Blood Pressure Variability in Children With Primary vs Secondary Hypertension

Secondary Hypertension in Children-Identifying and Investigating at Risk Children

PURPOSE OF REVIEW

We aim to review the most recent literature on demographic features and diagnostic workup of children with secondary hypertension, in order to provide a framework for health providers to determine which hypertensive pediatric patients warrant further investigation for secondary causes. By highlighting the utility of various diagnostic investigations, we aim to minimize unnecessary testing burden.

RECENT FINDINGS

A recent meta-analysis revealed that hypertensive children and adolescents with any of the following features were at increased risk of secondary hypertension: < 6 years of age, history of prematurity, family history of secondary hypertension, body mass index (BMI) < 10th percentile. Based on available evidence, we suggest a testing schema that is stratified by both age and BMI. Limited evidence suggest renal ultrasound may be one of the most useful initial investigations for secondary causes in asymptomatic hypertensive children. Lipid profile in overweight/obese children, and echocardiogram for end organ involvement may have high yield of abnormal results. Further studies on the diagnostic utility of tests for secondary hypertension are required, as the current body of evidence is limited.

Ambulatory blood pressure variability in prediction of target organ injury: the SHIP AHOY study

BACKGROUND

Ambulatory hypertension is associated with elevated left ventricular mass index (LVMI), cardiac dysfunction, and increased arterial stiffness in adolescents. Whether the addition of measures of BP variability improves the prediction of subclinical cardiovascular target organ damage (TOD) over mean BP measures is not known.

METHODS

We assessed clinic and ambulatory BP (ABP), anthropometrics, and TOD in 397 adolescents. ABP means standard deviation (SD), BP, and heart rate (HR) dipping were calculated; coefficients of variability (CV) were calculated (SD/mean) to assess ABP variabilities. Measures of TOD included LVMI, left ventricular hypertrophy (LVH), LV systolic shortening, LV diastolic function (e'/a'), and pulse wave velocity. General linear models were used to determine if increased ABP variability measures were significant determinants of TOD in models containing mean ABP percentiles, age, sex, race/ethnicity, BMI z-score, and HR.

RESULTS

Mean participant age was 15.6 ± 1.7 years (63% white, 59% male) with mean casual BP 122.6/71.6 mmHg ±12.4/10.5, and mean awake systolic ABP 124.2/72.0 ± 11.3/7.7 mmHg. In linear models, increased awake CV-DBP and HR dipping were significant determinants of LVMI. CV-HR was an independent determinant of diastolic (e'/a') but not systolic dysfunction. Using logistic regression, the combination of awake and asleep diastolic ABP variability and awake systolic ABP percentile improved the prediction of LVH.

CONCLUSIONS

Consideration of ABP variability in addition to ABP percentile may aid in identifying adolescents at risk for LVH.

Within-visit blood pressure variability in children and adolescents in the National Health and Nutrition Examination Survey (2013-2020)

BACKGROUND

Blood pressure (BP) varies depending on several factors. The objective of our study was to describe within-visit BP variability (BPV) in healthy children and compare BPV between manual and automated BP readings.

METHODS

We included individuals aged 8-17 years with three BP readings from NHANES 2013-2020 cycles. From 2013 to 2016, BP was obtained using auscultation (manual protocol, MP) and, subsequently, using oscillometry (automated protocol, AP). We excluded individuals with DBP 'zero'.

RESULTS

In 5656 individuals [MP group: 3365 (59.5%); AP group: 2291 (40.5%]), a ΔBP (difference between highest and lowest of three BP readings) at least 5 mmHg was noted in 49.1 and 60.7% of individuals for SBP and DBP, respectively. ΔDBP at least 10 mmHg was twice as common in the MP group as in the AP group. ΔDBP at least 20 mmHg was observed in 4.4% individuals. A difference of at least 5 mmHg between the initial and averaged second and third BP readings was noted in 24.9 and 34.5% of individuals for SBP and DBP, respectively. The highest of three BP readings was the first, second, or third in 44.2, 30.5, and 25.4% of individuals, for SBP, and 42.4, 29.8, and 27.7%, for DBP respectively.

