Ambulatory Blood Pressure in Chronic Kidney Disease

Patient-specific multifactorial mortality risk assessment using classification and regression tree analysis in the context of ambulatory blood pressure monitoring

BACKGROUND

Ambulatory blood pressure monitoring is essential for understanding blood pressure patterns beyond clinical visits, aiding in risk assessment, treatment evaluation, and managing hypertension. This retrospective cohort study aimed to identify risk factors for all-cause mortality and major cardiovascular events in patients who underwent ambulatory blood pressure monitoring.

METHODOLOGY

Eligible participants aged 18 or older, with an estimated glomerular filtration rate (eGFR) > 60 ml/min/1.73 m2, who underwent ambulatory blood pressure monitoring for various reasons, were included in the study. Data were gathered through telephone interviews, electronic health records, and the national health record system. Descriptive analysis and classification and regression tree modeling were used to uncover significant risk factors related to all-cause mortality and cardiovascular events, and to assess the model's performance compared to traditional Cox survival analysis.

RESULTS

The study included 1291 patients, primarily male (51.8%) with a mean age of 61.1 ± 15.2 years. During a mean follow-up of 46.9 months, 76 (5.9%) patients died of any cause, and 195 (15.1%) had a cardiovascular event. The highest survival rates were observed in patients with a diastolic blood pressure (BP) dipping percentage between - 2% and 29%, nighttime systolic BP variability below 32 mmHg, and age below 72. Conversely, smokers with a diastolic BP dipping percentage below - 10% showed the lowest survival rates. The best cardiovascular outcomes were observed in patients with diastolic BP dipping above - 11%, nighttime mean systolic BP < 144 mmHg, no statin use, normotensive status, and daytime mean heart rate ≥ 60 bpm. Conversely, the worst outcomes were seen in patients with diastolic BP dipping below - 11% and a morning surge ≥ 14 mmHg. In all-cause mortality and cardiovascular event analysis, the combined model demonstrated excellent calibration and predictive power, like the classification and regression tree model and traditional analysis.

CONCLUSION

These findings highlight the potential of a combined model for assessing mortality and cardiovascular event risk in patients who have undergone ambulatory blood pressure monitoring.

NaHCO3 loading causes increased arterial pressure and kidney damage in rats with chronic kidney disease

Sodium bicarbonate (NaHCO3) is commonly utilized as a therapeutic to treat metabolic acidosis in people with chronic kidney disease (CKD). While increased dietary sodium chloride (NaCl) is known to promote volume retention and increase blood pressure, the effects of NaHCO3 loading on blood pressure and volume retention in CKD remain unclear. In the present study, we compared the effects of NaCl and NaHCO3 loading on volume retention, blood pressure, and kidney injury in both 2/3 and 5/6 nephrectomy remnant kidney rats, a well-established rodent model of CKD. We tested the hypothesis that NaCl loading promotes greater volume retention and increases in blood pressure than equimolar NaHCO3. Blood pressure was measured 24 h daily using radio telemetry. NaCl and NaHCO3 were administered in drinking water ad libitum or infused via indwelling catheters. Rats were housed in metabolic cages to determine volume retention. Our data indicate that both NaHCO3 and NaCl promote hypertension and volume retention in remnant kidney rats, with salt-sensitivity increasing with greater renal mass reduction. Importantly, while NaHCO3 intake was less pro-hypertensive than equimolar NaCl intake, NaHCO3 was not benign. NaHCO3 loading significantly elevated blood pressure and promoted volume retention in rats with CKD when compared with control rats receiving tap water. Our findings provide important insight into the effects of sodium loading with NaHCO3 in CKD and indicate that NaHCO3 loading in patients with CKD is unlikely to be benign.

Identifying barriers and utility of obtaining ambulatory blood pressure monitoring in a pediatric chronic kidney disease population

BACKGROUND

Hypertension is a prevalent complication of Chronic Kidney Disease (CKD) and Ambulatory Blood Pressure Monitoring (ABPM) is the gold standard for diagnosis. The aim of our study was to assess the usefulness of obtaining ABPM and to identify barriers to ABPM in this pediatric patient population.

