Relationship between ambulatory BP and clinical outcomes in patients with hypertensive CKD

Masked phenomenon: renal and cardiovascular complications; review and updates

BACKGROUND

In the in-clinic blood pressure (BP) recording setting, a sizable number of individuals with normal BP and approximately 30% of patients with chronic renal disease (CKD) exhibit elevated outpatient BP records. These individuals are known as masked hypertension (MHTN), and when they are on antihypertensive medications, but their BP is not controlled, they are called masked uncontrolled hypertension (MUHTN). The masked phenomenon (MP) (MHTN and MUHTN) increases susceptibility to end-organ damage (a two-fold greater risk for cardiovascular events and kidney dysfunction). The potential extension of the observed benefits of MP therapy, including a reduction in end-organ damage, remains questionable.

AIM AND METHODS

This review aims to study the diagnostic methodology, epidemiology, pathophysiology, and significance of MP management in end-organs, especially the kidneys, cardiovascular system, and outcomes. To achieve the purposes of this non-systematic comprehensive review, PubMed, Google, and Google Scholar were searched using keywords, texts, and phrases such as masked phenomenon, CKD and HTN, HTN types, HTN definition, CKD progression, masked HTN, MHTN, masked uncontrolled HTN, CKD onset, and cardiovascular system and MHTN. We restricted the search process to the last ten years to search for the latest updates.

CONCLUSION

MHTN is a variant of HTN that can be missed if medical professionals are unaware of it. Early detection by ambulatory or home BP recording in susceptible individuals reduces end-organ damage and progresses to sustained HTN. Adherence to the available recommendations when dealing with masked phenomena is justifiable; however, further studies and recommendation updates are required.

24-Hour Blood Pressure Variability Via Ambulatory Monitoring and Risk for Probable Dementia in the SPRINT Trial

BACKGROUND

Blood pressure variability is an emerging risk factor for dementia, independent and oftentimes beyond mean blood pressure levels. Recent evidence from interventional cohorts with rigorously controlled mean blood pressure levels suggest blood pressure variability over months to years remains a risk for dementia, but no prior studies have investigated relationships with blood pressure variability over shorter time periods.

OBJECTIVES

To investigate the potential effect of ambulatory blood pressure variability on the rate of cognitive outcomes under intensive vs standard blood pressure lowering.

DESIGN

Post hoc analysis of the randomized, controlled, open-label Systolic Blood Pressure Intervention Trial clinical trial.

SETTING

Multisite Systolic Blood Pressure Intervention Trial.

PARTICIPANTS

793 participants at increased risk for cardiovascular disease and without history of dementia at study randomization.

INTERVENTION

Standard (<140 mmHg systolic blood pressure target) vs intensive (<120 mmHg systolic blood pressure target) lowering of mean blood pressure.

MEASUREMENTS

24-hour ambulatory blood pressure monitoring 27 months after treatment randomization (standard vs intensive) and follow-up cognitive testing. Intraindividual blood pressure variability was calculated as the average real variability over 24-hour, daytime, and nighttime periods. Participants were categorized into 3 adjudicated clinical outcomes: no cognitive impairment, mild cognitive impairment, probable dementia. Cox proportional hazards models examined the potential effect of ambulatory blood pressure variability on the rate of cognitive outcomes under intensive vs standard blood pressure lowering. Associations with mean blood pressure were also explored.

RESULTS

Higher systolic 24-hour blood pressure variability was associated with increased risk for probable dementia in the standard group (adjusted hazard ratio [HR]: 2.56 [95% CI 1.16, 5.62], p = 0.019) but not in the intensive group (HR: 0.54 [95% CI 0.24, 1.23], p = 0.141). Similar findings were observed with daytime systolic blood pressure variability but not nighttime blood pressure variability. Mean blood pressure was not associated with cognitive outcomes.

CONCLUSIONS

Higher systolic 24-hour and daytime blood pressure variability via ambulatory monitoring is associated with risk for dementia under standard blood pressure treatment. Findings support prior evidence that blood pressure variability remains a risk for dementia despite strict control of mean blood pressure levels.

Nocturnal systolic blood pressure dipping and progression of chronic kidney disease

The relationship between declining nocturnal blood pressure (BP) and adverse cardiovascular outcomes is well-recognized. However, the relationship between diurnal BP profile and the risk of chronic kidney disease (CKD) progression is unclear. Herein, we examined the association between nocturnal systolic SBP (SBP) dipping and CKD progression in 1061 participants at the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI). The main exposure was diurnal systolic BP (SBP) profile and diurnal SBP difference ([nighttime SBP-daytime SBP] × 100/daytime SBP). The primary outcome was CKD progression, defined as a composite of ≥ a 50% decline in the estimated glomerular filtration rate from baseline or the initiation of kidney replacement therapy. During 4749 person-years of follow-up (median, 4.8 years), the composite outcome occurred in 380 (35.8%) participants. Compared to dippers, the hazard ratios (HRs) for the risk of adverse kidney outcomes were 1.02 (95% confidence interval [CI], 0.64-1.62), 1.30 (95% CI, 1.02-1.66), and 1.40 (95% CI, 1.03-1.90) for extreme dipper, non-dipper, and reverse dipper, respectively. In a continuous modeling, a 10% increase in diurnal SBP difference was associated with a 1.21-fold (95% CI, 1.07-1.37) higher risk of CKD progression. Thus, decreased nocturnal SBP decline was associated with adverse kidney outcomes in patients with CKD. Particularly, patients with non-dipping and reverse dipping patterns were at higher risk for CKD progression than those with a dipping pattern.

Effects of Nondipping Blood Pressure Changes: A Nephrologist Prospect

Blood pressure (BP) variations depend on various internal, environmental, and behavioral factors. BP fluctuations occur both in normotensive and hypertensive people. Although it fluctuates over the 24-hr day and night, the morning BP increases after waking up and declines throughout sleep. It is typical for BP to decrease by 10% to 20%, while sleeping, known as dipping BP. However, if there is no decrease in nighttime mean systolic BP or a drop of less than 10 mmHg, it is called nondipping BP. Conversely, reverse dipping BP means an increase in mean systolic BP instead of a drop during the night. Reverse dipping is observed in hypertension (HTN), diabetes mellitus (DM), chronic kidney disease (CKD), and obstructive sleep apnea (OSA) syndrome. The introduction of ambulatory BP monitoring (ABPM) led to the emergence of identifying normal and elevated BP patterns. Non-dipping BP increases the risk of cardiovascular system (CVS) complications such as left ventricular hypertrophy, proteinuria, glomerular filtration rate (GFR) reduction, and CKD progression. A loss or blunting of the normal BP profile is recognized as a deleterious variant, and restoring abnormal BP patterns has been reported to significantly impact end-organ damage, morbidity, and mortality. In this non-systematic clinically-oriented, comprehensive review, we aim to update the BP variables and the pathophysiology of nondipping BP and point out the areas which need more investigation from a nephrology perspective because the nondipping BP increases the risk of proteinuria, GFR reduction, and CKD progression. A literature search of PubMed, Google, EMBASE, and Google Scholar was conducted. Checks of selected papers and relevant reviews complemented the electronic search. With improved BP measurement methods, the physiology of BP profile variations is readily detectable during the day and night. A nondipping BP profile is a distinct BP pattern that may have significant end-organ damage effects and therapeutic importance for nephrologists. The pathophysiology of the nondipping BP variant must be clarified to prevent complications, and further investigations are required. Furthermore, there is debate about the best BP index to utilize: systolic BP, diastolic BP, mean arterial pressure, or a mixture of all. All these areas are important and need new research projects.

Hypertension as Cardiovascular Risk Factor in Chronic Kidney Disease

Hypertension is the leading modifiable cause of premature death and hence one of the global targets of World Health Organization for prevention. Hypertension also affects the great majority of patients with chronic kidney disease (CKD). Both hypertension and CKD are intrinsically related, as hypertension is a strong determinant of worse renal and cardiovascular outcomes and renal function decline aggravates hypertension. This bidirectional relationship is well documented by the high prevalence of hypertension across CKD stages and the dual benefits of effective antihypertensive treatments on renal and cardiovascular risk reduction. Achieving an optimal blood pressure (BP) target is mandatory and requires several pharmacological and lifestyle measures. However, it also requires a correct diagnosis based on reliable BP measurements (eg, 24-hour ambulatory BP monitoring, home BP), especially for populations like patients with CKD where reduced or reverse dipping patterns or masked and resistant hypertension are frequent and associated with a poor cardiovascular and renal prognosis. Even after achieving BP targets, which remain debated in CKD, the residual cardiovascular risk remains high. Current antihypertensive options have been enriched with novel agents that enable to lower the existing renal and cardiovascular risks, such as SGLT2 (sodium-glucose cotransporter-2) inhibitors and novel nonsteroidal mineralocorticoid receptor antagonists. Although their beneficial effects may be driven mostly from actions beyond BP control, recent evidence underline potential improvements on abnormal 24-hour BP phenotypes such as nondipping. Other promising novelties are still to come for the management of hypertension in CKD. In the present review, we shall discuss the existing evidence of hypertension as a cardiovascular risk factor in CKD, the importance of identifying hypertension phenotypes among patients with CKD, and the traditional and novel aspects of the management of hypertensives with CKD.