CONCLUSION

Less than half of individuals had three DBP readings within 5 mmHg and some had ΔBP at least 20 mmHg. Initial BP is not always the highest; inclusion of the second and third BP readings may be more representative of the individual's actual BP. DBPV was higher with manual than with automated BP measurement.

Is there a characteristic pattern of ambulatory blood pressure profile in type 1 diabetic children and adolescents?

PURPOSE

To examine the characteristics of ambulatory blood pressure (ABP) including blood pressure variability (BPV) and its association with albuminuria in type 1 diabetic (T1D) children and to identify potential predictors of high-normal albuminuria and microalbuminuria.

METHODS

ABP monitoring was performed in 201 T1D children and adolescents (mean age, 14.7±3.8 years) with T1D duration over 1 year. The level of albuminuria was assessed as the albumin/creatinine ratio (ACR) and patients were further classified as low-normal, high-normal or microalbuminuria.

RESULTS

Fifteen T1D children (7.5%) were hypertensive using office blood pressure (BP) and 10 (5%) according to ABP. T1D subjects had elevated 24-hour systolic BP (SBP) and diastolic BP (DBP) (+0.2 and + 0.3 standard deviation score [SDS]) and nighttime SBP and DBP (+0.6 and +0.8 SDS) compared to reference values. Patients with microalbuminuria had significantly higher 24-hour, daytime and nighttime DBP compared to normoalbuminuric subjects. There was a high percentage of nondippers (74.1%). Nighttime diastolic BPV was significantly higher in subjects with high-normal compared to low-normal albuminuria (p=0.01). A weak correlation was found between ACR and daytime DBP SDS (r=0.29, p<0.001 and nighttime DBP SDS (r=0.21, p=0.003). Age and nighttime diastolic BPV were predictors of high-normal albuminuria while nighttime DBP was a strong predictor for microalbuminuria.

CONCLUSION

T1D children have impaired BP regulation although most of them do not fulfill the criteria for sustained hypertension. There is an association between diastolic ABP and diastolic BPV with rising levels of albuminuria pointing to a clear connection between BP and incipient diabetic nephropathy.

Ambulatory Blood Pressure Variability after Adenotonsillectomy in Childhood Sleep Apnea

OBJECTIVE

To investigate the influence of adenotonsillectomy (T&A) on ambulatory blood pressure (BP) variability in children with obstructive sleep apnea (OSA).

STUDY DESIGN

Prospective, interventional study.

METHODS

Children with OSA symptoms were recruited from a tertiary center. After OSA diagnosis was confirmed (ie, apnea-hypopnea index [AHI] > 1), these children underwent T&A for treatment. We performed polysomnography and 24-hour recordings of ambulatory BP before and 3 to 6 months postoperatively. Ambulatory BP variability was presented as the standard deviation of mean blood pressure in the 24-hour monitoring of ambulatory BP. Differences in BP variability among different subgroups were tested using a multivariable linear mixed model.

RESULTS

A total of 190 children were enrolled (mean age: 7.8 ± 3.3 years; 73% were boys; 34% were obese). The AHI significantly decreased from 12.3 ± 17.0 to 2.7 ± 5.5 events/hr after T&A. Overall, daytime, and nighttime ambulatory BP did not significantly change postoperatively, and overall, daytime, and nighttime ambulatory BP variability did not differ significantly preoperatively and postoperatively. In the subgroup analysis, children aged <6 years demonstrated a significantly greater decrease in ambulatory BP variability postoperatively than those aged >6 years (nighttime diastolic BP variability: 9.9 to 7.7 vs. 8.9 to 9.4). Children with hypertension also showed a significantly greater decrease in ambulatory BP variability than those without hypertension.

