Blood pressure and cardiovascular involvement in children with neurofibromatosis type1

We evaluated blood pressure in a sample of patients with neurofibromatosis type 1 (NF1), using ambulatory blood pressure monitoring (ABPM), to determine whether ABPM, when compared with casual BP recordings, allowed the detection of a higher risk for hypertension. We also evaluated the correlation between BP and vascular abnormalities. We studied 69 NF1 patients (36 males and 33 females) with a mean age of 11±4 years, divided into group A, with 24-h mean systolic blood pressure (SBP) or diastolic blood pressure (DBP) <95th percentile, and group B, with mean SBP or DBP >95th percentile. Standard electrocardiography and M-mode, two-dimensional echocardiography were performed and all patients were in sinus rhythm. ABPM identified 11 hypertensive patients (16%); 5 had a mean SBP >95th percentile, 3 mean SBP–DBP >95th percentile, and 3 a mean DBP >95th percentile. Laboratory and other investigations to exclude secondary hypertension were normal. Cardiac abnormalities were found in 13 of the 69 patients (18.8%) with NF1. There were no significant clinical and cardiac differences between the normotensive and hypertensive group. Our data emphasize the importance of periodic ABPM in NF1 patients to diagnose hypertension early and avoid target organ damage and increased mortality.     

Ambulatory blood pressure monitoring after renal transplantation in children

Hypertension occurs commonly following renal transplantation and may cause end organ damage, such as cardiac hypertrophy. This study seeks to determine which features of hypertension are related to cardiac hypertrophy in children after renal transplantation. Ambulatory blood pressure monitoring (ABPM) was performed in 45 pediatric patients, 4.9+/-3.0 years after renal transplantation. ABPM data were related to clinical features and echocardiographic measurements. Hypertension was demonstrated in 33% of patients by casual blood pressure (BP) measurement and in 40% by ABPM. The mean percentage nighttime decline in BP (dipping) was 8.9+/-5.0% for systolic and 13.9+/-7.7% for diastolic BP. Abnormal dipping (<10%) was seen in 58% of patients. BP load (percentage of BP recordings above 95th percentile) was >30% in 44% of patients. Patients taking antihypertensive medication had more abnormal dipping and greater nighttime BP load. The prevalence of left ventricular hypertrophy was 72% before transplantation, 75% after transplantation, and 54% near to ABPM. Left ventricular mass (LVM) indexed to height(3) decreased significantly after transplantation. (40.2+/-14.7 vs. 35.0+/-8.3 g/m(3), P=0.0002). There was no significant relationship between ABPM data and LVM. ABPM was not able to differentiate those patients with persistently elevated LVM. The results suggest that hypertension is not always associated with cardiac hypertrophy following pediatric renal transplantation.     

Ambulatory blood pressure monitoring in children: a large center’s experience

Ambulatory blood pressure monitoring (ABPM) is well established in adults and is becoming common in children. We reviewed 190 ABPM studies retrospectively (since 1990) to assess the failure rate, and analyzed the data from 97 patients 5–19 years old (1992–1996) to review the experience gained from the use of this technique in children and adolescents. Seventeen percent (32/190) of studies failed. Most children accepted ABPM, provided it was clearly explained in advance. There were differences between day and night readings of systolic blood pressure (BP), diastolic BP, and heart rate. BP did not correlate with height or weight. ”White coat” effect apparently exists in children: clinic systolic BPs were higher than daytime systolic ABPM (no difference in diastolic). Eighty-nine percent (86/97) had an elevated BP load (>30% of readings >95th percentile). The antihypertensive medications of 16% (16/97) of patients were changed after ABPM. The nocturnal fall in BP (expressed as a percentage of the individual mean daytime values) was approximately normally distributed and was independent of age and height. Nocturnal systolic and diastolic dipping were closely correlated. Attenuation of nighttime dipping was observed in children with kidney disease and those with organ transplants. There is a need for normative data for ABPM for North American children. In our study, the technique was useful in selected cases, such as borderline or secondary hypertension, and for therapeutic monitoring when BP control is difficult. Received: 1 March 1999 / Revised: 24 November 1999 / Accepted: 28 November 1999     

