Effect of salt supplementation of newborn premature infants on neurodevelopmental outcome at 10-13 years of age

Abstract

Background: The nutritional requirements of prematurely born infants are different from those of babies born at term. Inadequate or inappropriate dietary intake in the neonatal period may have long term adverse consequences on neurodevelopmental function. The late effect of neonatal sodium deficiency or repletion in the premature human infant on neurological development and function has not been examined, despite evidence in animals of a serious adverse effect of salt deprivation on growth of the central nervous system. Methods: Thirty seven of 46 children who had been born prematurely (gestational age of 33 weeks or less) and allocated to diets containing 1-1.5 mmol sodium/day (unsupplemented) or 4-5 mmol sodium/day (supplemented) from the 4th to the 14th postnatal day were recalled at the age of 10-13 years. Detailed studies of neurodevelopmental performance were made, including motor function and assessment of intelligence (IQ), memory and learning, language and executive skills, and behaviour. Sixteen of the children were found to have been in the supplemented group and 21 in the unsupplemented group. Results: Children who had been in the supplemented group performed better in all modalities tested than those from the unsupplemented group. The differences were statistically significant (analysis of variance) for motor function, performance IQ, the general memory index, and behaviour as assessed by the children's parents. The supplemented children outperformed the unsupplemented controls by 10% in all three components of the memory and learning tests (difference not significant but p < 0.1 for each) and in language function (p < 0.05 for object naming) and educational attainment (p < 0.05 for arithmetic age). Conclusions: Infants born at or before 33 weeks gestation require a higher sodium intake in the first two weeks of postnatal life than those born at or near term, and failure to provide such an intake (4-5 mmol/day) may predispose to poor neurodevelopmental outcome in the second decade of life.

Anthropogenic changes in sodium affect neural and muscle development in butterflies

“…Sodium is a key component of animal development, important for the function of neural and muscle tissue (10)(11)(12) and affecting the development of traits, such as brain size (13)(14)(15)(16). However, sodium availability is limited in most ecosystems (17)(18)(19), which is thought to have led to the evolution of sodium cravings (20,21) and specific foraging behavior to acquire sodium (22)(23)(24)(25).…”

Lowest neonatal serum sodium predicts sodium intake in low birth weight children

“…NLS occurred most frequently in the first 2 wk postnatal, consistent with the predominant occurrence of hyponatremia in this period (1). A regression model showed that gestational age, birth weight, and frequency of diuretic therapy were not predictors of childhood sodium intake.…”

“…It has been suggested that such comprehensive changes might alter taste-related behaviors, including sodium appetite (21,24,35,43). Another possible mechanism that can also have long-term effects is perturbation of the developing renin-angiotensinaldosterone system leading to greater neonatal salt loss and long-term increases in sodium appetite (1,12,23,31,40,41). Preterm infants of Ͻ32-35 wk gestation or Ͻ1,500 g at birth have obligate high renal and intestinal sodium losses during the first fortnight of life, leading to cumulative negative sodium balance in most and hyponatremia in many (1,20).…”

“…Hyponatremia during the first week of life (early onset) usually reflects free water excess due to increased maternal intake during labor, excess free water administration in the postnatal period, suboptimal sodium intake in oral feeds or parenteral fluids, nonosmotic release of vasopressin in perinatal asphyxia, respiratory distress, bilateral pneumothoraces, intraventricular hemorrhage, or with some medications. Hyponatremia in the latter half of the first month of life (late onset) is most commonly due to excessive renal losses due to high fractional excretion of sodium, particularly in infants born before 28 wk of gestation, inadequate sodium intake, retention of free water from excessive antidiuretic hormone release, renal failure or, less commonly, to edematous disorders (1,15). Sodium status of the neonates is routinely monitored by drawn blood, or if hyponatremia is indicated.…”

Comparison between homologous human milk supplements and a commercial supplement for very low birth weight infants

“…O sódio é necessário para manter a tonicidade extracelular, influenciando no balanço hídrico adequado, pré-requisito para o crescimento e desenvolvimento 21 . Considerando que a oferta de 160 mL/kg/dia das dietas (grupo I e II) oferecerá aproximadamente 2,4 mEq/kg/dia e que a necessidade de sódio de RNMBP segundo os comitês de nutrição é de 4 a 5 mEq/kg/dia, há necessidade de controle bioquímico desse mineral para recém-nascidos com idade gestacional menor que 32 semanas 3,16 .…”