Visit-to-Visit Variability of BP and CKD Outcomes: Results from the ALLHAT

Findings from the KNOW-CKD Study indicate that higher systolic blood pressure time in target range is associated with a lower risk of chronic kidney disease progression

Time-in-target range (TTR) of systolic blood pressure (SBP) is determined by the proportion of time during which SBP remains within a defined optimal range. TTR has emerged as a useful metric for assessing SBP control over time. However, it is uncertain if SBP-TTR can predict the progression of chronic kidney disease (CKD). Here, we investigated the association between SBP-TTR during the first year of enrollment and CKD progression among 1758 participants from the KNOW-CKD (KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease). Baseline median estimated glomerular filtration rate (eGFR) was 51.7 ml/min per 1.73 m2. Participants were categorized into four SBP-TTR groups (0%, 1-50%, 51-99%, and 100%). The primary outcome was CKD progression defined as 50% or more decline in eGFR from baseline measurement or the initiation of kidney replacement therapy. During the follow-up period (9212 person-years over a median 5.4 years), the composite outcome occurred in 710 participants. In the multivariate cause-specific hazard model, a one-standard deviation increase in SBP-TTR was associated with an 11% lower risk of the composite outcome with hazard ratio, 0.89 (95% confidence interval, 0.82-0.97). Additionally, compared to patients with SBP-TTR 0%, the respective hazard ratios for those with SBP-TTR 1-50%, 51-99%, and 100% were 0.85 (0.68-1.07), 0.76 (0.60-0.96), and 0.72 (0.55-0.94), and the respective corresponding slopes of eGFR decline were -3.17 (-3.66 to -2.69), -3.02 (-3.35 to -2.68), -2.62 (-2.89 to - 2.36), and -2.33 (-2.62 to -2.04) ml/min/1.73 m2. Thus, higher SBP-TTR was associated with a decreased risk of CKD progression in patients with CKD.

Blood Pressure Variability and the Progression of Chronic Kidney Disease: a Systematic Review and Meta-Analysis

BACKGROUND

Blood pressure variability (BPV) is a risk factor for poor prognosis including cardiovascular events, chronic kidney disease, and mortality, independent of elevated BP.

METHODS

We searched PubMed/Medline, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to November 23, 2022. Cohort studies reporting the association between BPV and chronic kidney disease (CKD) progression were selected. Hazard ratios were pooled using a random-effects model. Meta-regression, subgroup analyses, and sensitivity analyses were conducted.

RESULTS

A total of 23 studies were included in this systematic review and meta-analysis. Increased BPV was associated with progression of CKD (HR: 1.21, 95% CI: 1.09-1.33) and incidence of ESRD (HR: 1.08, 95% CI: 1.08-1.30). Among the different BPV metrics, high variation independent of mean (VIM), coefficient of variation (CV), standard deviation (SD), and average real variability (ARV) were indicated as predictors of CKD progression.

DISCUSSION

Increased BPV was associated with CKD progression.

Accelerated Peripapillary Retinal Nerve Fiber Layer Degeneration in Patients With Chronic Kidney Disease: A 2-Year Longitudinal Study

Purpose

To evaluate the longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) in patients with chronic kidney disease (CKD).

Methods

In this prospective cohort study, the CKD group consisted of patients with CKD stage ≥ 3. Age-matched healthy controls were enrolled at a 1:4 ratio. Spectral-domain optical coherence tomography was used to measure the pRNFL at baseline, 1 year, and 2 years. Within-group longitudinal changes and between-group comparisons were performed using linear mixed models.

Results

Overall, 152 patients with CKD and 40 controls were included (mean ages, 62.8 ± 9.1 years vs. 63.0 ± 9.3 years; P = 0.931). The CKD group showed faster loss of pRNFL than the control group (-0.87 µm/y vs. -0.26 µm/y; P = 0.004). Subgroup analysis found that the rate of pRNFL change was -0.41 µm/y in stage 3a CKD, -0.74 µm/y in stage 3b, -0.98 µm/y in stage 4/5, and -1.38 µm/y in end-stage renal disease. Multiple linear regression analysis revealed that CKD stage (coefficient = -0.549; 95% confidence interval [CI], -0.966 to -0.131; P = 0.010), hypertension (coefficient = -1.557; 95% CI -3.013 to -0.101; P = 0.036), and rim area (coefficient = -1.505; 95% CI, -2.940 to -0.070; P = 0.040) were factors associated with the pRNFL change over 2 years.

Conclusions

Patients with CKD experienced faster pRNFL loss than healthy controls did. Severity of CKD, hypertension, and rim area were independent factors associated with the loss of pRNFL.

Translational Relevance

This study contributes to our understanding of retinal neurodegeneration in normal aging and in patients with chronic kidney diseases.

Comparing statistical methods in assessing the prognostic effect of biomarker variability on time-to-event clinical outcomes

Background

In recent years there is increasing interest in modeling the effect of early longitudinal biomarker data on future time-to-event or other outcomes. Sometimes investigators are also interested in knowing whether the variability of biomarkers is independently predictive of clinical outcomes. This question in most applications is addressed via a two-stage approach where summary statistics such as variance are calculated in the first stage and then used in models as covariates to predict clinical outcome in the second stage. The objective of this study is to compare the relative performance of various methods in estimating the effect of biomarker variability.

Methods

A joint model and 4 different two-stage approaches (naïve, landmark analysis, time-dependent Cox model, and regression calibration) were illustrated using data from a large multi-center randomized phase III trial, the Ocular Hypertension Treatment Study (OHTS), regarding the association between the variability of intraocular pressure (IOP) and the development of primary open-angle glaucoma (POAG). The model performance was also evaluated in terms of bias using simulated data from the joint model of longitudinal IOP and time to POAG. The parameters for simulation were chosen after OHTS data, and the association between longitudinal and survival data was introduced via underlying, unobserved, and error-free parameters including subject-specific variance.

Results

In the OHTS data, joint modeling and two-stage methods reached consistent conclusion that IOP variability showed no significant association with the risk of POAG. In the simulated data with no association between IOP variability and time-to-POAG, all the two-stage methods (except the naïve approach) provided a reliable estimation. When a moderate effect of IOP variability on POAG was imposed, all the two-stage methods underestimated the true association as compared with the joint modeling while the model-based two-stage method (regression calibration) resulted in the least bias.

