Long-term visit-to-visit office blood pressure variability increases the risk of adverse cardiovascular outcomes in patients with chronic kidney disease

Impact of seasonal blood pressure changes on visit-to-visit blood pressure variability and related cardiovascular outcomes

BACKGROUND

Visit-to-visit blood pressure (BP) variability associates with an increased risk of cardiovascular events. We investigated the role of seasonal BP modifications on the magnitude of BP variability and its impact on cardiovascular risk.

METHODS

In 25 390 patients included in the ONTARGET and TRANSCEND trials, the on-treatment systolic (S) BP values obtained by five visits during the first two years of the trials were grouped according to the month in which they were obtained. SBP differences between winter and summer months were calculated for BP variability quintiles (Qs), as quantified by the coefficient of variation (CV) of on-treatment mean SBP from the five visits. The relationship of BP variability with the risk of cardiovascular events and mortality was assessed by the Cox regression model.

RESULTS

SBP was approximately 4 mmHg lower in summer than in winter regardless of confounders. Winter/summer SBP differences contributed significantly to each SBP-CV quintile. Increase of SBP-CV from Q1 to Q5 was associated with a progressive increase in the adjusted hazard ratio (HR) of the primary endpoint of the trials, i.e. morbid and fatal cardiovascular events. This association was even stronger after removal of the effect of seasonality from the calculation of SBP-CV. A similar trend was observed for secondary endpoints.

CONCLUSIONS

Winter/summer SBP differences significantly contribute to visit-to-visit BP variability. However, this contribution does not participate in the adverse prognostic significance of visit-to-visit BP variations, which seems to be more evident after removal of the BP effects of seasonality from visit-to-visit BP variations.

Long-term systolic blood pressure variability independent of mean blood pressure is associated with mortality and cardiovascular events: A systematic review and meta-analysis

The association between long-term systolic blood pressure variability (SBPV) and cardiovascular (CV) outcomes after being adjusted with mean blood pressure (BP) is questionable. This systematic review aims to evaluate the associations between mean BP adjusted long-term SBPV and CV outcomes. A systematic search was conducted on PubMed, Scopus, and Science Direct on January 4, 2023. A total of 9,944,254 subjects from 43 studies were included in this meta-analysis. Long-term SBPV increased the risk of all-cause mortality (HR 1.21 [95%CI 1.16-1.25], I2=100%), CV mortality (HR 1.10 [95%CI 1.07-11.4], I2 = 90%), MACE (HR 1.10 [1.07-1.13], I2 = 91%), cerebrovascular stroke (HR 1.22 [1.16-1.29], I2=100%), and myocardial infarction (HR 1.13 [95%CI (1.07-1.19)], I2=91%). European populations generally had higher risk compared to other continents. In conclusion, long-term SBPV is associated with all-cause mortality, CV mortality, MACE, MI, and stroke. Poor outcomes related to long-term SBPV seem more dominated by cerebrovascular than coronary events.

Blood pressure variability: methodological aspects, clinical relevance and practical indications for management - a European Society of Hypertension position paper ∗

Blood pressure is not a static parameter, but rather undergoes continuous fluctuations over time, as a result of the interaction between environmental and behavioural factors on one side and intrinsic cardiovascular regulatory mechanisms on the other side. Increased blood pressure variability (BPV) may indicate an impaired cardiovascular regulation and may represent a cardiovascular risk factor itself, having been associated with increased all-cause and cardiovascular mortality, stroke, coronary artery disease, heart failure, end-stage renal disease, and dementia incidence. Nonetheless, BPV was considered only a research issue in previous hypertension management guidelines, because the available evidence on its clinical relevance presents several gaps and is based on heterogeneous studies with limited standardization of methods for BPV assessment. The aim of this position paper, with contributions from members of the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability and from a number of international experts, is to summarize the available evidence in the field of BPV assessment methodology and clinical applications and to provide practical indications on how to measure and interpret BPV in research and clinical settings based on currently available data. Pending issues and clinical and methodological recommendations supported by available evidence are also reported. The information provided by this paper should contribute to a better standardization of future studies on BPV, but should also provide clinicians with some indications on how BPV can be managed based on currently available data.

Vascular Calcification Exacerbates Abnormal Blood Pressure Variability in Chronic Kidney Disease: A "Two-Step" Study in Rats

INTRODUCTION

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) with poor cardiovascular prognosis. The aim of this study was to explore the impact of VC on blood pressure variability (BPV) in animal models of CKD.

METHODS

Two optimal modelling methods, adenine high-phosphorus (HP) diet + calcitriol and 5/6 nephrectomy (Nx) + HP diet + calcitriol, for CKD-VC were chosen from the first-step experiment for the next step. A total of 36 male Wistar rats were randomly assigned to the standard-chow, sham-operated, adenine, 5/6Nx, adenine-VC, and 5/6Nx-VC groups. Continuous blood pressure (BP) measurement using the BP-2000 animal noninvasive BP analyser was started at the 9th week for the standard-chow, adenine, and adenine-VC groups and at the 7th week for the sham-operated, 5/6Nx, and 5/6Nx-VC groups. BPV metrics (BPVs), including the difference between maximum and minimum values, standard deviation, coefficient of variation, average real variability, and residuals derived from the generalized linear model of BP, were calculated.

RESULTS

The first experiment showed that the use of calcitriol accelerated the progression of VC in CKD rats (the modelling period was shortened from 16 weeks to 4-8 weeks) and confirmed the occurrence of VC at weeks 8 and 6 in the adenine-VC and 5/6Nx-VC groups, respectively. In the second experiment, 13 of 20 hour-to-hour BPVs increased significantly with the development of CKD and VC. BPV differences among the standard-chow, adenine, and adenine-VC groups were mainly due to the differences between the standard-chow and adenine-VC groups (7 of 10 BPVs were significantly different), followed by the differences between the standard-chow and adenine groups (3 of 10). BPV differences among the sham-operated, 5/6Nx, and 5/6Nx-VC groups were caused by the differences between the 5/6Nx-VC and 5/6Nx groups (4 of 10) or the 5/6Nx-VC and sham-operated groups (3 of 10).

CONCLUSION

An increased BPV is observed in CKD rats, and VC further aggravates the abnormality of BPVs independent of CKD.

Bidirectional association between SBP variability and arterial stiffness in patients with chronic kidney disease: findings from KNOW-CKD study

OBJECTIVE

Studies on the mutual relationship between blood pressure (BP) variability and arterial stiffness using time-dependent changes in arterial stiffness are scarce.