CONCLUSIONS

We concluded that overall ambulatory BP variability does not significantly change after T&A in children with OSA. Moreover, young-aged and hypertensive children demonstrate a significant decrease in BP variability after T&A.

LEVEL OF EVIDENCE

4 Laryngoscope, 132:2491-2497, 2022.

Blood pressure variability during pediatric cardiac surgery is associated with acute kidney injury

BACKGROUND

Blood pressure variability (BPV), defined as the degree of variation between discrete blood pressure readings, is associated with poor outcomes in acute care settings. Acute kidney injury (AKI) is a common and serious postoperative complication of cardiac surgery with cardiopulmonary bypass (CPB) in children. No studies have yet assessed the association between intraoperative BPV during cardiac surgery with CPB and the development of AKI in children.

METHODS

A retrospective chart review of children undergoing cardiac surgery with CPB was performed. Intraoperative BPV was calculated using average real variability (ARV) and standard deviation (SD). Multiple regression models were used to examine the association between BPV and outcomes of AKI, hospital and intensive care unit (PICU) length of stay, and length of mechanical ventilation.

RESULTS

Among 231 patients (58% males, median age 8.6 months) reviewed, 51.5% developed AKI (47.9% Stage I, 41.2% Stage II, 10.9% Stage III). In adjusted models, systolic and diastolic ARV were associated with development of any stage AKI (OR 1.40, 95% CI 1.08-1.8 and OR 1.4, 95% CI 1.05-1.8, respectively). Greater diastolic SD was associated with longer PICU length of stay (β 0.94, 95% CI 0.62-1.2). When stratified by age, greater systolic ARV and SD were associated with AKI in infants ≤ 12 months, but there was no relationship in children > 12 months.

CONCLUSIONS

Greater BPV during cardiac surgery with CPB was associated with development of postoperative AKI in infants, suggesting that BPV is a potentially modifiable risk factor for AKI in this high-risk population.

Blood pressure variability and night-time dipping assessed by 24-hour ambulatory monitoring: Cross-sectional association with cardiac structure in adolescents

Greater blood pressure (BP) is associated with greater left ventricular mass indexed to height2.7 (LVMi2.7) in adolescents. This study examined whether greater BP variability and reduced night-time dipping are associated with cardiac remodeling in a general population of adolescents. A cross-sectional analysis was undertaken in 587 UK adolescents (mean age 17.7 years; 43.1% male). BP was measured in a research clinic and using 24-hour ambulatory monitoring. We examined associations (for both systolic and diastolic BP) of: 1) clinic and 24-hour mean BP; 2) measures of 24-hour BP variability: standard deviation weighted for day/night (SDdn), variability independent of the mean (VIM) and average real variability (ARV); and 3) night-time dipping with cardiac structures. Cardiac structures were assessed by echocardiography: 1) LVMi2.7; 2) relative wall thickness (RWT); 3) left atrial diameter indexed to height (LADi) and 4) left ventricular internal diameter in diastole (LVIDD). Higher systolic BP was associated with greater LVMi2.7. Systolic and diastolic BP were associated with greater RWT. Associations were inconsistent for LADi and LVIDD. There was evidence for associations between both greater SDdn and ARV and higher RWT (per 1 SD higher diastolic ARV, mean difference in RWT was 0.13 SDs, 95% CI 0.045 to 0.21); these associations with RWT remained after adjustment for mean BP. There was no consistent evidence of associations between night-time dipping and cardiac structure. Measurement of BP variability, even in adolescents with blood pressure in the physiologic range, might benefit risk of cardiovascular remodeling assessment.

Hypertension in pediatric patients admitted to inpatient ward at King Abdulaziz Universty Hospital in Saudi Arabia: Prevalence, causes, and outcomes

Background:

The secondary hypertension (HTN) is the predominant form of HTN in pediatrics. Renal diseases and renovascular anomalies are the most commonly reported causes. In this study, we aimed to identify the prevalence, causes, and outcomes of secondary HTN in Saudi Arabia.