Conclusion

Regression calibration and joint modelling are the preferred methods in assessing the effect of biomarker variability. Two-stage methods with sample-based measures should be used with caution unless there exists a relatively long series of longitudinal measurements and/or strong effect size (NCT00000125).

Blood pressure changes impact corticospinal integrity and downstream gait and balance control

Blood pressure (BP) plays an important role in white matter integrity. We sought to determine the role of intra-individual BP changes on white matter and evaluate the impact on gait speed and imbalance by sex. We identified 990 eligible participants in the population-based Mayo Clinic Study of Aging and analyzed fractional anisotropy (FA) in white matter regions. Using structural equation models (SEM), we assessed the effect of BP slope on corticospinal tract (CST) FA and downstream effects on gait speed and imbalance after age and sex effects. Of 990 participants, 438 (44%) were female with mean age of 76 years. In linear models predicting CST FA, a greater change in BP slope (0.0004; p = 0.026) and female sex (0.017; p < 0.001) were significant predictors of lower CST FA. SEMs showed that older age, female sex, and higher BP slope predicted lower CST FA, and lower CST FA predicted worse downstream motor control. Therefore, intra-individual BP slope and variability impact corticospinal tract microstructural properties of white matter with females having increased susceptibility to damage.

Visit-to-visit variability in blood pressure and kidney disease progression in IgA nephropathy

Background

The visit-to-visit variability (VVV) in blood pressure (BP) is an important risk factor for stroke and coronary heart disease and may also be associated with kidney damage and the development of chronic kidney disease (CKD). Data on the association between VVV in BP and the risk of CKD progression among patients with immunoglobulin A nephropathy (IgAN) are limited. We aimed to evaluate the relationships of VVV in BP with the progression of IgAN.

Methods

We assessed 1376 patients with IgAN at Peking University First Hospital. The main VVV in BP was expressed as the standard deviation (SD), coefficient of variation (CV) and average real variability (ARV). The associations of variability in BP with composite kidney disease progression events, defined as a 50% decline in estimated glomerular filtration rate (eGFR) and kidney failure, were examined using Cox models.

Results

During a median follow-up of 44.1 months (interquartile range 23.0–76.7), 247 (18.0%) patients experienced composite kidney disease progression events. With a higher SD in systolic BP (SBP) values, the risk of kidney disease progression events increased {hazard ratio [HR] 1.07 [95% confidence interval (CI) 1.03–1.11]; P < .001} after maximal adjustment, including baseline SBP and mean SBP during the first 12-month period. Using the first quartile of SD SBP values as the reference, the risk of composite kidney disease progression events was higher among patients with higher SD SBP values; the HR was 2.12 (95% CI 1.31–3.44) in the highest quartile (P for trend < .001). A similar trend could be observed when analysing the SD of diastolic BP, but the risk was not significantly increased. The associations were similar when analysed with the CV and ARV.

Conclusion

SBP variability was significantly associated with kidney disease progression in IgAN.

Association Between Systolic Blood Pressure Variability and Major Adverse Cardiovascular Events in Korean Patients With Chronic Kidney Disease: Findings From KNOW-CKD

Background Whether visit-to-visit systolic blood pressure (SBP) variability can predict major adverse cardiovascular events (MACE) in patients with chronic kidney disease is unclear. Methods and Results We investigated the relationship between SDs of visit-to-visit SBP variability during the first year of enrollment and MACE among 1575 participants from KNOW-CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease). Participants were categorized into 3 groups according to tertiles of visit-to-visit SBP variability (SD). The study end point was MACE, defined as a composite of nonfatal myocardial infarction, unstable angina, revascularization, nonfatal stroke, hospitalization for heart failure, or cardiac death. During 6748 patient-years of follow-up (median, 4.2 years), MACE occurred in 64 participants (4.1%). Compared with the lowest tertile of visit-to-visit SBP variability (SD), the hazard ratios (HRs) for the middle and the highest tertile were 1.64 (95% CI, 0.80-3.36) and 2.23 (95% CI, 1.12-4.44), respectively, in a multivariable cause-specific hazard model. In addition, the HR associated with each 5-mm Hg increase in visit-to-visit SBP variability (SD) was 1.21 (95% CI, 1.01-1.45). This association was consistent in sensitivity analyses with 2 additional definitions of SBP variability determined by the coefficient of variation and variation independent of the mean. The corresponding HRs for the middle and highest tertiles were 2.11 (95% CI, 1.03-4.35) and 2.28 (95% CI, 1.12-4.63), respectively, in the analysis with the coefficient of variation and 1.76 (95% CI, 0.87-3.57) and 2.04 (95% CI, 1.03-4.03), respectively, with the variation independent of the mean. Conclusions Higher visit-to-visit SBP variability is associated with an increased risk of MACE in patients with chronic kidney disease. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01630486.

Associations of Long-Term Visit-to-Visit Blood Pressure Variability With Subclinical Kidney Damage and Albuminuria in Adulthood: a 30-Year Prospective Cohort Study

BACKGROUND

Recent evidence indicates that long-term visit-to-visit blood pressure variability (BPV) may be associated with risk of cardiovascular disease. We, therefore, aimed to determine the potential associations of long-term BPV from childhood to middle age with subclinical kidney damage (SKD) and albuminuria in adulthood.

METHODS

Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, which recruited children and adolescents aged 6 to 18 years at baseline, we assessed BPV by SD and average real variability (ARV) for 30 years (6 visits). Presence of SKD was defined as estimated glomerular filtration rate between 30 and 60 mL/min per 1.73 m² or elevated urinary albumin-to creatinine ratio at least 30 mg/g. Albuminuria was defined as urinary albumin-to creatinine ratio ≥30 mg/g.

