Ignite Creation Date:
2024-05-05 @ 11:20 AM
Last Modification Date:
2024-10-26 @ 9:04 AM
Study NCT ID:
NCT00005181
Status:
COMPLETED
Last Update Posted:
2014-02-25
First Post:
2000-05-25
Brief Title:
Blood Pressure Control in Juveniles - Longitudinal Study
Sponsor:
Indiana University
Organization:
Indiana University
Study Overview
Official Title:
None
Status:
COMPLETED
Status Verified Date:
2014-02
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
To correlate dietary factors and changes in pressor substances including aldosterone and norepinephrine with blood pressure during growth and sexual development from childhood through adolescence
Detailed Description:
BACKGROUND
Blood pressure increases with age and over time reaches proportions consistent with clinically defined hypertension in some individuals The age-dependent increase in blood pressure starts in mid-childhood and accelerates during puberty and in the post-pubertal period Thus mechanisms for the development of hypertension are likely present at an early age The National Heart Lung and Blood Institute sponsored the Workshop on Juvenile Hypertension in May 1983 The Workshop conclusions were that although a great deal had been accomplished in the past decade research in juvenile hypertension had slowed and little effort was evident in some important areas of the field They noted especially the paucity of effort in research relating to mechanisms of blood pressure regulation and elevation to clinical management of the hypertensive state and to identification of the prehypertensive state Based on the recommendations of the Workshop this study was initiated in response to a Request for Applications on Juvenile Hypertension and the Prehypertensive State released by the NHLBI in October 1984
DESIGN NARRATIVE
Production of aldosterone and norepinephrine is examined in a mixed-longitudinal study design in white and Black boys and girls beginning at ages 6 to 12 and extending to age 17 Levels of these pressor systems are determined in the basal state from measurements made in urine samples collected overnight To enhance the likelihood that school children would comply with the multiple observations required for this longitudinal study measurements are deliberately restricted to non-invasive ones Specifically aldosterone and norepinephrine excretion measured in sleep urine are obtained at six month intervals in addition to blood pressure heart rate weight height and skin-fold thickness Family history of hypertension and parental blood pressures are used as covariates in analysis of data in children A second part of the study concerns the observation that blood pressure increases at a faster rate during adrenarche a period of increasing adrenal androgen production and during puberty Androgen production during periods of adrenal and gonadal maturation may contribute to the increase in blood pressure The relationship of androgen to blood pressure is examined by distinguishing blood pressure responses to androgen production from effects of androgens on physical growth thus exploring the concept that androgens interact directly with pressor systems to raise blood pressure Androgen production during the adrenarche is determined by measurement of dehydroepiandrosterone-sulfate excretion and during puberty by measurement of luteinizing hormone excretion in sleep urine samples Studies continue on the relationship between aldosterone excretion rate dietary potassium intake and blood pressure A cross-over study is conducted to examine the effect of potassium supplementation on aldosterone production Segregation analysis of the low-aldosteronephenotype is performed on family members of children with low-aldosterone
The study was renewed in 1996 to continue the longitudinal study of children a biracial population ages 6-16 years for whom influences of hormones on blood pressure are being examined Twice yearly the children have had blood pressure and anthropometrics measured and overnight urine samples collected for measurement of aldosterone adrenal androgens AA luteinizing hormone LH sodium potassium and creatinine Rates of growth and the changes in blood pressure with age have been well characterized for this population From the original observations several differences were observed between racial groups specifically Black children were found to consume less potassium produce about 40 percent less aldosterone and have higher blood pressures than white children It was observed that children with positive families histories of hypertension were more likely to have lower aldosterone-excretion rates
As part of the proposed continuation of longitudinal studies the hypothesis is tested that children with low-aldosterone levels are predisposed to higher blood pressures Although Black children had lower potassium intakes cross-sectional data indicated that only part of the racial difference in aldosterone production was secondary to a lower intake of potassium potassium is a known stimulus of aldosterone production Subjects with known low-aldosterone production Blacks and whites have diets supplemented with potassium to test the hypothesis that Blacks with low-aldosterone production have a reduced responsiveness to potassium when compared to white children with low-aldosterone Families of children with potassium-resistant low-aldosterone production are screened for evidence of low-aldosterone production and segregation analyses is performed to establish the mode of inheritance of the low-aldosterone phenotype In cross-sectional studies AA-excretion rates were positively related to blood pressure in subjects greater than or equal to 10 years of age suggesting an important role for the adrenarche in determining blood pressure levels in young people In future longitudinal studies the role of AA as well as gonadal hormones will be studied as more children reach adolescence the current mean age of the cohort is 127 yr In addition to better distinguish the individual influences of adrenarche gonadarche and increases in body size on blood pressure a series of patients where these phenomenon are dissociated will be studied
The study was renewed in FY 2002 to identify new mechanisms for hypertension using a strategy which identifies the sodium transporters in kidney that account for why blacks retain more sodium than whites Three sites along the nephron will be studied based on compelling evidence that they are linked to the increased sodium-retention in blacks
Blood pressure increases with age and over time reaches proportions consistent with clinically defined hypertension in some individuals The age-dependent increase in blood pressure starts in mid-childhood and accelerates during puberty and in the post-pubertal period Thus mechanisms for the development of hypertension are likely present at an early age The National Heart Lung and Blood Institute sponsored the Workshop on Juvenile Hypertension in May 1983 The Workshop conclusions were that although a great deal had been accomplished in the past decade research in juvenile hypertension had slowed and little effort was evident in some important areas of the field They noted especially the paucity of effort in research relating to mechanisms of blood pressure regulation and elevation to clinical management of the hypertensive state and to identification of the prehypertensive state Based on the recommendations of the Workshop this study was initiated in response to a Request for Applications on Juvenile Hypertension and the Prehypertensive State released by the NHLBI in October 1984
DESIGN NARRATIVE
Production of aldosterone and norepinephrine is examined in a mixed-longitudinal study design in white and Black boys and girls beginning at ages 6 to 12 and extending to age 17 Levels of these pressor systems are determined in the basal state from measurements made in urine samples collected overnight To enhance the likelihood that school children would comply with the multiple observations required for this longitudinal study measurements are deliberately restricted to non-invasive ones Specifically aldosterone and norepinephrine excretion measured in sleep urine are obtained at six month intervals in addition to blood pressure heart rate weight height and skin-fold thickness Family history of hypertension and parental blood pressures are used as covariates in analysis of data in children A second part of the study concerns the observation that blood pressure increases at a faster rate during adrenarche a period of increasing adrenal androgen production and during puberty Androgen production during periods of adrenal and gonadal maturation may contribute to the increase in blood pressure The relationship of androgen to blood pressure is examined by distinguishing blood pressure responses to androgen production from effects of androgens on physical growth thus exploring the concept that androgens interact directly with pressor systems to raise blood pressure Androgen production during the adrenarche is determined by measurement of dehydroepiandrosterone-sulfate excretion and during puberty by measurement of luteinizing hormone excretion in sleep urine samples Studies continue on the relationship between aldosterone excretion rate dietary potassium intake and blood pressure A cross-over study is conducted to examine the effect of potassium supplementation on aldosterone production Segregation analysis of the low-aldosteronephenotype is performed on family members of children with low-aldosterone
The study was renewed in 1996 to continue the longitudinal study of children a biracial population ages 6-16 years for whom influences of hormones on blood pressure are being examined Twice yearly the children have had blood pressure and anthropometrics measured and overnight urine samples collected for measurement of aldosterone adrenal androgens AA luteinizing hormone LH sodium potassium and creatinine Rates of growth and the changes in blood pressure with age have been well characterized for this population From the original observations several differences were observed between racial groups specifically Black children were found to consume less potassium produce about 40 percent less aldosterone and have higher blood pressures than white children It was observed that children with positive families histories of hypertension were more likely to have lower aldosterone-excretion rates
As part of the proposed continuation of longitudinal studies the hypothesis is tested that children with low-aldosterone levels are predisposed to higher blood pressures Although Black children had lower potassium intakes cross-sectional data indicated that only part of the racial difference in aldosterone production was secondary to a lower intake of potassium potassium is a known stimulus of aldosterone production Subjects with known low-aldosterone production Blacks and whites have diets supplemented with potassium to test the hypothesis that Blacks with low-aldosterone production have a reduced responsiveness to potassium when compared to white children with low-aldosterone Families of children with potassium-resistant low-aldosterone production are screened for evidence of low-aldosterone production and segregation analyses is performed to establish the mode of inheritance of the low-aldosterone phenotype In cross-sectional studies AA-excretion rates were positively related to blood pressure in subjects greater than or equal to 10 years of age suggesting an important role for the adrenarche in determining blood pressure levels in young people In future longitudinal studies the role of AA as well as gonadal hormones will be studied as more children reach adolescence the current mean age of the cohort is 127 yr In addition to better distinguish the individual influences of adrenarche gonadarche and increases in body size on blood pressure a series of patients where these phenomenon are dissociated will be studied
The study was renewed in FY 2002 to identify new mechanisms for hypertension using a strategy which identifies the sodium transporters in kidney that account for why blacks retain more sodium than whites Three sites along the nephron will be studied based on compelling evidence that they are linked to the increased sodium-retention in blacks
Study Oversight
Has Oversight DMC:
Is a FDA Regulated Drug?:
Is a FDA Regulated Device?:
Is an Unapproved Device?:
Is a PPSD?:
Is a US Export?:
Is an FDA AA801 Violation?:
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| R01HL035795 | NIH | None | httpsreporternihgovquickSearchR01HL035795 |