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

Circadian variations in blood pressure and their implications for the administration of antihypertensive drugs: is dosing in the evening better than in the morning?

: Blood pressure (BP) follows a circadian rhythm with a physiological decrease during the night. Studies have demonstrated that nocturnal BP as well as its dipping pattern during night-time have a significant prognostic importance for mortality and the occurrence of cardiovascular events. Therefore, hypertension management guidelines recommend to ascertain that patients treated for hypertension have well controlled BP values around the clock. To improve hypertension control during the night and eventually further reduce cardiovascular events, it has been proposed by some to prescribe at least one antihypertensive medication at bedtime. In this review, we have examined the data which could support the benefits of prescribing BP-lowering drugs at bedtime. Our conclusion is that there is no convincing evidence that the administration of BP-lowering drugs in the evening provides any significant advantage in terms of quality of BP control, prevention of target organ damage or reduction of cardiovascular events. Before changing practice for unproven benefits, it would be wise to wait for the results of the ongoing trials that are addressing this issue.

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.

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.

Association of ambulatory blood pressure monitoring with renal outcome in patients with chronic kidney disease

Background

The significance of ambulatory blood pressure (ABP) in Korean patients with chronic kidney disease (CKD) in relation to renal outcome or death remains unclear. We investigated the role of ABP in predicting end-stage renal disease or death in patients with CKD.

Methods

We enrolled 387 patients with hypertension and CKD who underwent ABP monitoring and were followed for 1 year. Data on clinical parameters and outcomes from August 2014 to May 2018 were retrospectively collected. The composite endpoint was end-stage renal disease or death. Patients were grouped according to the mean ABP.

Results

There were 66 endpoint events, 52 end-stage renal disease cases, and 15 mortalities. Among all patients, one developed end-stage renal disease and died. Mean ABP in the systolic and diastolic phases were risk factors for the development of composite outcome with hazard ratios of 1.03 (95% confidence interval [CI], 1.01-1.04; P < 0.001) and 1.04 (95% CI, 1.02-1.07; P = 0.001) for every 1 mmHg increase in BP, respectively. Patients with mean ABP between 125/75 and 130/80 mmHg had a 2.56-fold higher risk for the development of composite outcome (95% CI, 0.72-9.12; P = 0.147) as compared to those with mean ABP ≤ 125/75 mmHg. Patients with mean ABP ≥ 130/80 mmHg had a 4.79-fold higher risk (95% CI, 1.68-13.70; P = 0.003) compared to those with mean ABP ≤ 125/75 mmHg. Office blood pressure (OBP) was not a risk factor for the composite outcome when adjusted for covariates.

Conclusion

In contrast to OBP, ABP was a significant risk factor for end-stage renal disease or death in CKD patients.

Hypertension in Chronic Kidney Disease: Novel Insights

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

Blood urea nitrogen is independently associated with renal outcomes in Japanese patients with stage 3-5 chronic kidney disease: a prospective observational study

Background

Blood urea nitrogen (BUN) is one of the substances that affects the calculated serum osmolality (cSosm). A previous study demonstrated that BUN and cSosm were independently associated with the development of chronic kidney disease (CKD) in patients with preserved kidney function. In advanced CKD stages, there is a concomitant increase in cSosm and BUN levels. However, it remains unclear whether BUN or cSosm levels are related to renal outcomes in patients with moderate to severe kidney dysfunction. The aim of this study was to clarify whether the BUN or cSosm level is associated with kidney disease progression in patients with advanced CKD.

Methods

In this prospective study, we enrolled 459 patients with CKD (stages 3–5). The composite renal endpoint was end-stage renal disease (ESRD) or death, and ESRD alone was added as an alternative outcome. A Cox proportional hazards model was utilized to determine the risk factors for a poor renal outcome. We adjusted for covariates including estimated glomerular filtration rate (eGFR). The cSosm (mOsm/kg) was calculated using the following formula: (2 × sodium) + (BUN/2.8) + (glucose/18).

Results

During a median follow-up of 25.8 months, the renal endpoint was observed in 210 patients. Multivariable Cox analysis determined the hazard ratio (HR) [95% confidence interval (CI)] for the composite renal outcome in the second, third, and fourth BUN quartiles were 1.36 (0.72–2.58), 1.87 (0.95–3.66), and 2.66 (1.23–5.76) (P for trend < 0.01), respectively compared with the first BUN quartile. Conversely, by multivariable Cox analysis, the HRs (95% CIs) for poor outcomes in the second, third, and fourth cSosm quartiles, compared with the first cSosm quartile, were 1.13 (0.69–1.87), 0.95 (0.58–1.55), and 1.26 (0.78–2.03), respectively (P for trend = 0.39). In addition, with regard to the renal outcome of ESRD alone, higher BUN quartiles had a significantly increased risk for the outcome, but cSosm levels were not associated with the outcome.

Conclusions

Higher BUN levels, but not cSosm levels, were associated with adverse renal outcomes independent of the eGFR, suggesting that BUN may be a useful marker for predicting kidney disease progression.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1306-1) contains supplementary material, which is available to authorized users.

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.

Greater Nocturnal Blood Pressure Is Associated With Natriuretic Peptide Level in Aortic Stenosis With Preserved Ejection Fraction

BACKGROUND

Although careful monitoring of asymptomatic severe aortic stenosis (AS) is recommended to prevent missing the optimal timing of surgical or transcatheter aortic valve replacement, prophylactic treatment that could extend the asymptomatic period remains unknown. In a hypertensive population, high blood pressure (BP) measured at the doctor's office is known to be associated with B-type natriuretic peptide (BNP) level, a surrogate marker for symptomatic deterioration in AS. Little is known regarding the association between nocturnal BP variables and BNP in severe AS with preserved ejection fraction (EF). Methods and Results: The subjects consisted of 78 severe AS patients (mean age, 79±6 years) with preserved EF. Nocturnal BP was measured hourly using a home BP monitoring device. On multiple regression analysis, nocturnal mean systolic BP (SBP) remained independently associated with BNP after adjustment for age, sex, body mass index, estimated glomerular filtration rate, antihypertensive medication class, early diastolic mitral annular velocity, and left ventricular mass index (P=0.03), whereas diastolic BP (DBP) and variables of BP variability were not.

CONCLUSIONS

Higher nocturnal SBP rather than DBP or indices of BP variability was independently associated with BNP in AS patients with preserved EF. Intervention for nocturnal SBP may therefore extend the asymptomatic period and improve prognosis.