Ambulatory Blood Pressure and Number of Subclinical Target Organ Injury Markers in Youth: The SHIP AHOY Study.

Background: Hypertension in adolescence is associated with subclinical target organ injury (TOI). We aimed to determine whether different blood pressure (BP) thresholds were associated with increasing number of TOI markers in healthy adolescents. Methods: 244 participants (mean age 15.5±1.8 years, 60.1% male) were studied. Participants were divided based on both systolic clinic and ambulatory BP (ABP), into low- (<75 th percentile), mid- (75 th -90 th percentile) and high-risk (>90 th percentile) groups. TOI assessments included left ventricular mass, systolic and diastolic function, and vascular stiffness. The number of TOI markers for each participant was calculated. A multivariable general linear model was constructed to evaluate the association of different participant characteristics with higher numbers of TOI markers. Results: 47.5% of participants had at least one TOI marker: 31.2% had one, 11.9% two, 3.7% three, and 0.8% four. The number of TOI markers increased according to the BP risk groups: the percentage of participants with more than one TOI in the low-, mid-, and high groups based on clinic BP was 6.7%, 19.1%, and 21.8% (p=0.02), and based on ABP was 9.6%, 15.8%, and 32.2% (p<0.001). In a multivariable regression analysis, both clinic BP percentile and ambulatory SBP index were independently associated with the number of TOI markers. When both clinic and ABP were included in the model, only the ambulatory SBP index was significantly associated with the number of markers. Conclusion: High SBP, especially when assessed by ABPM, was associated with an increasing number of subclinical cardiovascular injury markers in adolescents.

Cardiovascular Risk Factors and Target Organ Damage in Adolescents: The SHIP AHOY Study.

BACKGROUND: Development of cardiovascular disease in adults has been directly linked to an adverse metabolic phenotype. While there is evidence that development of these risk factors in childhood persists into adulthood and the development of cardiovascular disease, less is known about whether these risk factors are associated with target organ damage during adolescence. METHODS: We collected data from 379 adolescents (mean age 15.5, 60% male) with blood pressure between the 75th and 95th percentile to determine if there is a metabolic phenotype that predicts cardiovascular changes (left ventricular mass, systolic and diastolic function, pulse wave velocity, and renal function). We determined the number of risk factors for cardiovascular disease (hypertension, dyslipidemia, obesity, and insulin resistance) present in each participant. Generalized linear models were constructed to determine if the number of cardiovascular risk factors (CVRFs) were associated with measures of target organ damage. RESULTS: The number of CVRFs present were associated with statistically significant differences in increased left ventricular mass index, increased pulse wave velocity, decreased peak longitudinal strain, urine albumin to creatine ratio and echocardiographic parameters of diastolic dysfunction. Generalized linear models showed that dyslipidemia and insulin resistance were independently associated with markers of diastolic dysfunction (P ≤ .05) while increased blood pressure was associated with all makers of target organ damage (P ≤ .03). CONCLUSIONS: These data suggest the of the number of CVRFs present is independently associated with early changes in markers of target organ damage during adolescence.

Pediatric and Adult Ambulatory Blood Pressure Thresholds and Blood Pressure Load as Predictors of Left Ventricular Hypertrophy in Adolescents.

[Figure: see text].

Subclinical Systolic and Diastolic Dysfunction Is Evident in Youth With Elevated Blood Pressure.

Hypertension is associated with cardiovascular events in adults. Subclinical changes to left ventricular strain and diastolic function have been found before development of decreased left ventricular ejection fraction and cardiovascular events. Our objective was to study effects of blood pressure (BP) on ventricular function in youth across the BP spectrum. Vital signs and labs were obtained in 346 participants aged 11 to 19 years who had BP categorized as low-risk (N=144; systolic BP <75th percentile), mid-risk (N=83; systolic BP ≥80th and <90th percentile), and high-risk (N=119; systolic BP ≥90th percentile). Echocardiography was performed to assess left ventricular strain and diastolic function. Differences between groups were analyzed by ANOVA. General linear models were constructed to determine independent predictors of systolic and diastolic function. Mid-risk and high-risk participants had greater adiposity and more adverse metabolic labs (lower HDL [high-density lipoprotein], higher glucose, and higher insulin) than the low-risk group. Mid-risk and high-risk participants had significantly lower left ventricular ejection fraction and peak global longitudinal strain than the low-risk group (both P≤0.05). The E/e' ratio was higher in the high-risk group versus the low-risk and mid-risk groups, and the e'/a' ratio was lower in the high-risk versus the low-risk group (both P≤0.05). BP and adiposity were statistically significant determinants of left ventricular systolic and diastolic function. Subclinical changes in left ventricular systolic and diastolic function can be detected even at BP levels below the hypertensive range as currently defined.

Association of Blood Pressure Level With Left Ventricular Mass in Adolescents.

Hypertension is associated with left ventricular hypertrophy (LVH), a risk factor for cardiovascular events. Since cardiovascular events in youth are rare, hypertension has historically been defined by the 95th percentile of the normal blood pressure (BP) distribution in healthy children. The optimal BP percentile associated with LVH in youth is unknown. We aimed to determine the association of systolic BP (SBP) percentile, independent of obesity, on left ventricular mass index (LVMI), and to estimate which SBP percentile best predicts LVH in youth. We evaluated SBP, anthropometrics, and echocardiogram in 303 adolescents (mean age 15.6 years, 63% white, 55% male) classified by SBP as low-risk (L=141, <80th percentile), mid-risk (M=71, 80-<90th percentile), or high-risk (H=91, ≥90th percentile) using the mean of 6 measurements at 2 visits according to the 2017 guidelines. Logistic regression was used to determine the sensitivity and specificity of various SBP percentiles associated with LVH. Results: BP groups did not differ by age or demographics but differed slightly by body mass index. Mean BP, LVMI, and prevalence of LVH increased across groups (BP: L=111/75, M=125/82, and H=133/92 mm Hg; LVMI: L=31.2, M=34.2, and H=34.9 g/m2.7; LVH: L=13%, M=21%, H=27%, all P<0.03). SBP percentile remained a significant determinant of LVMI after adjusting for covariates. The 90th percentile for SBP resulted in the best balance between sensitivity and specificity for predicting LVH (LVMI≥38.6 g/m2.7). Abnormalities in cardiac structure in youth can be found at BP levels below those used to define hypertension.

SHIP-AHOY (Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth).

Although hypertension is identifiable in children and adolescents, there are many knowledge gaps on how to best define and manage high blood pressure in the young. SHIP-AHOY (Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth) is being conducted to address these knowledge gaps. Five hundred adolescents will be recruited and will undergo ambulatory blood pressure monitoring, echocardiographic, vascular, and cognitive assessments, as well as epigenetic studies to identify mechanisms that underlie the development of hypertensive target organ damage. Details of the design and methods that will be utilized in SHIP-AHOY are presented here, as well as baseline characteristics of the first 264 study participants. The primary aim of the study is to develop a risk-based definition of hypertension in the young that will result in better understanding of the transition from blood pressure in youth to adult cardiovascular disease.

Obesity hypertension in adolescents: epidemiology, evaluation, and management.

The prevalence of hypertension among all adolescents is approximately 3.5%, with somewhat higher rates of prehypertension. Obesity affects approximately 20% of adolescents in the United States, and the prevalence of hypertension is much higher among obese adolescents compared with nonobese adolescents. As in other populations, the evaluation of elevated blood pressure in obese adolescents should begin with a confirmation of the blood pressure elevation, followed by a focused diagnostic work-up to detect possible secondary causes of hypertension. Primary therapy for obesity-related hypertension in adolescents begins with weight loss, and may include antihypertensive medications if target-organ damage or other indications for drug therapy are present. The emphasis of management should be reduction of future cardiovascular risk.

The utility of fasting glucose for detection of prediabetes.

Treatment of prediabetes attenuates progression to type 2 diabetes mellitus. The American Diabetes Association (ADA) previously defined prediabetes as either impaired fasting glucose (IFG) = 6.1 to 6.9 mmol/L (110-125 mg/dL) and/or impaired glucose tolerance (IGT) (2-hour postload glucose of 7.8-11.0 mmol/L [140-199 mg/dL]). For practical reasons, fasting plasma glucose (FPG) is commonly used for diabetes screening. Recently, the ADA lowered the fasting glucose threshold value for IFG from 110 to 100 mg/dL. Our objective was to determine the utility of FPG alone for detecting prediabetes in African Americans. Oral glucose tolerance test (OGTT) data from a cohort of 304 young adult African American men and women were examined. We calculated prediabetes prevalence using the previous ADA criteria and examined the effect of lowering the IFG threshold value for IFG to 100 mg/dL. The prediabetes prevalence in this cohort using the previous ADA criteria was 20.4% (n = 62). Of the 62 cases, 8 had IFG, 45 had IGT, and 9 had IFG together with IGT. Fasting plasma glucose testing alone detected 17 (27.4%) prediabetic cases, whereas a complete OGTT detected 54 (87.1%). Lowering the IFG threshold value to FPG = 100 mg/dL identified 13 of the 45 IGT-only cases. However, this lower IFG threshold increased prediabetes prevalence in the overall cohort from 20.4% to 31.9%. In conclusion, in young adult African Americans, an ethnic group at high risk for developing diabetes, FPG testing alone may be inadequate for diagnosing prediabetes. Until alternative strategies are identified, an OGTT is presently the best method for detecting the prediabetic condition in these high-risk patients.

Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research.

Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.

Recommendations for blood pressure measurement in humans and experimental animals: Part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research.

Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.

Correlation of oral glucose tolerance test-derived estimates of insulin sensitivity with insulin clamp measurements in an African-American cohort.

The purpose of this study was to determine which measures obtained from an oral glucose tolerance test (OGTT) are the best estimates of insulin sensitivity measured directly using the euglycemic hyperinsulinemic clamp procedure. Data were examined from a study conducted on 307 young adult African-American men and women. An OGTT with insulin measurements was conducted after a 12-hour overnight fast. The euglycemic hyperinsulinemic clamp was used to measure insulin-stimulated glucose uptake (M) directly. Pearson's correlation analyses were performed to examine the relationship of OGTT-derived parameters with insulin sensitivity measured using the clamp. There were consistent statistically significant correlations between calculated estimates of insulin sensitivity (fasting insulin/fasting glucose, summed insulin/summed glucose, homeostasis model assessment [HOMA], Quantitative Insulin Sensitivity Check Index [QUICKI]) with insulin sensitivity measured by the insulin clamp (P <.001). The calculated estimates that correlated most strongly with clamp measured insulin sensitivity were QUICKI and the logarithm of summed insulin during the OGTT. These data indicate that fasting and OGTT-derived plasma insulin and glucose concentrations can be used to estimate insulin sensitivity in young adult African-Americans when it is not feasible to conduct the insulin clamp procedure. Calculated indices that include log transformation of plasma insulin concentration improve the estimation of insulin sensitivity.

Overweight as a risk factor in children: a focus on ethnicity.

The prevalence of overweight in youth is increasing dramatically in the United States. The intimate relationship of obesity and overweight with cardiovascular risk factors and diabetes in adults raises concern for the likelihood of subsequent disease development in children. Ethnic minorities are so disproportionately affected by overweight that a call to action is necessary. The International Society on Hypertension in Blacks convened this work group as part of a larger effort to focus on cardiovascular risk protection beginning in childhood and adolescence, entitled the "Children are Our Messengers: Changing the Health Message" initiative. This summary article reviews the data on cardiovascular risk factors and overweight in ethnic children and adolescents, and culminates in a practical algorithm for evaluating overweight children for cardiovascular risk.