Dipping Status, Ambulatory Blood Pressure Control, Cardiovascular Disease, and Kidney Disease Progression: A Multicenter Cohort Study of CKD

RATIONALE & OBJECTIVE

Ambulatory blood pressure (BP) monitoring allows concurrent evaluation of BP control and nocturnal BP dipping status, both related to adverse outcomes. However, few studies have assessed the prognostic role of combining information on dipping status and achieved ambulatory BP in patients with chronic kidney disease (CKD).

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

906 patients with hypertension and CKD attending 1 of 3 Italian nephrology clinics.

EXPOSURE

Four groups were defined by simultaneously classifying systolic ambulatory BP levels as being at goal (daytime SBP <135 and nighttime SBP <120 mm Hg) or above goal, and the presence or absence of nocturnal dipping (nighttime to daytime SBP ratio of <0.9 versus ≥0.9).

OUTCOME

The composite of time to initiation of maintenance dialysis or estimated glomerular filtration rate (eGFR) decline ≥50%, and the composite of fatal and nonfatal cardiovascular events.

ANALYTICAL APPROACH

Multivariable Cox proportional hazards models were used to estimate risks of kidney disease progression and cardiovascular disease in the 4 exposure groups where nocturnal dipping with systolic ambulatory BP at goal was the reference group.

RESULTS

The mean patient age was 63.8 years, 61% were male, and 26.4% had diabetes; eGFR was 41.1 ± 20.8 mL/min/1.73 m². The dipping prevalence in each of the 4 groups was as follows: nocturnal dipping with ambulatory BP at goal, 18.6%; no nocturnal dipping with ambulatory BP at goal, 20.5%; nocturnal dipping with ambulatory BP above goal, 11.8%; and no nocturnal dipping with ambulatory BP above goal, 49.1%. Among patients with ambulatory BP above goal, the risk of cardiovascular events was greater in the absence (HR, 2.79 [95% CI, 1.64-4.75]) and presence (HR, 2.05 [95% CI, 1.10-3.84]) of nocturnal dipping. The same held true for risk of kidney disease progression (HRs of 2.40 [95% CI, 1.58-3.65] and 2.11 [95% CI, 1.28-3.48] in the absence and presence of nocturnal dipping, respectively). Patients at the ambulatory BP goal but who did not experience nocturnal dipping had an increased risk of the cardiovascular end point (HR, 2.06 [95% CI, 1.15-3.68]) and the kidney disease progression outcome (HR, 1.82 [95% CI, 1.17-2.82]).

LIMITATIONS

Lack of a diverse cohort (all those enrolled were White). Residual uncontrolled confounding.

CONCLUSIONS

Systolic ambulatory BP above goal or the absence of nocturnal dipping, regardless of ambulatory BP, is associated with higher risks of cardiovascular disease and kidney disease progression among patients with CKD.

PLAIN-LANGUAGE SUMMARY

Among patients with chronic kidney disease (CKD), ambulatory blood pressure (BP) monitoring improves the identification of individuals at high risk of clinical disease outcomes. Those with uncontrolled ambulatory BP are known to have a higher risk of developing cardiovascular disease and kidney disease progression, particularly when their ambulatory BP does not decline by at least 10% at night. Whether this is also true for patients with presence of optimal ambulatory BP levels but a BP pattern of no nighttime decline is largely unknown. We measured ambulatory BP in 900 Italian patients with CKD and followed them for several years. We found that, independent of ambulatory BP level, the absence of nighttime reductions in BP was associated with worsening of CKD and more frequent cardiovascular events. The absence of nighttime declines in BP is an independent risk factor for adverse events among patients with CKD. Future studies are needed to examine whether treating the absence of nighttime declines in BP improves clinical outcomes.

Association of Nighttime Masked Uncontrolled Hypertension With Left Ventricular Hypertrophy and Kidney Function Among Patients with Chronic Kidney Disease Not Receiving Dialysis

IMPORTANCE

Nighttime hypertension is prevalent and associated with adverse outcomes in patients with chronic kidney disease (CKD), but nighttime hypertension, a subtype of masked uncontrolled hypertension (MUCH), is often undetected among patients with controlled office blood pressure. Little attention has been paid to patients with CKD and nighttime MUCH.

OBJECTIVE

To investigate the prevalence of nighttime MUCH and its associations with cardiovascular and kidney outcomes in patients with CKD who were not receiving dialysis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with nondialysis CKD and hypertension, enrolled in Shanghai, China, from July 2012 through November 2020 and followed up for a median of 39 months.

EXPOSURES

Participants were classified as having controlled hypertension, sustained hypertension, and MUCH, which was further divided into isolated nighttime MUCH and day-night MUCH, assessed by office and ambulatory blood pressure monitoring.

MAIN OUTCOMES AND MEASURES

Left ventricular hypertrophy (LVH) was determined by echocardiography. The composite kidney outcome consisted of end-stage kidney diseases (ESKD) and a reduction of estimated glomerular filtration rate (eGFR) by 50% or more. Logistic and Cox regression assessed the associations of hypertension subtypes with LVH and kidney outcomes.

RESULTS

The 675 patients (425 [63.0%] men; mean [SD] age, 50.8 [15.9] years; mean [SD] eGFR, 61.6 [29.4] mL/min/1.73 m2) included 125 (19.3%) with controlled hypertension, 244 (37.6%) with MUCH, and 280 (43.1%) sustained hypertension. Among patients with MUCH, 2 (0.8%) had isolated daytime MUCH, 154 (63.1%) had isolated nighttime MUCH, and 88 (36.1%) had day-night MUCH. During a median (IQR) follow-up of 39 (19-64) months, 130 composite kidney events, including 97 ESKD events, occurred. Compared with controlled hypertension, MUCH and sustained hypertension were associated with LVH (eg, MUCH: odds ratio [OR], 2.94; 95% CI, 1.18-7.34; P = .02) and the composite kidney outcome (eg, MUCH: hazard ratio [HR], 4.12; 95% CI, 1.75-9.73; P = .001) after adjustment for age, sex, proteinuria, eGFR, and other baseline risk factors. Multivariate-adjusted associations were also significant between day-night MUCH and LVH (OR, 3.26; 95% CI, 1.15-9.25) and between isolated nighttime MUCH and the composite kidney outcome (HR, 4.27; 95% CI, 1.69-10.77).

CONCLUSIONS AND RELEVANCE

In this cohort study, nighttime MUCH was common and associated with LVH and poor kidney outcomes among patients with hypertension and nondialysis CKD. These findings suggest that ambulatory blood pressure monitoring was inadequately used in patients with CKD and hypertension, calling for more widespread use, even in patients with controlled office hypertension.

Blood Pressure and Chronic Kidney Disease Progression: An Updated Review

Hypertension (HTN) is common in chronic kidney disease (CKD), and it may aggravate CKD progression. The optimal blood pressure (BP) value in CKD patients is not established yet, although systolic BP ≤130 mmHg is acceptable as a target. Continuous BP monitoring is essential to detect the different variants of high BP and monitor the treatment response. Various methods of BP measurement in the clinic office and at home are currently used. One of these methods is ambulatory BP monitoring (ABPM), by which BP can be closely assessed for even diurnal changes.

We conducted a non-systematic literature review to explore and update the association between high BP and the course of CKD and to review various BP monitoring methods to determine the optimal method for BP recording in CKD patients. PubMed, EMBASE, Google, Google Scholar, and Web Science were searched for published reviews and original articles on BP and CKD by using various phrases and keywords such as "hypertension and CKD", "CKD progression and hypertension", "CKD stage and hypertension", "BP control in CKD", "BP measurement methods", "diurnal BP variation effect on CKD progression", and "types of hypertension." We evaluated and discussed published articles relevant to the review objective. Before preparing the final draft of this article, each author was assigned a section of the topic to read, research deeply, and write a summary about the assigned section. Then a summary of each author's contribution was collected and discussed in several group sessions.

Early detection of high BP is essential to prevent CKD development and progression. Although the latest Kidney Disease Improving Global Outcomes (KDIGO) guidelines suggest that a systolic BP ≤120 mmHg is the target toprevent CKD progression, systolic BP ≤130 mmHg is universally recommended.ABPM is a promising method to diagnose and follow up on BP control; however, the high cost of the new devices and patient unfamiliarity with them have proven to be major disadvantages with regard to this method.

Sex differences in ambulatory blood pressure levels, control, and phenotypes of hypertension in kidney transplant recipients

OBJECTIVES

Ambulatory blood pressure (BP) control is worse in men compared with women with chronic kidney disease (CKD) and this may partially explain the faster CKD progression in men. This is the first study investigating possible sex differences in prevalence, control and phenotypes of hypertension in kidney transplant recipients (KTRs) with office-BP and 24-h ambulatory BP monitoring (ABPM).