RESULTS

During 30 years of follow-up, of the 1771 participants, 204 SKD events occurred. After adjustment for demographic, clinical characteristics, and mean BP during 30 years, higher SD_SBP , ARV_SBP , SD_DBP , ARV_DBP , SD_MAP , ARV_MAP , and ARV_PP were significantly associated with higher risk of SKD. When we used cumulative exposure to BP from childhood to adulthood instead of mean BP as adjustment factors, results were similar. In addition, greater long-term BPV was also associated with the risk of albuminuria. Long-term BPV from childhood to middle age was associated with higher risk of SKD and albuminuria in adulthood, independent of mean BP or cumulative exposure to BP during follow-up.

CONCLUSIONS

Identifying long-term BPV from early age may assist in predicting kidney disease and cardiovascular disease in later life.

Long-Term Blood Pressure Variability and Kidney Function in Participants of the ASPREE Trial

BACKGROUND

Whether long-term blood pressure variability (BPV) predicts kidney function decline in generally healthy older adults is unknown. We investigated this association in ASPirin in Reducing Events in the Elderly (ASPREE) trial participants.

METHODS

Between 2010 and 2014, Australian and US individuals aged ≥70 years (≥65 if US minority) were recruited and followed with annual study visits for a median of 4.7 years. Time-to-event analyses and linear mixed effects models were used to examine associations between incident chronic kidney disease (CKD), and trajectories of estimated glomerular filtration rate (eGFR) and log albumin-creatinine ratio (log ACR) with systolic BPV as a continuous measure, and, by tertile of SD of systolic blood pressure (BP). BPV was estimated using systolic BP measures from baseline through the second annual visit, and kidney outcomes were assessed following this period.

RESULTS

Incident CKD occurred in 1,829 of 6,759 participants (27.2%), and more commonly in BPV tertiles 2 (27.4%) and 3 (28.3%) than tertile 1 (25.5%); however, the risk was not significantly increased after covariate adjustment (tertile 3 hazard ratio = 1.02; 95% confidence interval: 0.91-1.14). Analysis of eGFR (n = 16,193) and log ACR trajectories (n = 15,213) showed individuals in the highest BPV tertile having the lowest eGFR and highest log ACR, cross-sectionally. However, the trajectories of eGFR and log ACR did not differ across BPV tertiles.

CONCLUSIONS

CKD and markers of reduced kidney function occur more commonly in individuals with higher BPV; however, BPV does not influence trajectory of decline in kidney function over time in older adults who are in generally good health.

CLINICAL TRIALS REGISTRATION

Trial Number NCT01038583 and ISRCTN83772183.

Association of Circulating Osteoprotegerin Level with Blood Pressure Variability in Patients with Chronic Kidney Disease

Circulating osteoprotegerin (OPG) is a biomarker for cardiovascular complications that are closely related to chronic kidney disease (CKD). To investigate the association between circulating OPG level with long-term visit-to-visit blood pressure variability (BPV) in patients with pre-dialysis CKD, a total of 1855 subjects with CKD from stage 1 to pre-dialysis stage 5 from a prospective cohort were analyzed. Long-term visit-to-visit BPV was determined by average real variability (ARV), standard deviation (SD), and coefficient of variation (CoV) of systolic and diastolic blood pressure (SBP and DBP). ARV of SBP (Adjusted β coefficient 0.143, 95% confidence interval 0.021 to 0.264) was significantly associated with serum OPG level. Although SD and CoV of SBP were not significantly associated with serum OPG level in multivariate linear regression analyses, restricted cubic spline visualized the linear correlation of serum OPG level with all of ARV, SD, and CoV. The association between serum OPG level and DBP variability was not significant. Subgroup analyses revealed that the association of serum OPG with BPV is more prominent in the subjects with Charlson comorbidity index ≤3 and in the subjects without history of diabetes mellitus. In conclusion, circulating OPG level is potentially associated with long-term visit-to-visit BPV in patients with pre-dialysis CKD.

Association of Urinary Potassium Excretion with Blood Pressure Variability and Cardiovascular Outcomes in Patients with Pre-Dialysis Chronic Kidney Disease

Dietary potassium intake is a dilemma in patients with chronic kidney disease (CKD). We investigated the association of urine potassium excretion, a surrogate for dietary potassium intake, with blood pressure variability (BPV) and cardiovascular (CV) outcomes in patients with pre-dialysis CKD. A total of 1860 participants from a cohort of pre-dialysis CKD (KNOW-CKD) patients were divided into the quartiles by spot urine potassium-to-creatinine ratio. The first quartile (26.423 ± 5.731 mmol/gCr) was defined as low urine potassium excretion. Multivariate linear regression analyses revealed an independent association of low urine potassium excretion with high BPV (adjusted β coefficient 1.163, 95% confidence interval 0.424 to 1.901). Cox regression analyses demonstrated that, compared to high urine potassium excretion, low urine potassium excretion is associated with increased risk of CV events (adjusted hazard ratio 2.502, 95% confidence interval 1.162 to 5.387) but not with all-cause mortality. In conclusion, low urine potassium excretion is associated with high BPV and increased risk of CV events in patients with pre-dialysis CKD. The restriction of dietary potassium intake should be individualized in patients with pre-dialysis CKD.

Cumulative hypertension burden and risk of end-stage renal disease

Hypertension is the leading risk factor for end-stage renal disease (ESRD). However, the association between sustained exposure to increased blood pressure (BP) and ESRD is not well established. This study investigated whether the cumulative hypertension burden is a substantial risk factor for ESRD. The incidence of ESRD among 2,144,801 participants identified from the Korean National Health Insurance Service database who had documented BP assessment data in their annual health check-up data from between 2006 and 2010, was determined. Over a median follow-up of 7.2 years, ESRD was identified in 1758 participants. Hypertension burden was defined as the cumulative exposure to hypertension (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) during four consecutive follow-up periods and ranged from 0 to 4. The hypertension burden was as follows: 0 (n = 1,164,488), 77.6%; 1 (n = 292,377), 13.6%; 2 (n = 114,397), 5.3%; 3 (n = 52,671), 2.5%; and 4 (n = 20,886), 1.0%. Compared to the hypertension burden of 0, the adjusted hazard ratio for ESRD was 1.35, 1.54, 1.51, and 2.28 for hypertension burdens of 1, 2, 3, and 4, respectively. A positive dose-dependent relationship between hypertension burden and ESRD was found (P for interaction < 0.001). This association was maintained for sustained exposure to both systolic and diastolic hypertension burden. In conclusion, hypertension burden increases the risk of ESRD. Our study underlines the usefulness of a new assessment of the hypertension burden over a certain period for predicting the risk of ESRD in a large population-based cohort.

