Association Between Nocturnal Blood Pressure Dipping and Chronic Kidney Disease Among Patients With Controlled Office Blood Pressure

While You Are Sleeping: Marital Ambivalence and Blunted Nocturnal Blood Pressure

Marital relationships offer health benefits, including a lower risk of cardiovascular disease (CVD). However, quality of the relationship matters; ambivalent behaviors may increase CVD risk by affecting blunted nocturnal blood pressure (BP) dipping. This study tracked daytime and nocturnal SBP and DBP in 180 normotensive individuals (90 couples; participant mean age 25.04; 91.58% white) over a 24 h period using ambulatory blood pressure monitors to explore the impact of martial quality. Results showed that perceptions of spousal ambivalence were associated with blunted nocturnal BP dipping. Perceptions of one's own behavior as ambivalent also showed blunted nocturnal dipping. When in an ambivalent relationship, a gender interaction was found such that women were most likely to have blunted SBP dipping, but men were more likely to have blunted nocturnal DBP dipping. Overall, this study found an association between ambivalence and BP dipping, thus uncovering one virtually unexplored pathway by which marital relationships may have adverse effects on health.

The association between blood pressure variability and renal damage in patients with primary aldosteronism

This research examines the association between blood pressure variability (BPV) and renal damage in a cohort of 129 primary aldosteronism (PA) patients, employing ambulatory blood pressure monitoring (ABPM) for comparative analysis with individuals diagnosed with essential hypertension (EH). The study reveals that PA patients exhibited significantly elevated levels of cystatin C and urine microalbumin/creatinine ratio (UACR). Additionally, a higher prevalence of non-dipping blood pressure patterns in PA patients suggests an increased risk of circadian blood pressure regulation disturbances. Notably, while most BPV indices were comparable between the two groups, the standard deviation of 24-h weighted diastolic blood pressure was markedly lower in the PA cohort, distinguishing it as a unique variable. Through multiple linear regression analysis, the duration of hypertension, angiotensin II concentrations, and daytime systolic blood pressure standard deviation emerged as significant determinants of estimated glomerular filtration rate (eGFR) in PA patients. Furthermore, UACR was significantly influenced by variables including the 24-h weighted standard deviation (wSD) of systolic BP, glycosylated hemoglobin levels, nocturnal systolic BP peaks, aldosterone-renin ratio (ARR), and total cholesterol, with the most pronounced association observed with the 24-h wSD of systolic BP (β = 0.383).The study also found significant correlations between the 24-h wSD of systolic BP, ARR, HbA1c, serum potassium levels, and 24-h urinary microalbumin, underscoring the critical role of the 24-h wSD of systolic BP (β = 0.267). These findings underscore the imperative of an integrated management strategy for PA, addressing the intricate interconnections among metabolic abnormalities, blood pressure variability, and renal health outcomes.

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.

Short-term blood pressure variability as a potential therapeutic target for kidney disease

Short-term blood pressure variability (BPV) measured with ambulatory blood pressure (BP) monitoring has been demonstrated to be significant in predicting various clinical outcomes. Short-term BPV is distinguished from long-term BPV based on the time interval in which BP fluctuations are measured. Increased short-term BPV has been linked to detrimental effects on the microvascular structure and contributes to subclinical organ damage in the heart, blood vessels, and kidneys, regardless of the average 24-h BP levels. Short-term BPV can be defined by various measures, including calculated metrics (standard deviation, coefficient of variation, average real variability, weighted standard deviation, variability independent of the mean) or dipping patterns. Nevertheless, the additional role of short-term BPV beyond the predictive value of average 24-h BPs or established risk factors for cardiovascular disease and kidney disease remains unclear. In particular, longitudinal studies that evaluate the association between short-term BPV and kidney function impairment are limited and no conclusive data exist regarding which short-term BPV indicators most accurately reflect the prognosis of kidney disease. The issue of how to treat BPV in clinical practice is another concern that is frequently raised. This paper presents a review of the evidence for the prognostic role of short-term BPV in kidney outcomes. Additionally, this review discusses the remaining concerns about short-term BPV that need to be further investigated as an independent risk modifier.