Repeated ambulatory blood pressure monitoring in adolescents with mild hypertension

The reproducibility of serial measurements of ambulatory blood pressure monitoring (ABPM) has not been well explored in children. We performed 24-h ABPM in 59 subjects (38 boys) aged 8-19 years with repeatedly elevated casual blood pressure (BP). According to the results of ABPM, the individuals were divided into a hypertensive group (mean 24-h systolic or diastolic BP >95th percentile for height, n=28) and a normotensive group (n=31). No antihypertensive agents were given. Both groups were reexamined after 1 year. In the hypertensive group, systolic and diastolic BP dropped significantly by an average of 2.1-4.5 mmHg when measured either during the daytime or over 24 h, but not at nighttime. In the normotensive group, only small BP changes were observed except for a significant increase in systolic BP at night. At the repeat examination after 1 year, 54% of the originally hypertensive subjects were defined as normotensive and 23% of the originally normotensive subjects as hypertensive. The study indicates that a single ABPM measurement is not sufficient for definitive classification of young individuals into hypertensives or normotensives.     

Correlation between fat mass and blood pressure in healthy children

Obesity is a well-known risk factor for arterial hypertension. The aim of this study was to analyze which surrogate marker of adiposity, i.e., body mass index (BMI) or fat mass (FM), as measured by bioimpedance analysis (BIA), best correlated with blood pressure in healthy children. Body weight, height, and casual blood pressure (BP) were measured in 193 healthy children (103 boys), aged 8–16 years. Body composition was determined by BIA. The correlation between BMI and age was linear, whereas the correlation between percentage of FM and age was nonlinear and it was different in boys and girls. Blood pressure standard deviation scores (SDS) correlated with FM SDS (BIA) over the entire normal range (systolic: r = 0.26, p = 0.002; diastolic: r = 0.33, p < 0.01). An evaluation of the children based on BP (three groups: BP < 50th percentile, 50th < BP > 95th percentile; BP > 95th percentile) revealed that hypertensive children had a higher BMI (17.6 vs. 19.4 vs. 26.2 kg/m², respectively) and a greater FM (14.0 vs. 16.8 vs. 30.2%, respectively). In conclusion, the divergence in FM in healthy boys and girls can be determined by BIA but not by BMI. In healthy children, BP within the entire normal range correlated with FM, children with established hypertension presented with a significantly higher FM. The study points to FM as an important determinant of BP pressure in obese and non-obese children.     

Twenty-four-hour ambulatory blood pressure monitoring in young children

 Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has many advantages for the diagnosis and follow-up of hypertension at all ages. This technique has so far not been documented as applicable to the very young. We studied the feasibility of ABPM in 61 healthy children and in 40 patients with renal diseases and/or hypertension, aged less than 6 years. A satisfactory ABPM profile (recording time = 24 h and >30 good recordings) was obtained in 77% of the healthy children. The mean number of good blood pressure (BP) measurements per 24 h increased with age from 46 (3–4 years) to 58 (6 years). The mean (±SD) systolic and diastolic BPs of healthy 3- to 6-year-old children (n = 47) were 110±5/67±5 mmHg during the day-time and 100±5/58±5 mmHg at night. In addition to the nocturnal decrease in BP, ABPM detected a second, day-time dip in BP during bed rest after lunch. Ninety percent of patients with renal disease and/or hypertension had successful ABPM recordings for 24 h, with an age-dependent increase in the mean number of reliable readings from 34 (< 2 years) to 48 (4 years). In 5 of 10 children with hypertensive results obtained by casual BP measurements, elevated BP was not confirmed by ABPM. We conclude that ABPM is a useful tool for the diagnosis and evaluation of hypertension in children under 6 years of age. Received March 5, 1996; received in revised form and accepted May 6, 1997     

Comparison of ambulatory blood pressure and Task Force criteria to identify pediatric hypertension

