Hypoglycemia and Comorbidities in Type 2 Diabetes

A systematic review of the association of Type I diabetes with sensorineural hearing loss

OBJECTIVES

Type 1 diabetes (T1D) has been associated with several comorbidities such as ocular, renal, and cardiovascular complications. However, the effect of T1D on the auditory system and sensorineural hearing loss (SNHL) is still not clear. The aim of this study was to conduct a systematic review to evaluate whether T1D is associated with hearing impairment.

METHODS

The databases PubMed, Science Direct, Scopus, and EMBASE were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Three reviewers independently screened, selected, and extracted data. The Joanna Briggs Institute (JBI) Critical Appraisal Tools for Analytical cross-sectional and case-control studies were used to perform quality assessment and risk of bias analysis on eligible studies.

RESULTS

After screening a total of 463 studies, 11 eligible original articles were included in the review to analyze the effects of T1D on the auditory system. The included studies comprised cross-sectional and case-control investigations. A total of 5,792 patients were evaluated across the 11 articles included. The majority of the studies showed that T1D was associated with hearing impairment compared to controls, including differences in PTAs and OAEs, increased mean hearing thresholds, altered acoustic reflex thresholds, and problems with the medial olivocochlear (MOC) reflex inhibitory effect. Significant risk factors included older age, increased disease duration, and higher HbA1C levels.

CONCLUSIONS

This systematic review suggests that there is a correlation between T1D and impairment on the auditory system. A multidisciplinary collaboration between endocrinologists, otolaryngologists, and audiologists will lead to early detection of hearing impairment in people with T1D resulting in early intervention and better clinical outcomes in pursuit of improving the quality of life of affected individuals.

REGISTRATION

This systematic review is registered in PROSPERO (CRD42023438576).

Ketogenic diet attenuates cognitive dysfunctions induced by hypoglycemia via inhibiting endoplasmic reticulum stress-dependent pathways

Hypoglycemia can potentially cause severe damage to the central nervous system. The ketogenic diet (KD), characterized by high-fat and extremely low-carbohydrate content, can modulate homeostasis and nutrient metabolism, thereby influencing body health. However, the effects and underlying mechanisms of KD on hypoglycemia-induced brain injury have not been thoroughly investigated. We aimed to explore the modulating effects of KD on cognitive functions and elucidate the underlying mechanisms. In this study, one-month-old mice were fed with KD for 2 weeks, and the changes in the gut microbiota were detected using the 16S rRNA gene amplicon sequencing method. The hypoglycemic model of mice was established using insulin, and the potential protective effect of KD on hypoglycemia-induced brain injury in mice was evaluated through immunofluorescence staining, western blotting, transmission electron microscopy, and Golgi staining. Our results showed that the intestinal flora of Dorea increased and Rikenella decreased in KD-fed mice. KD can not only alleviate anxiety-like behavior induced by hypoglycemia, but also increase the proportion of mushroom dendritic spines in the hippocampus by modulating changes in the gut microbiota. KD regulated synaptic plasticity by increasing the levels of SPN, PSD95, and SYP, which relieve cognitive impairment caused by hypoglycemia. Moreover, KD can promote the proliferation and survival of adult neural stem cells in the hippocampus, while reducing apoptosis by suppressing the activation of the IRE1-XBP1 and ATF6 endoplasmic reticulum stress pathways in mice with hypoglycemia. This study provides new evidence for demonstrating that KD may alleviate cognitive dysfunctions caused by hypoglycemia by modulating the gut microbiota.

To What Extent Is HbA1c Associated with Glycemic Variability in Patients with Type 1 Diabetes? A Retrospective, Noninterventional Study

BACKGROUND

Glycemic variability (GV) is a novel parameter used in evaluating the quality of diabetes management. Current guidelines recommend the use of GV indexes alongside the traditional parameter to evaluate glycemic control: hemoglobin A1c (HbA1c). This study aims to evaluate the extent to which HbA1c explains the GV phenomena in patients with Type 1 diabetes (T1DM).

METHODS

In 147 patients with T1DM, associations between HbA1c and several GV indexes were analyzed.

RESULTS

Patients with an HbA1c < 7% had a lower median standard deviation of glycemia (60 vs. 48; p < 0.001), a lower coefficient of variation (34.1 vs. 38.0; p < 0.001), and a significantly increased median time in range (78 vs. 58; p < 0.001). HbA1c was positively correlated with the coefficient of variation (r = 0.349; p < 0.001) and the standard deviation (r = 0.656; p < 0.001) but reversely correlated with a lower time in range (r = -0.637; p < 0.001).

CONCLUSIONS

HbA1c only partially explains the GV phenomena in patients with T1DM. The HbA1c value is associated more strongly with the time in range and standard deviation than with the coefficient of variation.

Dementia in Diabetes: The Role of Hypoglycemia

Hypoglycemia, a common consequence of diabetes treatment, is associated with severe morbidity and mortality and has become a major barrier to intensifying antidiabetic therapy. Severe hypoglycemia, defined as abnormally low blood glucose requiring the assistance of another person, is associated with seizures and comas, but even mild hypoglycemia can cause troubling symptoms such as anxiety, palpitations, and confusion. Dementia generally refers to the loss of memory, language, problem-solving, and other cognitive functions, which can interfere with daily life, and there is growing evidence that diabetes is associated with an increased risk of both vascular and non-vascular dementia. Neuroglycopenia resulting from a hypoglycemic episode in diabetic patients can lead to the degeneration of brain cells, with a resultant cognitive decline, leading to dementia. In light of new evidence, a deeper understating of the relationship between hypoglycemia and dementia can help to inform and guide preventative strategies. In this review, we discuss the epidemiology of dementia among patients with diabetes, and the emerging mechanisms thought to underlie the association between hypoglycemia and dementia. Furthermore, we discuss the risks of various pharmacological therapies, emerging therapies to combat hypoglycemia-induced dementia, as well as risk minimization strategies.

