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Ronald J Portman

Publications and source records attributed to Ronald J Portman.

12 recordsLinked to original sources
PubMed2004

Cardiovascular risk factors and sequelae in hypertensive children identified by referral versus school-based screening.

To determine whether systematic differences exist between hypertensive children referred for evaluation by primary care providers and children identified through community-based screening, cardiovascular risk factors and surrogate markers of hypertensive injury were compared based on subject source (referral versus screening). Children referred to a hypertension clinic for persistently elevated blood pressure were compared with children identified as hypertensive during school screening of 5102 students in Houston public schools. M-mode echocardiography of the left ventricle was performed and subsequently reviewed by 2 independent sonographers blinded to identifying subject information. Subsets of subjects also underwent carotid artery ultrasound for measurement of intimal-medial thickness, overnight urine collections for microalbuminuria, and fasting serum cholesterol, triglycerides, and glucose. Ninety-seven total subjects (54 screening and 43 referral) met inclusion criteria and had technically adequate echocardiography performed. The prevalence of left ventricular hypertrophy (LVH) was 37%. Referral subjects demonstrated significantly greater left ventricular mass index (38.8 versus 34.2 g/m(2.7); P<0.01) and a higher prevalence of LVH (49% versus 28%; P<0.05). Among subjects who underwent carotid ultrasound (n=75), carotid intimal-medial thickness was significantly higher in referral subjects (0.61 versus 0.57, P<0.05). When controlling for BMI z score, which was significantly higher in referral subjects, systematic differences by subject source did not persist. These findings suggest that hypertensive children who are predominantly overweight, independent of the manner in which patients come to medical attention, will manifest evidence of more severe cardiovascular disease assessed by surrogate markers such as left ventricular mass index or carotid artery intimal medial thickness.

Adolescent↗
PubMed2004

Characteristics of hypertensive children identified by primary care referral compared with school-based screening.

OBJECTIVES: To determine whether there are clinical differences between children referred for hypertension evaluation from a primary care practice and children with hypertension detected through school-based screening. Study design Referral patients (n=58) were compared with 44 screening patients with hypertension from school-based screening of 5102 students. All subjects underwent 24-hour ambulatory blood pressure (BP) monitoring. White coat hypertension was defined as 24-hour mean BP <95th percentile and BP load <25%. RESULTS: Referral subjects were more likely to be male and had higher body mass index than screening subjects but did not differ by age or ethnic distribution. Average clinic BP values tended to be higher among referral patients (140/79 vs 135/76 mm Hg, P=.07); however, the hypertension severity was closely matched when clinic BP was indexed to the subject-specific 95th percentile. Ambulatory mean BP, BP indices, and BP loads showed no differences by subject source for 24-hour, wake, or sleep periods. White coat hypertension prevalence did not differ between referral and screening subjects (28% vs 30%, P=.83). CONCLUSION: These findings suggest that hypertensive children identified by subspecialty referral are representative of the overall population of hypertensive children in the community, thereby supporting the generalizability of clinic-based research in pediatric hypertension.

Adolescent↗
PubMed2004

A randomized, placebo-controlled trial of amlodipine in children with hypertension.

OBJECTIVES: Evaluation of the efficacy and safety of amlodipine in hypertensive children. STUDY DESIGN: A randomized, double blinded, placebo-controlled, parallel-group, dose-ranging study was conducted at 49 centers in North and South America. The primary end point was the effect of amlodipine on systolic blood pressure (BP); secondary end points included the effect of amlodipine on diastolic BP, the effect of amlodipine as a function of dose and body size, and evaluation of safety. RESULTS: We enrolled 268 hypertensive children (mean age, 12.1 +/- 3.3 years); 84 (31.3%) had primary hypertension, and 177 (66%) were boys. Amlodipine produced significantly greater reductions in systolic BP than placebo; these were -6.9 mm Hg for 2.5 mg daily (P=.045 vs placebo) and -8.7 mm Hg for 5 mg daily (P=.005 vs placebo). The underlying cause of hypertension had no effect on the response to amlodipine. There was a significant dose-response effect of amlodipine on both systolic and diastolic BP beginning at doses > or =0.06 mg/kg per day. Systolic BP < or =95(th) percentile was achieved in 34.6% of subjects with systolic hypertension. Amlodipine was well tolerated, with just 6 children withdrawn from treatment because of drug-related adverse events. CONCLUSIONS: Amlodipine effectively lowers systolic BP in a dose-dependent manner in hypertensive children who require drug treatment.

Adolescent↗
PubMed2004

Measurement and treatment of elevated blood pressure in the pediatric patient with chronic kidney disease.

Hypertension, as in adults, is a frequent complication found in children with chronic kidney disease (CKD). Indeed, hypertension has now become one of the most prevalent chronic diseases of childhood. The most recent data available (2003) indicate that at least 38% of children with CKD in the United States are receiving antihypertensive therapy. Only recently has it been shown in children that hypertension, traditionally considered a marker for disease severity in children, is additionally a significant and independent risk factor for accelerated deterioration of kidney function and progression of CKD and a significant risk factor for cardiovascular disease. The following review outlines the differences and similarities of childhood versus adult hypertension with respect to measurement, diagnosis, treatment, and consequence in CKD. The definition of hypertension changes continually as a child grows with or without CKD. Despite numerous guidelines, the diagnosis of childhood hypertension continues to be based on epidemiologic data rather than evidence. For children, the current definition includes 2 categories: high normal, which is blood pressure (BP) between the 90th and 95th percentile, and hypertensive, which is BP above the 95th percentile. The evaluation of all hypertensive children should include a complete assessment of end-organ damage, including eyes, cardiovascular system (including blood vessels), kidneys, and nervous system. For children with CKD and end-stage renal disease (ESRD), a high percentage have left ventricular hypertrophy (LVH). The finding of end-organ damage or comorbidity (CKD, diabetes) in any child is an absolute indication for immediate pharmacologic therapy, whereas the presence of hypertension above the 95th percentile in children without CKD warrants initial intervention such as life style modification. The guidelines for measurement of BP in children with CKD are similar to those in children without CKD and include casual BP measurement, self-measured BP, and ambulatory BP monitoring. The recommendation for BP measurement in children is, when permitted, by auscultative method with a well-calibrated mercury manometer. Most casual BP measurements are performed with an automated oscillometric device whose validation has not been confirmed in children with CKD. The ambulatory BP monitor (ABPM) has 2 advantages: it significantly correlates with the presence of end-organ damage, and it identifies abnormal BP patterns that are frequently present in CKD patients, such as hypertension during the sleep period. An abnormal ABPM pattern can also be predictive of the development of end-organ damage. Treatment of hypertension in children, with and without CKD, is based on 3 factors: degree of BP elevation, the presence of cardiovascular risk factors, and the presence of end-organ damage. Additionally, the initial antihypertensive agent may be selected on available and age-appropriate formulations (eg, suspension and dosage selection). A physician treating a hypertensive child with CKD faces multiple challenges. They include selecting the convenience of available automated devices and the ABPM versus traditional auscultatory techniques upon which all normative standards have been based. Current research initiatives propose to develop pharmacokinetic and pharmacodynamics properties of antihypertensive medications and to study the effect of early intervention on end-organ damage.

Blood Pressure↗
PubMed2004

Overweight, ethnicity, and the prevalence of hypertension in school-aged children.

OBJECTIVES: To describe the current prevalence of pediatric hypertension and the relationships between gender, ethnicity, overweight, and blood pressure. METHODS: School-based screening was performed in 5102 children (13.5 +/- 1.7 years) from May through November 2002. Age, gender, ethnicity, weight, and height were ascertained, and body mass index (BMI) was calculated as weight (kg)/height (m2). Overweight was defined as BMI > or =95th percentile. Students with blood pressure >95th percentile on the first screening underwent a second screening 1 to 2 weeks later, and then a third screening if blood pressure was >95th percentile at the second screening. RESULTS: Ethnicity distribution was 44% white, 25% Hispanic, 22% African American, and 7% Asian. Overall, overweight prevalence was 20%, which varied significantly by ethnicity (31% Hispanic, 20% African American, 15% white, and 11% Asian). The prevalence of elevated blood pressure after first, second, and third screenings was 19.4%, 9.5%, and 4.5%, respectively. Elevated blood pressure on first screening was highest among Hispanics (25%) and lowest among Asians (14%). Ethnic differences in the prevalence of hypertension (elevated blood pressure on 3 screenings) were not significant after controlling for overweight. The prevalence of hypertension increased progressively as the BMI percentile increased from < or =5th percentile (2%) to > or =95th percentile (11%). After adjustment for gender, ethnicity, overweight, and age, the relative risk of hypertension was significant for gender (relative risk: 1.50; confidence interval: 1.15, 1.95) and overweight (relative risk: 3.26; confidence interval: 2.50, 4.24). CONCLUSIONS: These results confirm an evolving epidemic of cardiovascular risk in youth, as evidenced by an increase in the prevalence of overweight and hypertension, notably among ethnic minority children.

Adolescent↗
PubMed2003

Carotid ultrasonography for detection of vascular abnormalities in hypertensive children.

To determine whether hypertension and overweight status are associated with increased carotid intimal-medial thickness (cIMT) in children, vascular ultrasonography was performed in newly diagnosed hypertensive patients ( n=53) and normotensive controls ( n=33). Hypertensive subjects were identified either by referral or by systematic school-based hypertension screening. Hypertension was defined as blood pressure above the 95th percentile based on current Task Force criteria, and overweight was defined as body mass index (BMI) >25 kg/m(2). cIMT was assessed by high-resolution vascular ultrasonography of the distal common carotid artery. Hypertensive subjects had a higher cIMT than normotensive subjects (0.62 vs. 0.53 mm, P<0.00001). This difference remained significant after controlling for the effects of gender, race, age, height, weight, and BMI. Similarly, overweight subjects had a higher cIMT than normal-weight subjects (0.63 vs. 0.54 mm, P<0.0001). Subjects with both systolic and diastolic hypertension had higher cIMT than those with isolated systolic hypertension (0.67 vs. 0.60, P<0.05). cIMT showed significant positive pairwise correlation with age, height, weight, BMI, and systolic blood pressure. Among all clinical variables analyzed, cIMT was most strongly correlated with BMI ( r=0.53, P<0.001). These results provide further evidence that vasculopathy occurs in association with known cardiovascular risk factors such as hypertension and obesity during childhood.

Adolescent↗
PubMed2003

Ambulatory blood pressure monitoring in pediatric renal transplantation.

Over last two decades ABPM has evolved from a research device to an established and valuable clinical tool for BP evaluation. More than 10 yrs ago ABPM was introduced to pediatrics and since that time, its importance has been increasing in the management of hypertension in children and adolescents. This review summarizes the information gathered from the studies of ABPM in adult and pediatric patients with renal transplants. We will review the importance of hypertension in this patient subset, discuss the advantage of ABPM over CBP and focus on specific abnormalities and clinical significance of ABPM in renal transplant recipients.

Blood Pressure Monitoring, Ambulatory↗
PubMed2003

Carotid artery intimal-medial thickness and left ventricular hypertrophy in children with elevated blood pressure.

OBJECTIVES: To determine the association between carotid artery intimal-medial thickness (cIMT) and left ventricular mass index (LVMI) in children with elevated blood pressure. METHODS: Study subjects (n = 32; mean age: 13.9 +/- 2.7 years) were untreated new referrals to a pediatric hypertension clinic with confirmed elevated blood pressure. LVM was calculated from 2-dimensionally guided m-mode echocardiographic measurements of the left ventricle. LVMI was calculated as LVM (g)/height (m)2.7, and left ventricular hypertrophy (LVH) was defined as LVMI >95th percentile. Carotid artery duplex ultrasound was performed by protocol by experienced vascular sonographers who were unaware of the echocardiography results. The thickest IMT complex of the far wall of the distal common carotid artery was measured in longitudinal B-mode section using a high-resolution linear array of 8 MHz. RESULTS: The prevalence of LVH and increased cIMT was 41% and 28%, respectively. Subjects with increased cIMT had higher LVMI (46.8 g/m2.7 vs 31.4 g/m2.7) than those with normal cIMT. The LVH prevalence was 89% (8 of 9) among subjects with increased cIMT as compared with 22% (5 of 23) in subjects with normal cIMT. cIMT was positively correlated with body mass index (r = 0.43), interventricular septal thickness (r = 0.58), posterior wall thickness (r = 0.54), and LVMI (r = 0.54). cIMT and LVMI were positively associated after accounting for age, gender, and body mass index. CONCLUSIONS: These findings raise the possibility that carotid duplex ultrasound, by indicating the presence of early arterial wall changes, may be useful for predicting other cardiovascular sequelae in hypertensive children.

Adolescent↗
PubMed2002

Isolated systolic hypertension, obesity, and hyperkinetic hemodynamic states in children.

OBJECTIVE: To determine the factors that contribute to the pathogenesis of isolated systolic hypertension in children. METHODS: School-based measurement was performed of blood pressure (BP), heart rate, weight, and height in 2460 students (49% Hispanic, 31% black, 13% white) 12 to 16 years of age in 8 urban public schools. An independent group of 71 untreated children underwent 24-hour ambulatory BP monitoring (ABPM) to confirm clinic hypertension and assess circadian BP patterns. RESULTS: Hypertension and obesity were found in 17% and 23% of students, respectively. Among hypertensive students, 88% (363/413) had isolated systolic hypertension. Hypertension was more prevalent in obese than nonobese students (33% vs 11%, P <.0001). Obese hypertensive students had higher resting heart rate than nonobese normotensive patients (85.9 vs 79.6 beats/min, P <.001). Among patients who underwent ABPM, isolated systolic hypertension was found in 51% (36/71) by clinic BP and in 62% (18/29) with confirmed hypertension by ABPM. Blood pressure variability during daytime and sleep periods was higher in obese than nonobese patients for systolic BP (P <.01) and diastolic BP (P <.05). CONCLUSIONS: The findings of increased heart rate and BP variability in obese children with isolated systolic hypertension suggest that sympathetic nervous system hyperactivity may contribute to its pathogenesis.

Adolescent↗
PubMed2002

Circadian pattern of blood pressure, heart rate, and double product in liver glycogen storage disease.

The objective of this study was to determine systolic, diastolic, and mean arterial blood pressure (SBP, DBP, and MAP), heart rate (HR), double-product (DP: SBP x HR), and activity levels and their 24h pattern in liver glycogen storage disease (LGSD) patients. A case series of 12 (11 pediatric and one adult) diurnally active LGSD (seven type I, three type III, and two type IX) subjects were simultaneously assessed by 24h ambulatory blood pressure monitoring and wrist actigraphy. Nine subjects were judged to be hypertensive based on the criterion of an elevated 24h mean SBP and/or DBP being elevated beyond reference standards or the SBP and/or DBP load (percentage of time BP exceeds normal values) being greater than 25%. Two of the three other subjects, not viewed as hypertensive based on their 24h average SBP or DBP, exhibited daytime or nighttime SBP and/or DBP load hypertension. Each study variables displayed statistically significant (p < 0.001) group circadian rhythmicity. The SBP, DBP, and MAP displayed comparable 24h patterns of appreciable amplitude (total peak-trough variation equal to 17.7, 23.6, and 19.6%, respectively, of the 24h mean) with highest values (orthophase) occurring approximately 11 h after the commencement of daytime activity. The sleep-time trough (bathyphase) occurred approximately 4.5 h before morning awakening. The statistically significant (p < 0.006) circadian rhythms of HR (amplitude equal to 33.2% of the 24h mean) and DP (amplitude equal to 49.4% of the 24h mean) peaked earlier, approximately 7.4 h into the daytime activity span. The sleep-time trough occurred approximately 3 h before morning awakening. The 24h pattern in the cardiovascular variables was correlated with the 24h pattern of activity, with r ranging from 0.50 for DBP to 0.39 for HR.

Adolescent↗
PubMed2002

Ambulatory blood pressure and left ventricular mass index in hypertensive children.

To determine whether ambulatory blood pressure is more predictive of left ventricular hypertrophy than is casual blood pressure in hypertensive children, echocardiography and ambulatory blood pressure data from 37 untreated hypertensive children were analyzed. Left ventricular mass was calculated using the Devereux equation, left ventricular mass index was calculated as left ventricular mass (in grams)/height(2.7) (in meters), and left ventricular hypertrophy was defined as left ventricular mass index >51 g/m(2.7). Average blood pressure, blood pressure load, and blood pressure index (average blood pressure divided by pediatric ambulatory blood pressure 95th percentile) were calculated. Left ventricular mass index was strongly correlated with 24-hour systolic blood pressure index (r=0.43, P=0.008) and was also correlated with 24-hour systolic blood pressure (r=0.34, P=0.037), 24-hour systolic blood pressure load (r=0.38, P=0.020), wake systolic blood pressure load (r=0.37, P=0.025), sleep systolic blood pressure (r=0.33, P=0.048), and sleep systolic blood pressure load (r=0.38, P=0.021). Left ventricular mass index did not correlate with age, weight, clinic blood pressure, or ambulatory diastolic blood pressure. The overall prevalence of left ventricular hypertrophy was 27%. The prevalence of left ventricular hypertrophy was 47% (8 of 17) in patients with both systolic blood pressure load >50% and 24-hour systolic blood pressure index >1.0, compared with 10% (2 of 20) in patients without both criteria (P=0.015). These data suggest ambulatory blood pressure monitoring may be useful for the clinical assessment of hypertensive children by identifying those at high risk for the presence of end organ injury.

Adolescent↗