METHODS

In this prospective cohort of Korean patients with chronic kidney disease (CKD) G1-G5 without kidney replacement therapy, we studied the bidirectional association between visit-to-visit SBP variability (VVSV) and arterial stiffness in 1036 participants who underwent brachial-ankle pulse wave velocity (baPWV) measurement at baseline and year four. We constructed multivariable logistic regression models using two analytical sets. First, we determined the VVSV [standard deviation (SD)] of all SBP readings over 4 years, and then calculated the odds ratios (ORs) for arterial stiffness progression according to tertiles of VVSV. Arterial stiffness progression was defined as at least 75th percentile of the difference in baPWV between baseline and year four. Second, we analysed the ORs for at least 75th percentile of the 4-year VVSV according to tertiles of baseline baPWV.

RESULTS

Compared with the lowest tertile of VVSV (SD), the ORs [95% confidence interval (95% CI)] for arterial stiffness progression were 1.42 (0.96-2.10) and 1.64 (1.11-2.43) for the middle and highest tertiles, respectively. In the second analysis based on tertiles of baseline baPWV, the ORs for at least 75th percentile of VVSV (SD) were 1.41 (95% CI, 0.95-2.10) and 1.64 (95% CI, 1.04-2.61) for the middle and highest tertiles, respectively. This association was similar in both analytical models when VVSV and baPWV were treated as continuous variables.

CONCLUSION

There is a bidirectional relationship between BP variability and arterial stiffness in patients with CKD.

Is there a characteristic pattern of ambulatory blood pressure profile in type 1 diabetic children and adolescents?

PURPOSE

To examine the characteristics of ambulatory blood pressure (ABP) including blood pressure variability (BPV) and its association with albuminuria in type 1 diabetic (T1D) children and to identify potential predictors of high-normal albuminuria and microalbuminuria.

METHODS

ABP monitoring was performed in 201 T1D children and adolescents (mean age, 14.7±3.8 years) with T1D duration over 1 year. The level of albuminuria was assessed as the albumin/creatinine ratio (ACR) and patients were further classified as low-normal, high-normal or microalbuminuria.

RESULTS

Fifteen T1D children (7.5%) were hypertensive using office blood pressure (BP) and 10 (5%) according to ABP. T1D subjects had elevated 24-hour systolic BP (SBP) and diastolic BP (DBP) (+0.2 and + 0.3 standard deviation score [SDS]) and nighttime SBP and DBP (+0.6 and +0.8 SDS) compared to reference values. Patients with microalbuminuria had significantly higher 24-hour, daytime and nighttime DBP compared to normoalbuminuric subjects. There was a high percentage of nondippers (74.1%). Nighttime diastolic BPV was significantly higher in subjects with high-normal compared to low-normal albuminuria (p=0.01). A weak correlation was found between ACR and daytime DBP SDS (r=0.29, p<0.001 and nighttime DBP SDS (r=0.21, p=0.003). Age and nighttime diastolic BPV were predictors of high-normal albuminuria while nighttime DBP was a strong predictor for microalbuminuria.

CONCLUSION

T1D children have impaired BP regulation although most of them do not fulfill the criteria for sustained hypertension. There is an association between diastolic ABP and diastolic BPV with rising levels of albuminuria pointing to a clear connection between BP and incipient diabetic nephropathy.

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.

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.

Frequency of daily tooth brushing and subsequent cardiovascular events

OBJECTIVE

Although previous studies have shown an inverse association between the frequency of daily tooth brushing and cardiovascular risk factors, research on cardiovascular events is limited. This study aimed to evaluate the association between the frequency of daily tooth brushing and subsequent cardiovascular events.

METHODS AND RESULTS

A retrospective longitudinal study was conducted at a hospital in Tokyo, Japan. We included all participants who underwent health check-ups from 2005 to 2011 and followed up to 2018. Our outcomes were the development of cardiovascular events. Outcomes were compared by the frequency of daily tooth brushing with a generalized estimating equation, adjusting for potential confounders. A total of 71 221 participants were included. The mean age was 45.6 years and 50.3% were male. During a median follow-up of 2061 (interquartile range: 933-3311) days, 1905 participants developed cardiovascular events. The adjusted odds ratios (ORs) of cardiovascular events increased in a dose-dependent manner as the frequency of tooth brushing decreased. Even those who brushed their teeth once in a day had a higher adjusted OR of stroke (1.22; 95% confidence interval, 1.01-1.48) than did those who brushed after every meal.

CONCLUSIONS

Frequent tooth brushing was inversely associated with subsequent cardiovascular events in a dose-dependent manner. Even brushing one's teeth once a day may be related to an increased likelihood of stroke than brushing one's teeth after every meal. Less frequent tooth brushing may be considered to be a marker for subsequent cardiovascular disease and coronary heart disease, rather than a risk factor.

Visit-to-visit variability of blood pressure and cardiovascular events among the working-age population in Japan: findings from the Japan Epidemiology Collaboration on Occupational Health Study

Increased visit-to-visit variability (VVV) of blood pressure, which is calculated based on several readings, has been suggested to be a significant predictor of cardiovascular events and mortality, independent of mean blood pressure. This study examined associations between the VVV of systolic blood pressure (SBP) measured annually and cardiovascular disease (CVD) events among 72,617 Japanese subjects. Data were obtained from the Japan Epidemiology Collaboration on Occupational Health Study, which is an ongoing epidemiological survey of workers in Japan. VVV was calculated as the coefficient of variation of SBP readings from 2008 to 2011; information on fatal and nonfatal CVD events was collected from registries of specific outcomes between April 2012 and March 2019. A Cox proportional hazards model was applied to investigate associations after adjusting for mean SBP between 2008 and 2011 and covariates. During the 7-year follow-up period, there were 63 CVD fatalities and 314 CVD events (combining fatal and nonfatal events). The results showed that a one-standard deviation increase in VVV was associated with a significant increase in the risk of CVD mortality (hazard ratio [HR] = 1.42; 95% confidence interval [CI] = 1.32-1.54); those in the highest tertile had a 3.20 times (95% CI = 1.26-8.17) higher risk of CVD mortality than those in the lowest tertile. We found less pronounced associations regarding CVD events (HR = 1.08, 95% CI = 1.02-1.15). In conclusion, VVV was significantly associated with CVD mortality in our Japanese working population.