METHOD

In this retrospective analysis of patients with CKD stage 3-5 who were seen in one academic medical center's outpatient Pediatric Nephrology clinics between 2018 and 2021, we performed logistic regression to evaluate for associations between demographic factors and odds of having an ABPM.

RESULT

Among 96 patients included in the study, 48 patients carried a diagnosis of hypertension. 31 patients had ABPM performed with usable data. In those who had ABPM done, 21 had normotension and 10 had undertreated hypertension. Our study also showed 1 had masked hypertension and 5 had white coat hypertension or effect. We did not find a statistically significant difference in those who did or did not undergo ABPM evaluation based on gender, previous diagnosis of hypertension, distance from clinic, language preference, or racial or ethnic identity.

CONCLUSION

ABPM is a useful tool in our CKD population for the diagnosis and management of hypertension. We did not identify specific barriers to ABPM in our CKD population, and there were no differences in patients who obtained ABPM when looking at specific demographic and disease characteristics. Given these findings, we recommend focusing on areas of future improvement in spheres of patient and provider education as well as better quantification using surveys to further illuminate barriers.

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.

How Do I Manage Hypertension in Patients with Advanced Chronic Kidney Disease Not on Dialysis? Perspectives from Clinical Practice

In the general population, the prevalence of moderate and severe chronic kidney disease (CKD) is usually below 5% but this figure is often higher in specific groups of patients such as those with type 2 diabetes. Patients with advanced CKD (CKD stage 3b and 4) are at high or very high cardiovascular risk, and their risk of progressing towards end-stage kidney disease (CKD stage 5) and the need of renal replacement therapy are elevated. Hypertension is a major cause of poor cardiovascular and renal outcomes in severe CKD. Therefore, an adequate control of blood pressure (BP) is mandatory. However, normalizing BP is often challenging in these patients because the clinical management of hypertension in advanced CKD is not well defined and rarely supported by large randomized controlled trials. In the present review, we discuss the characteristics of hypertension in advanced CKD, excluding dialysis, and its management integrating data from recent clinical studies and a pragmatic approach enriched by a long-standing clinical experience.

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.

Effects of Erythropoietin-Stimulating Agents on Blood Pressure in Patients with Non-Dialysis CKD and Renal Anemia

INTRODUCTION

Erythropoietin-stimulating agents (ESAs) are used to treat renal anemia in patients with non-dialysis CKD, but this can lead to increases in blood pressure (BP).

OBJECTIVE

We investigated the effects of continuous erythropoietin receptor activator (CERA) and darbepoetin alfa (DA) on office/ambulatory BP in 36 patients with non-dialysis CKD and renal anemia who did not receive ESA treatment.

METHODS

Participants were randomly assigned to CERA or DA, and received ESA treatment for 24 weeks. ESA doses were adjusted to maintain hemoglobin (Hb) at 10-12 g/dL. Primary outcomes were office/ambulatory BP after 24 weeks of ESA treatment. Hb levels were within the target range at 24 weeks.

RESULTS

Office/ambulatory BP, renal function, and other parameters were not significantly different between groups. However, we could not exclude the possibility that differences may exist because our sample size was small. Therefore, we also performed analysis of all of the data that were compiled from the groups of per-protocol population. Although office/ambulatory BP profiles had not worsened after 24 weeks of ESA treatment, more than half of the patients required an increase in the antihypertensive agent dose.

CONCLUSIONS

CERA and DA may have similar effects on BP profiles in patients with non-dialysis CKD and renal anemia. ESA treatment often requires increases in the doses of antihypertensive agents.

Increased fibroblast growth factor-21 in chronic kidney disease is a trade-off between survival benefit and blood pressure dysregulation

Circulating levels of fibroblast growth factor-21 (FGF21) start increasing in patients with chronic kidney disease (CKD) since early stages during the cause of disease progression. FGF21 is a liver-derived hormone that induces responses to stress through acting on hypothalamus to activate the sympathetic nervous system and the hypothalamus-pituitary-adrenal endocrine axis. However, roles that FGF21 plays in pathophysiology of CKD remains elusive. Here we show in mice that FGF21 is required to survive CKD but responsible for blood pressure dysregulation. When introduced with CKD, Fgf21^−/− mice died earlier than wild-type mice. Paradoxically, these Fgf21^−/− CKD mice escaped several complications observed in wild-type mice, including augmentation of blood pressure elevating response and activation of the sympathetic nervous system during physical activity and increase in serum noradrenalin and corticosterone levels. Supplementation of FGF21 by administration of an FGF21-expressing adeno-associated virus vector recapitulated these complications in wild-type mice and restored the survival period in Fgf21^−/− CKD mice. In CKD patients, high serum FGF21 levels are independently associated with decreased baroreceptor sensitivity. Thus, increased FGF21 in CKD can be viewed as a survival response at the sacrifice of blood pressure homeostasis.

The Klotho proteins in health and disease

The Klotho proteins, αKlotho and βKlotho, are essential components of endocrine fibroblast growth factor (FGF) receptor complexes, as they are required for the high-affinity binding of FGF19, FGF21 and FGF23 to their cognate FGF receptors (FGFRs). Collectively, these proteins form a unique endocrine system that governs multiple metabolic processes in mammals. FGF19 is a satiety hormone that is secreted from the intestine on ingestion of food and binds the βKlotho-FGFR4 complex in hepatocytes to promote metabolic responses to feeding. By contrast, under fasting conditions, the liver secretes the starvation hormone FGF21, which induces metabolic responses to fasting and stress responses through the activation of the hypothalamus-pituitary-adrenal axis and the sympathetic nervous system following binding to the βKlotho-FGFR1c complex in adipocytes and the suprachiasmatic nucleus, respectively. Finally, FGF23 is secreted by osteocytes in response to phosphate intake and binds to αKlotho-FGFR complexes, which are expressed most abundantly in renal tubules, to regulate mineral metabolism. Growing evidence suggests that the FGF-Klotho endocrine system also has a crucial role in the pathophysiology of ageing-related disorders, including diabetes, cancer, arteriosclerosis and chronic kidney disease. Therefore, targeting the FGF-Klotho endocrine axes might have therapeutic benefit in multiple systems; investigation of the crystal structures of FGF-Klotho-FGFR complexes is paving the way for the development of drugs that can regulate these axes.

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.

Ambulatory Blood Pressure and Endothelial Dysfunction in Hematopoietic Cell Transplantation Recipients

Hematopoietic cell transplantation (HCT) is a common treatment for many disorders. Albuminuria post-HCT, which may represent endothelial injury or inflammation from graft- versus-host disease, increases the risk of chronic kidney disease and nonrelapse mortality at 1 year. HCT recipients also have abnormal blood pressure (BP) and increased rates of cardiovascular complications. We sought to determine the relationships among albuminuria, endothelial dysfunction, and BP in HCT recipients. Patients age  ≥12 years who underwent their first allogeneic HCT between 2012 and 2015 and survived through day 80 post-HCT were eligible. Peripheral endothelial function was assessed using the EndoPAT2000 device at day 80 along with 24-hour ambulatory BP monitoring (ABPM). Clinical and laboratory data were collected along with a urine sample for calculation of the albumin-to-creatinine ratio. Both logistic and linear regression analyses were used to identify associations between EndoPAT score and clinical variables. Sixty patients (median age, 48 years; range, 14 to 69 years) completed the study. The median EndoPAT score was 2.05 (range, 1.02 to 4.45), and 17 patients (28%) had abnormal endothelial function. Forty-two patients (72%) had ambulatory hypertension (HTN), and 38 (63%) had blunted nocturnal dipping. HTN on ABPM (P = .045) and blunted nocturnal dipping (P = .04) were associated with a lower EndoPAT score. Albuminuria was not associated with EndoPAT score. There was a lack of agreement between our clinical definition of HTN (office BP and/or use of medications) and ABPM results (P = .04). We did not find an association between lower EndoPAT scores and albuminuria, but did find an association between an abnormal nocturnal dip and HTN diagnosed by ABPM. This suggests that albuminuria may reflect local endothelial injury and inflammation rather than a systemic process. Office BP readings do not accurately reflect true BP, suggesting that 24-hour ABPM studies are needed to diagnose and treat HTN appropriately.

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.

Discrepancies in Clinic and Ambulatory Blood Pressure in Korean Chronic Kidney Disease Patients

Blood pressure (BP) control is considered the most important treatment for preventing chronic kidney disease (CKD) progression and associated cardiovascular complications. However, clinic BP is insufficient to diagnose hypertension (HT) and to monitor overall BP control because it does not correlate well with ambulatory blood pressure monitoring (ABPM). We enrolled 387 hypertensive CKD patients (stages G1-G4, 58.4% male with median age 61 years) from 3 hospitals in Korea. HT of clinic BP and ABPM was classified as ≥ 140/90 and ≥ 130/80 mmHg, respectively. Clinic BP control rate was 60.2%. The median 24-hour systolic blood pressures (SBPs) of CKD G3b and CKD G4 were significantly higher than those of CKD G1-2 and CKD G3a. However, the median 24-hour SBPs were not different between CKD G1-2 and CKD G3a or between CKD G3b and CKD G4. Of all patients, 5.7%, 38.0%. 42.3%, and 14.0% were extreme-dippers, dippers, non-dippers, and reverse-dippers, respectively. Non-/reverse-dippers independently correlated with higher Ca × P product, higher intact parathyroid hormone (iPTH), and lower albumin. Normal BP was 33.3%, and sustained, masked, and white-coat HT were 29.7%, 26.9%, and 10.1%, respectively. White-coat HT independently correlated with age ≥ 61 years and masked HT independently correlated with CKD G3b/G4. In conclusion, ABPM revealed a high prevalence of non-/reverse-dippers and sustained/masked HT in Korean CKD patients. Clinicians should try to obtain a CKD patient's ABPM, especially among those who are older or who have advanced CKD as well as those with abnormal Ca × P product, iPTH, and albumin.

Blood pressure response to acute and chronic exercise in chronic kidney disease

AIM

The current study was designed to determine if a relationship exists between acute and chronic blood pressure responses to aerobic exercise in pre-dialysis patients.

METHODS

Pre-dialysis kidney patients attended four sessions before being randomized to the treatment (n = 25) or control group (n = 21). In session 1, resting blood pressure was recorded, and these measurements were repeated during the second visit when peak oxygen uptake (VO_2peak ) was assessed. In the third and fourth sessions, blood pressures were taken prior to a 40 min walk or period of seated rest. After the 40 min walk or seated rest, blood pressures were monitored for 60 min in the laboratory and for the subsequent 24 h. After session 4, subjects in the treatment group trained aerobically at a moderate intensity, three times per week for 16 weeks. Control subjects were asked to be sedentary. All measurements were repeated after 16 weeks of training or sedentary living.

RESULTS

Training increased VO_2peak (mL/kg per minute) in the treatment group (baseline 19.6 ± 6.7 vs 21.2 ± 7.7, P < 0.05), with no change in the control (18.0 ± 6.0 vs 17.5 ± 5.7) group. Post-exercise hypotension occurred at baseline prior to training but was unaffected by 16 weeks of training.

CONCLUSION

Post-exercise hypotension occurs in pre-dialysis patients following aerobic exercise, but short-term moderate-intensity continuous aerobic training has no effect upon this response. There seems to be no relationship between the acute and chronic blood pressure responses to exercise in pre-dialysis kidney patients.

Home blood pressure monitor use in patients with chronic kidney disease

Home blood pressure monitoring (HBPM) is recommended in patients with chronic kidney disease (CKD) and hypertension (HTN). However, little is known about the use and pattern of HBPM in CKD patients. A cross-sectional study was conducted in an out-patient nephrology clinic. A total of 285 patients participated in the study. Of all patients, 66% reported using HBPM. Self-reported compliance with BP medications (93.9% vs. 85.1%, p 0.03), exercise >3 days/week (45.9 vs. 26.3%, p <0.001) and dietary sodium restriction (85.6% vs. 71.6%, p < 0.001) were more common in HBPM users vs. non-HBPM users. Most patients with HBPM used upper arm cuff (82.3%), reported receiving education on correct use of HBPM (82.5%), had perception that home BP was controlled (75.4%) and believed that HBPM is helpful in managing hypertension (85.4%). Most common reason for not using HBPM was lack of advice by a physician (43.4%). HBPM use is common in patients with CKD and HTN. HBPM users are more likely to follow life-style and dietary modifications for blood pressure control.

Nighttime Blood Pressure Patterns and Subclinical Atherosclerosis in Women with Systemic Lupus Erythematosus

Objective.

To compare 24-h ambulatory blood pressure (BP) monitoring (ABPM) values and patterns in women with systemic lupus erythematosus (SLE) with those of a matched control group and their relationship with the presence of subclinical atherosclerosis.

Methods.

ABPM was assessed in 70 women with SLE and in 65 sex- and age-matched controls without a history of clinic cardiovascular disease (CVD). Carotid-femoral pulse wave velocity (PWV), which is a marker of subclinical atherosclerosis and a predictor of future CVD, was measured. Multivariate logistic analysis was used to determine which explanatory variables were independently associated with the non-dipper pattern and the presence of nocturnal hypertension (HTN) in women with SLE.

Results.

No differences in PWV were found between patients and controls [median 7.3, interquartile range (IQR) 6.5–8.1 m/s vs median 7.1, IQR 6.5–7.8 m/s, p = 0.474]. The frequency of nondipper pattern (p = 0.025) and nocturnal HTN (p = 0.004) was significantly higher in women with SLE than in controls. White-coat and masked HTN were present in 10% and 11% of patients and in 20% and 8% of controls, respectively (p > 0.05 in all cases). The concordance between office and ambulatory HTN in the SLE and control groups was modest (κ = 0.325 and κ = 0.451, respectively). PWV and chronic kidney disease, and PWV and the Systemic Lupus Erythematosus Disease Activity Index were found to be independently associated with nocturnal HTN and nondipper pattern, respectively.

Conclusion.

Women with SLE were more likely to have an altered nighttime BP pattern than controls. In women with SLE, nondipper pattern and nocturnal HTN were independently associated with increased subclinical atherosclerosis measured by PWV.

Clinical value of ambulatory blood pressure: Is it time to recommend for all patients with hypertension?

Hypertension is a very common disease, and office measurements of blood pressure are frequently inaccurate. Ambulatory Blood Pressure Monitoring (ABPM) offers a more accurate diagnosis, more detailed readings of average blood pressures, better blood pressure measurement during sleep, fewer false positives by detecting more white-coat hypertension, and fewer false negatives by detecting more masked hypertension. ABPM offers better management of clinical outcomes. For example, based on more accurate measurements of blood pressure variability, ABPM demonstrates that taking antihypertensive medication at night leads to better controlled nocturnal blood pressure, which translates into less end organ damage and fewer clinical complications of hypertension. For these reasons, albeit some shortcomings which were discussed, ABPM should be considered as a first-line tool for diagnosing and managing hypertension.

Functional capacity and heart rate response: associations with nocturnal hypertension

Background

Absences of normative, 10–20 % declines in blood pressure (BP) at night, termed nocturnal non-dipping, are linked to increased cardiovascular mortality risks. Current literature has linked these absences to psychological states, hormonal imbalance, and disorders involving hyper-arousal. This study focuses on evaluating associations between nocturnal non-dipping and indices of functional cardiac capacity and fitness.

Methods

The current study was a cross-sectional evaluation of the associations between physical capacity variables e.g. Metabolic Equivalent (MET) and Maximum Heart Rate (MHR), Heart rate reserve (HRR), and degree of reduction in nocturnal systolic blood pressure (SBP) or diastolic blood pressure (DBP), also known as ‘dipping’. The study sample included 96 cardiac patient participants assessed for physical capacity and ambulatory blood pressure monitoring. In addition to evaluating differences between groups on nocturnal BP ‘dipping’, physical capacity, diagnoses, and medications, linear regression analyses were used to evaluate potential associations between nocturnal SBP and DBP ‘dipping’, and physical capacity indices.

Results

45 males and 14 females or 61.5 % of 96 consented participants met criteria as non-dippers (<10 % drop in nocturnal BP). Although non-dippers were older (p = .01) and had a lower maximum heart rate during the Bruce stress test (p = .05), dipping was only significantly associated with Type 2 Diabetes co-morbidity and was not associated with type of medication. Within separate linear regression models controlling for participant sex, MHR (β = 0.26, p = .01, R² = .06), HRR (β = 0. 19, p = .05, R² = .05), and METs (β = 0.21, p = .04, R² = .04) emerged as significant but small predictors of degree of nighttime SBP dipping. Similar relationships were not observed for DBP.