METHODS

This cross-sectional study included 136 male and 69 female stable KTRs who underwent office-BP measurements and 24-h ABPM. Hypertension thresholds for office and ambulatory BP were defined according to the 2017 ACC/AHA and 2021 KDIGO guidelines for KTRs.

RESULTS

Age, time from transplantation, eGFR and history of major comorbidities did not differ between groups. Office SBP/DBP levels were insignificantly higher in men than women (130.3 ± 16.3/77.3 ± 9.4 vs. 126.4 ± 17.8/74.9 ± 11.5 mmHg; P = 0.118/0.104) but daytime SBP/DBP was significantly higher in men (128.5 ± 12.1/83.0 ± 8.2 vs. 124.6 ± 11.9/80.3 ± 9.3 mmHg; P = 0.032/P = 0.044). No significant between-group differences were detected for night-time BP. The prevalence of hypertension was similar by office-BP criteria (93.4 vs. 91.3%; P = 0.589), but higher in men than women with ABPM (100 vs. 95.7%; P = 0.014). The use of ACEIs/ARBs and CCBs was more common in men. Office-BP control was similar (43.3 vs. 44.4%, P = 0.882), but 24-h control was significantly lower in men than women (16.9 vs. 30.3%; P = 0.029). White-coat hypertension was similar (5.1 vs. 7.6%; P = 0.493), whereas masked hypertension was insignificantly more prevalent in men than women (35.3 vs. 24.2%; P = 0.113).

CONCLUSION

BP levels, hypertension prevalence and control are similar by office criteria but significantly different by ABPM criteria between male and female KTRs. Worse ambulatory BP control in male compared with female KTRs may interfere with renal and cardiovascular outcomes.

Sex difference in ambulatory blood pressure control associates with risk of ESKD and death in CKD patients receiving stable nephrology care

BACKGROUND

It is unknown whether faster progression of chronic kidney disease (CKD) in men than in women relates to differences in ambulatory blood pressure (ABP) levels.

METHODS

We prospectively evaluated 906 hypertensive CKD patients (553 men) regularly followed in renal clinics to compare men versus women in terms of ABP control [daytime <135/85 and nighttime blood pressure (BP) <120/70 mmHg] and risk of all-cause mortality and end-stage kidney disease (ESKD).

RESULTS

Age, estimated glomerular filtration rate and use of renin-angiotensin system inhibitors were similar in men and women, while proteinuria was lower in women [0.30 g/24 h interquartile range (IQR) 0.10-1.00 versus 0.42 g/24 h, IQR 0.10-1.28, P = 0.025]. No sex-difference was detected in office BP levels; conversely, daytime and nighttime BP were higher in men (134 ± 17/78 ± 11 and 127 ± 19/70 ± 11 mmHg) than in women (131 ± 16/75 ± 11, P = 0.005/P < 0.001 and 123 ± 20/67 ± 12, P = 0.006/P < 0.001), with ABP goal achieved more frequently in women (39.1% versus 25.1%, P < 0.001). During a median follow-up of 10.7 years, 275 patients reached ESKD (60.7% men) and 245 died (62.4% men). Risks of ESKD and mortality (hazard ratio and 95% confidence interval), adjusted for demographic and clinical variables, were higher in men (1.34, 1.02-1.76 and 1.36, 1.02-1.83, respectively). Adjustment for office BP at goal did not modify this association. In contrast, adjustment for ABP at goal attenuated the increased risk in men for ESKD (1.29, 0.98-1.70) and death (1.31, 0.98-1.77). In the fully adjusted model, ABP at goal was associated with reduced risk of ESKD (0.49, 0.34-0.70) and death (0.59, 0.43-0.80). No interaction between sex and ABP at goal on the risk of ESKD and death was found, suggesting that ABP-driven risks are consistent in males and females.

CONCLUSIONS

Our study highlights that higher ABP significantly contributes to higher risks of ESKD and mortality in men.

Relationship between renal function and blood pressure dipping status in renal transplant recipients: a longitudinal study

Background

Hypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown.

Methods

We retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable.

Results

A total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m² respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m² higher eGFR. HT was negatively associated with eGFR (p = 0.003).

Conclusions

We confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02523-7.

Diabetic patients with chronic kidney disease: Non-invasive assessment of cardiovascular risk

The prevalence and burden of diabetes mellitus and chronic kidney disease on global health and socioeconomic development is already heavy and still rising. Diabetes mellitus by itself is linked to adverse cardiovascular events, and the presence of concomitant chronic kidney disease further amplifies cardiovascular risk. The culmination of traditional (male gender, smoking, advanced age, obesity, arterial hypertension and dyslipidemia) and non-traditional risk factors (anemia, inflammation, proteinuria, volume overload, mineral metabolism abnormalities, oxidative stress, etc.) contributes to advanced atherosclerosis and increased cardiovascular risk. To decrease the morbidity and mortality of these patients due to cardiovascular causes, timely and efficient cardiovascular risk assessment is of huge importance. Cardiovascular risk assessment can be based on laboratory parameters, imaging techniques, arterial stiffness parameters, ankle-brachial index and 24 h blood pressure measurements. Newer methods include epigenetic markers, soluble adhesion molecules, cytokines and markers of oxidative stress. In this review, the authors present several non-invasive methods of cardiovascular risk assessment in patients with diabetes mellitus and chronic kidney disease.

The Association of Orthostatic Hypotension With Ambulatory Blood Pressure Phenotypes in SPRINT

BACKGROUND

Clinic blood pressure (BP) when measured in the seated position, can miss meaningful BP phenotypes, including low ambulatory BP (white coat effects [WCE]) or high supine BP (nocturnal non-dipping). Orthostatic hypotension (OH) measured using both seated (or supine) and standing BP, could identify phenotypes poorly captured by seated clinic BP alone.

METHODS

We examined the association of OH with WCE and night-to-daytime systolic BP (SBP) in a subpopulation of SPRINT, a randomized trial testing the effects of intensive or standard (<120 vs. <140 mm Hg) SBP treatment strategies in adults at increased risk of cardiovascular disease. OH was assessed during follow-up (6, 12, and 24 months) and defined as a decrease in mean seated SBP ≥20 or diastolic BP ≥10 mm Hg after 1 min of standing. WCE, based on 24-hour ambulatory BP monitoring performed at 27 months, was defined as the difference between 27-month seated clinic and daytime ambulatory BP ≥20/≥10 mm Hg. Reverse dipping was defined as a ratio of night-to-daytime SBP >1.

RESULTS

Of 897 adults (mean age 71.5±9.5 years, 29% female, 28% black), 128 had OH at least once. Among those with OH, 15% had WCE (vs. 7% without OH). Moreover, 25% of those with OH demonstrated a non-dipping pattern (vs. 14% without OH). OH was positively associated with both WCE (OR=2.24; 95%CI: 1.28, 4.27) and reverse dipping (OR=2.29; 95% CI: 1.31, 3.99).

CONCLUSIONS

The identification of OH in clinic was associated with two BP phenotypes often missed with traditional seated BP assessments. Further studies on mechanisms of these relationships are needed.

CLINICAL TRIALS REGISTRATION

Trial Number NCT03569020.

BP in Young Adults with CKD and Associations with Cardiovascular Events and Decline in Kidney Function

BACKGROUND

BP is an important modifiable risk factor for cardiovascular events and CKD progression in middle-aged or older adults with CKD. However, studies describing the relationship between BP with outcomes in young adults with CKD are limited.

METHODS

In an observational study, we focused on 317 young adults (aged 21-40 years) with mild to moderate CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Exposures included baseline systolic BP evaluated continuously (per 10 mm Hg increase) and in categories (<120, 120-129, and ≥130 mm Hg). Primary outcomes included cardiovascular events (heart failure, myocardial infarction, stroke, or all-cause death) and CKD progression (50% decline of eGFR or ESKD). We used Cox proportional hazard models to test associations between baseline systolic BP with cardiovascular events and CKD progression.

RESULTS

Cardiovascular events occurred in 52 participants and 161 had CKD progression during median follow-up times of 11.3 years and 4.1 years, respectively. Among those with baseline systolic BP ≥130 mm Hg, 3%/yr developed heart failure, 20%/yr had CKD progression, and 2%/yr died. In fully adjusted models, baseline systolic BP ≥130 mm Hg (versus systolic BP<120 mm Hg) was significantly associated with cardiovascular events or death (hazard ratio [HR], 2.13; 95% confidence interval [95% CI], 1.05 to 4.32) and CKD progression (HR, 1.68; 95% CI, 1.10 to 2.58).

CONCLUSIONS

Among young adults with CKD, higher systolic BP is significantly associated with a greater risk of cardiovascular events and CKD progression. Trials of BP management are needed to test targets and treatment strategies specifically in young adults with CKD.

