Comprehensive nutritional and metabolic assessment in patients with spinal muscular atrophy: Opportunity for an individualized approach.

Optimal nutrition support is recommended for patients with spinal muscular atrophy (SMA). In a prospective study, we performed comprehensive nutritional assessments with the aim to guide best nutritional strategies for patients with SMA types II and III. We recorded a) anthropometry; b) macro- and micronutrient intakes; c) measured resting energy expenditure by indirect calorimetry; and d) body composition including dual X-ray absorptiometry. We enrolled a cohort of 21 patients aged 3 to 36 years of which 13 were female; 19 had SMA type II and 2 had SMA type III. The body mass index z-score ranged from -3 to 2.4. Forty-five percent of the cohort was either underfed or overfed, based on the difference between actual energy intake and measured resting energy expenditure. Vitamin D, E, K, folate and calcium intakes were low in a majority of the cohort. Forty-five percent of the cohort was either hypometabolic or hypermetabolic. Fat mass index (kg/m2) was significantly higher and lean body mass index (kg/m2) was significantly lower in the study cohort compared to population normalized values. Bone mineral density was low in 13 of 17 patients. In summary, we have described the prevalence of malnutrition, suboptimal feeding and alterations in body composition in children with SMA. A comprehensive nutritional assessment could guide individualized nutrition therapy in this vulnerable population.

Whole Body Protein Turnover and Net Protein Balance After Pediatric Thoracic Surgery: A Noninvasive Single-Dose 15 N Glycine Stable Isotope Protocol With End-Product Enrichment.

BACKGROUND: We used the 15 N glycine urinary end-product enrichment technique to quantify whole body protein turnover following thoracic surgery. MATERIALS AND METHODS: A single dose of 15 N glycine (2 mg/kg) was administered orally on postoperative day 1 to children (1-18 years) following thoracic surgery. 15 N enrichment of ammonia and urea was measured in mixed urine after 12 and 24 hours, respectively, and protein synthesis, breakdown, and net balance determined. Nitrogen balance (dietary intake minus urinary excretion) was calculated. Urinary 3-methylhistidine:creatinine ratio was measured as a marker of skeletal muscle protein breakdown. RESULTS: We enrolled 19 subjects-median (interquartile range): age, 13.8 years (12.2-15.1); weight, 49.2 kg (38.4-60.8)-who underwent thoracotomy (n = 12) or thoracoscopic (n = 7) surgery. Protein synthesis and breakdown by 15 N enrichment were 7.1 (5.5-9) and 7.1 (5.6-9) g·kg-1 ·d-1 with ammonia (12 hours) as the end product, and 5.8 (3.8-6.7) and 6.7 (4.5-7.6) with urea (24 hours), respectively. Net protein balance by the 15 N glycine and urinary urea nitrogen methods were -0.34 (-0.47, -0.3) and -0.48 (-0.65, -0.28) g·kg-1 ·d-1 , respectively (rs = 0.828, P < .001). Postoperative change in 3-methylhistidine:creatinine ratio did not correlate significantly with protein breakdown or balance. CONCLUSION: The single-dose oral administration of 15 N glycine stable isotope with measurement of urinary end-product enrichment is a feasible and noninvasive method to investigate whole body protein turnover in children. After major surgery, children manifest increased protein turnover and net negative balance due to increased protein breakdown.

Systemic Reactions in Pediatric Patients Receiving Standardized Allergen Subcutaneous Immunotherapy with and without Seasonal Dose Adjustment.

BACKGROUND: The 2003 Joint Task Force on Practice Parameters recommended standardizing allergen subcutaneous immunotherapy (SCIT). Data from longitudinal surveillance survey in North America reported a systemic reaction (SR) rate of 0.1% to 0.2% of injection visits. The rate of SR to standardized SCIT in pediatric patients has not been well evaluated. OBJECTIVE: The objective of this study was to evaluate the rate of SRs to standardized SCIT in pediatric patients aged 5 to 18 years in a single tertiary care center in the United States. METHODS: A retrospective chart review was conducted in 2 groups: group 1 started SCIT within a period extending from January 2009 to June 2012, whereas group 2 started SCIT within a period extending from January 2013 to June 2016. The protocol was modified in group 2 such that updosing and maintenance doses were adjusted in the spring for tree and grass pollen and in the fall for weed pollen. RESULTS: There were a total of 128 patients in group 1 and 118 patients in group 2. The rate of SR was 0.429% in group 1 and 0.364% in group 2, which was not significant. There was no difference in the severity of SR in the 2 groups with no-fatal or near-fatal SR noted. Asthma was a significant risk factor in the younger age subgroup aged 5 to 11 years. CONCLUSIONS: Standardized SCIT appears to be associated with an SR rate of 0.429% to 0.364% of visits in pediatric patients. Protocol modification did not lead to a significant drop in SR. Larger multicenter studies are required to further evaluate the rate of SRs from standardized SCIT.