Resting Energy Expenditure in Patients With Familial Dysautonomia: A Preliminary Study.

OBJECTIVES: Familial dysautonomia (FD) is a rare hereditary sensory and autonomic neuropathy characterized by chronic lung disease and cyclic vomiting due to hyper-adrenergic crises. Most FD patients are in a depleted nutritional state; however, the phenotype of the disease is quite different between patients, as for the severity of lung disease and the intensity and frequency of these pathognomonic crises. In this study we wanted to investigate whether resting energy expenditure (REE) levels are increased in this population, and if correlations exist between REE levels and phenotype severity. METHODS: Data was collected from 12 FD patients (6/6 m/f). REE measurements were conducted by indirect calorimeter. Measured REE % predicted were correlated with pulmonary function, severity of the scoliosis, serum C-reactive protein, yearly frequency of hyperadrenergic crisis, hospital admissions and the use of nocturnal noninvasive positive pressure ventilation. RESULTS: Mean REE was 112 ±13% predicted with 50% being in a hypermetabolic state (REE/HB > 110%). Body mass index (BMI) was below normal range in 75% of patients, and reduced energy intake was also decreased in 75%. No significant correlations to disease severity factors were found. When dividing the subjects to REE levels above or below 125% predicted, Patients with REE above 125% predicted presented with significantly lower inspiratory capacity (42.7% predicted vs 62.8% predicted; P = 0.04). CONCLUSIONS: Hypermetabolic state was described in 50% of FD patients. The Low BMI is explained by combination of relative anorexia and increased REE. The REE levels are related to the underling respiratory disease.

Assessment of Airway Bronchodilation by Spirometry Compared to Airway Obstruction in Young Children with Asthma.

A reversibility test by an increase of greater than 12% in FEV1 can support a diagnosis of asthma and alter a patient's treatment plan but may not be applicable to the young ages. We retrospectively gathered spirometric data from 85/271 asthmatic children having mild obstruction (FEV1 > 80% predicted), age 2.6-6.9 years. Spirometry was performed before and 20 min after inhalation of 200 mcg Albuterol. We defined a deviation below -1.64 z scores from control as obstruction and an increased above 1.64 scores from control as a positive response to bronchodilators. Sensitivity of the index was considered significant if it captured >68% of the participants. The sensitivity of detecting airway obstruction in these children by FEV1 was 15.3% and 62.4% by FEF25-75. A positive response to Albuterol was an increase of 9.2% for FEV1 (12% for adults) and 18.5% for FEF25-75. The sensitivity for detecting a response to Albuterol in mild asthma was 64.7% by FEV1 and 91.8% by FEF25-75. Young children having normal spirometry can demonstrate airway reversibility. The response of spirometry parameters to bronchodilators may be more sensitive than obstruction detection and may help to support the diagnosis of asthma and adjust treatment plan.