The aim of this study was to assess the level of agreement between central European ambulatory blood pressure monitoring (ABPM) and American Task Force (TF) criteria when applied to blood pressure (BP) measurements collected by ABPM to evaluate patients with hypertension. In 169 patients, we applied both sets of criteria and calculated mean daytime and nighttime BP and daytime BP loads. The frequency of hypertension for daytime systolic BP was significantly higher when TF criteria were used (p ≤ 0.001). However, the frequency of hypertension for nighttime systolic BP was significantly increased when ABPM criteria were applied (p ≤ 0.01). Therefore, with daytime ABPM measurements, hypertension was overdiagnosed with TF criteria, while nighttime hypertension was underdiagnosed using TF criteria. In contrast with previous reports, 40% of our patients with essential hypertension showed absence of nighttime dipping, regardless of the criteria used. The number of hypertensive patients was significantly higher using ABPM compared to TF criteria when patients with BP load ≥50% were evaluated (p ≤ 0.01). Therefore, current recommendations for ABPM use in children such as to define white coat hypertension or as a screening tool to differentiate between primary and secondary hypertension need to be validated using yet to be produced normative ABPM criteria in American children.     

Twenty-four-hour ambulatory blood pressure monitoring in infants and toddlers

During the past several years, 24-hour (24-h) ambulatory blood pressure monitoring (ABPM) has become a useful tool for the diagnosis and management of children and adolescents with elevated blood pressure (BP). Some reports have also provided blood pressure nomograms for particular devices. However, there are very few reports of the use of this method in very young children. In our study we investigated the applicability of ABPM in 97 healthy infants and toddlers, aged from 2 to 30 months. A satisfactory ABPM profile was obtained in 86.6% of the children, with an average of 75.0% satisfactory BP recordings. The mean ± SD systolic and diastolic BP of healthy infants and toddlers was 99±12/62±12 mmHg during the daytime and 95±11/57±10 mmHg during the night, with no gender difference being observed. The 24-h mean ± SD systolic and diastolic BP, which may be a more appropriate measure of BP in this particular age group, was found to be 97±12/59±11 mmHg. We also confirmed the increase in systolic and diastolic BP with increased height (length). There was only a slight nocturnal decrease in BP. We conclude that this method is applicable for the assessment of blood pressure in very young children.     

Masked hypertension in children and young adults

Masked hypertension, a high ambulatory blood pressure (ABP) in the presence of normal office blood pressure (BP), is recognized as a risk factor for cardiovascular complications in the adult population. We evaluated the prevalence of masked hypertension in pediatric patients. We studied 136 patients (59 boys and 77 girls, aged 6–25 years, mean 13.1±4.7 years). In all patients, office BP measurements with auscultatory technique were less than the 95th percentile for sex and age or <140/90 mmHg for those over 18 years. Masked hypertension was diagnosed when either systolic or diastolic daytime ABP values were equal to or greater than the 95th percentile for sex and height of reference values or 135 mmHg systolic or 85 mmHg diastolic BP for those over 15 years. Among 136 patients, 15 (11%) had masked hypertension. The prevalence of masked hypertension was higher in boys (19%) than in girls (5%), but not different between younger (15 years) and older (>15 years) patients (11% vs. 12%). The diagnoses in the group with masked hypertension included 3 patients with diabetic nephropathy, 2 with obesity, and 2 with orthostatic dysregulation. In conclusion, masked hypertension is present in pediatric patients, and is more common in boys. Further study is needed to identify patients who may benefit from recognition of masked hypertension.     

Reflux nephropathy and hypertension: correlation with the progression of renal damage

The aim of this study was to evaluate the relationship between blood pressure (BP), measured with ambulatory blood pressure monitoring (ABPM), and the progression of renal damage in 100 (70 females, 30 males) normotensive children with reflux nephropathy (RN). The patients, mean age of 13.5+/-5 years and almost 5 years of follow-up, were divided according to degree of RN into group A (I/II) and group B (III/IV). For each subject, 24-h systolic and diastolic BP (SBP-DBP), load (percentage of BP readings that exceeded the age- and sex-specific 95th percentile), and biochemical parameters were recorded. There was no significant difference in casual BP between the groups. The mean 24-h SBP-DBP and load were significantly higher in group B than A. There was a significant difference in creatinine (Cr) levels between the groups, and Cr correlated with BP in both groups. In group B, microalbuminuria correlated with ambulatory BP, and plasma renin activity failed to decrease with chronological age. Elevated load was shown in 8 of 50 patients in group A and in 21 of 50 in group B. In 3 of 12 patients of group B, with increased load BP, left ventricular geometry, by integrated backscatter, was abnormal. ABPM was useful in selected children at risk of hypertension.     

