We hypothesize that exposure to antenatal glucocorticoids (ANCS) in very low birth weight (VLBW;1501g) infantsis associated with elevated blood pressure at 14 years of age. ANCS are frequently given to mothers who are expectedto deliver prematurely to improve survival of premature infants. However, ANCS have been associated with elevatedblood pressure at 14 years of age. Childhood blood pressure is correlated with blood pressure in adulthood, and thelatter influences the risk of cardiovascular morbidity. Among VLBW babies, both the survival rate and the rate ofexposure to ANCS are high; thus, the proposed research is pertinent to a significant public health concern.Supporting the proposed link between ANCS and elevated blood pressure in adulthood, animals studies indicate thatANCS alter the developing kidney and brain, possibly by decreasing the activity of the renin-angiotensin system(RAS). These alterations lead to lifelong changes in kidney structure and function and altered cardiovascular control,predisposing the adult to hypertension.The subjects for the proposed study are VLBW children who were singleton births, born 1992-1995, cared for in ourintensive care nurseries, and followed in our out-patient neonatal follow up clinic through one year adjusted age. Inthis sample the frequency of ANCS exposure is 47%. We propose measurements of the following: 1) resting bloodpressure, height, and weight, at 3 visits in the year after the child's fourteenth birthday, 2) ambulatory blood pressure, 3)blood pressure response to exercise and cold stress, 4) heart rate variability, 5) salivary cortisol, 6) level of fitness andphysical activity, 7) body composition using DXA scans, 8) microalbuminuria, 9) elements of the RAS in the urine andblood, and 10) estimated glomerular filtration rate. Data on perinatal exposures and growth through one year adjustedage will be obtained from medical records and a computerized database. Multivariate analyses will be used to estimatethe difference in blood pressure between children exposed to ANCS and those not exposed to ANCS, adjusting forpotential confounders and a number of known correlates of blood pressure.
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