Impact of ESH and AAP hypertension guidelines for children and adolescents on office and ambulatory blood pressure-based classifications.

BACKGROUND: The objective was to assess the differences between the 2016 European Society of Hypertension (ESH) and the 2017 American Academy of Pediatrics (AAP) hypertension (HTN) guidelines in the distribution of office blood pressure (BP) categories as well as in the office and ambulatory BP mismatches. MATERIAL AND METHODS: The study included 4940 clinical evaluations performed in 2957 youth (5-18 years) of both sexes. BP and anthropometric parameters were measured following standard conditions. The classification of the BP measurements was normotension, high-normal, stages 1 and 2 HTN, following the criteria of both guidelines. In a subgroup of 2467 participants, 3941 office BP assessment was completed with 24-h ambulatory BP monitoring using an oscillometric monitor under standard conditions. The classification on white-coat (WCH) and masked HTN was recorded. RESULTS: The AAP classified more participants, 70 per 1000 BP evaluations in the categories of high-normal and stage 1 HTN, than the ESH did. The differences were greater in obese, but also present in normal weight participants. Likewise, significant discrepancies were observed in the prevalence of WCH and masked HTN. The AAP identified more participants with WCH, with greater differences in older participants, mainly in boys, independent of weight category. In contrast, the ESH identified more participants with masked HTN. The excess of WCH by AAP was three times higher than the excess of masked HTN by ESH. CONCLUSION: The application of the two guidelines may result in marked differences in the classification of high-normal BP and HTN and in the mismatched conditions when ambulatory BP monitoring is applied.

Changes in physical fitness of a home-based physical exercise program in childhood obesity: A quasi-experimental uncontrolled study.

Few studies have evaluated the changes in physical fitness (PF) of obese children and adolescents of a physical activity program for the treatment of obesity, and even fewer have explored the modality of home-based physical exercise. The objective of this study is to evaluate the changes in PF and body composition (BC) of a home-based physical exercise for treating childhood obesity. Thirty-three overweight/obese children and adolescents participated for six months in a home-based intervention that combined aerobics and muscular strength exercises. The results were compared, before and after the intervention, for the different PF components (VO2max, abdominal muscle resistance strength, and lower body explosive strength) and BC (body mass index Z-score (BMI-Z), percentage of body fat, and fat-free mass) variables. A significant reduction was observed in the percentage of body fat (4.7%) and the BMI- Z score (.23), and there was an increase in the fat-free mass of 2.9 kg ( p < .001). In addition, the VO2max showed a significant increase ( p < .05). The results of the different strength tests also showed significant improvements ( p < .05). Our findings support the effectiveness of this program improving not only BC but also PF. However, our results should be interpreted with caution due to lack of control group.

Blood pressure and obesity exert independent influences on pulse wave velocity in youth.

The objective was to analyze pulse wave velocity (PWV) in normotensive, high-normal, and hypertensive youths by using aortic-derived parameters from peripheral recordings. The impact of obesity on vascular phenotypes was also analyzed. A total of 501 whites from 8 to 18 years of age were included. The subjects were divided according to BP criteria: 424 (85%) were normotensive, 56 (11%) high-normal, and 21 (4%) hypertensive. Obesity was present in 284 (56%) and overweight in 138 (28%). Pulse wave analysis using a SphygmoCor device was performed to determine central blood pressure (BP), augmentation index, and measurement of PWV. Among the BP groups, differences appeared in age, sex, and height but not in body mass index. Significant differences in peripheral and central systolic and diastolic BPs and pulse pressures were observed within groups. A graded increase in PWV was present across the BP strata without differences in augmentation index. Using a multiple regression analysis, age, BP groups, and obesity status were independently associated with PWV. Older and hypertensive subjects had the highest PWV, whereas, from normal weight status to obesity, PWV decreased. Likewise, PWV was positively related to peripheral or central systolic BP and negatively related to body mass index z score. For 1 SD of peripheral systolic BP, PWV increased 0.329 m/s, and for 1 SD of body mass index z score PWV decreased 0.129 m/s. In conclusion, PWV is increased in hypertensive and even in high-normal children and adolescents. Furthermore, obesity, the factor most frequently related to essential hypertension in adolescents, blunted the expected increment in PWV of hypertensive and high-normal subjects.

Exercise intervention in childhood obesity: a randomized controlled trial comparing hospital-versus home-based groups.

