Maria Isabel Torro

Factors related to quality of ambulatory blood pressure monitoring in a pediatric population

To assess the factors related to the quality of ambulatory blood pressure monitoring in a pediatric population, we performed 24-h ambulatory blood pressure monitorings on 333 unselected children aged 3 to 18 years using a Spacelabs 90207 monitor. For each individual, the percentages of valid measurements (ratio between valid and total number of measurements, 76.4% +/-15.6%) and of successful measurements (percentage of valid preset measurements, 89.8% +/- 11.5%) were calculated. Two hundred eighty-one (84.1%) monitorings had a successful measurement rate of >80%. Two hundred thirteen (64%) were of excellent quality, as defined by the percentage of successful measurements being higher than or equal to 90%. Age (P < .0001) and 24-h systolic blood pressure (P < .04) were positively and independently associated (in multiple regression analysis) to the percentage of successful measurements, accounting for 8% of the variance. Furthermore, a significant negative correlation between causal pulse pressure and the number of erroneous measurements was observed (r = -0.18, P < .01). This study has shown that in a pediatric population, the quality of the monitoring depends only in part on age and ambulatory systolic blood pressure values when an oscillometric device is used. The results have demonstrated the important role pulse pressure amplitude plays when accounting for the number of erroneous measurements.

Associations of birth weight and postnatal weight gain with cardiometabolic risk parameters at 5 years of age.

The present prospective study assessed the impact of birth weight (BW) and postnatal weight gain on blood pressure and metabolic profile during the first 5 years of life. One hundred thirty-nine newborns (63 women) born at term after uncomplicated pregnancies and in the absence of perinatal illness were included. Subjects were divided according to size at birth in small, appropriate, and large for gestational age. After the initial evaluation on the second day of life, infants were followed up at 6 months and 2 and 5 years. Anthropometric parameters and blood pressure were measured at each visit and metabolic assessment was performed at 5 years of age. Among the BW groups, mothers did not differ in terms of age, smoking, and weight gain during pregnancy. BW was a positive determinant of systolic blood pressure at birth. Afterward, current weight was the strongest determinant, becoming significant at 2 years of age and progressively increasing in influence. At 5 years insulin, the homeostasis model assessment index and triglycerides were dependent on BW, current weight, and postnatal weight gain. In addition, BW was positively associated with high-density lipoprotein-cholesterol and inversely so to uric acid. A positive relationship among insulin, blood pressure values, and uric acid was observed even early in life. In conclusion, the acceleration of early infant weight gain may aggravate the effects of low BW. Multiple interactions between hemodynamic and metabolic parameters foreshadow the clustering of cardiometabolic risk factors later in life.

Sexual Dimorphism in the Transition From Masked to Sustained Hypertension in Healthy Youths

The risk and factors related to the development of hypertension among healthy youths with elevated ambulatory and normal conventional blood pressure, masked hypertension, have not been established. We performed a long-term follow-up study assessing how hypertension develops over time in healthy, masked hypertensive youths. The potential sex dimorphism in the incidence and timing of the development of hypertension has been analyzed. In a long-term follow-up study (median follow-up, 36 months), we enrolled 272 healthy conventional normotensive youths (aged 6–18 years; 55.8% girls) of whom 39 had masked hypertension at baseline. Development of sustained hypertension (hypertension in both conventional and ambulatory measurement) was recorded. The daytime systolic blood pressure increased from baseline to last available follow-up in boys (3.5 mm Hg; P<0.001) but not in girls (0.7 mm Hg; P=0.23), leading to a significant between-sex difference (P=0.0022). The incidence of sustained hypertension was 7.0/100 subjects/y (n=12) in masked hypertensives and 0.6/100 subjects/y (n=4) in normotensives. Masked hypertensive boys more frequently proceeded to sustained hypertension as compared with masked hypertensive girls (50.0% versus 17.4%; P=0.041). Masked hypertension at baseline (hazard ratio, 15.6; 95% confidence interval, 4.91–49.7; P<0.0001) and male sex (hazard ratio, 3.25; 95% confidence interval, 1.12–9.39; P=0.0295) were independent factors associated with the incidence of sustained hypertension during the follow-up. In youth, masked hypertension is a precursor of sustained hypertension. The risk of developing sustained hypertension is higher in boys than it is for girls. The fact that masked hypertension is not prognostically innocent increases the importance of the diagnosis at an early age.