Prognostic Value of Blood Pressure Variability for Patients With Acute or Subacute Intracerebral Hemorrhage: A Meta-Analysis of Prospective Studies

The results on the role of systolic blood pressure (SBP) variability in the functional outcome for patients with intracerebral hemorrhage (ICH) have been inconsistent. Hence, this meta-analysis of prospective studies was conducted to assess the association between SBP variability and poor outcomes in patients with acute or subacute ICH. PubMed, Embase, and the Cochrane Library were electronically searched for eligible studies from their inception to July 2020. The role of SBP variability assessed using standard deviation (SD), coefficient of variation (CV), successive variation (SV), average real variability (ARV), and residual standard deviation (RSD) in the risk of poor functional outcomes were assessed using odds ratio (OR) with 95% confidence interval (CI) through the random-effects model. Seven prospective studies involving 5,201 patients with ICH were selected for the final meta-analysis. Increased SBP variability was associated with an increased risk of poor functional outcomes, regardless of its assessment using SD (OR: 1.38; 95% CI: 1.14–1.68; P = 0.001), CV (OR: 1.98; 95% CI: 1.13–3.47; P = 0.017), SV (OR: 1.30; 95% CI: 1.08–1.58; P = 0.006), ARV (OR: 1.13; 95% CI: 1.03–1.24; P = 0.010), or RSD (OR: 1.22; 95% CI: 1.00–1.50; P = 0.049). Moreover, the role of SBP variability in the risk of poor functional outcomes for patients with ICH was affected by country, study design, mean age, stroke type, outcome definition, and study quality. This study indicated that SBP variability was a predictor of poor outcomes for patients with ICH.

Prognostic models for chronic kidney disease: a systematic review and external validation

BACKGROUND

Accurate risk prediction is needed in order to provide personalized healthcare for chronic kidney disease (CKD) patients. An overload of prognosis studies is being published, ranging from individual biomarker studies to full prediction studies. We aim to systematically appraise published prognosis studies investigating multiple biomarkers and their role in risk predictions. Our primary objective was to investigate if the prognostic models that are reported in the literature were of sufficient quality and to externally validate them.

METHODS

We undertook a systematic review and appraised the quality of studies reporting multivariable prognosis models for end-stage renal disease (ESRD), cardiovascular (CV) events and mortality in CKD patients. We subsequently externally validated these models in a randomized trial that included patients from a broad CKD population.

RESULTS

We identified 91 papers describing 36 multivariable models for prognosis of ESRD, 50 for CV events, 46 for mortality and 17 for a composite outcome. Most studies were deemed of moderate quality. Moreover, they often adopted different definitions for the primary outcome and rarely reported full model equations (21% of the included studies). External validation was performed in the Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of Nurse Practitioners trial (n = 788, with 160 events for ESRD, 79 for CV and 102 for mortality). The 24 models that reported full model equations showed a great variability in their performance, although calibration remained fairly adequate for most models, except when predicting mortality (calibration slope >1.5).

CONCLUSIONS

This review shows that there is an abundance of multivariable prognosis models for the CKD population. Most studies were considered of moderate quality, and they were reported and analysed in such a manner that their results cannot directly be used in follow-up research or in clinical practice.

Effect of ambulatory blood pressure monitoring guided antihypertensive treatment on renal progression in patients with chronic kidney disease: a randomized comparative study

OBJECTIVES

Adequate blood pressure (BP) control is pivotal for managing chronic kidney disease (CKD). The optimal approach for monitoring BP to delay CKD progression is not yet clear.

METHODS

Patients with hypertension and CKD stage 3-4 were randomized into ambulatory blood pressure monitoring (ABPM) or office BP groups. All patients had ABPM at baseline and 18 months, and the ABPM group additionally underwent ABPM at 3 and 6 months. Each ABPM result was notified only for the ABPM group. The BP target was daytime ABP less than 135/85 mmHg for the ABPM group and office BP less than 140/90 mmHg for the office BP group. The primary outcome was decrease in estimated glomerular filtration rate (eGFR) during 18 months.

RESULTS

A total of 146 patients were randomized into the ABPM (n = 69) and office BP groups (n = 77). Although office BP was comparable in the two groups at baseline, daytime ABP was higher in the ABPM group (median 140 vs. 132 mmHg). Initial eGFR was 35.7 ± 12.5 ml/min per 1.73 m2 in the ABPM group and 34.6 ± 12.0 ml/min per 1.73 m2 in the office BP group. eGFR change was -5.5 [95% confidence interval (95% CI) -7.7 to  -3.4] ml/min per 1.73 m2 in the ABPM group and -5.0 (95% CI -6.9 to -3.0) ml/min per 1.73 m2 in the office BP group (P = 0.704). Renal events occurred in 10 patients (15.6%) from the ABPM group and five (7.1%) from the office BP group (P = 0.120).

CONCLUSION

The present study did not show a beneficial effect of ABPM for controlling hypertension in CKD compared with conventional office BP monitoring in terms of renal outcomes.

Effects of Intensive Versus Standard Office-Based Hypertension Treatment Strategy on White-Coat Effect and Masked Uncontrolled Hypertension: From the SPRINT ABPM Ancillary Study

Guidelines recommend using out-of-office blood pressure (BP) measurements to confirm the diagnoses of hypertension and in the titration of antihypertensive medication. The prevalence of out-of-office BP phenotypes for an office systolic/diastolic BP goal <140/90 mm Hg has been reported. However, the prevalence of these phenotypes when targeting an office systolic/diastolic BP goal <120/80 is unknown. The SPRINT (Systolic Blood Pressure Intervention Trial) Ambulatory BP Ancillary study evaluated out-of-office BP using ambulatory BP monitoring in 897 participants 27 months after randomization to intensive versus standard BP targets (office systolic BP <120 versus <140 mm Hg). We used office and daytime BP to assess the proportion of participants with white-coat effect (standard target: office BP ≥140/90 mm Hg and daytime BP <135/85 mm Hg versus intensive target: office BP ≥120/80 mm Hg and daytime BP <120/80 mm Hg) and masked uncontrolled hypertension (standard target: office BP <140/90 mm Hg and daytime BP ≥135/85 mm Hg versus intensive target: office BP <120/80 mm Hg and daytime BP ≥120/80 mm Hg) in each treatment arm. The prevalence of white-coat effect and masked uncontrolled hypertension was 9% and 34%, in both treatment groups. Among participants with uncontrolled office BP, white-coat effect was present in 20% and 23% in the intensive and standard groups, respectively. Among participants with controlled office BP, masked uncontrolled hypertension was present in 62% and 56% in the intensive and standard groups, respectively. In conclusion, a more intensive BP target resulted in a similar proportion of patients with white-coat effect and masked uncontrolled hypertension compared with a standard target.

White-coat and masked hypertension diagnoses in chronic kidney disease patients

The purpose of this study was to analyze which 24-hour ambulatory blood pressure measurement (ABPM) parameters should be used on masked hypertension (MH) and white-coat hypertension (WCH) diagnoses in chronic kidney disease (CKD) patients. Non-dialysis CKD patients underwent 24-hour ABPM examination between 01/27/2004 and 02/16/2012. They were followed from the 24-hour ABPM to January/2014 in an observational study. The WCH definitions tested were as follows: (a) office blood pressure (BP) ≥ 140/90 mm Hg and daytime ABPM BP ≤ 135/85 mm Hg (old criterion); and (b) office BP ≥ 140/90 mm Hg and 24-hour ABPM BP ≤ 130/80 mm Hg, daytime ABPM BP ≤ 135/85 mm Hg, and nighttime ABPM BP ≤ 120/70 mm Hg (new criterion). The MH definitions tested were as follows: (a) office BP < 140/90 mm Hg and daytime ABPM BP > 135/85 mm Hg (old criterion); and (b) office BP < 140/90 mm Hg and 24-hour ABPM BP > 130/80 mm Hg or daytime ABPM BP > 135/85 mm Hg or nighttime ABPM BP > 120/70 mm Hg (new criterion). The two definitions' predictive capacity was compared, regarding both WCH and MH. Cardiovascular mortality was the primary and all-cause mortality was the secondary outcome. Cox regression was adjusted to the variables: glomerular filtration rate, age, diabetes mellitus, and active smoking. There were 367 patients studied. The old criterion (exclusive mean daytime ABPM BP) was the only to distinguish sustained hypertension from WCH (adjusted HR: 3.730; 95% CI: 1.068-13.029; P = .039), regarding all-cause mortality. Additionally, the old criterion was the only one to distinguish normotension and MH, regarding cardiovascular mortality (adjusted HR: 7.641; 95% CI: 1.277-45.738; P = .026). Therefore, WCH and MH definitions based exclusively on daytime ABPM BP values (old criterion) were able to better distinguish mortality in this studied CKD cohort.

Apparent Treatment-Resistant Hypertension Assessed by Office and Ambulatory Blood Pressure in Chronic Kidney Disease-A Report from the Chronic Renal Insufficiency Cohort Study

Background

Apparent treatment-resistant hypertension is common in patients with CKD. Whether measurement of 24-hour ambulatory BP monitoring is valuable for risk-stratifying patients with resistant hypertension and CKD is unclear.

