Glomerular filtration rate is related to dipping pattern in ambulatory blood pressure monitoring--a cross-sectional population-based study

Clinical and life style factors related to the nighttime blood pressure, nighttime dipping and their phenotypes in Korean hypertensive patients

BACKGROUND

Non-dipping or reverse dipping patterns are known to be associated with adverse cardiovascular prognosis among the general population and clinical cohort. Few large sized studies have explored factors including sleep duration and sleep quality related to nighttime blood pressure (BP) and nocturnal dipping patterns.

METHODS

Among 5,360 patients enrolled  in Korean multicenter nationwide prospective Registry of ambulatory BP monitoring (KORABP), 981 subjects with complete data on sleep duration, sleep quality assessed using a 4-point Likert scale, and clinical variables were included in the analysis. Phenotypes of nighttime BP pattern were categorized as extreme dipper, dipper, non-dipper, and reverse dipper. Hypertension was defined as a 24-h ambulatory BPs were 130/80 mmHg or higher.

RESULTS

Among 981 subjects, 221 were normotensive, 359 were untreated hypertensive, and 401 were treated hypertensive. Age of the participants were 53.87 ± 14.02 years and 47.1% were female. In overall patients, sleep duration was 431.99 ± 107.61 min, and one to four points of sleep quality were observed in 15.5%, 30.0%, 30.4%, and 24.2%, respectively. Of the 760 hypertensive patients, extreme dipper, dipper, non-dipper, and reverse dipper were observed in 58 (7.63%), 277 (36.45%), 325 (42.76%), and 100 (13.16%), respectively. In multiple linear regression analysis, sleep duration (β = 0.0105, p < 0.001) and sleep quality (β = -0.8093, p < 0.001) were associated with nighttime systolic BP and sleep quality was associated with extent of nighttime systolic BP dipping (β = 0.7622, p < 0.001) in hypertensive patients. In addition, sleep quality showed positive association with dipper pattern (odds ratio [OR] = 1.16, 95% confidence interval [CI] = 1.03-1.30) and showed negative association with reverse dipper pattern (OR = 0.73, 95% CI = 0.62-0.86) in multiple logistic regression analyses.

CONCLUSION

When adjusted covariates, less sleep duration and poor sleep quality were positively associated with nighttime systolic BP. Additionally, sleep quality was the independent associated factor for dipper and reverse dipper phenotypes. The study also found that male sex, low estimated glomerular filtration rate, high ambulatory BP, low office BP, and poor sleep quality were associated with blunted nighttime SBP dipping.

New Aspects in the Management of Hypertension in Patients with Chronic Kidney Disease not on Renal Replacement Therapy

With chronic kidney disease (CKD) being a global arising health problem, strategies for delaying kidney disease progression and reducing the high cardiovascular risk inherent to CKD, are the main objectives of the actual management of patients with kidney diseases. In these patients, the control of arterial hypertension is essential, as high blood pressure (BP) is a strong determinant of worst cardiovascular and renal outcomes. Achieving target blood pressures recommended by international guidelines is mandatory and often demands a multiple levels management, including several pharmacological and lifestyle measures. Even in the presence of adequate BP control, the residual cardiovascular risk remains high. In this respect, the recent demonstration that novel agents such as sodium glucose transporter 2 (SGLT2) inhibitors or the new non-steroidal mineralocorticoid antagonist finerenone can retard the progression of kidney diseases and reduce cardiovascular mortality on top of standard of care treatment with renin-angiotensin system inhibitors represent enormous progresses. These studies also demonstrate that cardiovascular and renal protection can be obtained beyond blood pressure control. Other promising novelties are still to come such as renal denervation and endothelin receptor antagonists in the setting of diabetic and non-diabetic kidney diseases. In the present review, we shall discuss the classic and the new aspects for the management of hypertension in CKD, integrating the new data from recent clinical studies.

Digital sleep measures and white matter health in the Framingham Heart Study

AIM

Impaired sleep quality and sleep oxygenation are common sleep pathologies. This study assessed the impact of these abnormalities on white matter (WM) integrity in an epidemiological cohort.

METHODS

The target population was the Framingham Heart Study Generation-2/Omni-1 Cohorts. Magnetic resonance imaging (diffusion tensor imaging) was used to assess WM integrity. Wearable digital devices were used to assess sleep quality: the (M1-SleepImage™ system) and the Nonin WristOx for nocturnal oxygenation. The M1 device collects trunk actigraphy and the electrocardiogram (ECG); sleep stability indices were computed using cardiopulmonary coupling using the ECG. Two nights of recording were averaged.

RESULTS

Stable sleep was positively associated with WM health. Actigraphic periods of wake during the sleep period were associated with increased mean diffusivity. One marker of sleep fragmentation which covaries with respiratory chemoreflex activation was associated with reduced fractional anisotropy and increased mean diffusivity. Both oxygen desaturation index and oxygen saturation time under 90% were associated with pathological directions of diffusion tensor imaging signals. Gender differences were noted across most variables, with female sex showing the larger and significant impact.

CONCLUSIONS

Sleep quality assessed by a novel digital analysis and sleep hypoxia was associated with WM injury, especially in women.

Oxidized LDL Modifies the Association between Proteinuria and Deterioration of Kidney Function in Proteinuric Diabetic Kidney Disease

Proteinuria is characterized by low accuracy for predicting onset and development of diabetic kidney disease (DKD) because it is not directly associated with molecular changes that promote DKD, but is a result of kidney damage. Oxidized low-density lipoprotein (ox-LDL) reflects oxidative stress and endothelial dysfunction, both underlying the development of proteinuria and loss of kidney function in DKD. We aimed to investigate whether ox-LDL modifies the association between proteinuria and progression of DKD in a cohort of 91 patients with proteinuric DKD and diabetic retinopathy, followed for 10 years. The primary endpoint was a combined kidney outcome of eGFR decline ≥30% or progression to end-stage kidney disease. After the end of the study, we considered the percentage change of eGFR over time as our secondary outcome. Proteinuria was associated with both outcomes, and ox-LDL amplified the magnitude of this link (p < 0.0001 for primary and p < 0.0001 for secondary outcome, respectively). After adjustment for duration of diabetes, history of cardiovascular disease and serum albumin, ox-LDL remained a significant effect modifier of the association between proteinuria and eGFR decline over time (p = 0.04). Our study shows that in proteinuric DKD, circulating ox-LDL levels amplified the magnitude of the association between proteinuria and progression of DKD.

Non-dipping blood pressure pattern and new-onset diabetes in a 21-year follow-up

Purpose: Non-dipping blood pressure (BP) pattern has been associated with metabolic changes and cardiovascular events. With regard of diabetes, studies are scarce. Our aim was to investigate if there is an association between changes in dipping patterns and incidence of diabetes. Materials and methods: A 24-h ambulatory BP measurement was recorded in addition to other laboratory measurements, and a questionnaire and physical examination were carried out in the baseline study and after 21-year follow-up among a study population (n = 449) consisting of randomly selected middle-aged Finnish females and males without diabetes. Results: 128 (28.5%) developed diabetes during the follow-up. The incidence of new-onset diabetes was the highest, 41.0%, among those subjects who were non-dippers (their systolic BP declined <10% from daytime to nighttime) in the baseline and also in the follow-up study, while the incidence of diabetes was 19.6% in the dipper - dipper (a nighttime decline of systolic BP 10% or more) group (p = 0.003). The difference remained statistically significant after adjustment with age, sex, body mass index, fasting glucose, triglycerides, and insulin levels, smoking status, 24-h mean systolic BP, high-sensitivity C-reactive protein, estimated glomerular filtration and diuretics use. In logistic regression analysis, the non-dipper - non-dippers were at higher risk of diabetes compared with dipper - dipper group (OR = 2.27, 95% CI: 1.13-4.56, p = 0.022). Conclusions: Our prospective study shows that there is an independent association between non-dipping BP pattern and the incidence of diabetes in a 21-year follow-up.

