Metabolic bone disease in premature infants receiving parenteral nutrition: Incidence, clinical, laboratory and nutritional profile

Background

Metabolic bone disease (MBD) of newborns (NB) is characterized by tissue reduction and inadequate postnatal bone mineralization with clinical, laboratory, and/or radiologic repercussions between the third and twelfth weeks of postnatal life, which, in its most severe forms, can lead to a growth deficit and fractures. The aim of our study is to evaluate the incidence of MBD in premature patients receiving parenteral nutrition for >15 days in the neonatal intensive care unit (NICU) and assess their clinical and laboratory characteristics.

Methods

Single-center retrospective cohort study. From 2015 to 2020, patients <33 weeks of gestational age or <1500 g birth weight receiving parenteral nutrition for >15 days who met the metabolic bone disease criteria (alkaline phosphatase >800 U/L and phosphorus <3.5 mg/dL and/or compatible radiological alterations) were evaluated. Exclusion criteria: skeletal dysplasia, orthopedic surgeries, intraventricular hemorrhage grades III and IV, periventricular leukomalacia and chronic renal failure or severe liver disease. Clinical, laboratory and radiological data were collected during the first 90 days of life and/or discharge/death.

Results

The MBD incidence was 17.7 % over a five-year period. The gestational age at birth was 26 ± 1.41 weeks; birth weight was 745 (592–858) grams; maximum alkaline phosphatase level was 1091 ± 243.87 U/L and phosphorus nadir was 2.45 ± 0.48 md/dL. Among the 14 patients with metabolic bone disease, twelve had laboratory diagnosis, six had radiological and four had both; two patients had fractures; 42 % of patients received enteral calcium and phosphorus supplementation, and 50 % received intravenous calcium replacement.

Conclusions

Metabolic bone disease incidence was in accordance with international literature. The metabolic bone disease diagnosis was, in most cases, based on surveillance of laboratory tests. However, treatment for metabolic bone disease requires more active and preventive measures in risk groups.