Methods

We analyzed data from the Chronic Renal Insufficiency Cohort study, a prospective study of participants (n=1186) with CKD. Office BP was measured using standardized protocols; ambulatory BP was measured using Spacelabs monitors. Apparent treatment-resistant hypertension was defined on the basis of office BP, ambulatory BP monitoring, and use of more than three antihypertensive medications. Outcomes were composite cardiovascular disease, kidney outcomes, and mortality. Groups were compared using Cox regression analyses with a control group of participants without apparent treatment-resistant hypertension.

Results

Of 475 participants with apparent treatment-resistant hypertension on the basis of office BP, 91.6% had apparent treatment-resistant hypertension confirmed by ambulatory BP monitoring. Unadjusted event rates of composite cardiovascular disease, kidney outcomes, and mortality were higher in participants with ambulatory BP monitoring-defined apparent treatment-resistant hypertension compared with participants without apparent treatment-resistant hypertension. In adjusted analyses, the risks of composite cardiovascular disease (hazard ratio, 1.27; 95% confidence interval [95% CI], 0.59 to 2.7), kidney outcomes (hazard ratio, 1.68; 95% CI, 0.88 to 3.21), and mortality (hazard ratio, 1.27; 95% CI, 0.5 to 3.25) were not statistically significantly higher in participants with ambulatory BP monitoring-defined apparent treatment-resistant hypertension compared with participants without apparent treatment-resistant hypertension.

Conclusions

In our study population with CKD, most patients with apparent treatment-resistant hypertension defined on the basis of office BP have apparent treatment-resistant hypertension confirmed by ambulatory BP monitoring. Although ABPM-defined apparent treatment-resistant hypertension was not independently associated with clinical outcomes, it identified participants at high risk for adverse clinical outcomes.

Short-Term Systolic Blood Pressure Variability and Kidney Disease Progression in Patients With Chronic Kidney Disease: Results From C-STRIDE

Background

It is unclear whether short‐term blood pressure variability is associated with renal outcomes in patients with chronic kidney disease.

Methods and Results

This study analyzed data from participants in the C‐STRIDE (Chinese Cohort Study of Chronic Kidney Disease) who had chronic kidney disease stages 1 to 4. Short‐term blood pressure variability was measured by calculating the weighted SD (w‐SD) of systolic blood pressure (SBP). Renal outcomes were defined as dialysis initiation and/or transplantation. Risk factors associated with w‐SD of SBP were evaluated by linear regression. Associations of short‐term SBP variability with renal outcomes were evaluated by Cox regression. In total, 1421 patients with chronic kidney disease were included in this study (mean age, 49.4±13.6 years; 56.2% men; estimated glomerular filtration rate, 50.5±29.3 mL/min per 1.73 m²; proteinuria, 0.9 [0.3–2.0] g/d). Mean w‐SD of SBP was 12.6±4.4 mm Hg. w‐SD of SBP was independently associated with older age, 24‐hour SBP, blood pressure circadian pattern, and angiotensin II receptor blocker treatment. During a median follow‐up of 4.9 years, 237 patients developed renal outcomes (37.01 per 1000 patient‐years). The incidence rate increased across the quartiles of w‐SD (log‐rank P=0.005). w‐SD of SBP was associated with an increased risk of renal outcomes, both as a continuous variable (hazard ratio [HR], 1.47; 95% CI, 1.09–1.99) and as a categorical variable (quartile 4 versus quartile 1: HR, 1.60; 95% CI, 1.08–2.36), independent of 24‐hour SBP, daytime SBP, and nighttime SBP.

Conclusions

Short‐term SBP was independently associated with the risk of dialysis initiation and/or transplantation in patients with chronic kidney disease.

Ambulatory Blood Pressure Phenotypes in Adults Taking Antihypertensive Medication with and without CKD

BACKGROUND AND OBJECTIVES

Recent guidelines recommend out-of-clinic BP measurements.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared the prevalence of BP phenotypes between 561 black patients, with and without CKD, taking antihypertensive medication who underwent ambulatory BP monitoring at baseline (between 2000 and 2004) in the Jackson Heart Study. CKD was defined as an albumin-to-creatinine ratio ≥30 mg/g or eGFR <60 ml/min per 1.73 m2. Sustained controlled BP was defined by BP at goal both inside and outside of the clinic and sustained uncontrolled BP as BP above goal both inside and outside of the clinic. Masked uncontrolled hypertension was defined by controlled clinic-measured BP with uncontrolled out-of-clinic BP.

RESULTS

CKD was associated with a higher multivariable-adjusted prevalence ratio for uncontrolled versus controlled clinic BP (prevalence ratio, 1.44; 95% CI, 1.02 to 2.02) and sustained uncontrolled BP versus sustained controlled BP (prevalence ratio, 1.66; 95% CI, 1.16 to 2.36). There were no statistically significant differences in the prevalence of uncontrolled daytime or nighttime BP, nondipping BP, white-coat effect, and masked uncontrolled hypertension between participants with and without CKD after multivariable adjustment. After multivariable adjustment, reduced eGFR was associated with masked uncontrolled hypertension versus sustained controlled BP (prevalence ratio, 1.42; 95% CI, 1.00 to 2.00), whereas albuminuria was associated with uncontrolled clinic BP (prevalence ratio, 1.76; 95% CI, 1.20 to 2.60) and sustained uncontrolled BP versus sustained controlled BP (prevalence ratio, 2.02; 95% CI, 1.36 to 2.99).

CONCLUSIONS

The prevalence of BP phenotypes defined using ambulatory BP monitoring is high among adults with CKD taking antihypertensive medication.

Blood Pressure Measurement: A KDOQI Perspective

The majority of patients with chronic kidney disease (CKD) have elevated blood pressure (BP). In patients with CKD, hypertension is associated with increased risk for cardiovascular disease, progression of CKD, and all-cause mortality. New guidelines from the American College of Cardiology/American Heart Association (ACC/AHA) recommend new thresholds and targets for the diagnosis and treatment of hypertension in patients with and without CKD. A new aspect of the guidelines is the recommendation for measurement of out-of-office BP to confirm the diagnosis of hypertension and guide therapy. In this KDOQI (Kidney Disease Outcomes Quality Initiative) perspective, we review the recommendations for accurate BP measurement in the office, at home, and with ambulatory BP monitoring. Regardless of location, validated devices and appropriate cuff sizes should be used. In the clinic and at home, proper patient preparation and positioning are critical. Patients should receive information about the importance of BP measurement techniques and be encouraged to advocate for adherence to guideline recommendations. Implementing appropriate BP measurement in routine practice is feasible and should be incorporated in system-wide efforts to improve the care of patients with hypertension. Hypertension is the number 1 chronic disease risk factor in the world; BP measurements in the office, at home, and with ambulatory BP monitoring should adhere to recommendations from the AHA.

Short-term blood pressure variability in nondialysis chronic kidney disease patients: correlates and prognostic role on the progression of renal disease

OBJECTIVE

In chronic kidney disease (CKD), few cross-sectional studies evidenced an association between short-term BP variability (BPV) derived from ambulatory blood pressure (ABP) monitoring and renal damage. However, no study has evaluated the association of short-term BPV with the risk of CKD progression.

METHODS

We performed a cohort study to assess the correlates and the predictive value for incident renal outcomes of short-term BPV in hypertensive patients with CKD stage G1-5. As measures of short-term BPV, we considered the weighted SD (W-SD), and the coefficient of variation of SBP (CV-24-h SBP). Primary outcome was a composite endpoint of ESRD (chronic dialysis or transplantation) or GFR decline of at least 50%.

RESULTS

We included 465 patients (63.5 ± 14.2 years; 54.7% men; eGFR: 44 ± 22 ml/min per 1.73 m; proteinuria: 0.2 [0.1-0.9] g/day); W-SD, CV-24-h SBP and 24 h SBP were 12.5 ± 3.3 mmHg, 11.1 ± 2.8% and 127 ± 16 mmHg, respectively. W-SD was independently associated with older age, history of cardiovascular disease, diagnosis of diabetic, hypertensive and polycystic nephropathy, and higher 24 h SBP whereas no association with eGFR and proteinuria was found. During follow-up (median, 6.4 years), 130 patients reached the renal outcome (107 ESRD and 23 GFR decline of ≥50%). Higher 24 h, daytime and night-time SBP robustly predicted the composite renal endpoint [1.18 (1.10-1.25) for 5 mmHg], whereas BPV as measured by the W-SD did not either when expressed as a continuous variable [hazard ratio 0.97 (95% CI 0.91-1.04)] or when categorized into tertiles [1.16 (0.70-1.92) and 0.95 (0.54-1.68) in II and III tertiles, respectively]. Similar findings were found with CV-24-h SBP.

CONCLUSION

In CKD patients, short-term BPV is strongly associated with 24 h, night-time and daytime BP but is independent from the eGFR and proteinuria and does not predict CKD progression.

