Association of Fructosamine Levels with Glycemic Control in Children with Type 1 Diabetes as Determined by Continuous Glucose Monitoring: Results from the CGM TIME Trial

OBJECTIVES

To determine the correlation between fructosamine, used to assess glycemia when HbA1c is not appropriate, with average blood glucose as measured by continuous glucose monitoring (CGM) in children with type 1 diabetes.

METHODS

97 blood samples were collected from 70 participants in the CGM TIME Trial. Each eligible participant had 3 weeks of CGM data with at least 60% CGM adherence prior to blood collection. Ordinary least squares linear regression incorporating restricted cubic splines was used to determine association between fructosamine and mean blood glucose.

RESULTS

An association was found between fructosamine levels and mean blood glucose with F-statistic of 9.543 p-value <0.001). Data were used to create formulae and a conversion chart for calculating mean blood glucose from fructosamine levels for clinical use.

CONCLUSIONS

There is a complex relationship between average blood glucose and fructosamine.

Motivational Stage at Continuous Glucose Monitoring (CGM) Initiation in Pediatric Type 1 Diabetes Is Associated With Current Glycemic Control but Does Not Predict Future CGM Adherence or Glycemic Control

OBJECTIVES

The Timing of Initiation of Continuous Glucose Monitoring in Established Pediatric Diabetes (CGM TIME) Trial is a multicenter, randomized controlled trial in children with type 1 diabetes, comparing simultaneous pump and CGM with CGM initiation 6 months later (Paradigm, Veo, Enlite Sensor, Medtronic Canada). This study addresses the ability of SOCRATES (Stages Of Change Readiness And Treatment Eagerness Scale) to classify children and parents into distinct motivational stages and identify the stages' association with glycated hemoglobin (A1C) at trial entry and outcomes 6 months after CGM initiation.

METHODS

Ninety-eight of 99 eligible children 10 to 18 years of age and 137 of 141 eligible parents completed SOCRATES at trial entry and 6 months later. Parent-child agreement for motivational stage was determined by weighted kappa. Linear regression was used to examine association between motivational stage and i) A1C at trial entry and ii) change in A1C and CGM adherence 6 months after CGM initiation.

RESULTS

More than 87% of children and 88% of parents were classified into distinct motivational stages, with weak parent-child agreement. At trial entry, motivational stage was associated with A1C, which was 1.02% higher for children in the Action stage than in the Precontemplation stage (p<0.0001). When compared with children of parents in Precontemplation, A1C for children of parents in the Maintenance and Action stages were 0.83% (p=0.02) and 0.36% (p=0.048) higher, respectively. Precontemplation was associated with shorter diabetes duration. Motivational stage at CGM initiation did not predict change in A1C or CGM adherence 6 months later.

CONCLUSIONS

SOCRATES can categorize children with type 1 diabetes and their parents into motivational stages. Although motivational stage was associated with glycemic control at trial entry, it did not predict future diabetes-related behaviour or A1C.

Fear of hypoglycemia in children with type 1 diabetes and their parents: Effect of pump therapy and continuous glucose monitoring with option of low glucose suspend in the CGM TIME trial

To determine if pump therapy with continuous glucose monitoring offering low glucose suspend (LGS) decreases fear of hypoglycemia among children with type 1 diabetes and their parents. The CGM TIME trial is a multicenter randomized controlled trial that enrolled 144 children with type 1 diabetes for at least 1 year (mean duration 3.4 ± 3.1 years) starting pump therapy (MiniMed™ Veo™, Medtronic Canada). CGM (MiniMed™ Enlite™ sensor) offering LGS was introduced simultaneously or delayed for 6 months. Hypoglycemia Fear Scale (HFS) was completed by children ≥10 years old and all parents, at study entry and 12 months later. Simultaneous and Delayed Group participants were combined for all analyses. Subscale scores were compared with paired t-tests, and individual items with paired Wilcoxon tests. Linear regression examined association with CGM adherence. 121/140 parents and 91/99 children ≥10 years had complete data. Mean Behavior subscale score decreased from 21.1 (SD 5.9) to 17.2 (SD 6.1) (p < .001) for children, and 20.7 (SD 7.5) to 17.4 (7.4) (p < .001) for parents. Mean Worry subscale score decreased from 17.9 (SD 11.9) to 11.9 (SD 11.4) (p < .001) for children, and 23.1 (SD 13.2) to 17.6 (SD 10.4) (p < .001) for parents. Median scores for 10/25 child items and 12/25 parent items were significantly lower at 12 months (p < .001). Linear regression found no association between HFS scores and CGM adherence. Insulin pump therapy with CGM offering LGS significantly reduced fear of hypoglycemia not related to CGM adherence in children with type 1 diabetes and their parents.

Timing of CGM initiation in pediatric diabetes: The CGM TIME Trial

OBJECTIVE

To determine whether timing of CGM initiation offering low glucose suspend (LGS) affects CGM adherence in children and youth starting insulin pump therapy.