Prevalence and factors related to urinary albumin excretion in obese youths.

Objectives: The aim of the present study is to assess whether obesity is associated with urinary albumin excretion and what the main determinants are. Methods: One hundred and thirty-four obese white children and adolescents of both sexes, ranging from 9 to 18 years of age (mean age 12.6 ± 2.0), were included in the study. Obesity was defined on the basis of a threshold BMI z-score of more than 2 (Coles LMS method) and overweight with a BMI from the 85th to 95th percentile. Office blood pressure was measured using a mercury sphygmomanometer. Urinary albumin excretion was measured in the first voiding urine of the morning and expressed in albumin/creatinine ratio in mg/g. Reproducibility of the urinary albumin excretion was studied by the Bland and Altman technique in a subgroup. Triglycerides, uric acid, fasting glucose and insulin were measured and the homeostatic model assessment (HOMA) index was calculated. Results: The prevalence of microalbuminuria was 2.4%. No differences in the prevalence of microalbuminuria were observed when the different groups of obesity degree were compared (0, 2.2 and 0% in overweight, moderate and severe obese, respectively). A significant relationship emerged between the Log urinary albumin excretion and BMI z-score, waist circumference, Log triglycerides, fasting insulin and HOMA index, adjusted by age and sex. In a multiple regression analysis, the main determinants of Log urinary albumin excretion were sex, waist circumference and Log triglycerides. In 17% of the individuals who fulfil criteria for metabolic syndrome, urinary albumin excretion was significantly higher than those without. Conclusion: The prevalence of elevated urinary albumin excretion is not prominent in obese children, and when it is increased, it depends mainly on metabolic factors.

Central blood pressure and pulse wave amplification across the spectrum of peripheral blood pressure in overweight and obese youth.

Objective: To identify vascular phenotypes across blood pressure (BP) conditions in overweight and obese youths, by assessing office BP (oBP), and central BP (cBP), and pulse pressure (PP) amplification. Whether or not 24-h ambulatory BP monitoring (ABPM) and pulse wave velocity (PWV) add insight to the issue has also been examined. Methods: White youths of both sexes with overweight or obesity and of European origin, ranging from 8 to 18 years of age, were included. oBP, cBP, PWV, and 24-h ABPM were measured. oBP conditions and ‘white-coat’ hypertension were defined as recommend by European Society Hypertension Guidelines in Children and Adolescents. Patients were divided into subgroups of ‘normal’ or ‘high’ according to cBP and PP ratio. Results: A total of 593 patients (mean age, 12.2 ± 2.3 years; 275 women) were included in the study. The largest differences between office SBP and central SBP correspond to the isolated systolic hypertension (ISH) group, in which only 25% of patients have high cBP, in contrast to 50% of the systo-diastolic hypertension (SDH) group. Two patterns emerged based on cBP and PP ratio – while the highest cBP was among the SDH, the highest PP amplitude was in the ISH group. Ninety percent of the SDH were confirmed with 24-h ABPM, in contrast to 75% of the ISH, who were white-coat hypertensive. PWV showed a progressive increment across the groups from normotension to SDH. Significant differences were observed only when compared with the normotensive, but not among all other groups. Conclusion: In overweight and obese hypertensive patients, ISH is prevalent, posing a challenge for the clinician of whether these may therefore be diagnosed and managed as hypertensive patients. Until prospective studies can give more knowledge, 24-h ABPM can offer information for making clinical decisions.

Determinants of Cardiometabolic Risk Factors in the First Decade of LifeNovelty and Significance: A Longitudinal Study Starting at Birth