Intravascular Renal Denervation in Renal Dialysis Patients with Uncontrolled Hypertension: A Case Series of Four Patients

Case series

Patient: Male, 24 • Female, 55 • Female, 56 • Male, 72

Final Diagnosis: Hypertension

Symptoms: Dyspnea

Medication: —

Clinical Procedure: Intravascular renal denervation

Specialty: Cardiology

Hyperfiltration, urinary albumin excretion, and ambulatory blood pressure in adolescents with Type 1 diabetes mellitus

Adolescents with Type 1 diabetes mellitus (T1DM) are at risk for hyperfiltration and elevated urinary albumin-to-creatinine ratio (ACR), which are early indicators of diabetic nephropathy. Adolescents with T1DM also develop early changes in blood pressure, cardiovascular structure, and function. Our aims were to define the relationships between hyperfiltration, ACR, and 24-h ambulatory blood pressure over time in adolescents with T1DM. Normotensive, normoalbuminuric adolescents ( n = 98) with T1DM underwent baseline and 2-yr 24-h ambulatory blood pressure monitoring, glomerular filtration rate (eGFR) estimated by cystatin C (Larsson equation), and ACR measurements. Linear regression models adjusted for diabetes duration, sex, and HbA1c were used to determine associations. Hyperfiltration (eGFR ≥ 133 ml/min) was present in 31% at baseline and 21% at 2-yr follow-up. Hyperfiltration was associated with greater odds of rapid GFR decline (>3 ml·min-1·yr-1) [OR: 5.33, 95%; CI: 1.87-15.17; P = 0.002] over 2 yr. Natural log of ACR at baseline was associated with greater odds of hyperfiltration (OR: 1.71, 95% CI: 1.00-2.92; P = 0.049) and 2-yr follow-up (OR: 2.14, 95%; CI: 1.09-4.19; P = 0.03). One SD increase in eGFR, but not ln ACR, at 2-yr follow-up conferred greater odds of nighttime nondipping pattern (OR: 1.96, 95% CI: 1.06-3.63; P = 0.03). Hyperfiltration was prevalent at baseline and at 2-yr follow-up, predicted rapid decline in GFR, and was related to ACR. Elevated GFR at 2-yr follow-up was associated with nighttime nondipping pattern. More work is needed to better understand early relationships between renal hemodynamic and systemic hemodynamic changes in adolescents with T1DM to reduce future cardiorenal complications.

Sleep Disturbances as a Risk Factor for Stroke

Sleep, a vital process of human being, is carefully orchestrated by the brain and consists of cyclic transitions between rapid eye movement (REM) and non-REM (NREM) sleep. Autonomic tranquility during NREM sleep is characterized by vagal dominance and stable breathing, providing an opportunity for the cardiovascular-neural axis to restore homeostasis, in response to use, distress or fatigue inflicted during wakefulness. Abrupt irregular swings in sympathovagal balance during REM sleep act as phasic loads on the resting cardiovascular system. Any causes of sleep curtailment or fragmentation such as sleep restriction, sleep apnea, insomnia, periodic limb movements during sleep, and shift work, not only impair cardiovascular restoration but also impose a stress on the cardiovascular system. Sleep disturbances have been reported to play a role in the development of stroke and other cardiovascular disorders. This review aims to provide updated information on the role of abnormal sleep in the development of stroke, to discuss the implications of recent research findings, and to help both stroke clinicians and researchers understand the importance of identification and management of sleep pathology for stroke prevention and care.

Renal sympathetic denervation in treating drug-resistant hypertension in a patient on hemodialysis

A 26-year-old man had an end-stage renal disease because of a neurogenic urinary bladder with a vesicourinary reflux. The first kidney transplant was lost in consequence of chronic allograft nephropathy. Immunosuppressive medication was withdrawn and transplantectomy was performed in November 2010. After transplantectomy, his blood pressure (BP) slowly increased up to 200/100 mmHg. Antihypertensive medication was intensified and a fluid overload was excluded with body composition bioimpedance measurements. Forty-eight-hour ambulatory BP was 180/109 mmHg in the daytime and 178/108 mmHg in the night-time. Bilateral renal denervation (RDN) was performed with a single electrode Symplicity catheter on May 2013. The effect of RDN became evident at the 6 months visit, and all the antihypertensive medicines were withdrawn at 12 months. Fifteen months after RDN, 48-h ambulatory BP was 120/63 mmHg in the daytime and 108/60 mmHg in the night-time. The patient was without antihypertensive medication until retransplantation in May 2015.

