) with a mean eGFR of 37 ± 12 mL/min/1.73 m2 and UAC 52 (5-472) mg/g. Mean PWV was 10.6 m/s. Median follow-up until first event was 4 (3-6) years with 44 and 89 patients reaching a CKD progression or composite endpoint, respectively. UAC (g/g) significantly predicted both CKD progression (HR 1.5 [1.2; 1.8]) and composite endpoints (HR 1.4 [1.1; 1.7]) in adjusted Cox regression. In contrast, PWV (m/s) was not associated with neither CKD progression (HR 0.99 [0.84; 1.18]) nor the composite endpoint (HR 1.03 [0.92; 1.15]).

CONCLUSION

In an aging CKD population, UAC predicted both CKD progression and a composite endpoint of CKD progression, cardiovascular events, or death, while PWV did not.

Plasma Homocysteine Is a Predictive Factor for Accelerated Renal Function Decline and Chronic Kidney Disease in a Community-Dwelling Population

BACKGROUND

Whether elevated plasma total homocysteine (tHcy) is a risk factor for the progression of kidney disease in general population has not been well established. The purpose of this study was to investigate the prognostic properties of plasma tHcy for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline.

METHODS

A total of 1,426 participants were enrolled and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and estimated glomerular filtration rate (eGFR) was evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of >3 mL/min per 1.73 m2 per year; the other was the new incidence of CKD.

RESULTS

At the end of follow-up, the incidence of rapid eGFR decline and new-onset CKD was 20.7 and 5.6%, respectively. In multivariate linear regression analysis, age, central pulse pressure, fasting blood glucose, and concentration of tHcy were independent determinants of the change in eGFR. There was a graded association between tHcy quartiles and eGFR decline. Compared with participants with the lowest quartile of tHcy levels, those with the highest quartile had significantly increased risk for rapid eGFR decline (adjusted odds ratio [aOR] = 1.81; 95% confidence interval [CI]: 1.25-2.94) and new onset of CKD (adjusted hazard ratio = 4.29; 95% CI: 1.42-12.99) after adjusting for various confounders. Similarly, significant associations were also found when baseline tHcy was classified as hyperhomocysteinemia (>15 μmol/L) versus normal tHcy level (≤15 μmol/L). However, there was only association between the change in tHcy levels and new occurrence of CKD but not with rapid eGFR decline (aOR = 0.99, p = 0.613).

CONCLUSIONS

In this prospective cohort of individuals from community-based population, elevated plasma tHcy emerged as an independent predictor of renal function decline and incident CKD, which might support selection of at-risk individuals.

Abnormal diurnal blood pressure profile and hypertension-mediated organ damage in nondiabetic chronic kidney disease G1-G3b patients

OBJECTIVE

Chronic kidney disease (CKD) is associated with high cardiovascular risk. Prevalence of hypertension and hypertension-mediated organ damage (HMOD) increases with CKD progression. Nocturnal blood pressure (BP) is a strong predictor of cardiovascular complications. This cross-sectional study investigated the link between the diurnal BP profile and HMOD in nondiabetic CKD G1-G3b patients.

METHODS

We investigated 109 CKD patients and 41 apparently healthy persons as controls. All subjects underwent 24-ambulatory blood pressure monitoring (ABPM), echocardiography with left ventricular mass index (LVMI) calculation and pulse wave velocity (PWV) measurement.

RESULTS

Hypertension was present in 84% of CKD patients. SBP-24 and DBP-24, SBP-day and DBP-day did not differ between CKD and controls. Significant differences were found in SBP-night and DBP-night. The nondipping BP profile (SBP-night/SBP-day ratio ≥0.9) was found in 62% of CKD patients and 32% of controls (P < 0.005). Nocturnal hypertension was found in 56% of CKD patients. LVMI was higher in CKD compared to controls, higher in nondipping than dipping CKD patients, and higher in patients with nocturnal hypertension than without nocturnal hypertension. Abnormal left ventricular geometry was found in 72% nondipping and 43% dipping CKD patients. PWV was higher in CKD than in controls, in patients with nocturnal hypertension than without nocturnal hypertension but did not differ between CKD nondippers and dippers.