The association of blood pressure variability with adverse outcomes in a primary care chronic kidney disease cohort

BACKGROUND

Hypertension is common in individuals with chronic kidney disease and both conditions are associated with adverse outcomes including cardiovascular morbidity. Therefore, it is clinically important to identify methods of risk prediction in individuals with chronic kidney disease. Blood pressure variability has recently emerged as a predictor of cardiovascular events and mortality in the general population, with growing evidence indicating that it may play a similar role in individuals with chronic kidney disease. However, there have been no large studies assessing blood pressure variability in individuals with chronic kidney disease in primary care, where the majority of these patients are managed.

METHOD

Using a retrospective observational study design, we analyzed routinely collected blood pressure readings from 16 999 individuals in The Leicester and County Chronic Kidney Disease cohort. Standard deviation, coefficient of variation and average real variability of SBP were used to calculate blood pressure variability.

RESULTS

During a median follow-up of 5.0 (IQR 3.3--5.0) years, 2053 (12.1%) patients had cardiovascular events, death occurred in 5021 (29.6%) individuals and 156 (0.9%) individuals had endstage kidney disease events. In adjusted models, standard deviation and coefficient of variation were associated with cardiovascular events, all-cause mortality and endstage kidney disease. Average real variability was associated with all-cause mortality and cardiovascular events, but not endstage kidney disease.

CONCLUSION

Blood pressure variability may be an accessible, routinely collected, noninvasive measure for stratifying the risk of adverse events in individuals with chronic kidney disease in a primary care setting.

Association of visit-to-visit variability in blood pressure and first stroke risk in hypertensive patients with chronic kidney disease

OBJECTIVE

Data on the association between visit-to-visit variability (VVV) in blood pressure (BP) and the risk of stroke among hypertensive patients with chronic kidney disease (CKD) is limited. We aimed to evaluate the relation of VVV in BP with the risk of stroke, and examine any possible effect modifiers in hypertensive patients with mild-to-moderate CKD.

METHODS

This is a post-hoc analysis of the China Stroke Primary Prevention Trial. A total of 3091 patients with estimated glomerular filtration rate 30-60 ml/min per 1.73 m and/or proteinuria at baseline, without occurring stroke and with BP measurements of at least two visits from randomization to the 12-month visit were included. The main VVV in BP was expressed as SD. The primary outcome was first stroke.

RESULTS

The median subsequent treatment duration was 3.7 years. After multivariable adjustment, including baseline SBP and mean SBP during the first 12-month follow-up, there was a significantly positive relationship of SD SBP with the risk of subsequent first stroke (per SD increment; odds ratio, 1.41; 95% confidence interval: 1.17-1.69) and first ischemic stroke (odds ratio, 1.55; 95% confidence interval: 1.26-1.90). Results were consistent across various subgroups, including age, sex, baseline SBP, treatment compliance, and mean SBP, concomitant usage of calcium channel blocker during the first 12-month follow-up period. Similar trends were also found for coefficient of variation SBP, and SD or coefficient of variation DBP. However, there was no significant association between BP variability and first hemorrhagic stroke.

CONCLUSION

In hypertensive adults with mild-to-moderate CKD, visit-to-visit variability in BP was significantly associated with the risk of subsequent first stroke.

Nocturnal Systolic Hypertension and Adverse Prognosis in Patients with CKD

BACKGROUND AND OBJECTIVES

Nocturnal hypertension is associated with adverse outcomes in patients with CKD. However, the individual association of entities of nocturnal hypertension according to achievement of systolic and/or diastolic BP goals with kidney failure and cardiovascular outcomes of CKD is not clear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study analyzed data from participants in the Chinese Cohort Study of Chronic Kidney Disease. Nocturnal hypertension was categorized into three entities: isolated nocturnal diastolic hypertension with diastolic BP ≥70 mm Hg and systolic BP <120 mm Hg, isolated nocturnal systolic hypertension with systolic BP ≥120 mm Hg and diastolic BP <70 mm Hg, and nocturnal systolic-diastolic hypertension with both systolic BP ≥120 mm Hg and diastolic BP ≥70 mm Hg. Associations of nocturnal hypertension entities with kidney failure and cardiovascular outcomes were evaluated by Cox regression.

RESULTS

In total, 2024 patients with CKD stages 1-4 were included in our analysis (mean age, 49±14 years; 57% men; eGFR=51±29 ml/min per 1.73 m²; proteinuria: 0.9 [0.4-2.1] g/d). Among them, 1484 (73%) patients had nocturnal hypertension, with the proportions of 26%, 8%, and 66% for isolated nocturnal diastolic hypertension, isolated nocturnal systolic hypertension, and nocturnal systolic-diastolic hypertension, respectively. Three hundred twenty kidney events and 148 cardiovascular events were recorded during median follow-up intervals of 4.8 and 5.0 years for kidney and cardiovascular events, respectively. After adjustment, isolated nocturnal systolic hypertension was associated with a higher risk for cardiovascular events (hazard ratio, 3.17; 95% confidence interval, 1.61 to 6.23). Nocturnal systolic-diastolic hypertension showed a higher risk for both kidney failure (hazard ratio, 1.71; 95% confidence interval, 1.17 to 2.49) and cardiovascular outcomes (hazard ratio, 2.19; 95% confidence interval, 1.24 to 3.86). No association was observed between isolated nocturnal diastolic hypertension with either kidney failure or cardiovascular events.

CONCLUSIONS

Nocturnal systolic hypertension, either alone or in combination with diastolic hypertension, is associated with higher risks for adverse outcomes in patients with CKD.

Glomerular filtration function decline, mortality, and cardiovascular events: data from the Strong Heart Study

BACKGROUND

Rapid kidney decline is associated with mortality and cardiovascular disease, even in the absence of chronic kidney disease. American Indians (AI) have particularly high burden of kidney disease, cardiovascular disease, and stroke. This study aims to examine extreme loss in glomerular function in this population in association with clinical outcomes.

METHODS

The Strong Heart Study, a large longitudinal cohort of adult AI participants, collected plasma creatinine at 3 examination visits between 1989-1999. Intraindividual regressions of estimated glomerular filtration rate (eGFR) provided linear estimates of change in kidney function over this time period. Surveillance with physician adjudication identified mortality and cardiovascular events between visit 3 through 2017.

RESULTS

Mean change in eGFR was loss 6.8 mL/min over the ten year baseline (range: -66.0 to +28.9 mL/min). The top 1 percentile lost approximately 5.7 mL/min/year. Participants with extreme eGFR loss were more likely to have diabetes (95% vs 71%), hypertension (49% vs 33%), or longer smoking history, among smokers (19 pack years vs 17 pack years). CKD (eGFR<60 mL/min) was associated only with mortality, independent of slope: HR 1.1 (95% CI 1.0-1.3). However, extreme loss in eGFR (>20 mL/min over baseline period) was associated with mortality, independent of baseline eGFR: HR 3.5 (95% CI 2.7-4.4), and also independently associated with composite CVD events and CHF: HR 1.4 and 1.7 (95% CI 1.1-1.9 and 1.2-2.6), respectively.

