Renal calcification: a complication of dexamethasone therapy in preterm infants with bronchopulmonary dysplasia

We have previously reported a case study in which renal calcification formation may have been a complication of dexamethasone exposure in an infant with bronchopulmonary dsyplasia. To determine whether dexamethasone is associated with renal calcification formation, we conducted a prospective, nonrandomized study of 36 infants < 30 weeks' gestation and weighing < 1250 gm treated with dexamethasone because of bronchopulmonary dysplasia and compared them with a group not receiving dexamethasone. We identified seven infants in the dexamethasone group (n = 19) but no infant in the comparison group (n = 17) with renal calcifications at 2 months of age (p = 0.008). The urinary calcium excretion tended to be increased (15.5 +/- 16.6 vs 6.9 +/- 6.7 mg/kg/day ¿p = 0.05¿) and the calcium/creatinine ratio was significantly greater in the dexamethasone group (1.2 +/- 1.0 vs 0.6 +/- 0.4 ¿p = 0.02¿). Infants who received dexamethasone were significantly smaller 819.1 +/- 141.1 vs 954.6 +/- 141 gm ¿p = 0.008¿), were younger (26.2 +/- 1.7 vs 27.7 +/- 1.2 weeks ¿p = 0.004¿), received ventilator support longer (33.3 +/- 14.7 vs 12.1 +/- 14.7 days ¿p = 0.0001¿), and required more days of supplemental oxygen (54.3 +/- 9.7 vs 36.4 +/- 23.8 days ¿p = 0.009¿). We conclude that smaller, younger, and sicker infants are at the highest risk for the development of renal calcifications and that dexamethasone may be associated with increased urinary calcium excretion, which contributes to renal calcification formation.