Long-term blood pressure variability, incidence of hypertension and changes in renal function in type 2 diabetes

OBJECTIVES

Long-term visit-to-visit SBP variability (VVV) predicts cerebro-cardiovascular and renal events in patients with hypertension. Whether VVV predicts hypertension and/or chronic kidney disease is currently unknown. We assessed the role of VVV on the development of hypertension and changes in renal function in patients with type 2 diabetes and normal blood pressure (NBP) in a real-life clinical setting.

METHODS

Clinical records from 8998 patients with type 2 diabetes, NBP, and normal estimated glomerular filtration rate (eGFR) were analyzed. VVV was measured by SD of the mean SBP recorded in at least four visits during 2 consecutive years before follow-up. Hypertension was defined as SBP at least 140 mmHg and DBP at least 90 mmHg or the presence of antihypertensive treatment. Renal function was defined as worsening of albuminuria status and/or a reduction in eGFR at least 30% from baseline.

RESULTS

After a mean follow-up time of 3.5 ± 2.8 years, 3795 patients developed hypertension (12.1 per 100 person-years). An increase of 5 mmHg VVV was associated with a 19% (P < 0.0001) and a 5% (P = 0.008) independent increased risk of developing hypertension and worsening of albuminuria, respectively. We found no association between VVV and eGFR decrease from baseline. Patients with VVV in the upper quartile (>12.8 mmHg) showed a 50% increased risk of developing hypertension (P < 0.0001) and an almost 20% increased risk of worsening albuminuria (P = 0.004) as compared with those in the lower one (<6.9 mmHg).

CONCLUSION

Increased VVV independently predicts incident hypertension and albuminuria worsening in type 2 diabetes and NBP.

Impact of home telemonitoring and management support on blood pressure control in non-dialysis CKD: a systematic review protocol

INTRODUCTION

Hypertension is a common public health problem and a key modifiable risk factor for cardiovascular (CV) and chronic kidney disease (CKD). Home blood pressure (BP) telemonitoring (HBPT) and management is associated with improved BP control, accelerated delivery of care and decision-making strategies that can reduce adverse outcomes associated with hypertension. The aim of this paper is to describe the protocol for a systematic review to assess the impact of HBPT interventions used for improving BP control and reducing CV and kidney outcomes in non-dialysis CKD patients.

METHODS

We developed this protocol using the Preferred Reporting Items for Systematic reviews and Meta-Analyses for Protocols 2015. We will search empirical databases such as MEDLINE, Embase, Cochrane Library, CINAHL, Web of Science and PsycINFO and grey literature for studies conducted in non-dialysis CKD patients on interventions using HBPT and reporting outcomes related to BP control and other outcomes such as CV events and kidney disease progression. All studies meeting these criteria, in adults and published from inception until 2020 with no language barrier will be included.

ETHICS AND DISSEMINATION

Ethical approval will not be required for this review as the data used will be extracted from already published studies with publicly accessible data. As this study will assess the impact of HBPT on BP control in non-dialysis CKD patients, evidence gathered through it will be disseminated using traditional approaches that includes open-access peer-reviewed publication, scientific presentations and a report. We will also disseminate our findings to appropriate government agencies.

PROSPERO REGISTRATION NUMBER

CRD42020190705).

Impact of visit-to-visit blood pressure variability on hypertensive-mediated target organ damage and future cardiovascular events: the Campania salute network

BACKGROUND

Exaggerated variability of blood pressure (BP) poses additional stress on cardiovascular system independent of BP average value, increasing risk of target organ damage (HMOD) and cardiovascular events. We assessed the impact of visit-to-visit variability (VVV) of BP on development of cardiovascular events and HMOD.

METHODS

Standard deviation (SD) and coefficient of variability of mean SBP and DBP were calculated in 3555 patients from the Campania Salute Network registry, with available echocardiogram and more than six visits during follow-up. Values from the first visit were excluded. The impact of VVV of BP on cardiovascular events, and mediation of HMOD were assessed at final visit.

RESULTS

Mean number of visits was 11 ± 6 with mean interval between visits of 9.1 ± 3.7 months. Mean visit-to-visit SD during follow-up was 13 ± 5 for systolic and 8 ± 3 mmHg for DBP; coefficients of variability were 9.7 ± 3.5 and of 9.6 ± 3.2, respectively. In multivariable analysis, left ventricular mass at follow-up was correlated with systolic VVV of BP independently of significant effect of age, BMI, mean SBP during follow-up and initial left ventricular mass. Follow-up GFR was inversely associated with systolic and diastolic VVV, independently of significant effect of age, mean glucose and SBP during follow-up, and initial GFR. In Cox regression, high VVV of BP was also associated with increased risk of cardiovascular events (hazard ratio 1.49, 95% confidence interval 1.08-2.06, P = 0.015), independently of significant effect of HMOD.

CONCLUSION

VVV is associated with prevalent HMOD and development of cardiovascular events, independently of mean BP value during follow-up and HMOD.

Blood pressure variability is related to faster cognitive decline in ischemic stroke patients: PICASSO subanalysis

Blood pressure variability (BPV) is associated with higher cardiovascular morbidity risks; however, its association with cognitive decline remains unclear. We investigated whether higher BPV is associated with faster declines in cognitive function in ischemic stroke (IS) patients. Cognitive function was evaluated between April 2010 and August 2015 using the Mini-mental State Examination (MMSE) and Montreal Cognitive Assessment in 1,240 Korean PICASSO participants. Patients for whom baseline and follow-up cognitive test results and at least five valid BP readings were available were included. A restricted maximum likelihood–based Mixed Model for Repeated Measures was used to compare changes in cognitive function over time. Among a total of 746 participants (64.6 ± 10.8 years; 35.9% female). Baseline mean-MMSE score was 24.9 ± 4.7. The median number of BP readings was 11. During a mean follow-up of 2.6 years, mean baseline and last follow-up MMSE scores were 25.4 ± 4.8 vs. 27.8 ± 4.4 (the lowest BPV group) and 23.9 ± 5.2 vs. 23.2 ± 5.9 (the highest BPV group). After adjusting for multiple variables, higher BPV was independently associated with faster cognitive decline over time. However, no significant intergroup difference in cognitive changes associated with mean systolic BP was observed. Further research is needed to elucidate how BPV might affect cognitive function.

