Mineral status of premature infants in early life and linear growth at age 3.

ABSTRACT

BACKGROUND: Preterm infants are at significant risk of reduced bone mineral content and subsequent bone disease (metabolic bone disease of prematurity, MBDP). MBDP is frequently found in very low-birthweight (VLBW) infants, but long-term height prognosis is not well known. METHODS: VLBW infants from two major neonatal intensive care units were studied. Medical records were reviewed. A total of 143 subjects were analyzed after excluding subjects who died, or who had severe complications that could affect linear growth, Silver-Russell syndrome, severe cholestasis, and/or chromosomal abnormality. The relationship between MBDP and height at age 3 was investigated. RESULTS: Height standard deviation score (SDS) at age 3 negatively correlated with peak serum alkaline phosphatase (ALP) activity in early life (r = -0.30, P = 0.0003) and positively correlated with serum phosphorus (P) at peak ALP (r = 0.33, P = 0.0002). In addition, serum P independently affected height SDS at 3 years of age (ß = 0.19, P = 0.018), and was significantly different between infants with and without catch-up growth in height (difference 0.23 mmol/L, 95%CI 0.09-0.36, P = 0.0010). CONCLUSIONS: MBDP, particularly hypophosphatemia in the early period of life, is associated with linear growth until 3 years of age in VLBW infants.