PurposeVitamin D deficiency is reported to be more common in type 1 diabetes patients and might be associated with the increased urinary loss of vitamin D binding protein (VDBP) consequent to impaired 25-hydroxyvitamin D (25(OH)D) circulation. We aimed to evaluate the possible increased urinary loss of VDBP, a correlation between VDBP and circulating 25(OH)D level, and risk factors influencing low vitamin D level in pediatric type 1 diabetes patients without microalbuminuria.MethodsThis is a cross-sectional study of subjects who visited Seoul National University Children’s Hospital between January and March 2013. Forty-two type 1 diabetes patients and 29 healthy controls were included. Biochemical parameters including serum and urine VDBP concentrations were analyzed.ResultsThere was no significant difference in the frequency of vitamin D deficiency or serum 25(OH)D level between the 2 groups. The serum and urine VDBP concentrations did not show any difference between the 2 groups. Serum 25(OH) D level did not correlate with serum or urine VDBP. Multivariate regression analysis revealed that daylight outdoor hours (β=2.948, P=0.003) and vitamin D intake (β=2.865, P=0.003) affected the 25(OH)D level; the presence of type 1 diabetes or urinary VDBP excretion was not significant.ConclusionsIn pediatric type 1 diabetes patients, urinary VDBP excretion did not contribute to low serum 25(OH)D level in the setting of normoalbuminuria. The factors associated with 25(OH)D level during winter periods were daylight outdoor hours and vitamin D intake. Further studies including both micro- and macroalbuminuria patients with type 1 diabetes are warranted.

PurposeWhether parental origin of the intact X chromosome and/or the presence of Y chromosome sequences (Yseq) play a role in three-year height response to growth hormone (GH) were investigated.MethodsPaternal (Xp) or maternal (Xm) origin of X chromosome was assessed by microsatellite marker analysis and the presence of hidden Yseq was analyzed. The first-, second-, and third-year GH response was measured as a change in height z-score (Z_Ht) in Turner syndrome (TS) patients with 45,Xp (n=10), 45,Xm (n=15), and 45,X/46,X,+mar(Y) (Xm_Yseq) (n=8).ResultsThe mean baseline Z_Ht did not differ according to Xp or Xm origin, however the mean baseline Z_Ht was higher in the Xm_Yseq group than in Xm group, after adjusting for bone age delay and midparental Z_Ht (P=0.04). There was no difference in the height response to GH between the 3 groups. The height response to GH decreased progressively each year (P<0.001), such that the third-year increase in Z_Ht was not significant. This third-year decrease in treatment response was unaffected by Xp, Xm, and Xm_Yseq groups. Increasing GH dosage from the second to third-year of treatment positively correlated with the increase in Z_Ht (P=0.017).ConclusionThere was no evidence of X-linked imprinted genes and/or Yseq affecting height response to 3 years of GH therapy. Increasing GH dosages may help attenuate the decrease in third-year GH response in TS patients with 45,X and/or 46,X/+mar(Y).

PurposeTo assess the usability and safety of the disposable pen compared to those of reusable devices in patients receiving recombinant human growth hormone (rhGH) treatment.Patients and methodsThis study was a multicenter, single-arm, open-label, switch-over, prospective, Phase IV trial. After screening, eligible patients who were previously treated with rhGH using a reusable device were enrolled to receive treatment with the disposable pen for 8 weeks. The ease of use, preference, and tolerability of the disposable pen compared to those of the reusable device were assessed by the subjects and/or their caregivers using a questionnaire. Adverse events were evaluated by the investigators.ResultsOf 116 subjects enrolled in this study, 115 received treatment with the disposable pen and 109 completed the study. The mean age of the subjects was 9.4 years. Compared to the previous reusable device, the disposable pen was assessed as significantly easier to use (mean value 7.88, 95% confidence interval (CI) [7.45–8.30] on a numerical scale ranging from 0 (far less easy) to 10 (far easier)). Furthermore, the percentage of subjects who preferred the disposable pen to the previously used reusable device was 75.7% (95% CI [67.6%–83.8%]). The percentages of subjects who rated pain and discomfort at the injection site as “not at all” were higher after using the disposable pen compared to the reusable device. No specific safety concerns were identified.ConclusionThe disposable pen is easier to use than the reusable devices and is preferred by approximately 75% of patients receiving rhGH treatment. Moreover, the disposable pen is safe and acceptable. Therefore, it could be a good alternative to reusable devices. The disposable pen is expected to provide benefits to patients receiving rhGH treatment.Clinicaltrials.gov identifierNCT03015909.