CONCLUSION

This is the first examination of decline in eGFR in association with mortality and CVD among AIs. The implications of these findings are broad: clinical evaluation may benefit from evaluating change in eGFR over time in addition to dichotomous eGFR. Also, these findings suggest there may be aspects of renal function that are not well-marked by clinical CKD, but which may have particular relevance to long-term renal and vascular health.

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.

Ambulatory blood pressure profile in office normotensive obese children: prevalence of masked hypertension and impact of parental hypertension

Objectives The objectives of this study were to analyze ambulatory blood pressure (ABP) data in office normotensive obese children, to determine the prevalence and characteristics of masked hypertension (MH) and to investigate the impact of parental hypertension (PH) on ABP. Methods Seventy-nine obese and 35 normal weight children were enrolled. Each weight group was further divided in accordance with the presence of PH. ABP was recorded in an outpatient setting. Results Obese children had higher systolic ABP (p<0.05) and heart rate (p<0.001) compared with normal weight children. In obese children with PH, only nighttime systolic ABP (p=0.01) was higher compared with obese without PH, whereas normal weight children with PH had higher 24 h and daytime systolic and diastolic BP (all p<0.05) and nighttime DBP (p<0.001) compared with those without PH. PH but not obesity was associated with nondipping phenomenon. Prevalence of MH in the whole group was 23.6% being significantly higher in obese than in nonobese subjects (31.6 vs. 5.7%; p=0.0026) as well as in obese subjects with PH compared with obese subjects without PH (48.7 vs. 15%; χ2=10.37; p=0.001). MH was diagnosed more frequently in obese with high-normal office BP compared with obese with normal office BP, although it did not reach statistical significance (50 vs. 26.2%; χ2=3.631; p=0.056). In the normal weight group, neither PH nor office BP category had an impact on the prevalence of MH. Conclusions Office normotensive obese children had higher ABP values. MH was associated with obesity, PH and high-normal BP.

Blood Pressure Variability and Outcomes in End-Stage Renal Disease Patients on Dialysis: A Systematic Review and Meta-Analysis

Objective: Previous studies have suggested that blood pressure variability (BPV) is associated with an increased risk of mortality and cardiovascular events in patients on dialysis. However, the results are inconsistent. A comprehensive literature review was conducted to analyze the association between BPV and outcomes in patients on dialysis. Methods: Articles in Embase, Medline, and Web of Science from the date of inception through January 1, 2020, were identified. The outcomes were all-cause and cardiovascular mortality and cardiovascular events. The risk of bias was assessed using the Newcastle-Ottawa scale tool. Random effects models were used to pool the overall effect sizes. Two reviewers extracted the data independently. Meta-regression and subgroup analyses were performed to explore potential heterogeneity. Results: Fifteen eligible studies were included, and all enrolled hemodialysis recipients only. The overall risk of bias for the included studies was low. A 1-SD increase in systolic BPV was associated with higher risks of all-cause mortality (HR = 1.18; 95% CI 1.11–1.26, I2 = 53.8%), cardiovascular mortality (HR = 1.23; 95% CI 1.10–1.37, I2 = 57.2%), and cardiovascular events (HR = 1.27; 95% CI 1.07–1.51, I2 = 69.3%). Likewise, a 1-SD increase in diastolic BPV was associated with higher HR for all-cause and cardiovascular mortality (HR = 1.14; 95% CI 1.05–1.23, I2 = 0.0%, and HR = 1.14; 95% CI 0.94–1.38, I2 = 0.0%, respectively). Conclusions: A greater BPV is associated with higher risks of cardiovascular and mortality outcomes in patients on hemodialysis. Further research is required to determine whether BPV may be useful either as a marker enabling individualized treatment of cardiovascular risk or as a treatment target in its own right.

Changes in pre-dialysis blood pressure variability in the first year of dialysis associate with mortality in European hemodialysis patients: a retrospective cohort study on behalf of the MONDO Initiative

Pre-hemodialysis systolic blood pressure variability (pre-HD SBPV) has been associated with outcomes. The association of a change in pre-HD SBPV over time with outcomes, and predictors of this change, has not yet been studied. Therefore, we studied this in a cohort of 8825 incident hemodialysis (HD) patients from the European Monitoring Dialysis Outcomes Initiative database. Patient level pre-HD SBPV was calculated as the standard deviation of the residuals of a linear regression model of systolic blood pressure (SBP) over time divided by individual mean SBP in the respective time periods. The pre-HD SBPV difference between months 1-6 and 7-12 was used as an indicator of pre-HD SBPV change. The association between pre-HD SBPV change and all-cause mortality in year 2 was analyzed by multivariate Cox models. Predictors of pre-HD SBPV change was determined by logistic regression models. We found the highest pre-HD SBPV tertile, in the first 6 months after initiation of HD, had the highest mortality rates (adjusted HR 1.44 (95% confidence intervals (95% CI): 1.15-1.79)). An increase in pre-HD SBPV between months 1-6 and 7-12 was associated with an increased risk of mortality in year 2 (adjusted HR 1.29 (95% CI: 1.05-1.58)) compared with stable pre-HD SPBV. A pre-HD SBPV increase was associated with female gender, higher mean pre-HD SBP and pulse pressure, and lower HD frequency.

Comparison of self- and nurse-measured office blood pressure in patients with chronic kidney disease

OBJECTIVE

As blood pressure (BP) control is very important in chronic kidney disease (CKD), we investigated how office BP is influenced by the measurement circumstances and compared nonautomated self- and nurse-measured BP values.

MATERIALS AND METHODS

Two hundred stage 1-5 CKD patients with scheduled visits to an outpatient clinic were randomized to either self-measured office BP (SMOBP) followed by nurse-measured office BP (NMOBP) or NMOBP followed by SMOBP. The participants had been educated to perform the self-measurement in at least one previous visit. The SMOBP and NMOBP measurement series both consisted of three recordings, and the means of the last two recordings during SMOBP and NMOBP were compared for the 174 (mean age 52.5 years) with complete BP data.