METHODS

A 5-site RCT of pump-naïve subjects (aged 5-18 years) with type 1 diabetes (T1D) for at least 1 year compared simultaneous pump and CGM initiation offering LGS vs standard pump therapy with CGM initiation delayed for 6 months. Primary outcome was CGM adherence (hours per 28 days) (MiniMed™ Paradigm™ Veo™ system; CareLink Pro™ software) over 6 months after CGM initiation. Secondary outcome HbA1c was measured centrally. Linear mixed-models and ordinary least squares models were fitted to estimate effect of intervention, and covariates baseline age, T1D duration, HbA1c, gender, ethnicity, hypoglycemia history, clinical site, and association between CGM adherence and HbA1c.

RESULTS

The trial randomized 144/152 (95%) eligible subjects. Baseline mean age was 11.5 ± 3.3(SD) years, T1D duration 3.4 ± 3.1 years, and HbA1c 7.9 ± 0.9%. Six months after CGM initiation, adjusted mean difference in CGM adherence was 62.4 hours per 28 days greater in the Simultaneous Group compared to Delayed Group (P = .007). There was no difference in mean HbA1c at 6 months. However, for each 100 hours of CGM use per 28-day period, HbA1c was 0.39% (95% CI 0.10%-0.69%) lower. Higher CGM adherence was associated with reduced time with glucose >10 mmol/L (P < .001).

CONCLUSION

CGM adherence was higher after 6 months when initiated at same time as pump therapy compared to starting CGM 6 months after pump therapy. Greater CGM adherence was associated with improved HbA1c.

Carnitine uptake defect due to a 5'UTR mutation in a pedigree with false positives and false negatives on Newborn screening

Carnitine Uptake Defect (CUD) is an autosomal recessive disorder due to mutations in the SLC22A5 gene. Classically patients present in infancy with profound muscle weakness and cardiomyopathy with characteristic EKG findings. Later presentations include recurrent hypoketotic hypoglycemia, proximal limb girdle myopathy,and/or recurrent muscle pain. Newborn screening detects most of these clinical variants but in addition has identified maternal CUD often in asymptomatic women. We describe a family ascertained through 3 newborn screening (NBS) positive infants found to be unaffected themselves but in whom the mothers (sisters) were affected. There were also two affected children born to an affected male and his heterozygous wife who were false negatives on NBS but had increased fractional excretion of free carnitine in the urine. Analysis on a Next Generation Sequencing panel specifically designed to fully cover newborn screening disease targets showed a homozygous change in the five probands (SLC22A5; NM_003060:c.-149G > A; p.?). The mutation segregates with the CUD within the family. It is in the 5' UTR and has a frequency within the gnomAd database of 0.001198. Plasma carnitine was decreased and fractional excretion of free carnitine was increased in all affected individuals. Functional carnitine uptake studies in cultured skin fibroblasts of one proband showed carnitine uptake at the 5 μM concentration to be 6% of controls. Relative expression of OCTN2 mRNA to beta-actin mRNA by qRT-PCR was increased in a proband relative to controls by a factor of 465-fold. Western blotting revealed a 120 kDa protein band, as well as a weaker 240 kDa band in the proband, the significance of which is unknown at this time.

The role of corticosteroid-binding globulin in the evaluation of adrenal insufficiency

Cortisol is a hydrophobic molecule that is largely bound to corticosteroid-binding globulin (CBG) in the circulation. In the assessment of adrenal insufficiency, many clinicians measure a total serum cortisol level, which assumes that CBG is present in normal concentrations and with a normal binding affinity for cortisol. CBG concentration and affinity are affected by a number of common factors including oral contraceptive pills (OCPs), fever and infection, as well as rare mutations in the serine protease inhibitor A6 (SERPINA6) gene, and as such, total cortisol levels might not be the ideal way to assess adrenal function in all clinical circumstances. This paper reviews the limitations of immunoassay and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the measurement of total cortisol, the challenges of measuring free serum cortisol directly as well as the difficulties in calculating an estimated free cortisol from total cortisol, CBG and albumin concentrations. Newer approaches to the evaluation of adrenal insufficiency, including the measurement of cortisol and cortisone in the saliva, are discussed and a possible future role for these tests is proposed.

Association between childhood obesity and subsequent Type 1 diabetes: a systematic review and meta-analysis

AIMS

To review and synthesize the published evidence on the possible association between childhood obesity and the subsequent risk of Type 1 diabetes.

METHODS

The PubMed database was systematically searched for studies using childhood obesity, BMI or %weight-for-height as the exposure variable and subsequent Type 1 diabetes as the outcome. Studies were only included if assessment of obesity preceded the diagnosis of Type 1 diabetes.

RESULTS

Eight case-control studies and one cohort study were included, comprising a total of 2658 cases. Of these nine studies, seven reported a significant association between childhood obesity, BMI or %weight-for-height and increased risk for Type 1 diabetes. Meta-analysis of the four studies that reported childhood obesity as a categorical exposure produced a pooled odds ratio of 2.03 (95% CI 1.46-2.80) for subsequent Type 1 diabetes; however, in those studies, age at obesity assessment varied from age 1 to 12 years. A dose-response relationship was supported by a continuous association between childhood BMI and subsequent Type 1 diabetes in a meta-analysis of five studies (pooled odds ratio 1.25 (95%CI 1.04-1.51) per 1 sd higher BMI).

CONCLUSION

There is overall evidence for an association between childhood obesity, or higher BMI, and increased risk of subsequent Type 1 diabetes. Several theories have been proposed for a causal relationship. Reduction in Type 1 diabetes should be considered as a potential additional benefit of preventing childhood obesity.