Visit-to-visit variability in blood pressure and the development of chronic kidney disease in treated general hypertensive patients

BACKGROUND

Data on the association between visit-to-visit variability (VVV) in blood pressure (BP) and the risk of chronic kidney disease (CKD) in general treated hypertensive patients were limited. We aimed to evaluate the relation of VVV in BP with the development of CKD, and examine any possible effect modifiers in hypertensive patients without prior cardiovascular diseases (CVDs) or CKD.

METHODS

This is a post hoc analysis of the Renal Sub-study of the China Stroke Primary Prevention Trial (CSPPT). A total of 10 051 hypertensives without CVD and CKD and with at least six visits of BP measurements from randomization to the 24-month visit were included. The main VVV in BP was expressed as standard deviation (SD). The primary outcome was the development of CKD, defined as a decrease in estimated glomerular filtration rate ≥30% and to a level of <60 mL/min/1.73 m2, or end-stage renal disease.

RESULTS

The median treatment duration was 4.4 years. After multivariable adjustment, including baseline systolic blood pressure (SBP) and mean SBP during the first 2-year treatment period, there was a significantly positive relationship of SD of SBP with the risk of CKD development (per SD increment; odds ratio, 1.27; 95% confidence interval: 1.10-1.46). The results were similar for coefficient of variation (CV) of SBP. Results across various subgroups, including age, sex, SBP at baseline, treatment compliance, concomitant antihypertensive medications and mean SBP during the first 24-month treatment period, were consistent.

CONCLUSIONS

SBP variability, irrespective of mean BP level, was significantly associated with the development of CKD in general treated hypertensive patients.

Establishment of a novel nomogram for the clinically diagnostic prediction of minimal change disease, -a common cause of nephrotic syndrome

Background

Minimal change disease (MCD) is one of the major causes of nephrotic syndrome (NS). A confirmed MCD diagnosis mainly depends on renal biopsy at present, which is an invasive procedure with many potential risks. The overall incidence of complications caused by renal biopsy procedures has been reported as approximately 11 and 6.6% outside and within China, respectively. Unfortunately, there is currently no noninvasive procedure or practical classification method for distinguishing MCD from other primary glomerular diseases available.

Method

A total of 1009 adult patients who underwent renal biopsy between January 2017 and November 2019 were enrolled in this study. Twenty-five parameters extracted from patient demographics, clinical manifestations, and laboratory test results were statistically analysed. LASSO regression analysis was further performed on these parameters. The parameters with the highest area under the curve (AUC) were selected and used to establish a logistic diagnostic prediction model.

Results

Of the 25 parameters, 14 parameters were significantly different (P < 0.05). MCD patients were mostly younger (36 (22, 55) vs. 41 (28.75, 53)) and male (59% vs. 52%) and had lower levels of diastolic blood pressure (DBP) (79 (71, 85.5) vs. 80 (74, 89)) and IgG (5.42 (3.17, 6.36) vs. 9.38 (6.79, 12.02)) and higher levels of IgM (1.44 (0.96, 1.88) vs. 1.03 (0.71, 1.45)) and IgE (160 (46.7, 982) vs. 47.3 (19, 126)) than those in the non-MCD group. Using the LASSO model, we established a classifier for adults based on four parameters: DBP and the serum levels of IgG, IgM, IgE. We were able to clinically classify adult patients with NS into MCD and non-MCD using this model. The validation accuracy of the logistic regression model was 0.88. A nomogram based on these four classifiers was developed for clinical use that could predict the probability of MCD in adult patients with NS.

Conclusions

A LASSO model can be used to distinguish MCD from other primary glomerular diseases in adult patients with NS. Combining the model and the nomogram potentially provides a novel and valuable approach for nephrologists to diagnose MCD, avoiding the complications caused by renal biopsy.

Impact of blood pressure control on retinal microvasculature in patients with chronic kidney disease

Chronic kidney disease (CKD) is an emerging disease worldwide. We investigated the relationship between blood pressure (BP) control and parafoveal retinal microvascular changes in patients with CKD. This case–control study enrolled 256 patients with CKD (stage 3–5) and 70 age‐matched healthy controls. Optical coherence tomography angiography showed lower superficial vascular plexus (SVP) vessel density, lower deep vascular plexus (DVP) vessel density, and larger SVP flow void area in the CKD group. The BP parameters at enrollment and during the year before enrollment were collected in patients with CKD. Partial correlation was used to determine the relationship between BP parameters and microvascular parameters after controlling for age, sex, diabetes mellitus, axial length, and intraocular pressure. The maximum systolic blood pressure (SBP) (p = 0.003) and within-patient standard deviation (SD) of SBP (p = 0.006) in 1 year were negatively correlated with SVP vessel density. The average SBP (p = 0.040), maximum SBP (p = 0.001), within-patient SD of SBP (p < 0.001) and proportion of high BP measurement (p = 0.011) in 1 year were positively correlated with the SVP flow void area. We concluded that long-term SBP was correlated with SVP microvascular injury in patients with CKD. Superficial retinal microvascular changes may be a potential biomarker for prior long-term BP control in these patients.

Visit-to-visit blood pressure variability and risk of chronic kidney disease: A systematic review and meta-analyses

Objective

Previous studies have shown that visit-to-visit blood pressure variability (BPV) is associated with chronic kidney disease (CKD). However, the results have not been consistent among studies. This systematic review and meta-analysis was conducted to comprehensively assess the association between visit-to-visit BPV and the risk of CKD.

Methods

Medline, Embase, and the Cochrane Library were searched from the date of inception through 1 August 2019 using the terms “blood pressure variability,” “chronic kidney disease,” “nephropathy,” and other comparable terms. The primary outcome was the development of CKD. Two reviewers extracted the data independently. Meta-analysis was performed using a random effects model.