Short-term Blood Pressure Variability and Incident CKD in Patients With Hypertension: Findings From the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI) Study

RATIONALE & OBJECTIVE

The association between short-term blood pressure variability (BPV) and kidney outcomes is poorly understood. This study evaluated the association between short-term BPV and kidney disease outcomes in people with hypertension.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

1,173 hypertensive participants in the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (2013-2018) Study with estimated glomerular filtration rate (eGFR) ≥60mL/min/1.73m².

EXPOSURE

Short-term BPV assessed by average real variability (ARV).

OUTCOME

Composite kidney disease outcome (30% decline in eGFR from baseline, new occurrence of eGFR <60mL/min/1.73m², or onset of UACR >300mg/g).

ANALYTICAL APPROACH

Multivariable Cox regression analyses to evaluate the association between systolic and diastolic BP ARV (SBP-ARV and DBP-ARV) and outcomes.

RESULTS

During a median follow-up of 5.4 [4.1-6.5] years, 271 events of the composite kidney disease outcome occurred (46.5 per 1,000 person-years). Multivariable Cox analysis revealed that the highest SBP-ARV and DBP-ARV tertiles were associated with a higher risk of the composite kidney disease outcome than the lowest tertiles, independent of the 24-hour SBP or DBP levels (HR, 1.64 [95% CI, 1.16-2.33], and 1.60 [95% CI, 1.15-2.24] for SBP-ARV and DBP-ARV, respectively). These associations were consistent when SBP-ARV and DBP-ARV were treated as continuous variables (HR per 1.0-unit greater SBP-ARV, 1.03 [95% CI, 1.01-1.06]; HR per 1.0-unit greater DBP-ARV, 1.04 [95% CI, 1.01-1.08]). These associations were consistent, irrespective of subgroups (age, sex, 24-hour SBP or DBP, and moderate albuminuria). However, other measures of short-term BPV including SD, coefficient of variation, and dipping patterns were not associated with the composite kidney disease outcome.

LIMITATIONS

Observational study design, the use of single measurement of 24-hour BP, lack of information on changes in antihypertensive medication during the follow-up.

CONCLUSIONS

Short-term BPV is associated with the development of a composite kidney disease outcome in hypertensive patients.

Role of the Circadian Clock and Effect of Time-Restricted Feeding in Adenine-Induced Chronic Kidney Disease

Most physiological functions exhibit circadian rhythmicity that is partly regulated by the molecular circadian clock. Herein, we investigated the relationship between the circadian clock and chronic kidney disease (CKD). The role of the clock gene in adenine-induced CKD and the mechanisms of interaction were investigated in mice in which Bmal1, the master regulator of the clock gene, was knocked out, and Bmal1 knockout (KO) tubule cells. We also determined whether the renoprotective effect of time-restricted feeding (TRF), a dietary strategy to enhance circadian rhythm, is clock gene-dependent. The mice with CKD showed altered expression of the core clock genes with a loss of diurnal variations in renal functions and key tubular transporter gene expression. Bmal1 KO mice developed more severe fibrosis, and transcriptome profiling followed by gene ontology analysis suggested that genes associated with the cell cycle, inflammation, and fatty acid oxidation pathways were significantly affected in the mutant mice. Tubule-specific deletion of BMAL1 in HK-2 cells by CRISPR/Cas9 led to upregulation of p21 and tumor necrosis α and exacerbated epithelial-mesenchymal transition-related gene expression upon transforming growth factor β stimulation. Finally, TRF in the mice with CKD partially restored the disrupted oscillation of the kidney clock genes, accompanied by improved cell cycle arrest and inflammation, leading to decreased fibrosis. However, the renoprotective effect of TRF was abolished in Bmal1 KO mice, suggesting that TRF is partially dependent on the clock gene. Our data demonstrate that the molecular clock system plays an important role in CKD via cell cycle regulation and inflammation. Understanding the role of the circadian clock in kidney diseases can be a new research field for developing novel therapeutic targets.

