Structural Gray and White Matter Differences in Patients With Type 1 Diabetes and Impaired Awareness of Hypoglycemia

Glucose pattern in children with classical congenital adrenal hyperplasia: evidence from continuous glucose monitoring

BACKGROUND

While the risk for hypoglycemia during acute illness is well described in children with classical congenital adrenal hyperplasia (CAH), there is little evidence for the prevalence of asymptomatic hypoglycemia and the daily glucose patterns in CAH. Herein, we explored the daytime glucose profile of children with classical CAH.

METHODS

We conducted an observational study in 11 children (6 female; age 3.1 years [1.4, 5.1]; body mass index 17.3 kg/m2 [15.6, 17.9]) with a genetic diagnosis of classical CAH receiving hydrocortisone and fludrocortisone replacement therapy. Participants underwent 2 14-day continuous glucose monitoring (CGM) sessions and an inpatient 24 h series cortisol and adrenocorticotropic hormone (ACTH) measures. Data were analyzed for 3 daytime lags (7 Am-4 Pm, 4 Pm-10pm, 10 Pm-7 Am) corresponding to the hydrocortisone dosing period with cortisol and ACTH measured before the hydrocortisone dose.

RESULTS

Eleven participants completed at least 1 CGM session, and 7 out of 11 underwent both the CGM session and the cortisol/ACTH serial measures. In the whole cohort, the percentage of time of sensor glucose values <70 mg/dL was higher during the 10 Pm-7 Am and the 7 Am-4 Pm time slots than in the late afternoon period (17% [7, 54] and 15% [6.8, 24] vs 2% [1.1, 16.7] during the periods 7 Am-4 Pm and 4 Pm-10 Pm, respectively [P = .006 and P = .003]). Nighttime hypoglycemia was mostly spent below the 65 mg/dL (10.9% [4.1, 34]). The glycemic pattern paralleled the nadir of daily cortisol at 7 Am (10.3±4.4 μg/dL). A greater percentage of time in hypoglycemia was associated with lower cortisol concentration at 7 Am and 10 Pm (P < .001 and P = .005).

CONCLUSIONS

Continuous glucose monitoring demonstrated a disrupted daily glucose pattern in children with CAH, paralleled by a lower cortisol concentration.

CLINICALTRIALS.GOV REGISTRATION

NCT04322435.

Prevalence and contributing factors of impaired awareness of hypoglycemia in patients with type 2 diabetes: a meta-analysis

AIMS

To conduct a systematic review to summarize the definition, measurement tools, prevalence, and contributing factors of impaired awareness of hypoglycemia (IAH) in type 2 diabetes mellitus (T2DM).

METHODS

A reproducible search strategy was used to identify factors affecting IAH in T2DM in PubMed, MEDLINE, EMBASE, Cochrane, PsycINFO, and CINAHL from inception until 2022. Literature screening, quality evaluation, and information extraction were performed independently by 2 investigators. A meta-analysis of prevalence was performed using Stata 17.0.

RESULTS

The pooled prevalence of IAH in patients with T2DM was 22% (95%CI:14-29%). Measurement tools included the Gold score, Clarke's questionnaire, and the Pedersen-Bjergaard scale. IAH in T2DM was associated with sociodemographic factors (age, BMI, ethnicity, marital status, education level, and type of pharmacy patients visited), clinical disease factors (disease duration, HbAlc, complications, insulin therapy regimen, sulfonylureas use, and the frequency and severity of hypoglycemia), and behavior and lifestyle (smoking and medication adherence).

CONCLUSION

The study found a high prevalence of IAH in T2DM, with an increased risk of severe hypoglycemia, suggesting that medical workers should take targeted measures to address sociodemographic factors, clinical disease, and behavior and lifestyle to reduce IAH in T2DM and thus reduce hypoglycemia in patients.

Exploratory Multisite MR Spectroscopic Imaging Shows White Matter Neuroaxonal Loss Associated with Complications of Type 1 Diabetes in Children

BACKGROUND AND PURPOSE

Type 1 diabetes affects over 200,000 children in the United States and is associated with an increased risk of cognitive dysfunction. Prior single-site, single-voxel MRS case reports and studies have identified associations between reduced NAA/Cr, a marker of neuroaxonal loss, and type 1 diabetes. However, NAA/Cr differences among children with various disease complications or across different brain tissues remain unclear. To better understand this phenomenon and the role of MRS in characterizing it, we conducted a multisite pilot study.

MATERIALS AND METHODS

In 25 children, 6-14 years of age, with type 1 diabetes across 3 sites, we acquired T1WI and axial 2D MRSI along with phantom studies to calibrate scanner effects. We quantified tissue-weighted NAA/Cr in WM and deep GM and modeled them against study covariates.

RESULTS

We found that MRSI differentiated WM and deep GM by NAA/Cr on the individual level. On the population level, we found significant negative associations of WM NAA/Cr with chronic hyperglycemia quantified by hemoglobin A1c (P < .005) and a history of diabetic ketoacidosis at disease onset (P < .05). We found a statistical interaction (P < .05) between A1c and ketoacidosis, suggesting that neuroaxonal loss from ketoacidosis may outweigh that from poor glucose control. These associations were not present in deep GM.

