Background: Obesity is usually correlated with a higher prevalence of 25OH vitamin D (25OHD) deficiency. This might be due to either volumetric dilution of vitamin D in the large fat mass or its increased uptake by adipose tissue. To our knowledge, a systematic study on 25OHD levels in Prader-Willi syndrome (PWS), a genetic disorder associated with severe obesity, is not available.
Objective and hypotheses: To analyze the 25OHD values in a population of pediatric PWS in comparison with a group of obese controls (CNT), highlighting the possible correlation with fat mass and GH therapy (GHT).
Methods: 52 PWS (25 males) and 111 CNT (57 males), gender-, age- and BMI-SD matched were included. None of them was on calcium or vitamin D, while 20 PWS were undergoing GHT.
Results: 16 PWS (30.7%) and 27 CNT (24.3%) had low 25OHD level (P=NS). Mean 25OHD was 28.9±12.5 in PWS GHT vs 26.9±12.6 ng/ml in no GHT (P=NS). The more relevant findings are reported in the table. Univariate analysis (Pearsons) showed in both groups a negative correlation between 25OHD and fat mass% (FM%) (PWS r=−0.0308; P=0.031; CNT r=−0.200; P=0.04). In the group of PWS, GHT was correlated with lumbar Z score (r=0.382; P=0.005).
|Pubertal stage |
|25OH vitD |
|Lumbar Z score||−0.03±1.3||0.59±1.1||0.002|
Conclusion: Our data showed that PWS had similar values of 25OHD compared to CNT. As already described, FM seems to be the only parameter influencing 25OHD levels. Finally, GHT does not seem to influence 25OHD metabolism in PWS.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology