Blood pressure increases with age, and over time, in some individuals, reaches proportions consisent with clinically defined hypertension. 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. Hypertension may be produced by an interplay of sodium retention and adrenergic pressor effects. In the present study, production of aldosterone (the major sodium retaining hormone) and the activity of the sympathetic nervous system (norepinephrine) will be examined in a mixed-longitudinal design in white and black boys and girls beginning at ages 6 to 12 and extending to age 17. Levels of these pressor systems will be determined in the basal state from measurements made in urine samples collected overnight (sleep urine). To enhance the likelihood that school children will comply with the multiple observations required for this longitudinal study, measurements will be deliberately restricted to non-invasive ones. Specifically, aldosterone and norepinephrine excretion measured in sleep urine (their rates adjusted for dietary intake of sodium and potassium as reflected in electrolyte urinary excretion) will be obtained at 6 month intervals in addition to blood pressure, heart rate, weight, height, and skin-fold thickness. In addition, family history of hypertension and parental blood pressures will be used as covariates in analysis of data in children. A second aspect of this study concerns the observation that blood pressure increases at a faster rate during adrenarche (a period of increasing adrenal androgen production) and puberty. Androgens produced during periods of adrenal and gonadal maturation may contribute to the increase in blood pressure in the relationship of androgens to blood pressure will be 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. Levels of androgen production during the adrenarche will be determined by measurement of dehydroepiandrosterone-sulfate excretion, and during puberty by measurement of luteinizing hormone excretion, in sleep urine samples. In summary, this study will be the first longitudinal study correlating changes in pressor substances with blood pressure during growth and sexual development in which biological indices of maturation will be employed.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL035795-01
Application #
3350100
Study Section
(SRC)
Project Start
1985-09-30
Project End
1990-09-29
Budget Start
1985-09-30
Budget End
1986-09-29
Support Year
1
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Type
Schools of Medicine
DUNS #
005436803
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Tu, Wanzhu; Eckert, George J; Decker, Brian S et al. (2017) Varying Influences of Aldosterone on the Plasma Potassium Concentration in Blacks and Whites. Am J Hypertens 30:490-494
Tu, Wanzhu; Pratt, J Howard (2016) Small Potassium Channels: Speculation on a Role to Regulate Aldosterone Production and Blood Pressure. Hypertension 68:542-3
Tu, Wanzhu; Eckert, George J; Hannon, Tamara S et al. (2014) Racial differences in sensitivity of blood pressure to aldosterone. Hypertension 63:1212-8
Palacios, Cristina; Wigertz, Karin; Braun, Michelle et al. (2013) Magnesium retention from metabolic-balance studies in female adolescents: impact of race, dietary salt, and calcium. Am J Clin Nutr 97:1014-9
Tu, Wanzhu; Pratt, J Howard (2013) A consideration of genetic mechanisms behind the development of hypertension in blacks. Curr Hypertens Rep 15:108-13
Deeg, Mark A; Xuei, Xiaoling; Eckert, George et al. (2012) Genetic variation of GPLD1 associates with serum GPI-PLD levels: a preliminary study. Biochim Biophys Acta 1821:381-5
Jung, Jeesun; Basile, David P; Pratt, J Howard (2011) Sodium reabsorption in the thick ascending limb in relation to blood pressure: a clinical perspective. Hypertension 57:873-9
Hancock 2nd, Michael L; Bichet, Daniel G; Eckert, George J et al. (2010) Race, sex, and the regulation of urine osmolality: observations made during water deprivation. Am J Physiol Regul Integr Comp Physiol 299:R977-80
Palacios, Cristina; Wigertz, Karin; Martin, Berdine R et al. (2010) Racial differences in potassium homeostasis in response to differences in dietary sodium in girls. Am J Clin Nutr 91:597-603
Tu, Wanzhu; Eckert, George J; Saha, Chandan et al. (2009) Synchronization of adolescent blood pressure and pubertal somatic growth. J Clin Endocrinol Metab 94:5019-22

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