No abstract

<b><i>Background:</i></b> Effective treatment and close monitoring in children with congenital hyperinsulinism (HI) are important to prevent hypoglycemic-associated brain damage. The current monitoring approach involves measuring plasma glucose intermittently, but this does not provide a comprehensive assessment of glycemic control and may fail to detect episodes of hypoglycemia. <b><i>Objective:</i></b> To determine whether Dexcom G5®, a continuous glucose monitoring system (CGMS), is an accurate and effective method for monitoring glycemic control in children with HI. <b><i>Methods:</i></b> Cross-sectional, observational study in 15 children with HI. Participants wore a blinded Dexcom G5® device for 2 weeks. At the end of 2 weeks, data from the Dexcom G5® and home glucose meter were downloaded and analyzed. <b><i>Results:</i></b> Fourteen children (15–67 months) completed the study. Using Bland-Altman analysis, the mean (SD) difference between 1,155 paired CGM and glucose meter readings was –8.09 (53.76). The sensitivity and specificity of CGM to detect hypoglycemia (&#x3c;70 mg/dL) were 86 and 81.4%, respectively. The positive predictive values for hypoglycemia and severe hypoglycemia (&#x3c;54 mg/dL) detected by CGM were low (50.3 and 14.8%, respectively), while the negative predictive values were high (96.4% for glucose &#x3c;70 mg/dL and 99.1% for glucose &#x3c;54 mg/dL). <b><i>Conclusion:</i></b> Our study showed that CGM is not a reliable method to monitor for hypoglycemia, given the high number of false positive hypoglycemia readings. However, CGM can be useful in preventing unnecessary checks by glucose meter during times of normoglycemia. Therefore, the benefits of using CGM in patients with HI would be in guiding the need to check plasma glucose by glucose meter rather than point accuracy.

No abstract

Hypocalcemia is one of the cardinal features of the chromosome 22q11.2 deletion syndrome (22q11.2DS), the most common cause of DiGeorge syndrome. Hypocalcemia and other features of 22q11.2DS including congenital heart disease (CHD) are primarily ascribed to problems with morphogenesis and function of the pharyngeal arch system derivatives including the parathyroid glands, the aortic arch, and the cardiac outflow tract. In light of the aforementioned embryology, we hypothesized that hypocalcemia would be identified more frequently in those patients with 22q11.2DS and CHD. We conducted a retrospective IRB approved chart review on 1,300 subjects with 22q11.2DS evaluated at the Children’s Hospital of Philadelphia. χ2 test was used to evaluate the statistical significance of differences in hypocalcemia between the two groups. Eight hundred fifty-two patients had calcium levels available for review. Of these, 466 (54.69%) had a history of hypocalcemia and 550 (64.55%) had CHD. Of those with CHD, 343 (62.36%) had a history of hypocalcemia, and of those without CHD, only 123 (40.73%) had a history of hypocalcemia. Thus, the frequency of diagnosed hypocalcemia was greater in patients with 22q11.2DS and CHD as compared to those without CHD (p < .001). We also analyzed age of onset of hypocalcemia and found that 66.47% of CHD/hypocalcemia group had neonatal/infantile hypocalcemia versus 43.09% in the non-CHD/hypocalcemia group. In our large cohort of patients with 22q11.2DS, the prevalence of diagnosed hypocalcemia is elevated among patients with CHD, in whom it is more likely to be diagnosed during the neonatal/infancy period.