The present prospective study assessed the association of birth weight (BW) and growth pattern on cardiometabolic risk factors in a cohort followed from birth to 10 years of age. One hundred and forty-five subjects (73 girls) who fulfilled the inclusion criteria and had all their data recorded at birth and at 5 years were enrolled. Of these, 100 (52 girls) also recorded data at 10 years. Anthropometric measurements, office and 24-hour blood pressure, and metabolic parameters were obtained. At 5 years, both BW and current weight were determinants of blood pressure and metabolic parameters; however, as the subjects got older, the impact of body size increased. Higher BW and maternal obesity increased the risk of becoming obese at 5 years while this was reduced if breastfeeding. Maternal obesity was the only factor associated with becoming obese at 10 years. Twenty-two children at 10 years had insulin values ≥15 U/L, some of whom were persistent from 5 years while in others it increased afterward. Subjects with insulin values ≥15 U/L showed significant higher values of office systolic blood pressure, triglycerides, and uric acid and lower values of high-density lipoprotein than did those with normal insulin values. Highest weight gain from 5 to 10 years and lowest BW were the main determinants of high insulin levels. In conclusion, although BW was a proxy of the events during fetal life and projected its influence later, the influence of gaining weight was a key determinant in the risk to develop obesity and metabolic abnormalities.

URIC ACID IS ASSOCIATED WITH CARDIOMETABOLIC RISK FACTORS IN OVERWEIGHT AND OBESE CHILDREN AND ADOLESCENTS

Objective: This study examined the association of serum uric acid (UA) with levels of cardiometabolic risk factors in overweight and moderate obese children and adolescents. Design and method: Three hundred and thirty three Caucasians of both sexes (149 females), of European origin, from 5 to 18 years of age (mean age 11.4 2.6) were included. Overweight and obesity were defined based on the extended international body mass index cut-offs. The subjects were divided into 3 groups according to serum UA: <5 mg/dl n = 118 subjects (35%); UA 5-6 mg/dl n = 130 subjects (39%) or UA>6 mg/dl n = 85 subjects (26%). Fasting blood was obtained and uric acid, glucose, insulin, and lipid profile, were measured. Likewise office BP and 24-hour ABPM were assessed. Hyperinsulinemia was defined from norms for pubertal stage. Abnormal fasting lipids were defined from normative data (Daniels et al, 2008). Subjects were qualified as normotensive, high-normal or hypertensive according to the ESH criteria (Lurbe et al, 2016). Results: There were significant differences among groups regarding, BMI, waist, fasting insulin, office SBP and night-time SBP increasing progressively across the serum UA groups. Controlling by age and sex, uric acid was significantly correlated with BMI (r = 0.27, p = 0.000), waist (r = 0.33; p = 0.000), birth weight (r = −0.11; p = 0.05), office SBP (r = 0.21; p = 0.000), daytime SBP, (r = 0.16; p = 0.03), nighttime SBP (r = 0.24; p = 0.000), insulin (r = 0.25; p = 0.000), and Log Tryglicerides (r = −0.137; p = 0.019). In a multiple regression analysis sex, waist, birth weight, SBP (office, daytime and nighttime), were independent determinants of uric acid when age, BMI, HDL-C and insulin were included (R2 = 0.29). The prevalence of hyperinsulinemia, low HDL-C, high-normal BP, and hypertension in each UA group are shown in the Figure. Figure. No caption available. Conclusions: In overweight and moderate obese children and adolescents there is a trend toward greater prevalence of cardiometabolic risk factors as the uric acid values rose. The role of hyperuricemia and its association with cardiometabolic risk factors should receive more attention, beginning in early childhood.

DIFFERENCES IN THE PREVALENCE OF BLOOD PRESSURE CONDITIONS USING ESH VS AAP GUIDELINES IN CHILDREN AND ADOLESCENTS

Objective: The objective is to assess differences in the prevalence of blood pressure (BP) conditions according to the European Society of Hypertension (ESH) guidelines (Lurbe, J Hypertens 2016) and the American Academy of Pediatrics (AAP) (Flynn, Pediatrics 2017) in children and adolescents. Design and method: Four thousand two hundred and ninety-six Caucasians of both sexes (1941 females), of European origin, from 5 to 18 years of age (mean age 11.5 3.3) in the absence of antihypertensive treatment were included. Overweight and obesity (n = 2243) were defined based on the extended international body mass index cut-offs. Office BP was measured in the non-dominant arm with cuff and bladder size adjusted to upper-arm girth. The three measurements of each office visit were averaged for analysis. Twenty-four-hour ambulatory BP monitoring was performed by using Spacelabs monitor 90207. Subjects were qualified as true normotensive (N), white-coat (WC), masked (M) or sustained hypertensive (HTN) according to the ESH and AAP criteria for office BP, and reference values for 24-hour ambulatory BP (Wühl, J Hypertens 2002). Results: The prevalence of N, WC, M and HTN were significantly different when the ESH or AAP were applied. Overall, the largest differences were observed in the prevalence of WC, which was double when the AAP criteria were used. The differences were larger for boys, older than 13 years of age. The presence of obesity did not reduce the higher prevalence of WC by the AAP criteria. In contrast, M was slightly higher when the ESH criteria were applied. The impact on the prevalence of WC and M is shown in the figure. Figure. No caption available. Conclusions: When applying the AAP criteria, compared with that of the ESH, the main difference is the higher prevalence of WC, especially in boys aged 13 years or older. The consequence is an increment of the HTN work-up in children and adolescents.

