Biomedical subjects

B Falkner

Publications and source records attributed to B Falkner.

96 records · Page 6Linked to original sources

PubMedDate not supplied

Cardiovascular characteristics in adolescents who develop essential hypertension.

The risk parameters for the development of essential hypertension (EH) were evaluated in a group of adolescents with borderline hypertension. A population comprised of 50 adolescents with systolic or diastolic blood pressure between the 90th and 95th percentile was compared to a normotensive (less than 90%) family history-negative control population. Evaluative parameters included genetic risk, resting blood pressure, resting heart rate, and cardiovascular response to mental stress. In a follow-up period of up to 41 months, 28 borderline hypertensive adolescents (56%) developed fixed EH. At the time of initial evaluation, these 28 hypertensive adolescents had a strong family history of EH, higher resting heart rate (p less than 0.01) and blood pressure (p less than 0.01), and a greater cardiovascular response to mental stress (p less than 0.001) compared to the normotensive family history-negative control population. Time series analysis of the stress phase also demonstrated a rhythmic cardiovascular response in the normotensive group (p less than 0.05) that was not present in the hypertensive group. These results indicate that adolescents with borderline hypertension displaying these characteristics have a greater risk for EH than previously reported.

Adolescent↗

PubMedDate not supplied

Effect of salt loading on the cardiovascular response to stress in adolescents.

This study investigated, in normotensive adolescents, three accepted risk factors for essential hypertension (EH): stress, dietary salt, and parental history (genetic risk). The cardiovascular response to mental stress was evaluated before and after salt loading in eight subjects without, and in seven with, a family history (FH) of EH. The effect of salt loading on the FH positive group was to increase significantly the stress-induced systolic and diastolic pressure while the heart rate response decreased. Salt loading resulted in no change in cardiovascular response to stress in the FH negative group.

Adolescent↗

PubMedDate not supplied

Red cell sodium countertransport and cotransport in normotensive and hypertensive blacks.

We have previously described elevated Lii -Nao countertransport (CT) and Na-K cotransport (CO) in red cells of Caucasian patients from Boston. In this study, we report both transport systems in black patients from Philadelphia. The maximal rate (Vmax) of CT was assayed by measuring the Nao-stimulated Li efflux from cells containing +/- 6 mmol Li/liter. The Vmax of outward cotransport was assayed by measuring the furosemide-sensitive component of Na and K efflux into Mg medium from cells containing 50 mmol/liter of both ions. The mean value of CT for 18 normotensive (NT) subjects with no family history of hypertension, (-) FHH , was 0.18 +/- 0.05 (mmol/liter cells X hour); and in 14 hypertensive (HT) patients, 0.18 +/- 0.07. The mean values of Na and K cotransport were, respectively (mmol/liter cells X hour), in 18 NT subjects with (-) FHH , 0.38 +/- 0.24 and 0.50 +/- 0.28 in 18 HT subjects, 0.25 +/- 0.17 and 0.24 +/- 0.14. We conclude that there is no difference in the Vmax for CT between the two groups of black subjects, but that the Vmax for Na-K CO was significantly reduced in the HT group. Notably, the offspring of HT patients (age 14 years, n = 17) also had a marked reduction in the Vmax of Na (0.15 +/- 0.17) K cotransport (0.19 +/- 14) in comparison with the mean value of Na (0.40 +/- 0.2) and K (0.60 +/- 0.3) cotransport measured in offspring (n = 10) of NT subjects (age 14 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Obesity and other risk factors in children.

The prevalence of obesity has increased over the past three decades, in children as well as in adults. When obesity develops in the childhood years, excess adiposity generally continues into adult years, and adult obesity with childhood onset is frequently more severe. The health consequences of obesity in adults are well established, including greater rates of hypertension, non-insulin dependent diabetes mellitus, and heart disease. This paper will discuss the risk factors for these adult disorders that are detectable in obese children. Compared to normal weight children, obese children have higher blood pressure, higher plasma insulin levels, and a more atherogenic lipid pattern. Thus, the characteristic features of Syndrome X, or the insulin resistant syndrome, can be detected in obese children and adolescents. The vascular consequences of exposure to these metabolic risk factors beginning in childhood have yet to be completely determined. However, it is very likely that childhood obesity does contribute significantly to cardiovascular disease. For these reasons, greater efforts should be mounted to reduce the currently rising rates.

Adipose Tissue↗

PubMedDate not supplied

Gender differences in the relationship between insulin-mediated glucose utilization and sex hormones in young African-Americans.

OBJECTIVE: To determine whether there are gender differences in insulin-mediated glucose utilization and if sex hormones correlate with measures of insulin sensitivity in young adult African-Americans. DESIGN: Cross-sectional case (women)-control (men) study. PARTICIPANTS: African-American men and women aged 27 to 35 years. Excluded were known diabetics, individuals on antihypertensive therapy, and women taking exogenous estrogen preparations. METHODS: Procedures included anthropometric and blood pressure measurement, oral glucose tolerance test, sex hormone assay, and euglycemic hyperinsulinemic clamp. Procedures for data analysis included two-way analysis of variance and Pearson's correlation coefficients. RESULTS: Data were analyzed on 104 men and 142 women with a mean age of 31.5 years. Insulin sensitivity was lower in women than in men. When insulin-mediated glucose utilization was corrected for body fat, there was no gender difference in insulin sensitivity. There was a significant correlation of androgen status with insulin sensitivity, but this relationship was divergent between men and women. For men, the correlation between insulin sensitivity and free testosterone was positive (r = .36, P < .001). For women, this correlation was negative (r = -.28, P = .001). CONCLUSION: These data on young African-Americans demonstrate no gender differences in insulin sensitivity when glucose utilization is corrected for adipose mass. Androgen status is significantly linked with insulin sensitivity, but the relationship is divergent in men and women. Insulin resistance in young women is strongly associated with relative androgen excess, which may augment the risk for cardiovascular disease.

Adult↗

PubMedDate not supplied

Determinants of blood pressure in infants admitted to neonatal intensive care units: a prospective multicenter study. Philadelphia Neonatal Blood Pressure Study Group.

There are few blood pressure (BP) data reported for premature and term newborn infants after 24 hours of age. To determine BP levels and BP trends in a representative population of infants admitted to neonatal intensive care units (NICUs), this study was conducted in 14 NICUs in the greater Philadelphia area. All infants admitted to the 14 NICUs during a 3-month period were entered into the study. BP data, along with data on clinical conditions and therapeutic interventions (independent variables), were prospectively collected by a uniform protocol. Systolic BP (SBP) and diastolic BP (DBP) were measured indirectly by oscillometry and recorded every 8 hours. Data from 608 infants followed up for 1 to 99 days after delivery generated 9911 infant-day records and 24,052 individual BP measurements. On day 1, birth weight and gestational age were strong correlates of SBP (r = 0.68, p < 0.0001 and r = 0.66, p < 0.0001, respectively) and DBP (r = 0.48, p < 0.0001 and r = 0.47, p < 0.001, respectively). During the first 5 days of life there was a progressive rise in SBP (2.23 to 2.67 mm Hg/day) and DBP (1.58 to 2.02 mm Hg/day) regardless of gestational age or weight at birth. After day 5 there was a more gradual increment in the daily SBP (0.24 to 0.27 mm Hg/day) and DBP (0 to 0.15 mm Hg/day). Stepwise linear multiple regressions were used to examine the multiple correlations among the independent variables and to build a regression model for BP. Gestational age and day of life emerged in the first two steps of the multiple regression analysis (multiple R = 0.463 and 0.655, respectively; p < 0.0001 for both). The multiple R values for day of life and gestational age were virtually identical to that for postconceptional age (day of life + gestational age at birth). Although other common diagnosis and treatment variables contributed a small amount to the total variance in BP, postconceptional age was the primary determinant of BP in this population of infants.

Birth Weight↗