Elevated systolic blood pressure in preterm very-low-birth-weight infants ≤3 years of life

Abstract

Preterm, very-low-birth-weight neonates (≤1500 gm, VLBW) exhibit elevated systolic blood pressures (SBP) in adolescence and adulthood; however, the age of onset and causes are unknown. We assessed SBP in a cross-sectional study of VLBW infants at 1, 2 and 3 years of age (n = 40 per cohort). SBP was manually measured using Doppler amplification (observed), and calm values were compared to reference ranges used for clinical purposes (expected). SBP was converted to age-, gender- and height-specific z-scores (SBPz). Perinatal variables and growth parameters measured between 6 and 36 months were assessed as predictors of an elevated SBP. Observed SBP and SBPz exceeded the expected value at each age (P < 0.01); for example 1 year SBP was 94 ± 10 (standard deviation) vs. 85 ± 3 mmHg, respectively. Although the expected SBP rose from 85 ± 3 to 90 ± 3 mmHg with advancing age (P < 0.05), VLBW SBP was unchanged (P > 0.1), averaging 93 mmHg across ages. Height and weight z-scores were below expected (P < 0.01), while weight-for-height z-scores exceeded zero at 6, 12 and 24 months (P < 0.05). Male subscapular skinfold thickness:abdominal circumference ratio decreased with advancing age, paralleling the decreases in SBPz. The VLBW neonates demonstrated an elevated SBP as early as 1 year of age. Although predictive perinatal variables were not identified, gender-specific relationships between infant growth and SBP were observed.

Salivary and serum cortisol and relation to blood pressure in infancy and early childhood in very-low-birth-weight infants

“…The present study confirms this association in early childhood in VLBW infants and supports the hypothesis that programming of the HPA axis may contribute to the high prevalence of raised blood pressure in this population (9,10). The correlation between cortisol and both systolic and diastolic blood pressure was significant only in boys.…”

“…We recently showed that at the corrected age of 2 y verylow-birth-weight (VLBW) infants (birth weight <1,500 g) have a high prevalence of raised blood pressure (systolic and/or diastolic ≥ 90th percentile for age, sex, and height) (9). Elevated blood pressure (compared to published reference standards) in early childhood in VLBW infants was also reported by Duncan et al (10).…”

Cardiovascular Consequences of Preterm Birth in the First Year of Life

“…Studies have shown that blood pressure is lower in preterm infants born at 28-32 weeks GA and studied longitudinally across the first six months after term CA compared to age matched term infants in both active sleep and quiet sleep (Witcombe et al, 2008). In contrast when awake a recent study has reported that systolic blood pressure in VLBW infants was elevated at one year of age compared to published reference values when adjusted for age, gender and height (Duncan et al, 2011). These findings suggest that the elevated blood pressure reported in adolescence and adulthood born preterm appears as early as the first year of life.…”

“…These findings suggest that the elevated blood pressure reported in adolescence and adulthood born preterm appears as early as the first year of life. Furthermore, there was no age related rise in blood pressure between one and three years of age (Duncan et al, 2011). In summary, it appears that heart rate and blood pressure are altered after preterm birth and these differences persist across the first year after term CA.…”

Racial Disparities in Blood Pressure Trajectories of Preterm Children: The Role of Family and Neighborhood Socioeconomic Status

“…Understanding the childhood roots of these enduring differences is crucial, particularly within at-risk samples of low-birth-weight and premature children (3,4). Premature birth is associated with elevated blood pressure beginning in infancy and early childhood (5,6), which in turn is a risk factor for adult hypertension, heart disease, and early mortality (7,8). Black/African-American (AA) infants are approximately twice as likely to be born premature as white/European-American (EA) infants (9) and consequently are at greater risk for a wide range of adult health problems (10).…”