Background: Numerous studies have shown that PWS patients demonstrate the preservation of insulin sensitivity despite severe obesity. Data about insulin secretion in PWS however, are still conflicting. Other reports showed that PWS subjects and simple obese controls had similar insulin levels and were both insulin resistant. These discrepancies could be due to the different clinical characteristics of the study groups, including age, weight excess levels and the presence/absence of GH therapy.
Objective and hypotheses: In this study we compared measures of insulin secretion and glucose levels in PWS children with those in BMI-, gender- and age-matched obese controls (OC), highlighting the influence of GH therapy on glucose metabolism.
Method: Three groups of children were studied: i) 12 PWS (eight males, median age 12.9 years and BMI-SDS: 3.37) on treatment with GH (PWS-GHT); ii) 8 PWS (two males, median age 13.1 years and BMI-SDS: 3.25) without GH therapy (PWS-noGHT); iii) 40 OC (21 males, median age 13.1 years and BMI-SDS: 3.7). All subjects underwent a standard OGTT, and the following parameters were evaluated: ISI, QUICKI, HOMA-IR, insulinogenic index (InsIn), and the area under the curve of insulin (In) and glucose (G). Diagnosis of altered glucose metabolism was defined according to the ADA criteria (2016).
Results: Impaired glucose tolerance was detected in 1 PWS-GHT (7%), 2 PWS-noGHT (25%) and 6 OC (15%). The more relevant findings are reported in the Table 1.
|G 0||In 120||ISI||InsIn|
|*p<0.05 vs OC; +p<0.02 vs OC; § p<0.03 vs OC; °p<0.02 vs OC|
Conclusion: Our data support the relative hypoinsulinemia and greater insulin sensitivity in obese children with PWS compared to OC. To be noted, GHT does not seem to negatively affect glucose and insulin homeostasis in PWS subjects.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology