Isolated nocturnal hypertension is associated with increased left ventricular mass index in children

Prospective Study of Modifiable Risk Factors of Arterial Hypertension and Left Ventricular Hypertrophy in Pediatric Patients on Hemodialysis

Introduction

Fluid and salt overload in patients on dialysis result in high blood pressure (BP), left ventricular hypertrophy (LVH) and hemodynamic instability, resulting in cardiovascular morbidity.

Methods

Analysis of 910 pediatric patients on maintenance hemodialysis/hemodiafiltration (HD/HDF), prospectively followed-up with 2758 observations recorded every 6-months in the International Pediatric Hemodialysis Network (IPHN).

Results

Uncontrolled hypertension was present in 55% of observations, with 27% of patients exhibiting persistently elevated predialysis BP. Systolic and diastolic age- and height-standardized BP (BP-SDS) were independently associated with the number of antihypertensive medications (odds ratio [OR] = 1.47, 95% confidence interval 1.39-1.56, 1.36 [1.23-1.36]) and interdialytic weight gain (IDWG; 1.19 [1.14-1.22], 1.09 [1.06-1.11]; all P < 0.0001). IDWG was related to urine output (OR = 0.27 [0.23-0.32]) and dialysate sodium (dNa; 1.06 [1.01-1.10]; all P < 0.0001). The prevalence of masked hypertension was 24%, and HD versus HDF use was an independent risk factor of elevated age- and height-standardized mean arterial pressure (MAP-SDS) (OR = 2.28 [1.18-4.41], P = 0.01). Of the 1135 echocardiograms, 51% demonstrated LVH. Modifiable risk factors included predialysis systolic BP-SDS (OR = 1.06 [1.04-1.09], P < 0.0001), blood hemoglobin (0.97 [0.95-0.99], P = 0.004), HD versus HDF modality (1.09 [1.02-1.18], P = 0.01), and IDWG (1.02 [1.02-1.03], P = 0.04). In addition, HD modality increased the risk of LVH progression (OR = 1.23 [1.03-1.48], P = 0.02). Intradialytic hypotension (IDH) was prevalent in patients progressing to LVH and independently associated with predialysis BP-SDS below 25th percentile, lower number of antihypertensives, HD versus HDF modality, ultrafiltration (UF) rate, and urine output, but not with dNa.

Conclusion

Uncontrolled hypertension and LVH are common in pediatric HD, despite intense pharmacologic therapy. The outcome may improve with use of HDF, and superior anemia and IDWG control; the latter via lowering dNa, without increasing the risk of IDH.

Masked Hypertension in Healthy Children and Adolescents: Who Should Be Screened?

PURPOSE OF REVIEW

The goal is to review masked hypertension (MH) as a relatively new phenomenon when patients have normal office BP but elevated out-of-office BP. Firstly, it was described in children in 2004. It has received increased attention in the past decade.

RECENT FINDINGS

The prevalence of MH in different pediatric populations differs widely between 0 and 60% based on the population studied, definition of MH, or method of out-of-office BP measurement. The highest prevalence of MH has been demonstrated in children with chronic kidney disease (CKD), obesity, diabetes, and after heart transplantation. In healthy children but with risk factors for hypertension such as prematurity, overweight/obesity, diabetes, chronic kidney disease, or positive family history of hypertension, the prevalence of MH is 9%. In healthy children without risk factors for hypertension, the prevalence of MH is very low ranging 0-3%. In healthy children, only patients with the following clinical conditions should be screened for MH: high-normal/elevated office BP, positive family history of hypertension, and those referred for suspected hypertension who have normal office BP in the secondary/tertiary center.

Reclassification of Adolescent Ambulatory Prehypertension and Unclassified Blood Pressures by 2022 American Heart Association Pediatric Ambulatory Blood Pressure Monitoring Guidelines

Background

The 2022 American Heart Association (AHA) pediatric ambulatory blood pressure monitoring (ABPM) guidelines eliminated the prehypertension phenotype and blood pressure loads in ABPM interpretation criteria. Adolescents who were prehypertensive or unclassified according to the 2014 AHA pediatric ABPM guidelines will be reclassified as having hypertension or normotension. The epidemiology and association of reclassification phenotype with target organ damage (TOD) is not yet known.

Methods

A single center retrospective review of adolescents ages 13-21 years old between 2015-2022 was performed. Adolescents diagnosed with prehypertension or unclassified by the 2014 AHA pediatric ABPM guidelines were reclassified by the 2022 definitions. Logistic regression models adjusted for body mass index z-score evaluated the association of reclassification phenotype with left ventricular hypertrophy (LVH).