RESULTS

SMOBP and NMOBP showed similar systolic (135.3 ± 16.6 vs 136.4 ± 17.4 mmHg, Δ = 1.1 mmHg, P = 0.13) and diastolic (81.5 ± 10.2 vs 82.2 ± 10.4 mmHg, Δ = 0.6 mmHg, P = 0.09) values. The change in BP from the first to the third recording was not different for SMOBP and NMOBP. In 17 patients, systolic SMOBP was ≥10 mmHg higher than NMOBP and in 28 patients systolic NMOBP exceeded SMOBP by ≥10 mmHg. The difference between systolic SMOBP and NMOBP was independent of CKD stage and the number of medications, but significantly more pronounced in patients above 60 years.

CONCLUSION

In a population of CKD patients, there is no clinically relevant difference in SMOBP and NMOBP when recorded at the same visit. However, in 25% of the patients, systolic BP differs ≥10 mmHg between the two measurement modalities.

Prognostic importance of visit-to-visit blood pressure variability for micro- and macrovascular outcomes in patients with type 2 diabetes: The Rio de Janeiro Type 2 Diabetes Cohort Study

BACKGROUND

The prognostic importance of an increased visit-to-visit blood pressure variability (BP-VVV) for the future development of micro- and macrovascular complications in type 2 diabetes has been scarcely investigated and is largely unsettled. We aimed to evaluate it in a prospective long-term follow-up study with 632 individuals with type 2 diabetes.

METHODS

BP-VVV parameters (systolic and diastolic standard deviations [SD] and variation coefficients) were measured during the first 24-months. Multivariate Cox analysis, adjusted for risk factors and mean BP levels, examined the associations between BP-VVV and the occurrence of microvascular (retinopathy, microalbuminuria, renal function deterioration, peripheral neuropathy) and macrovascular complications (total cardiovascular events [CVEs], major adverse CVEs [MACE] and cardiovascular and all-cause mortality). Improvement in risk discrimination was assessed by the C-statistic and integrated discrimination improvement (IDI) index.

RESULTS

Over a median follow-up of 11.3 years, 162 patients had a CVE (132 MACE), and 212 patients died (95 from cardiovascular diseases); 153 newly-developed or worsened diabetic retinopathy, 193 achieved the renal composite outcome (121 newly-developed microalbuminuria and 95 deteriorated renal function), and 171 newly-developed or worsened peripheral neuropathy. Systolic BP-VVV was an independent predictor of MACE (hazard ratio: 1.25, 95% CI 1.03-1.51 for a 1-SD increase in 24-month SD), but not of total CVEs, cardiovascular and all-cause mortality, and of any microvascular outcome. However, no BP-VVV parameter significantly improved cardiovascular risk discrimination (increase in C-statistic 0.001, relative IDI 0.9%).

CONCLUSIONS

Systolic BP-VVV was an independent predictor of MACE, but it did not improve cardiovascular risk stratification. The goal of anti-hypertensive treatment in patients with type 2 diabetes shall remain in controlling mean BP levels, not on decreasing their visit-to-visit variability.

Number of blood pressure measurements needed to estimate long-term visit-to-visit systolic blood pressure variability for predicting cardiovascular risk: a 10-year retrospective cohort study in a primary care clinic in Malaysia

OBJECTIVE

To determine the reproducibility of visit-to-visit blood pressure variability (BPV) in clinical practice. We also determined the minimum number of blood pressure (BP) measurements needed to estimate long-term visit-to-visit BPV for predicting 10-year cardiovascular (CV) risk.

DESIGN

Retrospective study SETTING: A primary care clinic in a university hospital in Malaysia.

PARTICIPANTS

Random sampling of 1403 patients aged 30 years and above without any CV event at baseline.

OUTCOMES MEASURES

The effect of the number of BP measurement for calculation of long-term visit-to-visit BPV in predicting 10-year CV risk. CV events were defined as fatal and non-fatal coronary heart disease, fatal and non-fatal stroke, heart failure and peripheral vascular disease.

RESULTS

The mean 10-year SD of systolic blood pressure (SBP) for this cohort was 13.8±3.5 mm Hg. The intraclass correlation coefficient (ICC) for the SD of SBP based on the first eight and second eight measurements was 0.38 (p<0.001). In a primary care setting, visit-to-visit BPV (SD of SBP calculated from 20 BP measurements) was significantly associated with CV events (adjusted OR 1.07, 95% CI 1.02 to 1.13, p=0.009). Using SD of SBP from 20 measurement as reference, SD of SBP from 6 measurements (median time 1.75 years) has high reliability (ICC 0.74, p<0.001), with a mean difference of 0.6 mm Hg. Hence, a minimum of six BP measurements is needed for reliably estimating intraindividual BPV for CV outcome prediction.

CONCLUSION

Long-term visit-to-visit BPV is reproducible in clinical practice. We suggest a minimum of six BP measurements for calculation of intraindividual visit-to-visit BPV. The number and duration of BP readings to derive BPV should be taken into consideration in predicting long-term CV risk.

Assessment of Blood Pressure: Techniques and Implications From Clinical Trials

Hypertension is a global health problem and without adequate diagnosis and treatment is a risk factor for morbidity and mortality. Proper assessment of blood pressure is key to diagnosis and management of hypertension. Different methods of measurement are available for use and varying techniques are applied to patient care. Understanding the proper methods of blood pressure measurement both in and out of the physician's office is crucial for providing appropriate care to an individual patient. In addition, understanding the techniques used in research, on which current guidelines are based, is critical for proper application to daily practice. In this article, we review the types of blood pressure measurement techniques, discuss the benefits and limitations to each, explore future technological advances in measurement devices, and provide insight into research techniques, which ultimately guide our practice.

Blood Pressure Variability, Mortality, and Cardiovascular Outcomes in CKD Patients

BACKGROUND AND OBJECTIVES

Short-term BP variability (derived from 24-hour ambulatory BP monitoring) and long-term BP variability (from clinic visit to clinic visit) are directly related to risk for cardiovascular events, but these relationships have been scarcely investigated in patients with CKD, and their prognostic value in this population is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a cohort of 402 patients with CKD, we assessed associations of short- and long-term systolic BP variability with a composite end point of death or cardiovascular event. Variability was defined as the standard deviation of observed BP measurements. We further tested the prognostic value of these parameters for risk discrimination and reclassification.