Results

Fourteen studies were included in the systematic review and meta-analysis. The risk of CKD was significantly greater in patients with high baseline systolic blood pressure variability (SBPV) than in patients with low baseline SBPV: the standard deviation (SD) showed relative risk (RR) of 1.69 and 95% CI of 1.38–2.08, the coefficient of variation (CV) showed RR of 1.23 and 95% CI of 1.12–1.36, and variance independent of mean (VIM) showed RR of 1.40 and 95% CI of 1.15–1.71. RRs for each unit increase in visit-to-visit SBPV and risk of CKD were 1.05 (95% CI: 1.03–1.07) for SD, 1.06 (95% CI: 1.03–1.09) for CV, and 1.1 (95% CI: 0.96–1.25) for VIM. Diastolic BPV was similarly predictive of CKD based on SD and CV.

Conclusions

Increased visit-to-visit BPV might be an independent risk factor for CKD. However, significant heterogeneity was present; thus, future prospective studies are needed to confirm our findings. Our results indicate that treatment of hypertension should control blood pressure levels and prevent abnormal fluctuations in blood pressure to reduce the risk of CKD.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Association of variability in uric acid and future clinical outcomes of patient with coronary artery disease undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

Hyperuricemia is independently associated with cardiovascular disease (CVD) and is considered to be one of the major risk factors for CVD. However, the impact of inter-visit uric acid (UA) variability on cardiovascular risk remains undetermined.

METHODS

We enrolled 3202 patients with coronary artery disease (CAD), who received successful coronary intervention, in a cohort from Taipei Veterans General Hospital from 2006 to 2015. All post-baseline visits UA measurements using standard deviation (SD) were analyzed to correlate with long-term outcome. The primary outcome was the composite of cardiac death, nonfatal MI, nonfatal stroke (MACE). The secondary event was MACE and hospitalization for heart failure.

RESULTS

During an average 65.06 ± 32.1-month follow-up, there were 66 cardiovascular deaths, 175 nonfatal myocardial infarctions, 64 nonfatal strokes, 287 hospitalizations for heart failure, and 683 revascularization procedures. There was a linear association between high UA SD and future adverse events. Compared to the lowest quartile SD, subjects in the highest quartile SD had a higher risk of MACE (HR: 2.53, 95% CI: 1.78-3.59), myocardial infarction (HR: 2.43, 95% CI: 1.53-3.86), cardiovascular death (HR: 6.45, 95% CI: 2.52-16.55), heart failure-related hospitalization (HR: 3.43, 95% CI: 2.32-5.05), and total major CV events (HR: 2.72, 95% CI: 2.09-3.56). Furthermore, compared to the average achieved on-treatment UA value, increasing UA SD had a stronger association of higher risk of developing MACE (HR: 1.51, 95% CI: 1.36-1.68), myocardial infarction (HR: 1.37, 95% CI: 1.38-1.68), ischemic stroke (HR: 1.43, 95% CI: 1.13-1.82), CV death (HR: 1.77, 95% CI: 1.50-2.11), HF (HR: 1.43, 95% CI: 1.29-1.58), and total major CV events (HR: 1.46, 95% CI: 1.34-1.58).

CONCLUSIONS

High UA variability is associated with a higher risk of developing future cardiovascular events, suggesting the importance of maintaining stable serum UA levels and avoiding large fluctuations in CAD patients after percutaneous coronary intervention (PCI).

Within subject variability of HDL-cholesterol in HIV-infected patients

Background and objective: Within-subject variability of cardiovascular risk factors may influence the development of cardiovascular disease. We aimed to improve knowledge on HDL-cholesterol variability and its clinical significance in HIV-infected patients, a population at high risk of cardiovascular disease.Methods: This was a cohort study to quantify the variability of HDL-cholesterol between two consecutive visits and to determine factors associated with such variability, in a group of HIV-infected patients.Results: A total of 307 patients were included, mean ± standard deviation of their age was 45.1 ± 8.5 years, and 225 of them (73.3%) were male. The absolute difference (after squaring and root squaring) of serum HDL-cholesterol level between the first and the second visit was 12.1 ± 9.2 mg/dL. In 65 patients (21.2%) the absolute value of the difference between both serum HDL-cholesterol level results were 20 mg/dL or higher. In a multivariable analysis the number of cigarettes smoked per day showed a significant, negative, correlation with the absolute difference in serum HDL-cholesterol level between the two visits (P = 0,009).Conclusions: Within-subject variability of HDL-cholesterol was substantial among our HIV-infected patients. Smoking was inversely correlated with such variability.

Association Between Systolic and Diastolic Blood Pressure Variability and the Risk of End-Stage Renal Disease

Recent data suggest that visit-to-visit variability of blood pressure (BP) is associated with cardiovascular events. We evaluated the role of BP variability as a determinant of end-stage renal disease (ESRD). Using nationally representative data from the Korean National Health Insurance System, 8 199 089 subjects had been enrolled during 2009 to 2010 who were free of ESRD and underwent ≥3 health examinations during 2005 to 2010 were followed to the end of 2017. BP variability was measured using the coefficient of variation, SD, and variability independent of the mean. The primary outcome was the development of ESRD, defined as a combination of the relevant disease code and the initiation of renal replacement therapy. The χ² test, t test, and log-rank test were used in the statistical analysis. There were 16 567 cases of ESRD during a median follow-up of 7.89±0.88 years. The highest quartile of systolic or diastolic BP showed a higher incident rate of ESRD compared with the other 3 quartiles. It was augmented in patients with the highest quartile of both systolic and diastolic BP variabilities. Among patients with the highest quartile of systolic and diastolic BP variabilities, the uncontrolled hypertension group (>140/90 mm Hg) taking antihypertensive medication showed the highest incidence rate of ESRD. These results were consistent when modeling variability of BP using coefficient of variation, SD, and variability independent of the mean and in various sensitivity analyses. Systolic and diastolic BP variabilities were independently associated with an increased incidence of ESRD, and it was augmented when both variabilities were present together.