Results

Among 88 adolescents with prehypertension, 68% (N = 60) were reclassified as hypertensive. The majority (58%, N = 35) of hypertensive reclassification was based on isolated nocturnal blood pressures ≥ 110/65 mmHg. Taller males were more likely to reclassify as hypertensive. Adolescents reclassified as hypertensive had a greater-than-six-fold increased odds of LVH in adjusted models [OR 6.4 95%CI 1.2-33.0, p = 0.027]. Of 40 adolescents with unclassified blood pressures, 37.5% (N = 15) reclassified to normotension. There were no significant clinical or demographic variables associated with reclassification category nor was there an association with LVH.

Conclusions

The new ABPM guidelines effectively reclassify adolescents who were previously prehypertensive as normotensive or hypertensive based on risk of TOD. Further studies are needed to describe the long-term outcomes of ABPM phenotypes with the implementation of these guidelines.

Racial-ethnic diversity in ambulatory blood pressure monitoring in children with chronic kidney disease

BACKGROUND

Black adults with chronic kidney disease (CKD) have higher rates of hypertension as compared to White adults with CKD. Little is known of how race and ethnicity associate with the prevalence of hypertension in pediatric CKD patients. The aim was to compare ambulatory blood pressure monitoring (ABPM) results for patients with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study across racial-ethnic groups.

METHODS

Patients from the CKiD study who identified as non-Hispanic White, non-Hispanic Black, or Hispanic were included to analyze differences in ABPM results across these racial-ethnic groups. The outcomes were fitted using 3 progressively adjusted models.

RESULTS

This study included 501 CKiD participants with at least one successful ABPM study. Compared to White participants, Black participants had 4.2 mmHg higher mean sleep systolic blood pressure and 2.7 mmHg higher mean sleep diastolic blood pressure (p = 0.001 and p = 0.004, respectively). Additionally, Black participants had higher odds of abnormal wake systolic load (OR 1.88, 1.21-2.91, p = 0.005), wake diastolic load (OR 1.68, 1.03-2.73, p = 0.04), sleep systolic load (OR 2.19, 1.36-3.5, p = 0.001), sleep diastolic load (OR 2.01, 1.28-3.15, p = 0.002), systolic non-dipping (OR 2.02, 1.31-3.10, p = 0.001), and diastolic non-dipping (OR 2.69, 1.60-4.51, p < 0.001). Compared to White participants, Hispanic participants demonstrated only a lower sleep diastolic load (OR 0.54, 0.31-0.95, p = 0.03).

CONCLUSIONS

Black children with CKD have higher absolute nocturnal blood pressures and higher rates of abnormal dipping. Further studies are needed to determine the etiology of these differences and the clinical implications of racial-ethnic differences in ABPM outcomes within the pediatric CKD population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Masked Hypertension in Pediatric Heart Transplant Recipients

BACKGROUND

Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT.

METHODS

A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant.

RESULTS

ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels.

CONCLUSIONS

ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

Nocturnal Hypertension in Children With Chronic Kidney Disease Is Common and Associated With Progression to Kidney Replacement Therapy

BACKGROUND

Nocturnal hypertension is a risk factor for chronic kidney disease (CKD) progression among adults. In children, effects of nocturnal hypertension on CKD progression is less studied.

METHODS

We investigated the relationships between nocturnal, daytime, or sustained hypertension and progression to kidney replacement therapy in children using Cox proportional hazards models. Nocturnal and diurnal hypertension respectively defined as: mean blood pressure >95th percentile and/or load >25% for either systolic or diastolic blood pressure within sleep or wake periods.

RESULTS

One thousand five hundred seventy-seven ambulatory blood pressure monitoring studies from 701 CKiD participants were reviewed. Nighttime, daytime, and both types of hypertension were 19%, 7%, and 33%, respectively. Participants with both daytime and nocturnal hypertension had the highest risk of kidney replacement therapy. Among children with CKD, compared with those who were normotensive, those with isolated nocturnal hypertension had a hazard ratio of 1.49 ([CI, 0.97-2.28]; P=0.068) while those with both daytime and nocturnal hypertension had a HR of 2.23 ([CI, 1.60-3.11]; P<0.001) when adjusted for age, race, sex, and baseline proteinuria and glomerular filtration. Estimates for risk were similar among glomerular and nonglomerular participants but not significant in glomerular due to smaller sample size.

CONCLUSIONS

The presence of both daytime and nocturnal hypertension is significantly associated with risk of kidney replacement therapy. Our study confirms the utility of ambulatory blood pressure monitoring in children with CKD. Identifying and controlling both daytime and nocturnal hypertension using ambulatory blood pressure monitoring may improve outcomes and delay CKD progression in this population.