RESULTS

Mean ± SD short-term systolic BP variability was 12.6±3.3 mm Hg, and mean ± SD long-term systolic BP variability was 12.7±5.1 mm Hg. For short-term BP variability, 125 participants experienced the composite end point over a median follow-up of 4.8 years (interquartile range, 2.3-8.6 years). For long-term BP variability, 110 participants experienced the composite end point over a median follow-up of 3.2 years (interquartile range, 1.0-7.5 years). In adjusted analyses, long-term BP variability was significantly associated with the composite end point (hazard ratio, 1.24; 95% confidence interval, 1.01 to 1.51 per 5-mm Hg higher SD of office systolic BP), but short-term systolic BP variability was not (hazard ratio, 0.92; 95% confidence interval, 0.68 to 1.25 per 5-mm Hg higher SD of 24-hour ambulatory systolic BP). Neither estimate of BP variability improved risk discrimination or reclassification compared with a simple risk prediction model.

CONCLUSIONS

In patients with CKD, long-term but not short-term systolic BP variability is related to the risk of death and cardiovascular events. However, BP variability has a limited role for prediction in CKD.

Twenty-four-hour systolic blood pressure variability and renal function decline in elderly male hypertensive patients with well-controlled blood pressure

Purpose

Increased variability in blood pressure (BP) is known to be closely associated with the development, progression and severity of renal damage in patients with chronic kidney disease. However, little is known about the association of BP variability (BPV) with the decline of renal function in elderly hypertensive patients with well-controlled BP. We, therefore, aimed to investigate the association between BPV and glomerular filtration rate in hypertensive elderly (age >60 years) and very elderly (age >80 years) male patients with BP controlled within the normal range by antihypertensive therapy.

Patients and methods

This study involved 484 hospitalized elderly male hypertensive patients with BP controlled within the normal range by antihypertensive therapy. BPV was defined as the SD from mean BP over a 24 h period. Renal function was estimated by estimated glomerular filtration rate (eGFR) which was calculated by the Chinese modified Modification of Diet in Renal Disease Equation. Participants were divided into three groups according to their eGFR data. Multivariate linear regression was then used to analyze the correlation between eGFR and BPV.

Results

The 24 h systolic BP (SBP) variability increased as eGFR decreased. There was no significant difference in 24 h SBP variability when compared between elderly and very elderly hypertensive patients. Multivariate linear regression analysis showed that SBP variability demonstrated a negative linear relationship with eGFR (P<0.05) after adjustment for potential confounding factors.

Conclusion

Among the parameters of 24 h ambulatory BP monitoring, 24 h SBP variability is the only independent risk factor for a decline in renal function in elderly and very elderly male hypertensive patients with well-controlled BP.

Pre-end-stage renal disease visit-to-visit systolic blood pressure variability and post-end-stage renal disease mortality in incident dialysis patients

OBJECTIVES

Higher SBP visit-to-visit variability (SBPV) has been associated with increased risk of adverse events in patients with chronic kidney disease, but the association of SBPV in advanced nondialysis-dependent chronic kidney disease with mortality after the transition to end-stage renal disease (ESRD) remains unknown.

METHODS

Among 17 729 US veterans transitioning to dialysis between October 2007 and September 2011, we assessed SBPV calculated from the SD of at least three intraindividual outpatient SBP values during the last year prior to dialysis transition (prelude period). Outcomes included factors associated with higher prelude SBPV and post-transition all-cause, cardiovascular, and infection-related mortality, assessed using multivariable linear regression and Cox and competing risk regressions, respectively, adjusted for demographics, comorbidities, medications, cardiovascular medication adherence, SBP, BMI, estimated glomerular filtration rate, and type of vascular access.

RESULTS

Modifiable clinical factors associated with higher prelude SBPV included higher SBP, use of antihypertensive medications and erythropoiesis-stimulating agents, inadequate cardiovascular medication adherence, and catheter use. After multivariable adjustment, higher prelude SBPV was significantly associated with higher post-ESRD all-cause and infection-related mortality, but not cardiovascular mortality [hazard/subhazard ratios (95% confidence interval) for the highest (vs. lowest) quartile of SBPV, 1.08 (1.01-1.16), 1.02 (0.89-1.15), and 1.41 (1.10-1.80) for all-cause, cardiovascular, and infection-related mortality, respectively].

CONCLUSION

High pre-ESRD SBPV is potentially modifiable and associated with higher all-cause and infection-related mortality following dialysis initiation. Further studies are needed to test whether modification of pre-ESRD SBPV can improve clinical outcomes in incident ESRD patients. VIDEO ABSTRACT:.

Antihypertensive therapy in nondiabetic chronic kidney disease: a review and update

Hypertension is an important contributor to progression of nondiabetic chronic kidney disease (CKD). Compelling observational evidence indicates that the divergence of blood pressure (BP) away from an ideal range in either direction is associated with a progressive rise in the risk of mortality and cardiovascular and renal disease progression. To date, various clinical trials and meta-analyses examining strict versus less intensive BP control in nondiabetic CKD have not conclusively demonstrated a renal advantage of one BP-lowering approach over another, except in certain subgroups such as proteinuric patients where evidence is circumstantial. As recent data have come to light suggesting that intensive BP control yields superior survival and cardiovascular outcomes in patients at high risk for cardiovascular disease, interest in the prospect of whether such benefit extends to individuals with CKD has surged. This review is a comprehensive analysis of antihypertensive literature in nondiabetic renal disease, with a particular emphasis on BP target.

Visit-to-visit blood pressure variability is a risk factor for all-cause mortality and cardiovascular disease: a systematic review and meta-analysis

OBJECTIVE

Clinical cohort studies have reported that visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular disease (CVD) or mortality. However, the results were not consistent in all studies. The current study is, therefore, aimed to conduct a systematic review and meta-analysis to determine the association between VVV of BP and CVD and all-cause mortality.

METHOD

PubMed and EMBASE were searched through 18 May 2014, using the following terms: VVV, BP, CVD, coronary heart disease (CHD), myocardial ischemia, stroke, and mortality. Overall, 84 records were identified, and 23 publications were enrolled into the current study. Data were extracted from selected publications, and meta-analysis was performed using a random effect model.

RESULT

VVV of SBP was significantly associated with outcomes of all-cause mortality with the relative risk (RR) and 95% confidence interval (CI) 1.14 (1.09, 1.18), CVD incidence (RR = 1.12, 95% CI: 1.05, 1.09), CVD mortality (RR = 1.18, 95% CI: 1.09, 1.28), CHD incidence (RR = 1.12, 95% CI: 1.06, 1.19), and stroke incidence (RR = 1.34, 95% CI: 1.11, 1.61).

CONCLUSION

In summary, among the wide heterogenetic population, modest associations between VVV of SBP and all-cause mortality, CVD incidence, CVD mortality, CHD incidence, and stroke incidence were found. Findings of the current study suggested that standardized approaches of monitoring VVV in the high-risk population, including patients with cardiac infarction, diabetes, stroke, and patients with chronic kidney disease or in dialysis, are necessary in designing a prospective clinical study on the association of VVV and patients' prognosis.