Increased blood pressure visit-to-visit variability in patients with systemic lupus erythematosus: association with inflammation and comorbidity burden

BACKGROUND

Blood pressure visit-to-visit variability is a novel risk factor for deleterious long-term cardiac and renal outcomes in the general population. We hypothesized that patients with systemic lupus erythematosus (SLE) have greater blood pressure visit-to-visit variability than control subjects and that blood pressure visit-to-visit variability is associated with a higher comorbidity burden.

METHODS

We studied 899 patients with SLE and 4172 matched controls using de-identified electronic health records from an academic medical center. We compared blood pressure visit-to-visit variability measures in patients with SLE and control subjects and examined the association between blood pressure visit-to-visit variability and patients' characteristics.

RESULTS

Patients with SLE had higher systolic blood pressure visit-to-visit variability 9.7% (7.8-11.8%) than the control group 9.2% (7.4-11.2%), P < 0.001 by coefficient of variation. Additional measures of systolic blood pressure visit-to-visit variability (i.e. standard deviation, average real variation, successive variation and maximum measure-to-measure change) were also significantly higher in patients with SLE than in control subjects. In patients with SLE, blood pressure visit-to-visit variability correlated significantly with age, creatinine, CRP, triglyceride concentrations and the Charlson comorbidity score (all P < 0.05). Hydroxychloroquine use was associated with reduced blood pressure visit-to-visit variability (P < 0.001), whereas the use of antihypertensives, cyclophosphamide, mycophenolate mofetil and corticosteroids was associated with increased blood pressure visit-to-visit variability (P < 0.05).

CONCLUSION

Patients with SLE had higher blood pressure visit-to-visit variability than controls, and this increased blood pressure visit-to-visit variability was associated with greater Charlson comorbidity scores, several clinical characteristics and immunosuppressant medications. In particular, hydroxychloroquine prescription was associated with lower blood pressure visit-to-visit variability.

Measurement of Blood Pressure in Humans: A Scientific Statement From the American Heart Association

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. This article provides an updated American Heart Association scientific statement on BP measurement in humans. In the office setting, many oscillometric devices have been validated that allow accurate BP measurement while reducing human errors associated with the auscultatory approach. Fully automated oscillometric devices capable of taking multiple readings even without an observer being present may provide a more accurate measurement of BP than auscultation. Studies have shown substantial differences in BP when measured outside versus in the office setting. Ambulatory BP monitoring is considered the reference standard for out-of-office BP assessment, with home BP monitoring being an alternative when ambulatory BP monitoring is not available or tolerated. Compared with their counterparts with sustained normotension (ie, nonhypertensive BP levels in and outside the office setting), it is unclear whether adults with white-coat hypertension (ie, hypertensive BP levels in the office but not outside the office) have increased cardiovascular disease risk, whereas those with masked hypertension (ie, hypertensive BP levels outside the office but not in the office) are at substantially increased risk. In addition, high nighttime BP on ambulatory BP monitoring is associated with increased cardiovascular disease risk. Both oscillometric and auscultatory methods are considered acceptable for measuring BP in children and adolescents. Regardless of the method used to measure BP, initial and ongoing training of technicians and healthcare providers and the use of validated and calibrated devices are critical for obtaining accurate BP measurements.

Long-term blood pressure variability and development of chronic kidney disease in type 2 diabetes

OBJECTIVE

Long-term visit-to-visit SBP variability (VVV) has been shown to predict cerebro-cardiovascular events and end-stage renal disease in chronic kidney disease (CKD) patients. Whether SBP VVV is also a predictor of CKD development in diabetes is currently uncertain. We assessed the role of SBP VVV on the development of CKD in patients with type 2 diabetes (T2D) and hypertension in real life.

METHODS

Clinical records from 30 851 patients with T2D and hypertension, with normal estimated glomerular filtration rate (eGFR) and regular visits during a 4-year follow-up were analyzed. SBP variability was measured by three metrics: coefficient of variation; SD of the mean SBP and average absolute difference of successive values in each individual. CKD was defined as eGFR less than 60 and/or a reduction in eGFR at least 30% from baseline.

RESULTS

Over the 4-year follow-up, 9.7% developed eGFR less than 60 and 4.5% an eGFR reduction at least 30% from baseline. Several clinical characteristics (older age, male sex, SBP, DBP, albuminuria, glycated hemoglobin, insulin treatment) were related to intraindividual SBP variability. Patients with VVV in the upper quintile showed an increased risk of developing both components of CKD [adjusted odds ratio (OR) 1.21, P < 0.001 and 1.32, P < 0.001, respectively]. The multivariable adjusted ORs of SBP coefficient of variation quintiles 2-5 for the incidence of CKD were incrementally higher (OR 1.04, P = 0.601, OR 1.05, P = 0.520, OR 1.21, P < 0.017 and OR 1.42, P < 0.001 as compared with the first quintile).

CONCLUSION

Increased long-term BP variability predicts CKD in patients with T2D and hypertension.

Labile hypertension: a new disease or a variability phenomenon?

Blood pressure (BP) is a physiological parameter with short- and long-term variability caused by complex interactions between intrinsic cardiovascular (CV) mechanisms and extrinsic environmental and behavioral factors. Available evidence suggests that not only mean BP values are important, but also BP variability (BPV) might contribute to CV events. Labile hypertension (HTN) is referred to sudden rises in BP and it seems to be linked with unfavorable outcomes. The aim of this article was to review and summarize recent evidence on BPV phenomenon, unraveling the labile HTN concept along with the prognostic value of these conditions.

Real World Home Blood Pressure Variability in Over 56,000 Individuals With Nearly 17 Million Measurements

BACKGROUND

Using the data from 56,365 individuals, from 185 countries, and a Nokia Health Wireless blood pressure (BP) monitor, we investigated real-world characteristics of BP variability (BPV).

METHODS

All included individuals self-measured and uploaded their BP using Bluetooth at least 20 times over a period of ≥1 month at a frequency and duration of their choosing. In total, 16,904,844 BP measurements were analyzed, with a median of 146 measurements per person (interquartile range [IQR] 73-321) over a median of 14 months (IQR 7-31). SD, coefficient of variation, maximum BP, and maximum minus minimum BP difference were all calculated as measures of BPV.