Conclusions

Since the variables reflecting basic heart function and fitness (MHR and METs), did not account for appreciable variances in nighttime BP, nocturnal hypertension appears to be a complex, multi-faceted phenomena.

The impact of kidney transplantation on 24-hour ambulatory blood pressure in end-stage renal disease patients

In this study, we prospectively investigated the impact of kidney transplantation (KT) on the status of hypertension, including circadian rhythm in end-stage renal disease (ESRD) patients. We performed 24-hour ambulatory blood pressure (BP) monitoring and office BP measurement in 48 patients before and 1 year after KT. According to the nocturnal reduction in systolic BP (ΔSBP), the patients were divided into dippers, non-dippers, and reverse dippers. After KT, the mean BP value in office BP and 24-hour ambulatory BP monitoring did not change, but the proportion of patients taking anti-hypertensive drugs and the pill number significantly decreased. In contrast, the mean ΔSBP significantly decreased, and the proportion of non-dippers and reverse dippers did not decrease. Decrease in ΔSBP after KT was associated with inferior allograft function during follow-up. Our study suggests that KT improved the overall BP level, but it did not affect abnormal circadian rhythm in ESRD patients.

Ambulatory blood pressure monitoring is recommended in the clinical management of children with a solitary functioning kidney

BACKGROUND

Children with a solitary functioning kidney are at increased risk of developing chronic kidney disease. Hypertension may be an early indicator of renal dysfunction in these patients. We determined blood pressure (BP) profiles of children with a solitary functioning kidney by using ambulatory BP monitoring (ABPM).

METHODS

To assess the occurrence with (pre)hypertension, we compared ABPM to office BP measurement in 47 children with a solitary functioning kidney. None of the subjects used antihypertensive agents or had been hypertensive during previous clinical visits.

RESULTS

Mean age of study subjects was 12.7 (±3.3) years. Hypertension was identified in ten (21 %) subjects with ABPM, whereas only two (4 %) children were hypertensive during office BP measurement (p < 0.01). Fifteen (32 %) children had an ABPM standard deviation (SD) value ≥90th percentile versus six (13 %) subjects based on office BP measurement (p = 0.051). Although 24-h ABPM SD scores were higher in the congenital type than in the acquired type of solitary functioning kidney (p ≤ 0.01), the proportions of subjects with 24-h ABPM hypertension were similar between groups (congenital 25 % versus acquired 16 %; p = NS).

CONCLUSIONS

Based on ABPM, one in five children with a solitary functioning kidney has hypertension. As the majority of these subjects were not hypertensive during office BP measurements, ABPM should be considered in the clinical management of solitary functioning kidney patients.

Practical use of home blood pressure monitoring in chronic kidney disease

Despite the availability of blood pressure (BP)-lowering medications and dietary education, hypertension is still poorly controlled in the chronic kidney disease (CKD) population. As glomerular filtration rate declines, the number of medications required to achieve BP targets increases, which may lead to reduced patient adherence and therapeutic inertia by the clinician. Home BP monitoring (HBPM) has emerged as a means of improving diagnostic accuracy, risk stratification, patient adherence, and therapeutic intervention. The definition of hypertension by HBPM is an average BP >135/85 mm Hg. Twelve readings over the course of 3-5 days are sufficient for clinical decision making. Diagnostic accuracy is especially important in the CKD population as approximately half of these patients have either white coat hypertension or masked hypertension. Preliminary data suggest that HBPM outperforms office BP monitoring in predicting progression to end-stage renal disease or death. When combined with additional support such as telemonitoring, medication titration, or behavioral therapy, HBPM results in a sustained improvement in BP control. HBPM must be adapted to provide information on the phenomena of nondipping (absence of nocturnal fall in BP) and reverse dipping (paradoxical increase in BP at night). These diurnal patterns are more prevalent in the CKD population and are important cardiovascular risk factors. Ambulatory BP monitoring provides nocturnal BP readings and unlike HBPM may be reimbursed by Medicare when certain criteria are met. Further studies are needed to determine whether HBPM is cost-effective in the current US healthcare system.