Christina V. Alamara

Reproducibility of home and ambulatory blood pressure in children and adolescents.

ObjectiveTo evaluate the reproducibility of blood pressure measured at home (HBP) in comparison with ambulatory (ABP) and clinic blood pressure (CBP) in children and adolescents. Participants and methodsIndividuals aged 8–17 years who had been referred for elevated CBP were included. CBP was measured at two visits, HBP on 5 days and ABP for 24 h. A second session including all the above measurements was performed after 8 weeks. The reproducibility of CBP (second visit of each session), HBP (average of days 2–5 of each session) and ABP (average 24-h, awake and asleep) was quantified using test–retest correlations coefficients (r) and the standard deviation of differences (SDD) between repeated measurements. ResultsSixteen individuals were included [mean age 13.3±2.9 (SD)] years, range 8–17, nine boys]. According to Task Force CBP criteria, eight were classified as hypertensives, three as high normal and five as normotensives. The reproducibility of HBP (systolic/diastolic r, 0.74/0.82, SDD 7.0/4.3) was superior to that of CBP (r, 0.63/0.80, SDD 10.4/6.3). However, ABP appeared to provide the most reproducible values (r, 0.87/0.84, SDD 5.5/4.3 for 24-h ABP; r, 0.85/0.76, SDD 5.9/5.0 for awake; r, 0.76/0.79, SDD 7.0/5.0 for asleep ABP). Aspects of the diurnal ABP variation were poorly reproducible (r, 0.62/0.14, SDD 6.8/5.5 for awake-asleep ABP difference; r, 0.55/0.26, SDD 0.07/0.11 for awake : asleep ratio). ConclusionThese data suggest that in children and adolescents home blood pressure measurements are more reproducible than clinic measurements. However, 24-h ambulatory monitoring appears to provide the most reproducible blood pressure values.

White-coat hypertension and masked hypertension in children.

The use of ambulatory blood pressure monitoring in addition to the conventional office measurements makes possible the detection of individuals with white-coat hypertension and masked hypertension. In children referred for elevated blood pressure, both these phenomena appear to be common (10-15% for each). In a population of healthy children, white-coat hypertension appears to be as common as hypertension, whereas masked hypertension appears to be more common than white-coat hypertension or hypertension. In children with persistent white-coat or masked hypertension, assessment of target organ damage by echocardiography is required. Preliminary evidence suggests that, in contrast to white-coat hypertension, which is not associated with target organ damage, masked hypertension in children is associated with increased left ventricular mass. Children with masked hypertension should be followed up and possibly treated for hypertension if the phenomenon persists or there is evidence of target organ damage.

Office and out-of-office blood pressure measurement in children and adolescents.

Office and out-of-office blood pressure measurements are being used for the diagnosis of hypertension in children and adolescents. The US National Heart, Lung, and Blood Institute have recently presented a new classification of blood pressure. On the basis of office measurements the 90th, 95th and 99th percentile for gender, age and height are used to classify children and adolescents as normotensive, pre-hypertensive and stage-1 or stage-2 hypertensive. Although auscultation using a standard mercury sphygmomanometer remains the recommended method, accumulating evidence suggests that ambulatory blood pressure monitoring is useful for the detection of white-coat hypertension and the prediction of target organ damage in children and adolescents. Studies have shown ambulatory blood pressure to be more reproducible than office measurements and normative tables for ambulatory measurements have been developed from cross-sectional studies in children and adolescents. In regard to home measurements in children, there are limited data from small trials showing lower blood pressure levels than daytime ambulatory blood pressure. In conclusion, ambulatory blood pressure monitoring is already finding a role as a supplementary source of information in children and adolescents, whereas at present home measurements should not be used for decision making in this population.

Home Blood Pressure Monitoring in Children: How Many Measurements are Needed?

OBJECTIVE To investigate the minimum schedule of blood pressure (BP) measurements necessary to provide a reliable assessment of home BP (HBP) in children and adolescents. METHODS Subjects aged 6-18 years referred for elevated BP were assessed with HBP monitoring (6 workdays, duplicate morning and evening measurements) and 24-h ambulatory BP monitoring (ABP). Criteria for HBP reliability were its reproducibility (test-retest correlations and SD of differences (SDDs) between repeated measurements), its stability (average home BP of an increasing number of readings and its SD), and its relationship with ABP. RESULTS Data from 100 subjects were analyzed (mean age 13 +/- 2.8 (SD) years, 61 boys). The reproducibility of 3-day HBP (r 0.88/0.79, SDDs 5.1/4.9, systolic/diastolic) was superior to that of a single (r 0.79/0.65, SDDs 7.6/7.1) or 2-day HBP (r 0.85/0.72, SDDs 6.1/5.4). By averaging up to 12 readings (3 days), there was a progressive decline in average HBP, with no further decline thereafter. The SD of average HBP was also progressively reduced, with little change after day 3. The association of HBP with ABP was improved by averaging more readings up to 12, with no further improvement when more readings were averaged. The exclusion of first-day measurements slightly increased the SD of average HBP and weakened the correlation with ABP, probably due to reduced number of readings. CONCLUSIONS In children and adolescents, 3-day monitoring with duplicate morning and evening measurements appears to be the minimum schedule for the reliable assessment of HBP.

Prediction of albuminuria by different blood pressure measurement methods in type 1 diabetes: a pilot study

In type 1 diabetes, the risk of nephropathy is strongly influenced by the level of blood pressure (BP). Ambulatory BP (ABP) monitoring has revealed an association between disturbed nocturnal BP drop and albuminuria and suggested a role of BP in microalbuminuria development. This study investigated the relationship between the urinary albumin excretion ratio (AER) and home BP (HBP) compared with ABP and clinical BP (CBP) measurements. A total of 50 adolescents and young adults with type 1 diabetes without hypertension or overt proteinuria (mean age 20±3.8 (s.d.) years, 21 male) had measurements of CBP (3 visits), HBP (6 days), 24-h ABP and AER (daytime and nighttime in the same 24 h with ABP monitoring). AER of 24 h was correlated with systolic 24-h (r=0.31), daytime (r=0.33) and nighttime ABP (r=0.36), without significant correlation with diastolic ABP, CBP or HBP (systolic or diastolic). Nighttime AER was correlated with 24-h (r=0.39/0.35, systolic/diastolic), daytime (r=0.36/0.32) and nighttime ABP (r=0.44/0.28). HBP was not associated with nighttime AER, but CBP was (diastolic BP only, r=0.41). No significant correlations were found between daytime AER and BP measurements. The nocturnal BP dip was not associated with any BP value. In non-dippers, nighttime AER showed strong correlations with ABP (24-h: r=0.45/0.42, systolic/diastolic; daytime: r=0.46/0.45; nighttime: r=0.49/0.35), HBP (r=0.34/0.31) and CBP (r=0.39/0.47). No such associations were found in dippers (r=0.05-0.10). These preliminary data suggest that in the early stage of diabetes-1, 24-h ABP monitoring seems to be the optimal method of revealing the association between BP and albuminuria, and cannot be replaced by HBP monitoring.