Important determinants of diabetes control in insulin pump therapy in patients with type 1 diabetes mellitus.

BACKGROUND: Insulin pumps are equipped with advanced functions. Intensive training and adherence are required for optimum use of the technology. We aimed to assess the association of various key elements in insulin pump functions on blood glucose control. PATIENTS AND METHODS: Patients on insulin pump therapy were enrolled. Insulin pumps were downloaded (CareLink(®) Pro 3 software; Medtronic Minimed, Northridge, CA), and data were collected over an 8-12-week period. Glycemic control of patients was classified as controlled (hemoglobin A1c [HbA1c] level of 7.5% or less in adults and 8% or less in children) and uncontrolled based on HbA1c level at enrollment. Variables studied were use of sensors and duration, frequency of blood glucose monitoring, Bolus Wizard (Medtronic Minimed) use, frequency of correction boluses, and frequency of cannula changing. RESULTS: Seventy-two patients were enrolled (50 children). Median age was 12 years for children and 27.5 years for adults. Respective median numbers of blood glucose checks were 4.4 and 3.2 for controlled and uncontrolled children (P<0.021) and 3.1 and 2.8 for controlled and uncontrolled adults, respectively. Respective frequency of Bolus Wizard use per day showed a median of 6 and 4.15 for controlled and uncontrolled children (P<0.001) and 3.8 and 3.5 for controlled and uncontrolled adults. Controlled children wore sensors for longer (5 vs. 2.9 days/week) and did more corrections (3.9 vs. 2.5). There was no difference in the frequency of changing the infusion cannula in children's or adults' groups. CONCLUSIONS: We conclude that the frequency of blood glucose monitoring and Bolus Wizard use have a favorable association with glycemic control. These observations were more significant in the children's groups. Our data shows that patients with better control tend to bolus more for correction and wear sensors longer.

A novel CLDN16 mutation in a large family with familial hypomagnesaemia with hypercalciuria and nephrocalcinosis.

BACKGROUND: Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis is a rare tubulopathy leading to renal calcification and progressive renal failure. CASE PRESENTATION: We report a consanguineous Arab family (of Qatari origin) with 7 affected siblings with variable phenotypes including hypomagnesaemia, hypercalciuria, nephrocalcinosis and renal stones. Presenting features included haematuria and recurrent urinary tract infections. As the biochemical and clinical phenotypes of this family resembled familial hypomagnesaemia with hypercalciuria and nephrocalcinosis, we performed genetic investigation in order to provide a precise molecular diagnosis. We screened all coding regions of the CLDN16 gene and identified a novel mutation (c.G647A, p.R216H) which was found homozygously in the six severely affected cases, who manifested significant nephrocalcinosis, often nephrolithiasis and sometimes reduced GFR. Parents were both heterozygous for the mutation and, together with children carrying the mutation in its heterozygous state, exhibited mild or no biochemical phenotypes. CONCLUSION: Mutations in CLDN16 underlie familial hypomagnesaemia with hypercalciuria and nephrocalcinosis but remain a rare cause of nephrocalcinosis and nephrolithiasis. Management includes reduction of hypercalciuria with thiazide diuretics, correction of serum magnesium and close monitoring of renal function given the significant risk of end stage renal failure with this inherited form of nephrocalcinosis.