Bone metabolism in patients with type 1 neurofibromatosis: key role of sun exposure and physical activity.

Bone metabolism has been rarely investigated in children affected by Neurofibromatosis type 1 (NF1). Aim of the present study was to assess bone mineral metabolism in children and adults NF1 patients, to determine the relevant factors potentially involved in the development of reduced bone mineral density (BMD), and provide possible therapeutic intervention in NF1 patients. 114 NF1 patients and sex and age matched controls were enrolled into the study. Clinical and biochemical factors reflecting bone metabolism were evaluated. Factors potentially affecting BMD were also investigated including: physical activity, sun exposure, vitamin D intake. Whenever the presence of vitamin D deficiency was recorded, cholecalciferol supplementation was started and z-score data obtained at Dual-Energy X-ray Absorptiometry (DXA) during supplementation were compared with previous ones. NF1 patients showed lower Z-scores at Dual-Energy X-ray Absorptiometry DXA than controls. Physical activity was significantly reduced in NF1 patients than in controls. Sun exposure was significantly lower in NF1 compared to control subjects. At linear regression analysis vitamin D was the most predictive factor of reduced z-score at DXA (p = 0.0001). Cholecalciferol supplementation significantly increased BMD z-score (p < 0.001). We speculated that a combination of different factors, including reduced sun exposure, possibly associated with reduced serum vitamin D levels, and poor physical activity, concur to the impaired bone status in NF1 patients. We also demonstrated that treatment with vitamin D can be effective in improving z-score value in NF1 patients, including children. In conclusion, the findings of the current study are expected to have important implications for the follow-up and prevention of osteopenia/osteoporosis in this common genetic disease.

Waist Circumference and Healthy Lifestyle Preferences/Knowledge Monitoring in a Preschool Obesity Prevention Program.

Weight and body mass index (BMI) changes appear to be poor measures for assessing the success of most pediatric obesity prevention programs (POPP). The aim of this study is to evaluate the effectiveness of the preschool-age prevention program (3P) in improving and maintaining overtime preschoolers' knowledge/preferences about healthy nutrition and physical activity (PA), and the relationship between acquired healthy behaviors and anthropometrics including waist circumference (WC). Twenty-five preschoolers underwent a 24-month healthy lifestyle multi-component pilot intervention followed by a one-year wash-out period; 25 age-matched served as controls. Anthropometric/behavioral data were monitored. After the 2-year study and wash-out, the rates of children overweight and with obesity decreased only in the intervention group, where, also, normal-weight children with visceral obesity attained WC normal values (p = 0.048). While mean values of BMI Z-scores remained unchanged in both the intervention and control groups, WC (values and percentiles) showed a significant reduction only in the intervention group. Children's adherence to the Mediterranean diet remained acceptable among the entire sample. Although daily sweet beverage consumption remained unchanged in both groups, knowledge/preferences improved significantly more in the intervention group. In conclusion, WC may be more sensitive than BMI for monitoring preschoolers in POPP and reflects healthy behavioral changes acquired during the intervention.