Methods:

A retrospective study was conducted among 3,640 pediatric patients aged between 0 and 18 years, admitted to the pediatric nephrology ward at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. The study has been approved by the ethics review committee of King Abdulaziz University.

Results:

Prevalence of secondary HTN due to renal disease was (77.0%). Most of the cases were diagnosed with stage 5 renal disease (78.3%). Small kidney size was frequently diagnosed (n = 29, 11.9%), followed by large kidney size (n = 26, 10.7%). One third of the cases (n = 79, 32.4%) were under control, 49 (20.1%) lost follow-up, and 24 (10.1%) deceased. A total of 61 (33.1%) patients progressed to end-stage renal disease and patientswere managed by different types of treatments.

Conclusion:

The prevalence of secondary HTN due to renal disease is considered to be high in pediatric patients admitted to King Abdulaziz University. Several renal diseases in the renal system are associated with secondary HTN mostly attriubuted to renal malformation. In addition, renal affection, cerebral infarction, bleeding, left ventricular hypertrophy, and valvular lesion are the highest reported complications in our population. Follow-up with ECHO and brain CT is highly recommended in pediatric HTN. Future studies on a larger sample and vigorous follow-up are recommended.

White-Coat and Reverse White-Coat Effects Correlate with 24-h Pulse Pressure and Systolic Blood Pressure Variability in Children and Young Adults

Masked hypertension (MH) and white-coat hypertension (WCH) are associated with organ damage. In the present study, we examined the correlation between the magnitude of white-coat effect (WCE) or reverse WCE (RWCE) and 24-h pulse pressure (PP), an indicator of target organ damage and arterial stiffness, in children and young adults. We also examined the relationship of WCE or RWCE and blood pressure (BP) variability, another predictor of clinical outcomes. One hundred and ninety-eight subjects were studied. According to the office BP and ambulatory BP, they were divided into normotension, WCH, MH, and hypertension. The magnitude of WCE or RWCE, along with male gender and 24-h systolic BP, was the determinant of 24-h PP. In subjects with 24-h PP ≥ 61 mmHg, the magnitude of WCE or RWCE, age, male ratio, height, weight, BMI, the percentage of secondary hypertension, that of MH, office systolic BP, and 24-h systolic BP were significantly greater. There was a progressive increase in 24-h PP from normotension, WCH, MH, to hypertension. BP variability in subjects with MH was numerically highest in both systolic and diastolic. Diastolic BP variability of WCH, MH, and hypertension was significantly higher than that of normotension. Finally, the magnitude of WCE or RWCE in systolic showed a significant correlation with systolic BP variability. In conclusion, the magnitude of WCE or RWCE correlates with 24-h PP and systolic BP variability, which may suggest increased arterial stiffness in WCH and MH.

Relationship Between Short-Term Blood Pressure Variability and Subclinical Renal Damage in Essential Hypertensive Patients

The authors aimed to analyze the relationship between subclinical renal damage, defined as the presence of microalbuminuria or an estimated glomerular filtration rate (eGFR) between 30 mL/min/1.73 m(2) and 60 mL/min/1.73 m(2) and short-term blood pressure (BP) variability, assessed as average real variability (ARV), weighted standard deviation (SD) of 24-hour BP, and SD of daytime and nighttime BP. A total of 328 hypertensive patients underwent 24-hour ambulatory BP monitoring, 24-hour albumin excretion rate determination, and eGFR calculation using the Chronic Kidney Disease Epidemiology Collaboration equation. ARV of 24-hour systolic BP (SBP) was significantly higher in patients with subclinical renal damage (P=.001). This association held (P=.04) after adjustment for potential confounders. In patients with microalbuminuria, ARV of 24-hour SBP, weighted SD of 24-hour SBP, and SD of daytime SBP were also independently and inversely related to eGFR. These results seem to suggest that in essential hypertension, short-term BP variability is independently associated with early renal abnormalities.