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.

Long-Term Visit-to-Visit Blood Pressure Variability and Renal Function Decline in Patients With Hypertension Over 15 Years

BACKGROUND

Visit-to-visit variability of systolic blood pressure (SBP) has been shown to contribute to cardiovascular events and all-cause mortality. However, little is known about its long-term effect on renal function. We aim to examine the relationship between visit-to-visit blood pressure variability (BPV) and decline in renal function in patients with hypertension and to determine the level of systolic BPV that is associated with significant renal function decline.

METHODS AND RESULTS

This is a 15-year retrospective cohort study of 825 hypertensive patients. Blood pressure readings every 3 months were retrieved from the 15 years of clinic visits. We used SD and coefficient of variation as a measure of systolic BPV. Serum creatinine was captured and estimated glomerular filtration rate was calculated at baseline, 5, 10, and 15 years. The mean SD of SBP was 14.2±3.1 mm Hg and coefficient of variation of SBP was 10.2±2%. Mean for estimated glomerular filtration rate slope was -1.0±1.5 mL/min per 1.73 m2 per year. There was a significant relationship between BPV and slope of estimated glomerular filtration rate (SD: r=-0.16, P<0.001; coefficient of variation: r=-0.14, P<0.001, Pearson's correlation). BPV of SBP for each individual was significantly associated with slope of estimated glomerular filtration rate after adjustment for mean SBP and other confounders. The cutoff values estimated by the receiver operating characteristic curve for the onset of chronic kidney disease for SD of SBP was 13.5 mm Hg and coefficient of variation of SBP was 9.74%.

CONCLUSIONS

Long-term visit-to-visit variability of SBP is an independent determinant of renal deterioration in patients with hypertension. Hence, every effort should be made to reduce BPV in order to slow down the decline of renal function.

Visit-to-visit variability of blood pressure and death, end-stage renal disease, and cardiovascular events in patients with chronic kidney disease

OBJECTIVES

Visit-to-visit variability of blood pressure (VVV of BP) is an important independent risk factor for premature death and cardiovascular events, but relatively little is known about this phenomenon in patients with chronic kidney disease (CKD) not yet on dialysis.

METHODS

We conducted a retrospective study in a community-based cohort of 114 900 adults with CKD stages 3-4 (estimated glomerular filtration rate 15-59 ml/min per 1.73 m). We hypothesized that VVV of BP would be independently associated with higher risks of death, incident treated end-stage renal disease, and cardiovascular events. We defined systolic VVV of BP using three metrics: coefficient of variation, standard deviation of the mean SBP, and average real variability.

RESULTS

The highest versus the lowest quintile of the coefficient of variation was associated with higher adjusted rates of death (hazard ratio 1.22; 95% confidence interval 1.11-1.34) and hemorrhagic stroke (hazard ratio 1.91; confidence interval 1.36-2.68). VVV of BP was inconsistently associated with heart failure, and was not significantly associated with acute coronary syndrome and ischemic stroke. Results were similar when using the other two metrics of VVV of BP. VVV of BP had inconsistent associations with end-stage renal disease, perhaps because of the relatively low incidences of this outcome.

CONCLUSION

Higher VVV of BP is independently associated with higher rates of death and hemorrhagic stroke in patients with moderate to advanced CKD not yet on dialysis.

Impact of baseline systolic blood pressure on visit-to-visit blood pressure variability: the Kailuan study

Background

To investigate the relationship between baseline systolic blood pressure (SBP) and visit-to-visit blood pressure variability in a general population.

Methods

This is a prospective longitudinal cohort study on cardiovascular risk factors and cardiovascular or cerebrovascular events. Study participants attended a face-to-face interview every 2 years. Blood pressure variability was defined using the standard deviation and coefficient of variation of all SBP values at baseline and follow-up visits. The coefficient of variation is the ratio of the standard deviation to the mean SBP. We used multivariate linear regression models to test the relationships between SBP and standard deviation, and between SBP and coefficient of variation.

Results

Approximately 43,360 participants (mean age: 48.2±11.5 years) were selected. In multivariate analysis, after adjustment for potential confounders, baseline SBPs <120 mmHg were inversely related to standard deviation (P<0.001) and coefficient of variation (P<0.001). In contrast, baseline SBPs ≥140 mmHg were significantly positively associated with standard deviation (P<0.001) and coefficient of variation (P<0.001). Baseline SBPs of 120–140 mmHg were associated with the lowest standard deviation and coefficient of variation. The associations between baseline SBP and standard deviation, and between SBP and coefficient of variation during follow-ups showed a U curve.

Conclusion

Both lower and higher baseline SBPs were associated with increased blood pressure variability. To control blood pressure variability, a good target SBP range for a general population might be 120–139 mmHg.

Blood pressure variability and cardiovascular disease: systematic review and meta-analysis

OBJECTIVE

 To systematically review studies quantifying the associations of long term (clinic), mid-term (home), and short term (ambulatory) variability in blood pressure, independent of mean blood pressure, with cardiovascular disease events and mortality.

DATA SOURCES

 Medline, Embase, Cinahl, and Web of Science, searched to 15 February 2016 for full text articles in English.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

 Prospective cohort studies or clinical trials in adults, except those in patients receiving haemodialysis, where the condition may directly impact blood pressure variability. Standardised hazard ratios were extracted and, if there was little risk of confounding, combined using random effects meta-analysis in main analyses. Outcomes included all cause and cardiovascular disease mortality and cardiovascular disease events. Measures of variability included standard deviation, coefficient of variation, variation independent of mean, and average real variability, but not night dipping or day-night variation.

RESULTS

 41 papers representing 19 observational cohort studies and 17 clinical trial cohorts, comprising 46 separate analyses were identified. Long term variability in blood pressure was studied in 24 papers, mid-term in four, and short-term in 15 (two studied both long term and short term variability). Results from 23 analyses were excluded from main analyses owing to high risks of confounding. Increased long term variability in systolic blood pressure was associated with risk of all cause mortality (hazard ratio 1.15, 95% confidence interval 1.09 to 1.22), cardiovascular disease mortality (1.18, 1.09 to 1.28), cardiovascular disease events (1.18, 1.07 to 1.30), coronary heart disease (1.10, 1.04 to 1.16), and stroke (1.15, 1.04 to 1.27). Increased mid-term and short term variability in daytime systolic blood pressure were also associated with all cause mortality (1.15, 1.06 to 1.26 and 1.10, 1.04 to 1.16, respectively).

