Objectives: To test whether nutrition early in infants' development programmes later blood pressure and whether the reported relation between low birth weight and later high blood pressure is due to poor nutrition or growth before full term.
Design: Prospective randomisation of preterm infants to early diets differing greatly in nutrient content in four parallel multicentre trials, with blinded follow up 7.5-8 years later.
Setting: Neonatal units at Cambridge, Ipswich, King's Lynn, Norwich, and Sheffield.
Subjects: 758 children weighing under 1850 g at birth.
Main outcome measure: Blood pressure at age of 7.5-8 years.
Results: There were major differences in nutrient intake from randomised diets (preterm formula v standard formula and preterm formula v donor breast milk; in each case with or without mother's milk), but follow up showed no differences in later blood pressure. Individual subjects showed large variation in protein and energy intakes and in growth performance, including degrees of growth failure seldom seen in utero, but these factors were also unrelated to later blood pressure.
Conclusion: Extremes of nutritional intake and growth performance in preterm infants do not programme later blood pressure at 7.5-8 years of age. These findings do not support the hypothesis that high blood pressure has early nutritional origins. We suggest that the long term rise in blood pressure reported in individuals who had low birthweight (at full term) is not, as previously speculated, due to poor fetal nutrition or growth as such.