Lucia Pacifico, Eleonora Poggiogalle, Francesco Costantino, Caterina Anania, Flavia Ferraro, Francesco Chiarelli, and Claudio Chiesa
Ghrelin, a peptide mainly derived from the stomach, plays a pivotal role in the regulation of food intake, energy metabolism, and storage, as well as in insulin sensitivity. Ghrelin circulates in acylated (A-Ghr) and nonacylated (NA-Ghr) forms, and their potential differential associations with insulin resistance (IR) in childhood obesity remain undefined.
We investigated the associations of ghrelin forms with IR in normal weight and obese children and the impact of metabolic syndrome (MS) on their plasma values.
A total of 210 children in four subgroups of normal weight/obese children with and without components of MS were studied. Fasting blood glucose, insulin, lipid profile, and acylated and total ghrelin were examined. IR was determined by a homeostasis model assessment (HOMA) of IR.
In the entire population, plasma insulin and HOMA-IR were associated negatively with T-Ghr and NA-Ghr, but positively with the ratio of A/NA-Ghr after adjustment for age, gender, and Tanner stage. Obese metabolically abnormal children had lower T-Ghr and NA-Ghr, but comparable A-Ghr and a higher A/NA-Ghr ratio than obese metabolically normal subjects. Compared with lean healthy children, lean metabolically abnormal subjects had higher A-Ghr and the A/NA-Ghr ratio, but comparable T-Ghr and NA-Ghr. A multiple regression analysis showed that A-Ghr and the A/NA-Ghr ratios were positively associated with HOMA-IR, independent of age, gender, Tanner stage, and body mass index (or waist circumference) and other components of MS.
A-Ghr excess may negatively modulate insulin action in obese and nonobese children, and may contribute to the association of IR and MS.
Riccardo Bonfanti, Dario Iafusco, Ivana Rabbone, Giacomo Diedenhofen, Carla Bizzarri, Patrizia Ippolita Patera, Petra Reinstadler, Francesco Costantino, Valeria Calcaterra, Lorenzo Iughetti, Silvia Savastio, Anna Favia, Francesca Cardella, Donatella Lo Presti, Ylenia Girtler, Sarah Rabbiosi, Giuseppe D’Annunzio, Angela Zanfardino, Alessia Piscopo, Francesca Casaburo, Letizia Pintomalli, Lucia Russo, Valeria Grasso, Nicola Minuto, Mafalda Mucciolo, Antonio Novelli, Antonella Marucci, Barbara Piccini, Sonia Toni, Francesca Silvestri, Paola Carrera, Andrea Rigamonti, Giulio Frontino, Michela Trada, Davide Tinti, Maurizio Delvecchio, Novella Rapini, Riccardo Schiaffini, Corrado Mammì, Fabrizio Barbetti, and the Diabetes Study Group of ISPED
Transient neonatal diabetes mellitus (TNDM) is caused by activating mutations in ABCC8 and KCNJ11 genes (KATP/TNDM) or by chromosome 6q24 abnormalities (6q24/TNDM). We wanted to assess whether these different genetic aetiologies result in distinct clinical features.
Retrospective analysis of the Italian data set of patients with TNDM.
Clinical features and treatment of 22 KATP/TNDM patients and 12 6q24/TNDM patients were compared.
Fourteen KATP/TNDM probands had a carrier parent with abnormal glucose values, four patients with 6q24 showed macroglossia and/or umbilical hernia. Median age at diabetes onset and birth weight were lower in patients with 6q24 (1 week; −2.27 SD) than those with KATP mutations (4.0 weeks; −1.04 SD) (P = 0.009 and P = 0.007, respectively). Median time to remission was longer in KATP/TNDM than 6q24/TNDM (21.5 weeks vs 12 weeks) (P = 0.002). Two KATP/TNDM patients entered diabetes remission without pharmacological therapy. A proband with the ABCC8/L225P variant previously associated with permanent neonatal diabetes entered 7-year long remission after 1 year of sulfonylurea therapy. Seven diabetic individuals with KATP mutations were successfully treated with sulfonylurea monotherapy; four cases with relapsing 6q24/TNDM were treated with insulin, metformin or combination therapy.
If TNDM is suspected, KATP genes should be analyzed first with the exception of patients with macroglossia and/or umbilical hernia. Remission of diabetes without pharmacological therapy should not preclude genetic analysis. Early treatment with sulfonylurea may induce long-lasting remission of diabetes in patients with KATP mutations associated with PNDM. Adult patients carrying KATP/TNDM mutations respond favourably to sulfonylurea monotherapy.