Does Extremely Low Birth Weight Predispose to Low-Renin Hypertension?

Area of Science:

• Pediatric Nephrology
• Cardiovascular Health
• Developmental Origins of Health and Disease

Background:

• Low birth weight and prematurity are established risk factors for adult hypertension.
• Limited research exists on plasma renin activity (PRA) in children born preterm or full-term.
• The role of renin in hypertension development related to prematurity is not well understood.

Purpose of the Study:

• To investigate the hypothesis that renin modulates hypertension incidence in prematurely born children.
• To compare renal function, blood pressure, and PRA in extremely low birth weight (ELBW) children and healthy term-born controls at approximately 11 years of age.

Main Methods:

• A cohort study comparing 93 ELBW children (<1000 g) with 87 healthy term-born controls.
• Assessment of renal length, glomerular filtration rate (GFR) using cystatin C, blood pressure (BP), 24-hour urinary sodium excretion, and PRA.
• Analysis of sodium load per nephron and the relationship between PRA, BP, and sodium load.

Main Results:

• ELBW children exhibited significantly lower renal length and GFR, and higher systolic/diastolic BP compared to controls.
• Odds of systolic prehypertension/hypertension were substantially increased in ELBW individuals.
• PRA was significantly lower in ELBW children, and PRA inversely correlated with systolic BP, independent of sodium load or birth group.

Conclusions:

• Extremely low birth weight is a significant risk factor for developing low-renin hypertension in young adolescents.
• The inverse relationship between PRA and BP is maintained in ELBW individuals, suggesting a potential pathway for hypertension development.
• Findings highlight the long-term cardiovascular implications of prematurity and low birth weight.