Ambulatory arterial stiffness index correlates with ambulatory pulse pressure but not dipping status in patients with grade 1/grade 2 essential hypertension

OBJECTIVE

To evaluate the relationship between ambulatory arterial stiffness index (AASI) and other parameters derived from ambulatory blood pressure (BP) monitoring, including dipping status, in patients with grade 1/grade 2 hypertension.

METHODS

This retrospective analysis included baseline data from Chinese outpatients enrolled into a previous study, who had clinic diastolic BP of 90-109 mmHg and systolic BP <180 mmHg, had undergone 24-h ambulatory BP monitoring and routine blood chemistry investigations, and had estimated glomerular filtration rate (eGFR) data.

RESULTS

Out of 120 patients screened, 87 were included. No significant difference in 24-h AASI was found between dippers and nondippers. The 24-h AASI significantly correlated with age, systolic BP and pulse pressure, and inversely correlated with 24-h diastolic BP variation and eGFR. In dippers and nondippers, AASI correlated with daytime pulse pressure, daytime diastolic BP variation and eGFR; in nondippers, AASI also correlated with 24-h systolic BP and 24-h pulse pressure. The 24-h AASI was significantly associated with 24-h pulse pressure and daytime pulse pressure.

CONCLUSION

In patients with grade 1/grade 2 essential hypertension, AASI shows a significant correlation with ambulatory pulse pressure.

Chronic kidney disease in adolescent and adult patients with phenylketonuria

OBJECTIVES

A lifelong phenylalanine-restricted diet with supplementation of a phenylalanine-free amino acid formula is recommended in patients with phenylketonuria (PKU). The effect of a long-term PKU diet on renal function and blood pressure has not been investigated yet.

DESIGN

We analyzed renal function in 67 patients with PKU, aged 15-43 years, by measuring glomerular filtration rate (GFR) and effective renal plasma flow by isotope clearance ((51)Cr-EDTA, (123)J-Hippuran), estimated GFR, blood retention parameters, urinary protein and electrolyte excretion. Renal ultrasound and 24 h ambulatory blood pressure monitoring were performed additionally. Patients were divided into three groups according to their: 1) current diet (CD), i.e., daily protein intake: ICD <0.8 g/kg, IICD 0.8-1.04 g/kg, IIICD >1.04 g/kg; 2) life-long diet time (LDT), i.e., cumulative years of life in which daily protein intake exceeded dietary recommendations: ILDT <15 years, IILDT 15-19 years, IIILDT >19 years.

RESULTS

GFR was decreased in 19 % of the patients. With increasing protein intake, GFR decreased significantly (ICD 111 ml/min; IICD 105 ml/min; IIICD 99 ml/min. ILDT 112 ml/min; IILDT 103 ml/min; IIILDT 99 ml/min). Proteinuria was detected in 31 %, microalbuminuria in 7 %, and hypercalciuria in 23 % of the patients. 23 % of the patients had arterial hypertension, and 41 % revealed a nocturnal non-dipping status.

CONCLUSIONS

In patients with PKU on a lifelong diet we could detect impaired renal function in 19 %, proteinuria in 31 %, and arterial hypertension in 23 %. Thus, chronic kidney disease may develop in PKU patients, and routine renal function tests should be performed during long-term follow-up.

Blood pressure measurement: clinic, home, ambulatory, and beyond

Blood pressure traditionally has been measured in the clinic setting using the auscultatory method and a mercury sphygmomanometer. Technologic advances have led to improvements in measuring clinic blood pressure and allowed for measuring blood pressures outside the clinic. This review outlines various methods for evaluating blood pressure and the clinical utility of each type of measurement. Home blood pressures and 24-hour ambulatory blood pressures have improved our ability to evaluate the risk of target-organ damage and hypertension-related morbidity and mortality. Measuring home blood pressures may lead to more active participation in health care by patients and has the potential to improve blood pressure control. Ambulatory blood pressure monitoring enables measuring nighttime blood pressures and diurnal changes, which may be the most accurate predictors of risk associated with elevated blood pressure. Additionally, reducing nighttime blood pressure is feasible and may be an important component of effective antihypertensive therapy. Finally, estimating central aortic pressures and pulse wave velocity are 2 of the newer methods for assessing blood pressure and hypertension-related target-organ damage.