title: Impaired stress-induced pressure natriuresis is related to left ventricle structure in blacks.
abstract: The mechanisms through which stress may contribute to the racial difference in the prevalence of essential hypertension and associated target organ damage remain unclear. This study examined differences in stress-induced pressure natriuresis in 69 black and 52 white normotensives age 14 to 27 years, all with a positive family history of hypertension. Urine samples for sodium excretion were collected before and after a series of tasks (video game challenge, forehead cold stimulation). The average blood pressure across the 2 tasks and the average increase in blood pressure to the 2 tasks were calculated. Blacks had higher mean systolic (131+/-12 versus 126+/-12 mm Hg, P<0.02) and diastolic (77+/-8 versus 72+/-9 mm Hg, P<0.001) blood pressure and a greater average change in systolic blood pressure (15+/-9 versus 11+/-7 mm Hg, P<0.04). This was associated with a smaller change in sodium excretion (2+/-6 versus 7+/-10 mEq/h, P<0.002). The change in sodium excretion was related to the change in systolic (r=0.31, P<0.03) and diastolic (r=0.27, P<0.05) blood pressure in whites but not in blacks. Relative wall thickness was greater in blacks (0.31+/-0.04 versus 0.29+/-0.03, P<0.002). In conclusion, impaired stress-induced pressure natriuresis in blacks may contribute to racial differences in essential hypertension and its sequelae.
authors.affiliation: Georgia Prevention Institute in the Department of Pediatrics, Medical College of Georgia, Augusta 30912-4534, USA. Gharshfi@mail.mcg.edu
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Harshfield
authors.forename: Frank A
authors.initials: FA
authors.lastname: Treiber
authors.forename: Harry
authors.initials: H
authors.lastname: Davis
authors.forename: Gaston K
authors.initials: GK
authors.lastname: Kapuku
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People; D001794:Blood Pressure; D005260:Female; D006352:Heart Ventricles / Q000166:cytology* / Q000000981:diagnostic imaging; D006439:Hemodynamics; D006801:Humans; D006977:Hypertension, Renal / Q000208:ethnology / Q000209:etiology; D008297:Male; D009318:Natriuresis; D011312:Pressure; D012964:Sodium / Q000652:urine; D013312:Stress, Physiological / Q000150:complications*; D014463:Ultrasonography
chemical_list: D012964:Sodium