CONCLUSIONS

 Long term variability in blood pressure is associated with cardiovascular and mortality outcomes, over and above the effect of mean blood pressure. Associations are similar in magnitude to those of cholesterol measures with cardiovascular disease. Limited data for mid-term and short term variability showed similar associations. Future work should focus on the clinical implications of assessment of variability in blood pressure and avoid the common confounding pitfalls observed to date.

SYSTEMATIC REVIEW REGISTRATION

 PROSPERO CRD42014015695.

What is the relationship between renal function and visit-to-visit blood pressure variability in primary care? Retrospective cohort study from routinely collected healthcare data

OBJECTIVE

To determine the relationship between renal function and visit-to-visit blood pressure (BP) variability in a cohort of primary care patients.

DESIGN

Retrospective cohort study from routinely collected healthcare data.

SETTING

Primary care in Nijmegen, the Netherlands, from 2007 to 2012.

PARTICIPANTS

19 175 patients who had a measure of renal function, and 7 separate visits with BP readings in the primary care record.

OUTCOME MEASURES

Visit-to-visit variability in systolic BP, calculated from the first 7 office measurements, including SD, successive variation, absolute real variation and metrics of variability shown to be independent of mean. Multiple linear regression was used to analyse the influence of estimated glomerular filtration rate (eGFR) on BP variability measures with adjustment for age, sex, diabetes, mean BP, proteinuria, cardiovascular disease, time interval between measures and antihypertensive use.

RESULTS

In the patient cohort, 57% were women, mean (SD) age was 65.5 (12.3) years, mean (SD) eGFR was 75.6 (18.0) mL/min/1.73m(2) and SD systolic BP 148.3 (21.4) mm Hg. All BP variability measures were negatively correlated with eGFR and positively correlated with age. However, multiple linear regressions demonstrated consistent, small magnitude negative relationships between eGFR and all measures of BP variability adjusting for confounding variables.

CONCLUSIONS

Worsening renal function is associated with small increases in measures of visit-to-visit BP variability after adjustment for confounding factors. This is seen across the spectrum of renal function in the population, and provides a mechanism whereby chronic kidney disease may raise the risk of cardiovascular events.

Visit-to-Visit Variability of Systolic Blood Pressure and Cardiovascular Disease

Visit-to-visit variability of blood pressure (VVV of BP) is gaining interest as a prognostic marker for stroke, cardiovascular disease, and all-cause mortality. In this review, we discuss different metrics used to define VVV of BP, explore the potential sources of this phenomenon including patient characteristics and antihypertensive medication classes, and discuss recent evidence of its relation with cardiovascular outcomes. Current evidence relies on secondary analyses of clinical trials or on observational studies, none of which was designed to examine VVV of BP specifically. More research is required to develop standardized definitions of VVV of BP, to confirm the value of VVV as a prognostic indicator, and to ascertain whether efforts to reduce VVV of BP in addition to mean BP will improve outcomes.

Epidemiology of CKD Regression in Patients under Nephrology Care

Chronic Kidney Disease (CKD) regression is considered as an infrequent renal outcome, limited to early stages, and associated with higher mortality. However, prevalence, prognosis and the clinical correlates of CKD regression remain undefined in the setting of nephrology care. This is a multicenter prospective study in 1418 patients with established CKD (eGFR: 60–15 ml/min/1.73m²) under nephrology care in 47 outpatient clinics in Italy from a least one year. We defined CKD regressors as a ΔGFR ≥0 ml/min/1.73 m²/year. ΔGFR was estimated as the absolute difference between eGFR measured at baseline and at follow up visit after 18–24 months, respectively. Outcomes were End Stage Renal Disease (ESRD) and overall-causes Mortality.391 patients (27.6%) were identified as regressors as they showed an eGFR increase between the baseline visit in the renal clinic and the follow up visit. In multivariate regression analyses the regressor status was not associated with CKD stage. Low proteinuria was the main factor associated with CKD regression, accounting per se for 48% of the likelihood of this outcome. Lower systolic blood pressure, higher BMI and absence of autosomal polycystic disease (PKD) were additional predictors of CKD regression. In regressors, ESRD risk was 72% lower (HR: 0.28; 95% CI 0.14–0.57; p<0.0001) while mortality risk did not differ from that in non-regressors (HR: 1.16; 95% CI 0.73–1.83; p = 0.540). Spline models showed that the reduction of ESRD risk associated with positive ΔGFR was attenuated in advanced CKD stage. CKD regression occurs in about one-fourth patients receiving renal care in nephrology units and correlates with low proteinuria, BP and the absence of PKD. This condition portends better renal prognosis, mostly in earlier CKD stages, with no excess risk for mortality.

Association between 24-hour blood pressure variability and chronic kidney disease: a cross-sectional analysis of African Americans participating in the Jackson heart study

Background

Studies suggest 24-h blood pressure (BP) variability has prognostic value for cardiovascular disease. Several factors associated with high 24-h BP variability are also common among individuals with chronic kidney disease (CKD). We hypothesized 24-h BP variability would be higher for individuals with versus without CKD.

Methods

We analyzed 1,022 Jackson Heart Study participants who underwent ambulatory blood pressure monitoring (ABPM). Twenty-four hour BP variability was defined by two metrics: day-night standard deviation (SD_dn) and average real variability (ARV). CKD was defined as ACR ≥30 mg/g or eGFR <60 mL/min/1.73 m².

Results

The mean SD_dn of systolic BP (SBP) was 10.2 ± 0.2 and 9.1 ± 0.1 mmHg and the mean ARV of SBP was 9.2 ± 0.2 and 8.6 ± 0.1 mmHg for those with and without CKD, respectively (each p ≤ 0.001). After adjustment for age and sex, SD_dn and ARV were 0.98 mmHg (95 % CI 0.59, 1.38) and 0.52 mmHg (95 % CI 0.18, 0.86), respectively, higher among participants with versus without CKD. These differences were not statistically significant after further multivariable adjustment including 24-h mean SBP. Older age, and higher total cholesterol and 24-h mean SBP were associated with higher SD_dn and ARV of SBP among participants with CKD. Mean SD_dn and ARV of diastolic BP (DBP) were higher for participants with versus without CKD but these associations were not present after multivariable adjustment.

Conclusion

Data from the current study suggest that CKD is associated with higher 24-h BP variability, but the association is primarily explained by higher mean BP among those with CKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0085-6) contains supplementary material, which is available to authorized users.