Abnormal circadian blood pressure regulation in children with nocturnal enuresis

Introduction: To investigate autonomic nervous system function in enuretic children by performing ambulatory blood pressure monitor (ABPM) for 24?h. Methods: Twenty-eight children ranging in age from 6 to 15 years with primary nocturnal enuresis and 27 age-matched healthy controls were enrolled and they get 24?h ABPM. Hypertension was defined as standard deviation score (SDS)?>?1.64 (i.e., >95th percentile) adjusted for gender and height. Urinalysis, urine electrolyte levels, urinary culture, and urinary system ultrasound were carried out in all children. They have also requested to have a diary about daily fluid intake and urine volume. Results: Although the mean 24-h and daytime diastolic blood pressure (BP) did not differ between the groups, systolic BP (SBP) was significantly higher in enuretic children (p?<?0.05). The mean night-time SBP, DBP values, SDS and BP loads were found to be significantly higher than those in the controls (p?<?0.01). A lack of nocturnal decrease was more prevalent in the enuretic children compared with the control subjects, the difference was statistically significant for DBP but not for SBP. Patients with elevated night-time BP load was found to have higher frequency of urinary incontinence per week as well as per night when compared with enuretic children with normal night-time BP load (r?=?0.72, r?=?0.69, p?<?0.01, respectively). Conclusion: Subtle abnormalities of circadian BP regulation in enuretic children indicated by a selective elevation of nocturnal SBP, DBP, and MAP, and attenuated nocturnal dipping may reflect sympathetic hyper activation and its possible role in pathogenesis of enuresis.     

Ambulatory blood pressure monitoring and renal functions in children with a solitary kidney

The aim of this study is to investigate the blood pressure (BP) profile, microalbuminuria, renal functions, and relations with remaining normal kidney size in children with unilateral functioning solitary kidney (UFSK). Sixty-six children with UFSK were equally divided into three groups: unilateral renal agenesis (URA), unilateral atrophic kidney (UAK), and unilateral nephrectomy (UNP). Twenty-two age-, weight-, and height-matched healthy children were considered as a control group. The serum creatinine level and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods. Also, the BP profile was determined by ambulatory blood pressure monitoring (ABPM). We found that the serum creatinine level was higher and creatinine clearance was lower in each patient groups compared to those of the control group (p < 0.05). Compared with the controls, each group of patients had mean office, 24-h, daytime, and night-time systolic and diastolic BP values similar to those of the controls (p > 0.05). An inverse correlation was found between the renal size standard deviation scores (SDS) of normal kidneys and 24-h systolic and diastolic BP load SDS in all of the patients (p < 0.05; r = −0.372, r = −0.295, respectively). The observed relationship between renal size SDS and 24-h mean arterial pressure (MAP), systolic and diastolic BP load SDS suggests that children with UFSK should be evaluated by using ABPM for the risk of hypertension.     

Ambulatory blood pressure monitoring after recovery from hemolytic uremic syndrome

The outcome of acute renal failure due to diarrhea-associated hemolytic uremic syndrome (D+ HUS) is generally predicted to be good. However, there are only a few long-term observations with detailed reports on long-term sequelae. Specifically, adequate long-term blood pressure (BP) evaluations are scarce. The present study evaluated BP in pediatric patients after childhood D+ HUS. The study group comprised 28 patients (20 males) aged 6-23.5 years (median 10.1 years). All patients had a history of D+ HUS at a median age of 1.1 years (range 0.5-6 years). Based on the duration of oliguria and/or anuria, the primary disease was classified as mild (n=6), moderate (n=6), or severe (n=16). The BP in these patients was studied at a median time of 8.4 years (range 2.3-22.9 years) after manifestation of D+ HUS by means of office BP measurements and 24-h ambulatory BP monitoring (ABPM) using a Spacelabs 90207 oscillometric monitor. Measurements were compared with normal values of published standards for healthy children and adolescents. Conventional office BP measurements were above the 95th percentile in 1 patient. By ABPM, 2 patients were diagnosed to have mean systolic daytime and nighttime values in the hypertensive range, and systolic and diastolic hypertension was confirmed in the first patient. All these patients had a severe form of D+ HUS in the past. By applying ABPM, BP anomalies were detected in 5 additional patients. Elevated systolic BP loads were found in 4 patients, and daytime systolic and diastolic hypertension in the other 1. At the time of the study, 2 of them were classified as "recovered." The late outcome of D+ HUS may be worse than anticipated. BP anomalies as long-term sequelae of D+ HUS could be identified by ABPM but not by office BP measurements. These findings may represent an isolated sign of residual renal disturbance.     