CONCLUSIONS

Our pilot study suggests that MRSI differentiates GM and WM by NAA/Cr in this population, disease complications may lead to neuroaxonal loss in WM in children, and deeper investigation is warranted to further untangle how diabetic ketoacidosis and chronic hyperglycemia affect brain health and cognition in type 1 diabetes.

Alterations in Functional Connectivity of Thalamus and Primary Somatosensory Cortex in Painful and Painless Diabetic Peripheral Neuropathy

OBJECTIVE

In this study we aimed to investigate the functional connectivity of brain regions involved in sensory processing in diabetes with and without painful and painless diabetic peripheral neuropathy (DPN) and the association with peripheral nerve function and pain intensity.

RESEARCH DESIGN AND METHODS

In this cross-sectional study we used resting-state functional MRI (fMRI) to investigate functional brain connectivity of 19 individuals with type 1 diabetes and painful DPN, 19 with type 1 diabetes and painless DPN, 18 with type 1 diabetes without DPN, and 20 healthy control subjects. Seed-based connectivity analyses were performed for thalamus, postcentral gyrus, and insula, and the connectivity z scores were correlated with peripheral nerve function measurements and pain scores.

RESULTS

Overall, compared with those with painful DPN and healthy control subjects, subjects with type 1 diabetes without DPN showed hyperconnectivity between thalamus and motor areas and between postcentral gyrus and motor areas (all P ≤ 0.029). Poorer peripheral nerve functions and higher pain scores were associated with lower connectivity of the thalamus and postcentral gyrus (all P ≤ 0.043). No connectivity differences were found in insula (all P ≥ 0.071).

CONCLUSIONS

Higher functional connectivity of thalamus and postcentral gyrus appeared only in diabetes without neuropathic complications. Thalamic/postcentral gyral connectivity measures demonstrated an association with peripheral nerve functions. Based on thalamic connectivity, it was possible to group the phenotypes of type 1 diabetes with painful/painless DPN and type 1 diabetes without DPN. The results of the current study support that fMRI can be used for phenotyping, and with validation, it may contribute to early detection and prevention of neuropathic complications.

Transition From Pediatric to Adult Care for Individuals With Type 1 Diabetes: Opportunities and Challenges

OBJECTIVES

Type 1 diabetes (T1D) is a chronic disease with patients across the age spectrum that has high potential for morbidity and mortality. Unfortunately, patients transitioning from pediatric to adult care continue to demonstrate worsened glycemic control in part due to lack of understanding of transition of care best practices.

METHODS

This review highlights the impact of existing transition of care interventions, assessment tools, and other recently published strategies for providers to consider to improve care of adolescent and young adult (AYA) patients with T1D in both hospital- and clinic-based settings.

RESULTS

Many barriers impact patients with T1D during the transition period and disparities by race, sex, insurance status, and comorbid illness persist. As diabetic care continues to evolve and the prevalence of adolescents and young adults living with T1D increases, an intentional approach to transition of care is more pressing than ever. While current literature on transition of care models is limited, many show promise in improving clinic attendance and decreasing hospitalization. There are critical discussions that providers should lead with AYA patients to improve their outcomes and increase diabetes self-management, such as re-addressing carbohydrate counseling, sleep hygiene, and reproductive planning.

CONCLUSION

While further research on transition of care is needed, many care models offer the promise of improved T1D outcomes, enhancements in our approach to care, and increased value for our health care system at large.

Gray Matter Brain Alterations in Type 1 Diabetes - Findings Based on Detailed Phenotyping of Neuropathy Status

AIMS

This study investigated brain structure in patients of type 1 diabetes with diabetic peripheral neuropathy (DPN) and type 1 diabetes with neuropathic pain and the associations to clinical, peripheral, and cognitive measurements.

METHODS

Sixty individuals with type 1 diabetes and 20 healthy controls were included in the study. Nineteen individuals with type 1 diabetes and neuropathic pain, 19 with type 1 diabetes and DPN, 18 with type 1 diabetes without DPN, and 20 healthy controls were included in the brain analyses. We utilized structural brain magnetic resonance imaging to investigate total and regional gray matter volume.

RESULTS

Significant lower gray matter volume was found in type 1 diabetes with neuropathic pain and in type 1 diabetes without DPN compared to healthy controls (p=0.024 and p=0.019, respectively). Lower insula volume was observed in all three diabetes groups (all p≤0.050). Thalamus and hippocampus volume was lower in type 1 diabetes with neuropathic pain, cerebellum volume was lower in type 1 diabetes with DPN, and somatosensory cortex volume was lower in type 1 diabetes without DPN (all p≤0.018). Attenuated memory was associated with lower gray matter volume in type 1 diabetes with DPN. No associations were found between gray matter volume and clinical/peripheral measurements.

CONCLUSION

We demonstrated lower gray matter volume in individuals with type 1 diabetes regardless of the presence of DPN and neuropathic pain. Hence, central gray matter alteration was not associated with peripheral alterations.