OBJECTIVE: The aim of this study was to compare the effect of a hospital clinic group- versus home-based combined exercise-diet program for the treatment of childhood obesity. METHODS: One hundred ten overweight/obese Spanish children and adolescents (6-16 years) in 2 intervention groups (hospital clinic group-based [n = 45] and home-based [n = 41]) and a sex-age-matched control group (n = 24) were randomly assigned to participate in a 6-month combined exercise (aerobic and resistance training) and Mediterranean diet program. Anthropometric values (including body weight, height, body mass index, BMI-Z score, and waist circumference) were measured pre- and postintervention for all the participants. Percentage body fat was also determined with a body fat analyzer (TANITA TBF-410 M). RESULTS: Our study showed a significant reduction in percentage body fat and body mass index Z-score among both intervention-group participants (4%, 0.16, hospital clinic group-based; 4.4%, 0.23, home-based; P < .0001). There was also a significant reduction in waist circumference in the home-based group (4.4 cm; P = .019). Attendance rates at intervention sessions were equivalent for both intervention groups (P = .805). CONCLUSIONS: The study findings indicate that a simple home-based combined exercise and Mediterranean diet program may be effective among overweight and obese children and adolescents, because it improves body composition, is feasible and can be adopted on a large scale without substantial expenses.

Influence of concurrent obesity and low birth weight on blood pressure phenotype in youth.

The aim of this study was to assess the impact of obesity and low birth weight on both office and ambulatory blood pressure (BP) values, as well as on aortic-derived parameters in youths. A total of 422 white youths, from 10 to 18 years of age, were included. Subjects were divided into 4 groups according to the presence (234; 55%) or the absence (188; 45%) of obesity and according to low (114; 27%) or normal (308; 73%, birth weight. Spacelabs 90207 was used to measure ambulatory BP during a 24-hour period. SphygmoCor radial/aortic transform software was used to estimate aortic pressure waveform. Office, 24-hour, daytime, and nighttime systolic BP values were significantly higher in those subjects with low birth weight who became obese. The lowest BP values were present in nonobese subjects in the absence of low birth weight. In the middle, with similar BP values, were nonobese subjects with low birth weight and obese subjects in the absence of low birth weight. No interaction existed between obesity and low birth weight in the office (P=0.165) or ambulatory (P=0.603) systolic BP values. Augmentation index, an estimate of the pulse wave reflection, was significantly higher in the nonobese low birth weight group when compared with the other groups after controlling for height, heart rate, and diastolic BP. A significant interaction between low birth weight and obesity (P<0.005) existed. In conclusion, although the low birth weight children who become obese have the highest systolic BP values, the presence of obesity blunts the increment of the reflecting wave observed in low birth weight subjects.

Birth weight and characteristics of endothelial and smooth muscle cell cultures from human umbilical cord vessels.

BACKGROUND: Low birth weight has been related to an increased risk for developing high blood pressure in adult life. The molecular and cellular analysis of umbilical cord artery and vein may provide information about the early vascular characteristics of an individual. We have assessed several phenotype characteristics of the four vascular cell types derived from human umbilical cords of newborns with different birth weight. Further follow-up studies could show the association of those vascular properties with infancy and adulthood blood pressure. METHODS: Endothelial and smooth muscle cell cultures were obtained from umbilical cords from two groups of newborns of birth weight less than 2.8 kg or higher than 3.5 kg. The expression of specific endothelial cell markers (von Willebrand factor, CD31, and the binding and internalization of acetylated low-density lipoprotein) and the smooth muscle cell specific alpha-actin have been evaluated. Cell culture viability, proliferation kinetic, growth fraction (expression of Ki67) and percentage of senescent cells (detection of beta-galactosidase activity at pH 6.0) have been determined. Endothelial cell projection area was determined by morphometric analysis of cell cultures after CD31 immunodetection. RESULTS: The highest variation was found in cell density at the confluence of endothelial cell cultures derived from umbilical cord arteries (66,789 +/- 5,093 cells/cm(2) vs. 45,630 +/- 11,927 cells/cm(2), p < 0.05). Morphometric analysis indicated that the projection area of the artery endothelial cells (1,161 +/- 198 and 1,544 +/- 472 microm(2), p < 0.05), but not those derived from the vein from individuals with a birth weight lower than 2.8 kg was lower than that of cells from individuals with a birth weight higher than 3.5 kg. CONCLUSION: The analysis of umbilical cord artery endothelial cells, which demonstrated differences in cell size related to birth weight, can provide hints about the cellular and molecular links between lower birth weight and increased adult high blood pressure risk.

Added impact of obesity and insulin resistance in nocturnal blood pressure elevation in children and adolescents.

The aim of the present study was to analyze the relationship between insulin resistance and the ambulatory blood pressure components in obese children and adolescents. Eighty-seven overweight and obese white children and adolescents of both sexes, of European origin from 6 to 18 years of age (mean age: 10.9+/-2.7 years), were selected. Obesity was defined on the basis of a threshold body mass index z score >2 (Cole's least mean square method) and overweight with a body mass index from the 85th to 97th percentile. A validated oscillometric method was used to measure ambulatory BP (Spacelabs 90207) during 24 hours. Fasting glucose and insulin were measured, and the homeostasis model assessment index was calculated. Subjects were grouped into tertiles of homeostasis model assessment index. No significant differences in terms of age, sex, and body mass index z score distribution were observed among groups. When adjusted by age, sex, and height, nocturnal systolic blood pressure and heart rate were significantly higher in subjects in the highest homeostasis model assessment index tertile (>4.7) as compared with those of the other groups, whereas no differences were observed for awake systolic blood pressure or heart rate. Whereas body mass index z score was more closely related with blood pressure and heart rate values, waist circumference was strongly related with insulin resistance. Moreover, both waist circumference and insulin resistance were mainly associated with higher nocturnal but not with awake blood pressure. The early increment of nocturnal blood pressure and heart rate associated with hyperinsulinemia may be a harbinger of hypertension-related insulin resistance and may contribute to heightened cardiovascular risk associated with this condition.

Cold medication containing oral phenylephrine as a cause of hypertension in children.

A 5-year-old girl presented hypertension [24-h blood pressure (BP) average 135/80 mmHg, above the 99th BP percentile], as confirmed by ambulatory BP monitoring, following the use of a cold preparation (2.5 ml every 8 h for 4 days) containing phenyephrine (1 mg/ml). There was a clear relationship between the administration of the medication and hypertension, and between normalized BP values (24-h BP average 109/66 mmHg, 90th percentile) and the withdrawal of the medication. Alternative causes of hypertension could not be found. This is the first reported case of children's hypertension related with oral administration of phenylephrine. The potential risk of medicines containing sympathomimetic drugs should not be underestimated, and cold preparations should be included in the differential diagnosis of the etiology of hypertension in children.

Procedure to consistently obtain endothelial and smooth muscle cell cultures from umbilical cord vessels.

The prenatal history of an individual can be responsible to some extent for the occurrence of several diseases later in life. Thus, low birth weight has been related to an increased risk of developing hypertension or type 2 diabetes. The molecular and cellular basis of this increased risk could be found in body fluids and cell types that can be obtained just after birth. To get this unique information, a methodology was developed to consistently obtain cultures of 4 cell types, endothelial and smooth muscle cells from both the vein and the arteries present in the umbilical cord of an individual. From 21 umbilical cords processed, 82 of the 84 possible cell cultures were obtained. The cell cultures exhibit the expected cell morphology and cellular characteristics. Thus, endothelial cells express the von Willebrand factor, CD31, as well as bind and internalize acetylated low-density lipoprotein. Vascular smooth muscle cells express the distinctive alpha-actin. Cell cultures can be cryopreserved and grow healthy for several passages. No influence of birth weight of the newborn has been found in the time required to obtain a primary cell culture for any of the 4 cell types. In conclusion, the procedure developed allows one to routinely obtain actively growing vascular cell cultures that could be used to study the molecular and cellular basis of vascular diseases that emerge in adulthood.

First-year blood pressure increase steepest in low birthweight newborns.

AIM: The present research has been undertaken prospectively to study the impact of birthweight and growth pattern on blood pressure changes from birth through the first year of life. METHODS: Parents of newborns born at term (gestational age > 37 weeks) after uncomplicated pregnancies and in the absence of perinatal illness were randomly invited to allow their children to participate in the study. One hundred and forty-nine (84 male and 65 female) newborns were included in the present analysis. The newborns were divided into four groups according to birthweight: < 2500 g (n = 23); 2500-2999 g (n = 39); 3000-3500 g (n = 48); and > 3500 g (n = 39). RESULTS: At birth systolic and diastolic blood pressure were significantly lower and heart rate was significantly higher in those children with the lowest birthweight as compared to those in the other groups. During the first month of life a significant trend, inversely related to birthweight, was present for systolic as well as diastolic blood pressure. After the first month of life, at 3, 6, 9 and at 12 months, systolic and diastolic blood pressure were similar across birthweight groups. In a multiple regression analysis, birthweight was a positive independent determinant of systolic blood pressure at birth and an inverse independent determinant of the increment of systolic blood pressure during the first month of life and of the systolic blood pressure at the end of the first year. CONCLUSIONS: In summary, the present study goes further towards understanding blood pressure changes in low birthweight babies. Beginning at birth, both blood pressure values, as well as changes in blood pressure, provide information about the impact of intrauterine life on the risk of developing hypertension later in life.

The impact of the degree of obesity on the discrepancies between office and ambulatory blood pressure values in youth.

OBJECTIVES: Obesity is an increasingly frequent problem among children and adolescents, and may lead to blood pressure (BP) increase. The aim of the present study was to assess the prevalence of hypertension, white-coat and masked hypertension in obese adolescents making systematic use of both office BP and 24-h ambulatory BP measurement. The impact of different degrees of obesity on BP and heart rate variability was also investigated. METHODS: Office and ambulatory BP were obtained in 285 overweight and obese Caucasian adolescents (11-18 years old) and in 180 age- and sex-matched controls. The extent of obesity was quantified using body mass index z score. RESULTS: A significant positive relationship between body mass index z score and both office and ambulatory systolic BP was found after adjusting for age and height in both boys and girls. Obese youths had not only higher BP levels, but also higher BP variability compared with controls. Among obese youths, 20.8% had abnormal BP conditions, 6.6% were white-coat hypertensives, 9.2% were masked hypertensives and 5% were sustained hypertensives. CONCLUSIONS: The prevalence of these abnormal BP conditions, which can be identified thanks to ambulatory BP monitoring, further emphasizes the usefulness of this diagnostic tool in obese youths.

Prevalence, persistence, and clinical significance of masked hypertension in youth.

Masked hypertension, an elevated daytime ambulatory blood pressure in the presence of a normal office blood pressure, confers an increased cardiovascular risk to adults. We investigated the prevalence, persistence, and clinical significance of masked hypertension in children and adolescents. We enrolled 592 youths (6 to 18 years old). Youths with masked hypertension (n=34) and a random sample of the normotensive participants (n=200) were followed-up. In a nested case-control study, we compared echocardiographic left ventricular mass among cases with persistent masked hypertension and normotensive controls. At baseline, mean age was 10.2 years; 535 youths were normotensive on office and daytime ambulatory blood pressure measurement (90.4%), and 45 had masked hypertension (7.6%). Compared with normotensive controls, participants with masked hypertension had a higher ambulatory pulse rate, were more obese, and were 2.5-times more likely to have a parental history of hypertension. Among 34 patients with masked hypertension (median follow-up 37 months), 18 became normotensive, 13 had persistent masked hypertension, and 3 had sustained hypertension. Patients with persistent masked hypertension (n=17) or who progressed from masked to sustained hypertension (n=3) had a higher left ventricular mass index (34.9 versus 29.6 g/m2.7; P=0.023) and a higher percentage with left ventricular mass index above the 95th percentile (30% versus 0%; P=0.014) than normotensive controls. In children and adolescents, masked hypertension is a precursor of sustained hypertension and left ventricular hypertrophy. This condition warrants follow-up and, once it becomes persistent, is an indication for blood pressure-lowering treatment.

The impact of birth weight on pulse pressure during adolescence.

BACKGROUND: The objective was to study the influence of birth weight on office and ambulatory pulse pressure. METHODS AND RESULTS: Three hundred healthy children (176 girls), aged 10-18 years, born at term after a normotensive pregnancy were included. The subjects were divided according to birth weight: 2.000-2.500 kg, 2.501-3.000 kg, 3.001-3.500 kg and >3.500 kg. For each subject, office and 24-h ambulatory blood pressure monitoring were performed according to the protocol designed. There were significant differences among groups in 24-h ambulatory systolic blood pressure, and pulse pressure (PP). No differences were observed in terms of sex, current age, weight and height. Using a multiple linear regression analysis, sex, but not birth weight was the only independent factor related to office PP after controlling for current age, weight and height. Twenty-four hour pulse pressure was significantly related not only to current weight but also inversely to birth weight after controlling for sex, current age, and height. CONCLUSIONS: The results disclose a relationship between birth weight and ambulatory pulse pressure while seeking to advance knowledge about the possible associations between birth weight and cardiovascular risk.