The role of ambulatory blood pressure measurements in adolescence and young adults

INTRODUCTION: Ambulatory blood pressure measurements (ABPM) are currently used for the diagnosis and treatment of hypertension. It is widely recognized that the casual/clinic blood pressure is less representative of the true blood pressure than the average ABP. METHODS: Among the 15 records for 14 patients analyzed, 80% were obtained from type I diabetics. The overall age, ranged between 11 and 23 years (mean = 17.2 years). ABPM was performed using the Quiet Trak 98 model by Welch Allyn automatic auscultatory sphygmomanometer for a 24-hour period, for those with clinic documented hypertension. The BP was considered high if recorded as systolic > 140 and diastolic > 90 for the whole period or for period I (7 am to 11 pm), and >120 systolic and >85 diastolic for period II (11 pm to 7 am), or >130 systolic and >85 diastolic for diabetic patients. RESULTS: The BP was recorded as normal in 20% of the patients; in 33% it was normal during the daytime but high during the nighttime, and 80% of the diabetic patient were found to be nondippers during night time. CONCLUSION: ABPM is helpful to exclude White coat hypertension and nondippers especially among diabetic patients.     

Office and ambulatory blood pressure elevation in children with chronic renal failure

Hypertension is a frequent complication in patients with chronic renal insufficiency (CRI) and is associated with target organ damage, including left ventricular hypertrophy (LVH). To better assess hypertension in pediatric patients with CRI, we performed 24-h ambulatory blood pressure monitoring (ABPM) and evaluated the relationship between ABPM parameters and LVH in 29 children, mean age 12.4+/-3.8 years. There was no significant difference in the frequency of hypertension comparing casual systolic blood pressure (SBP) (21%) with the mean 24-h (21%) or daytime mean SBP (21%). However, diastolic hypertension was detected more frequently using ABPM: 24% for 24-h diastolic blood pressure (DBP), 14% for daytime DBP, and 7% for casual DBP. Nighttime systolic hypertension as well as diastolic hypertension was detected in 12 (41%) children. Seventeen (59%) patients had attenuated dipping for SBP and 9 (31%) had abnormal DBP dipping. Lower SBP dipping was associated with lower glomerular filtration rate (r=0.44, P<0.05). LVH was found in 6 (21%) patients. LVM index was significantly correlated with 24-h SBP (r=0.43, P<0.05). Multiple regression analysis confirmed that higher 24-h SBP was the only independent predictor for increased LVM index (P=0.001). No significant relationship was found between LVM index and office blood pressure. These results confirm a high prevalence of blood pressure abnormalities using ABPM criteria in children with CRI and suggest that ABP may better predict end-organ damage in these patients than casual BP.     

Ambulatory blood pressure monitoring in healthy children with parental hypertension

The aim of this study was to compare ambulatory blood pressure monitoring (ABPM) parameters in offspring with at least one hypertensive parent (HP) to offspring with normotensive parents (NP) and to determine whether gender of parent or child might influence the association between parental hypertension and blood pressure (BP). Eighty-nine healthy children (mean age 11.1 ± 3.9 years) with HP and 90 controls (mean age 10.5 ± 3.1 years) with NP were recruited. Age, gender, and height did not differ between the two groups, whereas children of HP had higher weight, body mass index (BMI), and waist circumference compared with healthy controls. No difference was found in casual BP between the two groups. In contrast, during ABPM daytime and nighttime mean systolic and diastolic BP and mean arterial pressure (MAP) standard deviation scores (SDS) were significantly elevated in children with HP. The mean percentage of nocturnal BP decline (dipping) was not significantly different between the two groups. Children with hypertensive mothers had higher daytime systolic and MAP SDS than controls; no such difference was detected for children with hypertensive fathers. Daytime systolic and MAP SDS were significantly elevated in boys with HP compared with boys with NP but failed to be significant in girls. Multiple linear regression analysis showed that parental history of hypertension (B = 0.29) and BMI (B = 0.03) were independently correlated with increase of daytime MAP SDS. Early changes in ambulatory BP parameters were present in healthy children of HP. BP in HP offspring was influenced by the gender of the affected parent and the offspring.     