Effect of Intensive and Standard Clinic-Based Hypertension Management on the Concordance Between Clinic and Ambulatory Blood Pressure and Blood Pressure Variability in SPRINT

Background Blood pressure ( BP ) varies over time within individual patients and across different BP measurement techniques. The effect of different BP targets on concordance between BP measurements is unknown. The goals of this analysis are to evaluate concordance between (1) clinic and ambulatory BP , (2) clinic visit-to-visit variability and ambulatory BP variability, and (3) first and second ambulatory BP and to evaluate whether different clinic targets affect these relationships. Methods and Results The SPRINT (Systolic Blood Pressure Intervention Trial) ambulatory BP monitoring ancillary study obtained ambulatory BP readings in 897 participants at the 27-month follow-up visit and obtained a second reading in 203 participants 293±84 days afterward. There was considerable lack of agreement between clinic and daytime ambulatory systolic BP with wide limits of agreement in Bland-Altman plots of -21 to 34 mm Hg in the intensive-treatment group and -26 to 32 mm Hg in the standard-treatment group. Overall, there was poor agreement between clinic visit-to-visit variability and ambulatory BP variability with correlation coefficients for systolic and diastolic BP all <0.16. We observed a high correlation between first and second ambulatory BP ; however, the limits of agreement were wide in both the intensive group (-27 to 21 mm Hg) and the standard group (-23 to 20 mm Hg). Conclusions We found low concordance in BP and BP variability between clinic and ambulatory BP and second ambulatory BP . Results did not differ by treatment arm. These results reinforce the need for multiple BP measurements before clinical decision making.

Masked Hypertension in CKD: Increased Prevalence and Risk for Cardiovascular and Renal Events

PURPOSE OF REVIEW

Hypertension and chronic kidney disease (CKD) are inextricably linked. The causal nature of the relationship is bidirectional. This relationship holds when blood pressure is assessed in the clinic and outside the clinic with home and ambulatory blood pressure monitoring. Patients with CKD are more likely to have high-risk hypertension phenotypes, such as masked and sustained hypertension, and are at increased risk for cardiovascular disease. The purpose of this review is to describe the increased prevalence of masked hypertension in patients with CKD and then describe the increased risk for target organ damage and adverse clinical events associated with masked hypertension in patients with CKD.

RECENT FINDINGS

The prevalence of masked hypertension is greater in patients with CKD than that of the general population. Recent studies have demonstrated that masked hypertension is associated with increased risk for target organ damage including left ventricular hypertrophy, elevated pulse wave velocity, proteinuria, and decreased estimated glomerular filtration rate in patients with CKD. Additionally, in patients with CKD, masked hypertension is associated with increased risk for cardiovascular disease, end-stage renal disease, and all-cause mortality. Patients with CKD are at increased risk for masked hypertension. Masked hypertension is associated with increased risk for target organ damage and adverse cardiovascular and renal outcomes in patients with CKD. Further research is necessary to better understand the pathophysiology of masked hypertension, the optimal method for diagnosing masked hypertension, and to determine whether masked hypertension is a modifiable risk factor.

Magnitude of the Difference Between Clinic and Ambulatory Blood Pressures and Risk of Adverse Outcomes in Patients With Chronic Kidney Disease

Background Obtaining 24-hour ambulatory blood pressure ( BP ) is recommended for the detection of masked or white-coat hypertension. Our objective was to determine whether the magnitude of the difference between ambulatory and clinic BP s has prognostic implications. Methods and Results We included 610 participants of the AASK (African American Study of Kidney Disease and Hypertension) Cohort Study who had clinic and ambulatory BPs performed in close proximity in time. We used Cox models to determine the association between the absolute systolic BP ( SBP ) difference between clinic and awake ambulatory BPs (primary predictor) and death and end-stage renal disease. Of 610 AASK Cohort Study participants, 200 (32.8%) died during a median follow-up of 9.9 years; 178 (29.2%) developed end-stage renal disease. There was a U-shaped association between the clinic and ambulatory SBP difference with risk of death, but not end-stage renal disease. A 5- to <10-mm Hg higher clinic versus awake SBP (white-coat effect) was associated with a trend toward higher (adjusted) mortality risk (adjusted hazard ratio, 1.84; 95% CI, 0.94-3.56) compared with a 0- to <5-mm Hg clinic-awake SBP difference (reference group). A ≥10-mm Hg clinic-awake SBP difference was associated with even higher mortality risk (adjusted hazard ratio, 2.31; 95% CI, 1.27-4.22). A ≥-5-mm Hg clinic-awake SBP difference was also associated with higher mortality (adjusted hazard ratio, 1.82; 95% CI, 1.05-3.15) compared with the reference group. Conclusions A U-shaped association exists between the magnitude of the difference between clinic and ambulatory SBP and mortality. Higher clinic versus ambulatory BPs (as in white-coat effect) may be associated with higher risk of death in black patients with chronic kidney disease.

Ambulatory Blood Pressure Monitoring: Profiles in Chronic Kidney Disease Patients and Utility in Management

Optimal control of blood pressure (BP) may reduce the risk of progression of CKD. Misclassification of hypertension (HTN) and status of control may result in suboptimal management. Clinic or home BP may overestimate or underestimate status of control compared with ambulatory BP monitoring (ABPM), which is considered the gold standard. The latter relates not only to the superiority of ABPM concerning outcome prognosis but also to its ability to accurately diagnose white coat and masked HTN, which is critical in assuring adequate BP control. However, ABPM has not gained widespread use in practice because of limited third-party reimbursement and a paucity of high quality randomized controlled intervention studies evaluating its use. Herein, we review HTN phenotypes that have been identified in patients with CKD, and the potential value of ABPM in this high-risk population.

Impact of Blood or Erythrocyte Membrane Fatty Acids for Disease Risk Prediction: Focusing on Cardiovascular Disease and Chronic Kidney Disease

Fatty acids (FAs) are essential nutrients and main constituents of cell membranes that are involved in the signaling pathway and associated with health conditions. We investigated if blood or erythrocyte membrane FAs can predict the risk of cardiovascular disease (CVD), chronic kidney disease (CKD), and related complications. Omega-3 (n-3) FAs are important predictors for metabolic syndrome, diabetes, CVD, and CKD risks, and the n-3 index is also a good biomarker for sudden cardiac death in coronary artery disease. Linoleic acid, which is one of the major n-6 FAs reflecting recent dietary FA intake, may predict CVD risk and mortality in the general population and patients with CKD. Monounsaturated FAs (MUFAs) are also related to diabetes or diabetic nephropathy. Oleic acid, a major MUFA, is an emerging marker that is related to acute coronary syndrome, low glomerular filtration rate, and vascular calcification in patients with CKD, and can be modified by n-3 FA supplementation. Saturated FAs, trans-FAs, and FA desaturation/elongation are associated with CVD risk; however, few studies have been conducted on patients with CKD. In summary, blood or erythrocyte membrane FA measurements are important for CVD and CKD risk prediction and management. Further studies are needed to elucidate the FAs for their risk predictions.

Variations in 24-Hour BP Profiles in Cohorts of Patients with Kidney Disease around the World: The I-DARE Study

BACKGROUND AND OBJECTIVES

Ambulatory BP is increasingly recognized as a better measure of the risk for adverse outcomes related to hypertension, an important comorbidity in patients with CKD. Varying definitions of white-coat and masked hypertension have made it difficult to evaluate differences in prevalence of these BP patterns across CKD cohorts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The International Database of Ambulatory BP in Renal Patients collaborative group established a large database of demographic, clinical, and ambulatory BP data from patients with CKD from cohorts in Italy, Spain, the Chronic Renal Insufficiency Cohort (CRIC) and the African American Study of Kidney Disease and Hypertension Cohort Study (AASK) in the United States, and the CKD Japan Cohort (CKD-JAC). Participants (n=7518) with CKD were included in the present analyses. Cutoffs for defining controlled BP were 140/90 mm Hg for clinic and 130/80 mm Hg for 24-hour ambulatory BP.

RESULTS

Among those with controlled clinic BP, compared with CKD-JAC, AASK participants were more likely to have masked hypertension (prevalence ratio [PR], 1.21; 95% confidence interval [95% CI], 1.04 to 1.41) whereas CRIC (PR, 0.82; 0.72 to 0.94), Italian (PR, 0.73; 0.56 to 0.95), and Spanish participants (PR, 0.75; 0.64 to 0.88) were less likely. Among those with elevated clinic BP, AASK participants were more likely to have sustained hypertension (PR, 1.22; 95% CI, 1.13 to 1.32) whereas Italian (PR, 0.78; 0.70 to 0.87) and Spanish participants (PR, 0.89; 0.82 to 0.96) were less likely, although CRIC participants had similar prevalence as CKD-JAC. Prevalence of masked and sustained hypertension was elevated in males, patients with diabetes, participants on four or more antihypertensives, and those with moderate-to-severe proteinuria.

CONCLUSIONS

In a large, multinational database, the prevalence of masked and sustained hypertension varied across cohorts independent of important comorbidities.

