Pankaja S. Venkataraman

Follow-up of school-age children with bronchopulmonary dysplasia

OBJECTIVE To investigate the outcome of school-age children with bronchopulmonary dysplasia (BPD) in terms of nutrition, pulmonary function, and intelligence, and to compare the results with a preterm cohort matched for gestational age and birth weight, and with a term control group. DESIGN Cross-sectional. SETTING Follow-up clinic at level III neonatal intensive care unit, university-affiliated hospital, Childrens Hospital. SUBJECTS Twelve children who had BPD as infants and 2 control groups of 12 children each. MAIN OUTCOME VARIABLES Anthropometric measurements, dietary intake, resting energy expenditure, pulmonary function, body composition measurements by dual energy x-ray absorptiometry, and Weschler intelligence test scores. RESULTS Children with BPD had decreased forced expiratory volume at 1 second, decreased forced expiratory flow between 25% and 75% of vital capacity, and decreased maximal expiratory flow velocity at 50% of vital capacity compared with age-matched normal inborn subjects (p = 0.025, p = 0.005, and p = 0.0013, respectively). Both children with BPD and matched preterm control children were shorter than infants in the term control group (p = 0.018). There were no significant differences in the other anthropometric parameters studied. The groups did not differ in resting energy expenditure. Lean body mass was lower in the BPD group compared with the term control groups (p = 0.017). Bone mineral content was lower in the BPD group compared with both the preterm and term control infants (p = 0.050 and p = 0.059, respectively). The mean performance intelligence quotient (IQ) and full-scale IQ scores in the BPD group were lower than in the term control group (p = 0.011 and p = 0.029, respectively). The proportion of children with borderline or intellectually deficient scores was significantly higher in the preterm group compared with the term group for verbal, performance, and full-scale IQ scales (p = 0.046, p = 0.018, and p = 0.048 respectively). The proportion of children with BPD who had borderline or deficient performance IQ scores was higher than for the term group (p = 0.046). CONCLUSIONS The lower height and intelligence scores in children with BPD may be related to prematurity and perinatal events rather than pulmonary disease. Subclinical pulmonary dysfunction in children with BPD persists at school age. The lower amount of lean body mass and possible decrease in bone mineral content in children with BPD may be related to their smaller size.

Hypercalcitoninemia and hypocalcemia in acutely ill children: Studies in serum calcium, blood ionized calcium, and calcium-regulating hormones

We studied the hypotheses that serum calcium and blood ionized calcium would be low in acutely ill children and would rise with clinical improvement. In 15 children admitted to the pediatric intensive care unit, the blood ionized calcium level was 4.45 +/- 0.06 mg/dl (1.11 +/- 0.015 mmol/L) on entry versus 5.17 +/- 0.03 mg/dl (1.29 +/- 0.01 mmol/L) in control subjects (p less than 0.005), rose significantly on days 2 and 3, and was 5.12 +/- 0.04 mg/dl (1.28 +/- 0.01 mmol/L) at discharge (p less than 0.005). Changes in serum calcium level were similar, whereas serum magnesium and phosphorus levels were normal and did not change. Basal serum parathyroid hormone concentrations were elevated, rose further during the study, and were normal at discharge. Serum parathyroid hormone levels correlated inversely with blood ionized calcium levels, indicating that compensatory hyperparathyroidism occurs with low blood ionized calcium concentrations. Basal serum calcitonin values were evaluated on entry and decreased with clinical improvement. Serum calcitonin levels correlated significantly with low blood ionized calcium levels, indicating that hypercalcitoninemia may play a role in the pathogenesis of hypocalcemia in these children. Urine calcium excretion was not increased in the four children studied. We speculate that with clinical improvement, a rise in serum parathyroid hormone levels and a decline in serum calcitonin levels may help restore normocalcemia in these acutely ill children.

Evaluation by dual-energy X-ray absorptiometry of age-related changes in body composition of male rats

The purpose of this study was to determine the feasibility of using a recently developed procedure, dual-energy x-ray absorptiometry, to determine body composition in rats as a function of aging. Results were obtained that were consistent with previous findings for male rats.