[OP.6A.06] VASCULAR PHENOTYPES BY ASSESSING PERIPHERAL AND CENTRAL BLOOD PRESSURE IN OBESE YOUTH.

Objective: To identify vascular phenotypes across BP conditions in overweight and obese youths, by assessing office (oBP) and central BP (cBP), and pulse pressure amplification. Whether or not 24-hour ambulatory BP monitoring and pulse wave velocity (PWV) add insight to the issue has also been examined. Design and method: White youths of both sexes with overweight or obesity and of European origin, ranging from 8 to 18 years of age, were included. Office BP, cBP, PWV, and 24-hour ABPM were measured. Office BP conditions and “white-coat” HTN were defined as recommend by ESH Guidelines in Children and Adolescents. Subjects were divided into subgroups of “normal” or “high” according to cBP and PP ratio. Results: A total of 593 subjects (mean age, 12.2 ± 2.3 years; 275 females) were included in the study. The largest differences between oSBP and cSBP correspond to the isolated systolic HTN (ISH) group, in which only 25% of subjects have high cBP, in contrast to 50% of the systo-diastolic HTN (SDH) group. In the hypertensive youth two patterns emerged based on cBP and PP ratio. The highest cBP was among the SDH and the highest PP ratio in the ISH group (see Figure). While, 90% of the SDH were confirmed with 24-hour ABPM, 75% of the ISH were white-coat. PWV showed a progressive increment across the groups from NT to SDH. Significant differences were observed only when compared to the NT, but not among all other groups. Figure. No caption available. Conclusions: In overweight and obese hypertensives, ISH is prevalent posing a challenge for the clinician of whether these may therefore be diagnosed and managed as hypertensives. Until prospective studies can give more information, 24-hour ABPM can offer information for making clinical decisions.

2B.04: FACTORS RELATED TO THE LINK BETWEEN URIC ACID AND SYSTOLIC BLOOD PRESSURE IN YOUTHS.

Objective: The present research was undertaken to analyze factors related to the link between uric acid (UA) and office blood pressure (BP) in normotensive, high-normal and untreated essential hypertensive youths. Design and method: Six hundred and forty three Caucasians of both sexes (321 females), of European origin, predominantly obese, from 6 to 18 years of age (mean age 11.7 2.4) were included. The subjects were divided into 3 groups: normotensives 559 (87%; 92 non-obese), high-normal BP 58 (9%; 19 non-obese) or hypertensives 26 (4%; 5 non-obese) according to the ESH office BP criteria (Lurbe et al, J Hypertens 2009). Fasting blood was obtained and glucose, insulin, lipid profile, and UA were assessed. Results: In relation to the general characteristics, there were no differences among groups regarding age, BMI, BMI-zscore, HDL and insulin. Uric acid increases across the BP range from normotensive to hypertensive groups. Controlling by age and sex, UA was significantly correlated with BMI (r = 0.180, p = 0.000), BMI Z-score (r = 0.175; p = 0.000), SBP (r = 0.20; p = 0.000), insulin (r = 0.23; p = 0.000), and HDL (r = -0.149; p = 0.000). In a multiple regression analysis office SBP, insulin, and HDL cholesterol were independent determinants of UA when age, sex, and BMI were included (r2 = 0.25). Office systolic BP was the main determinant of UA in a stepwise analysis. Even though UA was corrected by body size, UA/BMI ratio, systolic BP was the main determinant in boys (See figure). Figure. No caption available. Conclusions: Uric acid is associated with BP, independently of metabolic factors in boys. The clinical implications require further investigation.