CONCLUSION

The nondipping BP profile and nocturnal hypertension are associated with HMOD in G1-G3b CKD patients. Hence, there is a need for more extensive use of ABPM for individual risk assessment and personalization of antihypertensive treatment in CKD patients.

Noninvasive central pulse pressure is an independent determinant of renal function

The purpose of this study was to investigate the prognostic properties of different BP measurements for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline. A total of 1426 participants were included and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and central hemodynamic profile and estimated glomerular filtration rate (eGFR) were evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of greater than 3 mL/min per 1.73 m² per year; the other was the new incidence of CKD. At the end of follow-up, mean eGFR decreased from 93.39 ± 13.46 mL/min per 1.73 m² to 85.72 ± 14.81 mL/min per 1.73 m² , and the incidence of rapid eGFR decline and CKD were 20.7% and 5.6%, respectively. In multivariate linear regression analysis, central pulse pressure (PP), age, fasting blood glucose, and concentration of homocysteine were independent determinants of the change in renal function. Not only in the prediction of rapid eGFR decline but also in the incident of CKD, baseline central PP was the only BP component that consistently independently associated with both outcomes after adjustment for various confounders. When compared with subjects in the lowest quartile of central PP, those in the highest quartile demonstrated a significantly increased risk of CKD (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.08-2.96; P = .006). The study showed that central PP emerged as an independent predictor of the decline in renal function.

Hypertension in Chronic Kidney Disease: Novel Insights

Management of arterial hypertension in patients with chronic kidney disease (CKD) remains a major challenge due to its high prevalence and associations with cardiovascular disease (CVD) and CKD progression. Several clinical trials and meta-analyses have demonstrated that aggressive treatment of hypertension in patients with and without CKD lowers the risk of CVD and all-cause mortality, nevertheless the effects of blood pressure (BP) lowering in terms of renal protection or harm remain controversial. Both home and ambulatory BP estimation have shown that patients with CKD display abnormal BP patterns outside of the office and further investigation is required, so as to compare the association of ambulatory versus office BP measurements with hard outcomes and adjust treatment strategies accordingly. Although renin-angiotensin system blockade appears to be beneficial in patients with advanced CKD, especially in the setting of proteinuria, discontinuation of renin-angiotensin system inhibition should be considered in the setting of frequent episodes of acute kidney injury or hypotension while awaiting the results of ongoing trials. In light of the new evidence in favor of renal denervation in arterial hypertension, the indications and benefits of its application in individuals with CKD need to be clarified by future studies. Moreover, the clinical utility of the novel players in the pathophysiology of arterial hypertension and CKD, such as microRNAs and the gut microbiota, either as markers of disease or as therapeutic targets, remains a subject of intensive research.

Association of brachial and central hemodynamic parameters to eGFR and proteinuria in Gujarati diabetics with mild-to-moderate nephropathy

Introduction:

Diabetes mellitus (DM) is a significant risk factor for nephropathy and cardiovascular morbidity. Pulse wave analysis (PWA) gives direct inference of brachial hemodynamics (BH) and central hemodynamics (CH). We studied relation of them with diabetic nephropathy (DN) among type-2 diabetics (T2D).

Methods:

We studied oscillometric PWA by a cross-sectional study in 160 T2Ds. Using Mobil-o-Graph (IEM, Germany), we derived BH (blood pressure, pulse pressure index, rate pressure product) and CH (aortic pressure, cardiac index, stroke volume index, stroke work). They were further compared and associated with DN in terms of creatinine, proteinuria, and estimated glomerular filtration rate (eGFR).

Results:

There were 89 males, mean age 56 years, mean duration 4.8 years, 80% hypertensive predominantly using ACE inhibitors, poor glycemic blood pressure (BP) control, mainly mild-to-moderate DN, mean eGFR 88.2, 34% prevalence of proteinuria. Arterial stiffness was high with female disadvantage. BH and CH parameters were not different with or without DN using proteinuria or eGFR (60 cutoff) criteria. BH, CH correlated insignificantly with creatinine and eGFR. Female disadvantage, correlation with bSBP and aSBP were only significant results.

Conclusions:

BH and CH are not related to eGFR and proteinuria in predominantly hypertensive, Gujarati diabetics with mild-to-moderate nephropathy suggesting need of other cardiovascular parameters.