Persistence of high diastolic blood pressure in thin children. The Bogalusa Heart Study

A 5-Week Guided Active Play Program Modulates Skin Microvascular Reactivity in Healthy Children

PURPOSE

Children's poor levels of physical activity (PA) participation and early-onset vascular aging are identified as global health challenges. Children's guided activity play (GAP)-based PA programs have emerged as effective strategies to improve cardiovascular risk factors and health-related fitness. This study proposes to investigate whether GAP improves children's cutaneous microvascular reactivity and health-related fitness.

METHODS

Children's (n = 18; 9.8 [1.5] y) PA during a 5-week (4 d/wk; 1 h/d) GAP program was assessed (accelerometry) with preassessments and postassessments for anthropometric, musculoskeletal fitness, blood pressure, estimated aerobic power, and cutaneous microvascular reactivity.

RESULTS

PA averaged 556 (132) kcal·week-1 at 34.7% (7.5%) time at moderate to vigorous intensity. Resting heart rate (-9.5%) and diastolic blood pressure (-7.8%) were reduced without changes in health-related fitness indices. Cutaneous microvascular reactivity to sodium nitroprusside iontophoresis increased the average perfusion (+36.8%), average cutaneous vascular conductance (+30%), the area under the curve (+28.8%), and a faster rise phase (+40%) of perfusion (quadratic modeling; P ≤ .05). Chi-square and crosstabulation analysis revealed significant association between children's PA levels and sodium nitroprusside average perfusion levels, where children with PA levels ≥205.1 kcal.55 minute-1 were overrepresented in the medium/high levels of sodium nitroprusside perfusion.

CONCLUSION

A 5-week GAP modified the microvascular reactivity in children without changes in body mass, musculoskeletal fitness, or estimated aerobic power.

Isolated diastolic high blood pressure: a distinct clinical phenotype in US children

BACKGROUND

Screening studies have shown that 0.7-4.5% of generally healthy children have isolated diastolic high BP. We therefore studied the characteristics of children with diastolic BP in the elevated and hypertensive ranges according to current guidelines in US children from the National Health and Nutrition Examination Survey (NHANES, 1999-2016).

METHODS

We studied 17,362 children (8-18 years) with BP measured by sphygmomanometry. High BP was categorized as isolated systolic (iSH), isolated diastolic (iDH), or Mixed.

RESULTS

Overall, 86.0% (95% CI =  85.0-87.0) of the population had normal BP, 8.7% (8.0-9.3) elevated BP, 4.9% (4.4-5.5) Stage 1, and 0.4% (0.4-0.6) Stage 2. Moreover, 11.1% (10.3-12.0) had iSH, 1.9% (1.5-2.2) iDH, and 1.0% (0.8-1.2) Mixed. Children with iDH were more likely to be female, younger, white, and leaner than those with iSH, with lower rates of overweight/obesity. iDH was generally between normals and iSH. Resting heart rate was significantly higher in iDH even after adjustment for known covariates.

CONCLUSIONS

Children with iDH may have a distinct clinical picture. A leaner habitus and higher resting heart rate may reflect differences in underlying pathophysiology. Longitudinal follow-up studies are needed to better define the pathogenesis, progression, and long-term prognosis in iDH.

IMPACT

Using gold-standard auscultation and 2017 guidelines, isolated diastolic high BP (iDH) is found in 1.9% (95% CI 1.5-2.2) of American children; these children are younger, leaner, more female, and have fewer cardiometabolic risks. Resting heart rate is significantly higher in iDH compared to both normals and iSH even after adjustments for known covariates. Autonomic hyperactivity in iDH may speak to both etiology and therapeutic approaches. iDH appears to be a distinct clinical phenotype characterized by differences in anthropometric measures, sex, age, and resting heart rate. Follow-up studies are clearly needed to clarify its pathogenesis, progression, and prognosis.

Blood pressure and related cardiovascular disease risk factors in 6-18 year-old students in Italy

OBJECTIVES

The aims of this study were to provide data on blood pressure (BP) levels, to measure prevalence of high-normal or high BP and to identify a set of conditions that may predict high BP (HBP) in a population of children and adolescents in Italy.

METHODS

A random sample of students 6-18 years old attending randomly selected schools in Catanzaro, Italy, was recruited. All students completed a questionnaire on their health and on health behaviours, such as physical activity, diet, drinking and smoking. Blood pressure, heart rate, height, weight and body mass index (BMI) were recorded.

RESULTS

Of the 603 subjects examined, 12.8% had high-normal BP, 3.5% hypertension (HTN) and 11.1% were obese. High-normal or high diastolic BP (DBP) was significantly more likely in older subjects with a higher BMI, in those with a smoker mother and in preterm children, whereas high-normal or high systolic BP (SBP) was significantly more likely to be found in older subjects with a higher BMI and in those who had at least one parent with HTN. High-normal or high DBP or SBP were significantly predicted by BMI and age.

CONCLUSIONS

Interventions should focus at reducing obesity and encouraging proper dietary habits, sufficient exercise and cessation of smoking habit in parents too, especially in children with a family history of HTN.

Multivariate genetic analysis of blood pressure and body size. The Medical College of Virginia Twin Study

BACKGROUND

In subjects of all ages, those who weigh the most often have the highest blood pressure. Thus, in epidemiological studies, weight is the most important correlate of blood pressure. Using the data from the Medical College of Virginia Twin Study, we asked these questions: 1) Do the same genetic paths that regulate body size also regulate systolic and diastolic blood pressure? 2) Are there distinct genetic pathways that regulate each of these variables? 3) Does environment play a major regulatory role? 4) Are the correlations among these variables mainly due to genetic or environmental effects? 5) Do genetic paths that regulate body size mediate the correlation between systolic blood pressure and diastolic blood pressure?

METHODS AND RESULTS

We ascertained 253 Caucasian twin pairs living in the Commonwealth of Virginia. The average age was 11.2 +/- 0.2 years. We used multivariate path analyses to investigate the genetic relations among systolic blood pressure, diastolic blood pressure, and body size. We found that there was a highly significant genetic relation between systolic blood pressure and body size and between systolic and diastolic blood pressure. There are genetic paths that are shared within these two sets of variables, but in each case, the paths for each pair appear to be separate from one another.

CONCLUSIONS

These analyses provide a method to partition correlation coefficients found in epidemiological studies into genetic and environmental components. The correlations found among these three variables are in large part due to these genetic relations. We found no genetic relation between diastolic blood pressure and body size.