Blood pressure and renal function in autosomal dominant polycystic kidney disease

  The purpose of this study was to identify hypertension in children and adolescents in an early stage of autosomal dominant polycystic kidney disease (ADPKD) by the application of ambulatory blood pressure monitoring (ABPM) over 24 h; 32 children and adolescents (mean age 12.3±4.7 years) were examined. The diagnosis was based on family history and ultrasound examination. In 21 children ADPKD was confirmed by molecular genetic analysis. At the time of the study, 45% patients were asymptomatic and all had glomerular filtration rates (GFRs) ≥65 ml/min per 1.73 m². By ABPM, 11 patients (34%) were defined as hypertensive (systolic or diastolic blood pressure >95th percentile), including 4 with an exclusive nocturnal hypertension. Of 7 patients with daytime hypertension, 4 had normal blood pressure by casual measurements. The nocturnal dip in blood pressure was reduced in 2 patients. Blood pressure correlated with renal size, but not with GFR, concentrating capacity, proteinuria, and plasma renin activity. The study reveals an early trend for increased blood pressure in children with ADPKD, requiring close supervision. Received October 18, 1996; received in revised form and accepted March 11, 1997     

Measurement and treatment of elevated blood pressure in the pediatric patient with chronic kidney disease

Hypertension, as in adults, is a frequent complication found in children with chronic kidney disease (CKD). Indeed, hypertension has now become one of the most prevalent chronic diseases of childhood. The most recent data available (2003) indicate that at least 38% of children with CKD in the United States are receiving antihypertensive therapy. Only recently has it been shown in children that hypertension, traditionally considered a marker for disease severity in children, is additionally a significant and independent risk factor for accelerated deterioration of kidney function and progression of CKD and a significant risk factor for cardiovascular disease. The following review outlines the differences and similarities of childhood versus adult hypertension with respect to measurement, diagnosis, treatment, and consequence in CKD. The definition of hypertension changes continually as a child grows with or without CKD. Despite numerous guidelines, the diagnosis of childhood hypertension continues to be based on epidemiologic data rather than evidence. For children, the current definition includes 2 categories: high normal, which is blood pressure (BP) between the 90th and 95th percentile, and hypertensive, which is BP above the 95th percentile. The evaluation of all hypertensive children should include a complete assessment of end-organ damage, including eyes, cardiovascular system (including blood vessels), kidneys, and nervous system. For children with CKD and end-stage renal disease (ESRD), a high percentage have left ventricular hypertrophy (LVH). The finding of end-organ damage or comorbidity (CKD, diabetes) in any child is an absolute indication for immediate pharmacologic therapy, whereas the presence of hypertension above the 95th percentile in children without CKD warrants initial intervention such as life style modification. The guidelines for measurement of BP in children with CKD are similar to those in children without CKD and include casual BP measurement, self-measured BP, and ambulatory BP monitoring. The recommendation for BP measurement in children is, when permitted, by auscultative method with a well-calibrated mercury manometer. Most casual BP measurements are performed with an automated oscillometric device whose validation has not been confirmed in children with CKD. The ambulatory BP monitor (ABPM) has 2 advantages: it significantly correlates with the presence of end-organ damage, and it identifies abnormal BP patterns that are frequently present in CKD patients, such as hypertension during the sleep period. An abnormal ABPM pattern can also be predictive of the development of end-organ damage. Treatment of hypertension in children, with and without CKD, is based on 3 factors: degree of BP elevation, the presence of cardiovascular risk factors, and the presence of end-organ damage. Additionally, the initial antihypertensive agent may be selected on available and age-appropriate formulations (eg, suspension and dosage selection). A physician treating a hypertensive child with CKD faces multiple challenges. They include selecting the convenience of available automated devices and the ABPM versus traditional auscultatory techniques upon which all normative standards have been based. Current research initiatives propose to develop pharmacokinetic and pharmacodynamics properties of antihypertensive medications and to study the effect of early intervention on end-organ damage.     

