Visceral adipose tissue resides within the reference range in children with Prader-Willi syndrome receiving nutritional intervention on a regular basis.

Nutritional intervention for maintaining an appropriate body composition is central to the management of Prader-Willi syndrome (PWS). Despite evidence that visceral adipose tissue (VAT) is associated with increased metabolic risks, the effects of nutritional intervention on fat distribution have not been evaluated for PWS children. We herein investigated fat distribution in 20 genetically diagnosed PWS children (9 males and 11 females); 17 of which received nutritional intervention with or without growth hormone (GH) treatment [GH-treated group (n = 8), GH-untreated group (n = 9)]. GH treatment continued for median of 4.9 years. GH treatment significantly increased height standard deviation score (SDS) whereas body weight SDS and body mass index SDS were not affected in GH-treated group. In GH-untreated group, height SDS significantly decreased during approximately 5 years of follow-up. Fat distribution was evaluated at the median age of 6.93 years in GH-treated group and 7.01 years in GH-untreated group. VAT was maintained within the reference range in both groups. Subcutaneous adipose tissue (SAT) was elevated in GH-untreated groups compared to reference values whereas it was not in GH-treated group. The remaining three subjects, who had never received nutritional intervention or GH treatment, showed increased VAT and SAT. In conclusion, nutritional intervention is beneficial in maintaining VAT within the reference range during childhood, although excessive nutritional intervention may cause unfavorable effect on linear growth.

Visceral adipose tissue increases shortly after the cessation of GH therapy in adults with Prader-Willi syndrome.

GH therapy in pediatric patients with Prader-Willi syndrome (PWS) improves body composition, but discontinuation of GH after achieving adult height has been implicated in its deterioration. Although there is evidence for the deleterious effects of visceral adipose tissue (VAT) rather than subcutaneous adipose tissue (SAT) on the development of obesity-related complications, the effects of GH discontinuation on fat distribution in adults with PWS has not been fully investigated. Therefore, we utilized dual-energy X-ray absorptiometry (DEXA) and abdominal computed tomography (CT) to compare the fat distribution between before and 6 months or 12 months after the cessation of GH therapy in 7 adult PWS patients. GH therapy was initiated at a mean age of 4.1 ± 1.4 years and discontinued at a mean age of 18.9 ± 1.8 years. Serum IGF-1 levels were decreased by discontinuation of GH therapy. Fat mass was significantly increased 6 and 12 months after GH cessation, whereas muscle mass and bone mineral density were unchanged during both study periods. Abdominal CT analysis revealed that elevations in fat mass were due to increases in VAT rather than SAT. Circulating low-density lipoprotein (LDL) cholesterol levels were significantly elevated 6 months after GH cessation. In conclusion, discontinuation of GH therapy caused rapid increases in visceral adipose tissue and LDL cholesterol levels. These findings indicate that continuation of GH therapy may be a therapeutic option to maintain body composition; however, further studies regarding the long-term benefits and adverse effects of GH therapy in adults with PWS are required.

Resting energy expenditure in short-stature children.

It is not clear what dietary intake standards should be used for children with abnormal body size. To investigate the energy requirements of short-stature children with no underlying diseases, their resting energy requirements (REE) were measured by indirect calorimetry. The short-stature group consisted of 30 prepubertal children with short stature and with no underlying diseases (age 6y±2) and the control group consisted of 13 age-matched children with standard stature. Fasting REE and the respiration quotient (RQ) with subjects in the supine position were measured by canopy indirect calorimetry. Actual measurements and body-size-adjusted REEs were compared between the groups. Also, REE measurements were compared with the basal metabolic rate (BMR) calculated using the Dietary Reference Intakes for Japanese (Dietary Reference Intakes). REE in the control group was significantly higher than that in the short-stature group. However, body-size-adjusted REEs were significantly higher for the short-stature group. When the actual REE was compared with the calculated BMR within both the control group and the short-stature group, which was acquired using the Dietary Reference Intakes, there was no difference within the control group but the actual REE measurements were significantly higher than the calculated BMR in the short-stature group. The same pattern was seen within the short-stature group when subjects were matched for height. There were no significant differences in RQ between the two groups.

Selenium deficiency in children and adolescents nourished by parenteral nutrition and/or selenium-deficient enteral formula.

The authors analyzed serum selenium levels of 95 children and adolescents with intestinal dysfunction and/or neurological disabilities [age range: 7 months-20 years; mean±standard deviation (SD): 8.0±5.3 years] who received parenteral nutrition (PN) and/or enteral nutrition (EN) with either reduced or no selenium doses for more than 3 months. Twenty-eight patients (29%) showed serum selenium levels below 4.0µg/dL. Five patients whose serum selenium levels were below 2µg/dL presented various clinical manifestations, including hair browning (n=5), macrocythemia (n=4), nail whitening (n=3) and cardiac dysfunction (n=1). None of these 5 patients were nourished through ordinary diets. Three of these patients were nourished through selenium-free enteral nutritional products, 1 through selenium-deficient PN and 1 through PN and a formula with reduced selenium. After selenium supplement therapy for 1 year, all 5 patients exhibited improvement in their serum selenium levels and clinical features of selenium deficiency. It is important to be cautious about secondary selenium deficiency in children and adolescents nourished only through EN/PN without an adequate dose of selenium.