Decline in serum calcium, magnesium, and phosphorus values with oral glucose in normal neonates: Studies of serum parathyroid hormone and calcitonin*

In 10 normal term infants aged 52 +/- 2.5 hours, serum calcium, magnesium, phosphorus, ionized calcium, parathyroid hormone, and calcitonin were studied at 0, 1/2, 1, and 2 hours after administration of 1.77 +/- 0.08 gm/kg glucose orally over 20 minutes. In response to glucose administration, serum glucose concentration rose and serum P, Ca, and Mg concentrations fell. Serum PTH concentration rose significantly, and blood ionized Ca and pH were unaltered. Serum calcitonin was elevated, as compared with adult values, and did not change. We suggest that in neonates, as in adults, oral ingestion of glucose lowers serum Ca, Mg, and P, and a compensatory rise in serum PTH concentration maintains blood ionized Ca concentration.

Understanding the different phases of fetal growth.

Fetal growth was studied in 78 newborns who had serial scans in pregnancy. Weight at birth correlated with growth in the first 2 trimesters but better with the growth between 28 and 32 weeks. The correlations for weight at growth cessation were better than those for weight at birth. Crown-heel length at cessation did not correlate with fetal growth in the first 2 trimesters. Maternal weight increase correlated with fetal weight and crown-heel length but not with head circumference at cessation. Maternal prepregnancy weight correlated with fetal growth between 28 and 32 weeks, but not with fetal growth in the second trimester. A negative correlation was found between estimated duration of growth cessation and relative head circumference at birth.

Lowered serum Ca, blood ionized Ca, and unresponsive serum parathyroid hormone with oral glucose ingestion in infants of diabetic mothers

Oral glucose ingestion may lower serum Ca in infants of diabetic mothers (IDMs). Six metabolically stable IDMs were studied following ingestion of 1.7 +/- 0.1 g/kg (mean +/- SE) of glucose over 20 min and serum Ca, Mg, P, blood iCa, serum PTH, and CT were measured at 0, 1/2, 1, and 2 h. Data obtained in IDMs were compared with previously reported findings in 10 normal neonates. In IDMs as in normal neonates, serum Ca, Mg, P declined significantly after oral glucose ingestion. Blood Ca2+ was significantly lower at +1/2 h in IDMs versus normal neonates, and by analysis of covariance, trends in blood Ca2+ were significantly different in IDMs versus normal neonates, (p less than 0.05). Serum PTH concentrations were unaltered in IDMs versus a significant rise in serum PTH noted in normal neonates. The difference between the two groups was significant statistically (p less than 0.05). Baseline serum CT was elevated in both groups and did not change. Thus, in IDMs responses to oral glucose ingestion differs from that seen in normal neonates as follows: blood Ca2+ is lowered in IDMs versus normal neonates, and serum parathyroid hormone (PTH) does not respond to a decline in blood Ca2+ in IDMs, whereas in normal neonates serum PTH rises and blood Ca2+ is maintained. We speculate that relative parathyroid gland unresponsiveness occurs in IDMs, which may result in lowered blood Ca2+ after oral glucose ingestion in these infants.

Effect of intravenous calcium infusions on serum chemistries in neonates.

In 36 newborn infants admitted to the Childrens Hospital of Oklahoma, we studied the hypotheses that intravenous bolus infusions of Ca as calcium gluconate over 10 min may (a) result in acute metabolic acidosis, (b) increase serum osmolality, (c) increase serum free bilirubin, and (d) decrease serum phosphorus concentrations. All infants received 18 mg/kg of elemental calcium, as either a 5 or 10% solution of calcium gluconate. Blood ionized calcium (iCa) rose significantly with i.v. bolus Ca infusion (p < 0.005) and blood pH and serum P declined significantly (p < 0.05) with i.v. bolus Ca infusion in infants. Serum free bilirubin was not significantly altered. Serum osmolality rose significantly from baseline with bolus infusion of Ca as a 10% calcium gluconatc solution and did not change significantly with bolus infusion of a diluted 5% solution. In neonates, intravenous bolus calcium infusion (a) decreases blood pH, (b) infusion of 10% but not 5% calcium gluconate increases serum osmolality, (c) serum free bilirubin concentrations were not altered, and (d) serum phosphorus concentrations were decreased.