RESULTS

BPV showed a distinct pattern, influenced by season of year, day of week, and time of day. BPV index was higher in females compared with males (P < 0.001) and increased with age (P < 0.001). Compared to the weekend, the weekday BPV index was significantly higher, and this finding was more prominent in females (P = 0.001). In multivariate analysis, BPV index were significantly associated with age, gender, geographic location, and mean BP values.

CONCLUSION

Using the largest BP data set we are aware of, with the benefits and limitations of real-world measurement, we could show the pattern of BPV and provide reference values that may be helpful in understanding the nature of BPV as self-measurement at home becomes more common, and help guide individualized management.

Aging and death-associated changes in serum albumin variability over the course of chronic hemodialysis treatment

Background

Several epidemiological studies have demonstrated associations between variability in a number of biological parameters and adverse outcomes. As the variability may reflect impaired homeostatic regulation, we assessed albumin variability over time in chronic hemodialysis (HD) patients.

Methods

Data from 1346 subjects who received chronic HD treatment from May 2001 to February 2015 were analyzed according to three phases of HD treatment: post-HD initiation, during maintenance HD treatment, and before death. The serum albumin values were grouped according to the time interval from HD initiation or death, and the yearly trends for both the albumin levels and the intra-individual albumin variability (quantified by the residual coefficient of variation: Alb-rCV) were examined. The HD initiation and death-associated changes were also analyzed using generalized additive mixed models. Furthermore, the long-term trend throughout the maintenance treatment period was evaluated separately using linear regression models.

Results

Albumin levels and variability showed distinctive changes during each of the 3 periods. After HD initiation, albumin variability decreased and reached a nadir within a year. During the subsequent maintenance treatment period (interquartile range = 5.2–11.0 years), the log Alb-rCV showed a significant upward trend (mean slope: 0.011 ± 0.035 /year), and its overall mean was -1.49 ± 0.08 (equivalent to an Alb-rCV of 3.22%). During the 1–2 years before death, this upward trend clearly accelerated, and the mean log Alb-rCV in the last year of life was -1.36 ± 0.17. The albumin levels and variability were negatively correlated with each other and exhibited exactly opposite movements throughout the course of chronic HD treatment. Different from the albumin levels, albumin variability was not dependent on chronological age but was independently associated with an individual’s aging and death process.

Conclusion

The observed upward trend in albumin variability seems to be consistent with a presumed aging-related decline in homeostatic capacity.

Blood Pressure and Visit-to-Visit Blood Pressure Variability Among Individuals With Primary Proteinuric Glomerulopathies

Hypertension and blood pressure variability (BPV; SD and average real variability) in primary proteinuric glomerulopathies are not well described. Data were from 433 participants in the NEPTUNE (Nephrotic Syndrome Study Network). Hypertensive BP status was defined as previous history of hypertension or BP ≥140/90 mm Hg for adults/≥95th percentile for children at baseline. BPV was measured in participants with ≥3 visits in the first year. Two-hundred ninety-six adults (43 years [interquartile range, 32-57.8 years], 61.5% male) and 147 children (11 years [interquartile range, 5-14 years], 57.8% male) were evaluated. At baseline, 64.8% of adults and 46.9% of children were hypertensive. Histological diagnosis was associated with hypertensive status in adults (P=0.036). In adults, hypertensive status was associated with lower hazard of complete remission (hazard ratio, 0.36; 95% confidence interval, 0.19-0.68) and greater hazard of achieving the composite end point (end-stage renal disease or estimated glomerular filtration rate decline >40%; hazard ratio, 4.1; 95% confidence interval, 1.4-12). Greater systolic and diastolic SD and average real variability were also associated with greater hazard of reaching the composite end point in adults (all P<0.01). In children, greater BPV was an independent predictor of composite end point (determined by systolic SD and average real variability) and complete remission (determined by systolic and diastolic average real variability; all P<0.05). Hypertensive status was common among adults and children enrolled in NEPTUNE. Differences in hypertensive status prevalence, BPV, and treatment were found by age and histological diagnosis. In addition, hypertensive status and greater BPV were associated with poorer clinical outcomes.

Association of Systolic Blood Pressure Variability With Mortality, Coronary Heart Disease, Stroke, and Renal Disease

BACKGROUND

Intraindividual blood pressure (BP) fluctuates dynamically over time. Previous studies suggested an adverse link between greater visit-to-visit variability in systolic blood pressure (SBP) and various outcomes. However, these studies have significant limitations, such as a small size, inclusion of selected populations, and restricted outcomes.

OBJECTIVES

This study investigated the association of increased visit-to-visit variability and all-cause mortality, cardiovascular events, and end-stage renal disease (ESRD) in a large cohort of U.S. veterans.

METHODS

From among 3,285,684 U.S. veterans with and without hypertension and normal estimated glomerular filtration rates (eGFR) during 2005 and 2006, we identified 2,865,157 patients who had 8 or more outpatient BP measurements. Systolic blood pressure variability (SBPV) was measured using the SD of all SBP values (normally distributed) in 1 individual. Associations of SD quartiles (<10.3, 10.3 to 12.7, 12.7 to 15.6, and ≥15.6 mm Hg) with all-cause mortality, incident coronary heart disease (CHD), stroke, and ESRD was examined using Cox models adjusted for sociodemographic characteristics, baseline eGFR, comorbidities, body mass index, SBP, diastolic BP, and antihypertensive medication use.

RESULTS

Several sociodemographic variables (older age, male sex, African-American race, divorced or widowed status) and clinical characteristics (lower baseline eGFR, higher SBP and diastolic BP), and comorbidities (presence of diabetes, hypertension, cardiovascular disease, and lung disease) were all associated with higher intraindividual SBPV. The multivariable adjusted hazard ratios and 95% confidence intervals for SD quartiles 2 through 4 (compared with the first quartile) associated with all-cause mortality, CHD, stroke, and ESRD were incrementally higher.

CONCLUSIONS

Higher SBPV in individuals with and without hypertension was associated with increased risks of all-cause mortality, CHD, stroke, and ESRD. Further studies are needed to determine interventions that can lower SBPV and their impact on adverse health outcomes.