Nighttime blood pressure, systolic blood pressure variability, and left ventricular mass index in children with hypertension

Background

Nighttime blood pressure (BP) and systolic BP variability on ambulatory blood pressure monitoring (ABPM) have been strongly associated with target-organ damage in hypertensive adults. The clinical relevance of these variables in children with hypertension remains under-studied.

Methods

The study group included children aged 5–18 years old referred to the outpatient nephrology clinic for an elevated casual BP who underwent an ABPM and echocardiography (ECHO) study and did not have secondary hypertension. The interpretation of ABPM parameters and left ventricular mass index (LVMI) was based on normative references.

Results

Seventy-two children fulfilled the inclusion criteria. The association of various potential predictors including age, BMI z-score, casual BP z-score and ABPM parameters (BP z-score, BP load, nocturnal dipping and BP variability- within-subject standard deviation (SD) of BP) with LVMI was analyzed. On adjusted regression analysis, nighttime systolic BP load [standardized regression coefficient (β) 0.23; p?<?0.05] and daytime systolic BP variability (β 0.37; p?<?0.05) had significant association with LVMI.

Conclusions

In children with primary hypertension, nighttime systolic BP load and daytime systolic BP variability had a stronger association with LVMI than casual BP and other ABPM parameters. Future longitudinal studies are needed to establish the causality among these variables.     

Blood pressure assessment in haemodialysis patients: Comparison between pre-dialysis blood pressure and ambulatory blood pressure measurement

Aim: Hypertension is common in haemodialysis (HD) patients. Determining the most appropriate method of blood pressure (BP) measurement, representative of target organ damage, is still an issue. BP variations between pre‐ and post‐HD treatment, or between on‐dialysis day and off‐dialysis day, are common. The aim of this study was to examine the possible differences between pre‐HD office BP (OBP) levels, inter‐HD (iHD) or HD day 24 h ambulatory BP measurement (ABPM) with 48 h ABPM, where the latter was considered the gold standard. Methods: 163 HD patients were studied. BP was monitored consecutively for 48 h with a Takeda TM2421 device, then sub‐analysed into two periods of 24 h: HD and iHD day. An average of 12 sessions pre‐HD OBP measurements was determined. Results: OBP significantly overestimates systolic (SBP) and diastolic BP (DBP) when compared with 48 h ABPM. SBP and DBP are significantly higher on iHD day than on HD day: 141.2 ± 20.8 versus 137.9 ± 20.9, and 77.1 ± 11.1 versus 76.1 ± 10.9 (P < 0.01). No differences of SBP night/day ratio were reported between 48 h ABPM and iHD 24 h ABPM or HD 24 h ABPM. The highest correlations were reported between 48 h SBP/DBP with iHD or HD 24 h ABPM (r² = 0.95, P < 0.001), while the lowest between 48 h SBP/DBP and OBP (r² = 0.40, P < 0.01, r² = 0.12, P < 0.01). The narrowest limits of agreement using the Bland and Altman test were reported between 48 h SBP or DBP and 24 h iHD or HD day ABPM. Considering 48 h ABPM, 80.5% of patients had BP higher than the norm, compared with 61.7% of patients in the case of OBP (χ² = 13.28, P < 0.001). The sensibility for detecting hypertension for iHD day 24 h ABPM was 98.4%, with specificity of 90%. The sensibility of 24 h HD day ABPM was 90.3%, with specificity 96.6%. In the case of OBP, sensibility and specificity were considerably lower, that is, 72.6% and 83.3% respectively. Conclusion: Significant differences are shown between OBP and 48 h ABPM in the recognition of a hypertensive state. OBP measurement has a lower sensibility and specificity than 24 h ABPM, which remains a valid alternative approach to 48 h ABPM in HD patients. Errors of OBP estimation should be taken into account, with possible negative impact on treatment strategies and epidemiology studies.