Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) <50 nmol/L or 20 ng/mL) is common in Europe and the Middle East. It occurs in <20% of the population in Northern Europe, in 30–60% in Western, Southern and Eastern Europe and up to 80% in Middle East countries. Severe deficiency (serum 25(OH)D <30 nmol/L or 12 ng/mL) is found in >10% of Europeans. The European Calcified Tissue Society (ECTS) advises that the measurement of serum 25(OH)D be standardized, for example, by the Vitamin D Standardization Program. Risk groups include young children, adolescents, pregnant women, older people (especially the institutionalized) and non-Western immigrants. Consequences of vitamin D deficiency include mineralization defects and lower bone mineral density causing fractures. Extra-skeletal consequences may be muscle weakness, falls and acute respiratory infection, and are the subject of large ongoing clinical trials. The ECTS advises to improve vitamin D status by food fortification and the use of vitamin D supplements in risk groups. Fortification of foods by adding vitamin D to dairy products, bread and cereals can improve the vitamin D status of the whole population, but quality assurance monitoring is needed to prevent intoxication. Specific risk groups such as infants and children up to 3 years, pregnant women, older persons and non-Western immigrants should routinely receive vitamin D supplements. Future research should include genetic studies to better define individual vulnerability for vitamin D deficiency, and Mendelian randomization studies to address the effect of vitamin D deficiency on long-term non-skeletal outcomes such as cancer.
Paul Lips, Kevin D Cashman, Christel Lamberg-Allardt, Heike Annette Bischoff-Ferrari, Barbara Obermayer-Pietsch, Maria Luisa Bianchi, Jan Stepan, Ghada El-Hajj Fuleihan, and Roger Bouillon
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.