BP Measurement Techniques: What They Mean for Patients with Kidney Disease

Patients with CKD typically have hypertension. Manual BP measurement in the office setting was used to define hypertension, establish eligibility, and assess BP targets in the epidemiologic studies and early randomized, controlled trials that inform current management of hypertension. Use of automated oscillometric devices has largely replaced manual BP measurement in the office and clinical trials. These newer devices may reduce the white coat effect and facilitate guideline-adherent measurement protocols. Obtaining BP measurements outside of the office with home and ambulatory BP monitoring is now more common. Out of office BPs are especially important in patients with CKD, because reduced GFR and proteinuria are associated with masked hypertension (normal office BP and elevated BP outside of the office), elevated nighttime BP, and abnormal diurnal variation in BP, all of which are associated with higher risk for target organ damage and adverse outcomes. Also, it is now feasible to routinely measure central BP and central hemodynamics. These measures are of greater importance to patients with CKD given the higher prevalence of increased sympathetic tone, arteriosclerosis, and inflammation as well as impaired sodium excretion and endothelial dysfunction, which lead to alterations in central BPs in this population. In this review, we describe various BP measurement techniques and how they apply to the care of patients with CKD.

Masked hypertension and kidney function decline: the Jackson Heart Study

BACKGROUND

Hypertension diagnosed by blood pressure (BP) measured in the clinic is associated with rapid kidney function decline (RKFD) and incident chronic kidney disease (CKD). The extent to which hypertension defined using out-of-clinic BP measurements is associated with these outcomes is unclear.

METHODS

We evaluated the association of any masked hypertension (daytime SBP/DBP ≥ 135/85 mmHg, night-time SBP/DBP ≥ 120/70 mmHg or 24-h SBP/DBP ≥ 130/80 mmHg) with RKFD and incident CKD among 676 African-Americans in the Jackson Heart Study with clinic-measured SBP/DBP less than 140/90 mmHg who completed ambulatory BP monitoring in 2000-2004. RKFD was defined as a decline in estimated glomerular filtration rate (eGFR) at least 30% and incident CKD was defined as development of eGFR less than 60 ml/min per 1.73 m with an at least 25% decline in eGFR between 2000-2004 and 2009-2013.

RESULTS

The mean age of participants was 57.6 years, 28.8% were men and 52.7% had any masked hypertension. After a median follow-up of 8 years, 13.8 and 8.6% of participants had RKFD and incident CKD, respectively. In unadjusted analyses, masked hypertension was associated with an increased odds for incident CKD [odds ratio (OR) 2.20, 95% confidence interval (CI) 1.22, 3.97]. This association remained statistically significant after adjustment for demographic characteristics, baseline eGFR and albumin-to-creatinine ratio (OR 1.95, 95% CI 1.04, 3.67) but was eliminated after propensity score adjustment (OR 1.62, 95% CI 0.87, 3.00). There was no association between masked hypertension and RKFD.

CONCLUSION

Masked hypertension may be associated with the development of CKD in African-Americans.

Role and prognostic value of individual ambulatory blood pressure components in chronic kidney disease

Hypertension is a key risk factor for chronic kidney disease (CKD), but can also be a detrimental consequence of established CKD. Unsurprisingly, the majority of subjects with abnormal creatinine in the general population are also hypertensive, with a huge toll on national health care systems worldwide due to a staggering increase in the risk of cardiovascular complications and end-stage renal disease requiring renal replacement therapy. In this setting, a comprehensive and careful assessment of the whole 24-h blood pressure (BP) profile could be of paramount importance in ensuring a timely diagnosis of hypertension and an optimal therapeutic control. Hence, ambulatory BP monitoring (ABPM) has the potential to become the preferred method for optimal clinical management of CKD patients. ABPM might better define the relationship between BP, target organ damage (TOD), and clinical outcomes. Current evidence suggests that specific day-night BP components, along with average BP values, may have clinical relevance in such patients, despite the suboptimal statistical power of available studies and inconsistencies on the prognostic value of individual BP components. The main aim of our review is to scrutinize the evidence for the usage of ABPM in CKD patients, including the relationship between ambulatory BP recordings and cardiovascular events, and the distinctive features of ABPM in these subjects.

[What is the goal blood pressure in non-diabetic chronic kidney disease?]

High blood pressure during renal disease is highly prevalent and an important risk factor for cardiovascular disease and renal progression. Its optimal management is therefore necessary to improve the prognosis of patients. Several trials concerning the blood pressure target in patients with chronic non-diabetic kidney disease have been published in recent years, we will detail them in this article in order to determine which blood pressure target provides the best benefit in terms of progression of renal diseases and cardiovascular prevention.

Altered Circadian Timing System-Mediated Non-Dipping Pattern of Blood Pressure and Associated Cardiovascular Disorders in Metabolic and Kidney Diseases

The morning surge in blood pressure (BP) coincides with increased cardiovascular (CV) events. This strongly suggests that an altered circadian rhythm of BP plays a crucial role in the development of CV disease (CVD). A disrupted circadian rhythm of BP, such as the non-dipping type of hypertension (i.e., absence of nocturnal BP decline), is frequently observed in metabolic disorders and chronic kidney disease (CKD). The circadian timing system, controlled by the central clock in the suprachiasmatic nucleus of the hypothalamus and/or by peripheral clocks in the heart, vasculature, and kidneys, modulates the 24 h oscillation of BP. However, little information is available regarding the molecular and cellular mechanisms of an altered circadian timing system-mediated disrupted dipping pattern of BP in metabolic disorders and CKD that can lead to the development of CV events. A more thorough understanding of this pathogenesis could provide novel therapeutic strategies for the management of CVD. This short review will address our and others' recent findings on the molecular mechanisms that may affect the dipping pattern of BP in metabolic dysfunction and kidney disease and its association with CV disorders.

Arterial stiffness and its relationship to clinic and ambulatory blood pressure: a longitudinal study in non-dialysis chronic kidney disease

Background

Both arterial stiffness and systolic blood pressure (BP) are established cardiovascular risk factors, yet little is known about their interrelationship in chronic kidney disease (CKD). The goal of this prospective study was to describe the trajectory of aortic pulse wave velocity (PWV) and BP and to compare the longitudinal interrelationship of BP (clinic and 24 h ambulatory recording) with the PWV.

Methods

Clinic BP was taken in two ways: at the time of the measurement of the PWV (Clinic-S) and as an average of triplicate measurements on three separate occasions within 1 week (Clinic-M). 24 h ambulatory BP was measured using a validated monitor and PWV was measured in the aorta using an echo-Doppler technique.

Results

Among 255 veterans with CKD followed for over up to 4 years, the rate of change of log PWV was inversely related to the baseline PWV; the trajectories were variable among individuals and the net population change was no different from zero. In contrast, systolic BP significantly increased, but linearly, and a strong relationship was seen between cross-sectional and longitudinal changes in Clinic-M systolic BP and log PWV. In contrast, a longitudinal relationship between Clinic-S and log PWV was absent. In the case of 24-h ambulatory BP, a strong cross-sectional change was seen between awake and 24 h systolic BP but not between sleep BP and log PWV.

Conclusion

In conclusion, among people with CKD, the PWV changes over time and is inversely related to the baseline PWV. An average of clinic BP measurements taken over three visits, but not single measurements, are useful to assess the PWV and its change over time. Differences exist between ambulatory BP monitoring recording during the sleep and awake states in their ability to predict the PWV. Taken together, these data support the view that among those with CKD not on dialysis, targeting clinic BP taken on multiple occasions using a standardized methodology or daytime ambulatory systolic BP may slow the progression of arterial damage.

BP Measurement in Clinical Practice: Time to SPRINT to Guideline-Recommended Protocols

Hypertension is the leading chronic disease risk factor in the world and is especially important in patients with CKD, nearly 90% of whom have hypertension. Recently, in the Systolic BP Intervention Trial (SPRINT), intensive lowering of clinic systolic BP to a target <120 mm Hg, compared with a standard BP target of <140 mm Hg, reduced risk for cardiovascular disease and all-cause mortality. However, because BP was measured unobserved using an automated device, some investigators have questioned the ability to translate SPRINT results into routine clinical practice, in which measurement of BP is typically less standardized. In this review, we discuss the BP measurement techniques used in major observational studies and clinical trials that form the evidence base for our current approach to treating hypertension, evaluate the effect of measurement technique on BP readings, and explore how ambulatory BP data from the SPRINT trial may inform this discussion. We conclude by arguing for implementation of guideline-recommended BP measurement techniques in routine clinical practice.

Comparison of Prognostic Values of Daytime and Night-Time Systolic Blood Pressures on Renal Outcomes in Patients With Chronic Kidney Disease

BACKGROUND

Differences in the predictive value of daytime systolic blood pressure (SBP) and night-time SBP by ambulatory blood pressure monitoring on renal outcomes have not been fully investigated in chronic kidney disease (CKD) patients. This study compared the prognostic value between daytime and night-time SBP on renal outcomes in CKD.Methods and Results:This prospective observational study included 421 patients. The composite renal endpoint was endstage renal disease (ESRD) or death. Cox models were used to determine associations of daytime and night-time SBP with renal outcomes. There were 150 renal events (ESRD, 130; death, 20). Multivariable Cox analyses demonstrated that hazard ratios (HRs) [95% confidence interval (CI)] for composite renal outcomes of every 10-mmHg increase in daytime and night-time SBP levels were 1.13 (1.02-1.26) (P=0.02) and 1.15 (1.05-1.27) (P<0.01), respectively. In addition, compared with the 1st daytime or night-time SBP quartile, HRs (95% CI) for outcomes in the 2nd, 3rd, and 4th quartiles were: daytime SBP, 1.25 (0.70-2.25), 1.09 (0.61-1.94), and 1.58 (0.88-2.85; P=0.13) (P for trend=0.16); night-time SBP, 1.09 (0.61-1.96), 1.31 (0.76-2.28), and 1.82 (1.00-3.30; P=0.049) (P for trend=0.03), respectively.

CONCLUSIONS

Night-time SBP appeared superior to daytime SBP for predicting renal outcomes in this population of patients.

Circadian blood pressure abnormalities in patients with primary nephrotic syndrome

BACKGROUND

Only a few studies have evaluated the abnormalities of ambulatory blood pressure (ABP) in patients with nephrotic syndrome (NS).

METHODS

The 24-h ABPs were measured in primary NS patients with acute onset of disease and analyzed in relation to the clinical variables.

RESULTS

Our subjects comprised 21 patients: 17 with minimal change disease and 4 with focal segmental glomerulosclerosis. Of these patients, 8 (38%) had daytime hypertension, 13 (62%) had nighttime hypertension, and 13 (62%) were non-dippers (nighttime-to-daytime ratio of ABP: NDR > 0.9). The serum sodium level was correlated with the average 24-h ABP and NDR, after adjustment for other clinical variables, such as the increase in body weight, serum albumin level, and urinary protein excretion. The data from repeated ABP measurements, before and after the achievement of remission, showed a marked decrease in the average 24-h ABP after remission. Furthermore, change in the serum sodium level was significantly correlated with the change in NDR.

CONCLUSION

These results suggest that alteration in renal handling of sodium and water, which might be reflected in serum sodium level, is involved in the abnormality of circadian blood pressure in primary NS patients.

Strict blood pressure control associates with decreased mortality risk by APOL1 genotype

Although APOL1 high-risk genotype partially accounts for the increased susceptibility of blacks to chronic kidney disease (CKD), whether APOL1 associates differentially with mortality risk remains controversial. Here we evaluate the association between APOL1 genotype and risk of death and determine whether APOL1 status modifies the association between strict versus usual blood pressure control and mortality risk. We performed a retrospective analysis of the African American Study of Kidney Disease and Hypertension trial that randomized black participants with CKD to strict versus usual blood pressure control from 1995 to 2001. This included 682 participants with known APOL1 genotype (157 with high-risk genotype) previously assigned to either strict (mean arterial pressure [MAP] 92 mm Hg or less) versus usual blood pressure control (MAP 102-107 mm Hg) during the trial. During a median follow-up of 14.5 years, risk of death did not differ between individuals with high- versus low-risk APOL1 genotypes (unadjusted hazard ratio 1.00 [95% confidence interval 0.76-1.33]). However, a significant interaction was detected between the APOL1 risk group and blood pressure control strategy. In the APOL1 high-risk group, the risk of death was 42% lower comparing strict versus usual blood pressure control (0.58 [0.35-0.97]). In the APOL1 low-risk group, the risk of death comparing strict versus usual blood pressure control was not significantly different (1.09 [0.84-1.43]). Thus, strict blood pressure control during CKD associates with a lower risk of death in blacks with the high-risk CKD APOL1 genotype. Knowledge of APOL1 status could inform selection of blood pressure treatment targets in black CKD patients.

Effect of Intensive Versus Standard Clinic-Based Hypertension Management on Ambulatory Blood Pressure: Results From the SPRINT (Systolic Blood Pressure Intervention Trial) Ambulatory Blood Pressure Study

The effect of clinic-based intensive hypertension treatment on ambulatory blood pressure (BP) is unknown. The goal of the SPRINT (Systolic Blood Pressure Intervention Trial) ambulatory BP ancillary study was to evaluate the effect of intensive versus standard clinic-based BP targets on ambulatory BP. Ambulatory BP was obtained within 3 weeks of the 27-month study visit in 897 SPRINT participants. Intensive treatment resulted in lower clinic systolic BP (mean difference between groups=16.0 mm Hg; 95% confidence interval, 14.1-17.8 mm Hg), nighttime systolic BP (mean difference=9.6 mm Hg; 95% confidence interval, 7.7-11.5 mm Hg), daytime systolic BP (mean difference=12.3 mm Hg; 95% confidence interval, 10.6-13.9 mm Hg), and 24-hour systolic BP (mean difference=11.2 mm Hg; 95% confidence interval, 9.7-12.8 mm Hg). The night/day systolic BP ratio was similar between the intensive (0.92±0.09) and standard-treatment groups (0.91±0.09). There was considerable lack of agreement within participants between clinic systolic BP and daytime ambulatory systolic BP with wide limits of agreement on Bland-Altman plots. In conclusion, targeting a systolic BP of <120 mm Hg, when compared with <140 mm Hg, resulted in lower nighttime, daytime, and 24-hour systolic BP, but did not change the night/day systolic BP ratio. Ambulatory BP monitoring may be required to assess the effect of targeted hypertension therapy on out of office BP. Further studies are needed to assess whether targeting hypertension therapy based on ambulatory BP improves clinical outcomes.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835249.

Prognostic Effect of Isolated Nocturnal Hypertension in Chinese Patients With Nondialysis Chronic Kidney Disease

BACKGROUND

Isolated nocturnal hypertension (INH) has been studied among the general population and hypertensive patients. However, little insight is available on the prognostic effect of INH in patients with chronic kidney disease (CKD). This study investigated the prognostic effect of INH in a cohort of Chinese patients with nondialysis CKD.

METHODS AND RESULTS

A total of 588 Chinese CKD patients who were admitted to the Third Affiliated Hospital of Sun Yat-Sen University were enrolled in this study. We monitored blood pressure (BP) throughout the day and followed health outcomes in the 588 CKD patients admitted to our hospital division. We recorded time to total mortality, cardiovascular mortality, renal events, and cardiovascular events. A total of 370 (62.92%) individuals had nocturnal hypertension, which included 136 (23.13%) patients with INH. Multivariable Cox regression analyses showed that nocturnal BP was a significant risk factor for renal events and cardiovascular events in CKD patients, even when adjusted for clinic BP, 24-hour BP, or daytime BP. Patients with nocturnal hypertension showed a worse prognosis compared with patients with nocturnal normotension (P<0.05), and nocturnal hypertension (versus nocturnal normotension) was associated with an increased risk for renal events (hazard ratio [HR], 3.81; 95% CI, 1.74-8.36) and cardiovascular events (HR, 8.34; 95% CI, 1.98-35.07). In addition, patients with INH had a worse prognosis than patients with normotension (P<0.017), whereas INH (versus normotension) was associated with a higher risk of renal events (HR, 2.78; 95% CI, 1.16-6.65) and cardiovascular events (HR, 6.82; 95% CI, 1.52-30.63).

CONCLUSIONS

INH was associated with a poor prognosis in Chinese nondialysis CKD patients.

Prognostic Value of Reverse Dipper Blood Pressure Pattern in Chronic Kidney Disease Patients not Undergoing Dialysis: Prospective Cohort Study

The "reverse dipping" blood pressure (BP) pattern has been studied among the general population and in individuals suffering from hypertension. However, the prognosis of this pattern in chronic kidney disease (CKD) patients is not known. We monitored BP throughout the day and followed health outcomes in 588 CKD patients admitted to our hospital. Time to all-cause mortality, cardiovascular mortality, renal events and cardiovascular events was recorded. Multivariate-adjusted Cox regression analyses were carried out to detect the prognostic value of a reverse dipping BP pattern. Prevalence of a "dipper", "non-dipper" and "reverse dippers" was 34.69%, 43.54% and 18.03%, respectively. Patients with a reverse dipping pattern had a higher prevalence of total mortality, cardiovascular mortality, renal events and cardiovascular events than patients with a dipping pattern (P < 0.025). Multivariate-adjusted Cox regression analyses showed that reverse dippers (versus dippers) were associated with a higher risk of total mortality (hazard ratio [HR], 5.08; 95% confidence interval [CI], 1.79~14.47), cardiovascular mortality (4.17; 1.25~13.88), renal events (3.00; 1.59~5.65) and cardiovascular events (4.12; 1.78~9.51) even after adjustment by 24-h systolic BP. These data suggest that a reverse dipping BP pattern, independent of 24-h levels of systolic BP, has prognostic value in CKD patients not undergoing dialysis.

Hypertension Management in Transition: From CKD to ESRD

Hypertension is present in ∼90% of patients in late-stage CKD. There are scarce data focusing on the transition period between CKD Stages 4 and 5 (end-stage kidney disease) as it relates to hypertension evaluation and management. Here, we propose that a combination of the principles used in the management of patients with CKD Stages 4 and 5 be applied to patients in this transition. These include the use of out-of-office blood pressure (BP) monitoring (eg, home BP), avoidance of excessively tight BP goals, emphasis of sodium restriction, preferential use of blockers of the renin-angiotensin system and diuretics, and consideration of the use of beta blockers.