Arterial stiffness and nocturnal hypertension in preterm children and adolescents

BACKGROUND AND OBJECTIVES

Preterm birth has been associated with increased risk for developing hypertension and other chronic diseases during childhood and adulthood. The aim of the current prospective case-control study was to investigate the associations of preterm birth with ambulatory blood pressure (BP) levels and arterial stiffness during childhood and adolescence.

METHODS

The study population included 52 children and adolescents born preterm and 26 healthy children born full term with similar age. The participants underwent ambulatory BP monitoring (ABPM) and assessment of carotid-femoral pulse wave velocity (PWV).

RESULTS

Preterm children presented higher night SBP z score values compared to controls, but did not differ in other ABPM parameters, office peripheral and central SBPs. Nocturnal hypertension was found in 78% (7/9) of ex-preterm children with ambulatory BP hypertension. Preterm birth was an independent predictor of PWV z score adjusted for heart rate. Estimated marginal means for PWV z score adjusted for age, sex, presence of kidney disease at birth, office BPs, night BPs, central SBP, and BMI z scores were significantly higher in preterm individuals compared to controls (0.703, 95% confidence interval [CI] 0.431-0.975 versus -0.19, 95% CI -0.574-0.536, respectively, P  = 0.027). Preterm children who were overweight presented the highest values of night SBP and PWV z score.

CONCLUSION

Preterm birth is associated with higher nocturnal BP and increased arterial stiffness in childhood and adolescence. Increased awareness for detection of hypertension and prevention of obesity in childhood could prevent future adverse cardiovascular outcomes in preterm individuals.

Isolated nocturnal hypertension in relation to host and environmental factors and clock genes

Isolated nocturnal hypertension (INH) is a special type of out-of-office hypertension. Its determinants and pathophysiology remain unclear. In a nested case-control study, we intend to investigate the host, environmental, and genetic factors in relation to INH. Among 2030 outpatients screened from December 2008 till June 2015, 128 patients with INH were identified, and then 128 normotensives were matched according to sex and age. INH was an elevated nocturnal blood pressure (BP ≥120/70 mmHg) in the presence of a normal daytime BP (< 135/85 mmHg). Host factors included age, sex, body mass index, smoking and drinking, sleep time and duration, heart rate, serum lipids, and serum creatinine. Environmental cues encompassed season, ambient temperature, atmospheric pressure, humidity, and wind speed, and genetic cues 29 single-nucleotide polymorphisms (SNPs) in 12 clock genes. Daytime and nighttime BPs averaged 124.9/80.7  and 114.5/73.7 mmHg, respectively, in the INH patients and 121.0/76.5 and 101.8/63.3 mmHg in the normotensive controls. Stepwise logistic regression analyses revealed that INH was associated with nighttime heart rate (P = .0018), sleep duration (P = .0499), and relative humidity (P = .0747). The odds ratios (95% CI) for each 10 beats/min faster nighttime heart rate and 10% lower relative humidity were 1.82 (1.25-2.65) and 0.82 (0.67-1.00), respectively. Irrespective of the genetic models, no significant association was observed between INH and the SNPs (P ≥ .054). In conclusion, INH was associated with host and environmental factors rather than genetic markers.

Isolated nocturnal hypertension in pediatric kidney transplant recipients

BACKGROUND

Isolated nocturnal hypertension (INH) is defined as nighttime hypertension in the setting of normal daytime blood pressure (BP), diagnosed by ambulatory BP monitoring (ABPM).

METHODS AND RESULTS

Hypertension affects 60%-80% of pediatric kidney transplant recipients, and INH is the most common type of ambulatory hypertension. INH is associated with an increased prevalence of hypertension-mediated target organ damage such as left ventricular hypertrophy in adults and in pediatric kidney transplant recipients.

CONCLUSION

Ambulatory BP monitoring should be performed annually in all pediatric kidney transplant recipients to diagnose hypertension phenotypes that are not detectable by office BP such as masked hypertension, white-coat hypertension, or INH. Isolated nocturnal hypertension in pediatric transplant patients requires study as a treatment target.

Isolated Nocturnal Hypertension in Children

Isolated nocturnal hypertension (INH) is attracting attention because it has been shown to correlate with target organ damage as well as cardiovascular events in adults. INH has also been reported in children especially in those with underlying diseases including chronic kidney disease and some studies reported association with markers of early target organ damage. INH occupies the majority of nocturnal hypertension. On the other hand, masked hypertension is largely attributed to INH. INH is usually diagnosed by ambulatory blood pressure monitoring. Recently, it became possible to monitor sleep blood pressure by an automated home blood pressure device feasible also in children. The epidemiology, methodology and reproducibility, pathophysiology, relation to target organ damage, and treatment of INH in children will be reviewed here along with adult data.