Bedtime dosing of antihypertensive medications: systematic review and consensus statement: International Society of Hypertension position paper endorsed by World Hypertension League and European Society of Hypertension

Antihypertensive drug therapy is one of the most efficient medical interventions for preventing disability and death globally. Most of the evidence supporting its benefits has been derived from outcome trials with morning dosing of medications. Accumulating evidence suggests an adverse prognosis associated with night-time hypertension, nondipping blood pressure (BP) profile and morning BP surge, with increased incidence of cardiovascular events during the first few morning hours. These observations provide justification for complete 24-h BP control as being the primary goal of antihypertensive treatment. Bedtime administration of antihypertensive drugs has also been proposed as a potentially more effective treatment strategy than morning administration. This Position Paper by the International Society of Hypertension reviewed the published evidence on the clinical relevance of the diurnal variation in BP and the timing of antihypertensive drug treatment, aiming to provide consensus recommendations for clinical practice. Eight published outcome hypertension studies involved bedtime dosing of antihypertensive drugs, and all had major methodological and/or other flaws and a high risk of bias in testing the impact of bedtime compared to morning treatment. Three ongoing, well designed, prospective, randomized controlled outcome trials are expected to provide high-quality data on the efficacy and safety of evening or bedtime versus morning drug dosing. Until that information is available, preferred use of bedtime drug dosing of antihypertensive drugs should not be routinely recommended in clinical practice. Complete 24-h control of BP should be targeted using readily available, long-acting antihypertensive medications as monotherapy or combinations administered in a single morning dose.

Differences in estimated glomerular filtration rate are associated with different patterns of 24-h ambulatory blood pressure in the general population

BACKGROUND

Alterations of the circadian blood pressure rhythm are associated with cardiovascular and chronic kidney diseases. We investigated the relationship between 24-h ambulatory blood pressure monitoring (ABPM) patterns and eGFR differences in participants without chronic kidney disease.

METHOD

This cross-sectional study was conducted using data from the ongoing Korean Genome and Epidemiology Study, which involves 1733 participants (age, 60 ± 7 years; 938 women) with an eGFR >60 ml/min per 1.73 m2. The blood pressure dipping status was stratified as reverse-dipper (<0%), nondipper (0 to <10%), and dipper (≥10%). They were also categorized into eGFR quartiles (Q4, 128.6-101.6; Q3, 101.5-95.7; Q2, 95.6-87.4; and Q1, 87.3-60.5), and Q4 was fixed as the reference.

RESULTS

The proportion of dippers progressively decreased and the proportions of reverse and nondippers significantly increased from the highest to the lowest eGFR quartile (P < 0.001). In the univariate analyses, the Q1 and Q2 groups were significantly associated with increasing odds ratios (ORs) for the nondipper, reverse-dipper, and nondipper plus reverse-dipper groups. After adjustment, the lowest eGFR group was significantly associated with the reverse-dipper and nondipper plus reverse-dipper patterns in comparison with the highest eGFR group [OR = 1.685, 95% confidence interval (CI), 1.002-2.834; OR = 1.422, 95% CI, 1.023-1.978, respectively). The significant linear trend for an association of the nondipper plus reverse-dipper pattern with a decrease in eGFR was confirmed with the test for trend (P = 0.023).

CONCLUSION

Differences in eGFR are associated with different 24-h ABPM patterns in non-CKD individuals. ABPM can identify individuals with a nondipper status in this population.

Determinants of reverse dipping blood pressure in normotensive, non-diabetic population with an office measurement below 130/85mmHg

Objective: The role of dipping blood pressure pattern in normotensives is unclear. The study aims to search the circadian blood pressure rhythm and the clinical determinants related to reverse dipping pattern in a strictly selected, normotensive population.Methods: The study population was divided into three groups depending on the nocturnal dipping pattern as dipping, non-dipping, and reverse dipping. Basal clinical characteristics, anthropometric measurements, and spot urine samples from the first-morning void were collected. Clinical determinants related to the presence of reverse dipping pattern were tested by the Multiple Binary Logistic Regression analysis.Results: A total of 233 participants were involved in the study population (median age 45 years [40-50]). Dipping pattern was detected in 55.4%, non-dipping pattern in 33.0%, and reverse dipping pattern in 11.6% of the study population. There was no difference between the groups in terms of basal clinical features. Albumin-to-creatinine ratio (ACR) (p < .001) and hs-CRP levels (p = .006) were also statistically significant across the groups. ACR (HR: 1.195, 95% CI: 1.067-1.338, p = .002) and hs-CRP (HR: 2.438, 95% CI: 1.023-5.808, p = .044) were found to be related to the presence of reverse dipping blood pressure pattern.Conclusions: The absence of nocturnal physiological dipping is seen at a remarkable rate in the normotensive Turkish population. ACR and hs-CRP are the clinical determinants related to the presence of reverse dipping blood pressure pattern.