Associations of hyperglycemic emergency and severe hypoglycemia incidences with seasonality and ambient temperature among pregnant women with diabetes: a nested case-control study in Taiwan

BACKGROUND

Associations of acute glycemic complications with season and ambient temperature have been reported in general population with diabetes. However, little is known about the risks of acute glycemic complications in relation to season and ambient temperature in pregnant women, who are likely to be even more vulnerable. This work aimed to investigate the associations of season and ambient temperature with pregnancies complicated with hyperglycemia emergency or severe hypoglycemia.

METHODS

Two separate case-control studies were nested within 150,153 pregnancies by women with type 1, type 2, or gestational diabetes between 2009 and 2014 in Taiwan. Hyperglycemia emergency (mainly diabetic ketoacidosis and hyperosmolar hyperglycemic state) and severe hypoglycemia occurred in 77 and 153 diabetic pregnancies (cases), respectively. Ten control pregnancies were randomly selected for each case by matching each case pregnancy on type of diabetes (i.e., T1DM, T2DM, or GDM), maternal age on the date of acute glycemic complication occurrence (i.e., index date), and "length of gestation at risk" (i.e., period between conception and index date). Meteorological parameters were retrieved from 542 meteorological monitoring stations across Taiwan during 2008-2014. Conditional logistic regression analysis with generalized estimation equation was separately performed to estimate the covariate adjusted odds ratios (ORs) of each of the two acute glycemic complications in association with season and ambient temperature within 30 days prior to the index date.

RESULTS

Compared to summer, winter season was associated with a significantly elevated risk of severe hypoglycemia with an OR of 1.74 (95% confidence interval (CI) 1.08-2.79). The OR of hyperglycemic emergency was also elevated in winter season at OR of 1.88, but the significance is only marginal (95% CI 0.97-3.64, p = 0.0598). Subgroup analyses further noted that such seasonal variation was also observed in pregnancies with pre-pregnancy type 1 diabetes and gestational diabetes. On the other hand, ambient temperature was not significantly associated with the two acute glycemic complications.

CONCLUSIONS

A moderately but significantly elevated risk of severe hypoglycemia was found in pregnant women with diabetes during winter season, and such increased risk was more evident in pregnancies with T1DM.

Depressive symptoms in adolescent girls at-risk for type 2 diabetes and their parents

Few studies have characterized the relation between parent's depression symptoms and adolescent's depression symptoms in adolescents at-risk for type 2 diabetes (T2D). We evaluated the associations of parental depression symptoms with the depression symptoms and metabolic functioning of adolescent offspring at-risk for T2D. One-hundred sixteen parents and adolescent girls with a family history of diabetes completed surveys of depression symptoms. Adolescents' degree of metabolic risk for T2D was estimated from body mass index (BMI; kg/m²) standard score, percent adiposity from dual-energy x-ray absorptiometry scan, and whole body insulin sensitivity index determined from glucose/insulin concentrations during a two-hour oral glucose tolerance test. Parents' and adolescents' depression symptoms were significantly associated, even after accounting for race/ethnicity, age, puberty, body composition, and parental diabetes/BMI. Adjusting for similar covariates, parent depression symptoms also were positively related to adolescents' BMI standard score and had a trend-level association with adiposity. There was an inverse relation between parental depression symptoms and adolescent insulin sensitivity, which was entirely accounted for by adolescent body composition. The associations of parental depression symptoms with more elevated depression symptoms and higher BMI in adolescents at-risk for T2D has potential implications for interventions addressing these co-morbid health conditions.

Antisense Inhibition of Glucagon Receptor by IONIS-GCGRRx Improves Type 2 Diabetes Without Increase in Hepatic Glycogen Content in Patients With Type 2 Diabetes on Stable Metformin Therapy

OBJECTIVE

To evaluate the safety and efficacy of IONIS-GCGR_Rx, a 2'-O-methoxyethyl antisense oligonucleotide targeting the glucagon receptor (GCGR), and the underlying mechanism of liver transaminase increases in patients with type 2 diabetes on stable metformin therapy.

RESEARCH DESIGN AND METHODS

In three phase 2, randomized, double-blind studies, patients with type 2 diabetes on metformin received weekly subcutaneous injections of IONIS-GCGR_Rx (50-200 mg) or placebo for 13 or 26 weeks.

RESULTS

Significant reductions in HbA_1c were observed after IONIS-GCGR_Rx treatment versus placebo at week 14 (-2.0% 200 mg, -1.4% 100 mg, -0.3% placebo; P < 0.001) or week 27 (-1.6% 75 mg, -0.9% 50 mg, -0.2% placebo; P < 0.001). Dose-dependent increases in transaminases were observed with IONIS-GCGR_Rx, which were attenuated at lower doses and remained mostly within the normal reference range at the 50-mg dose. There were no other significant safety observations and no symptomatic hypoglycemia or clinically relevant changes in blood pressure, LDL cholesterol, or other vital signs. At week 14, IONIS-GCGR_Rx 100 mg did not significantly affect mean hepatic glycogen content compared with placebo (15.1 vs. -20.2 mmol/L, respectively; P = 0.093) but significantly increased hepatic lipid content (4.2 vs. -2.7%, respectively; P = 0.005) in the presence of transaminase increases.

CONCLUSIONS

IONIS-GCGR_Rx is a potent inhibitor of hepatic glucagon receptor expression with a potential to improve glycemic control at low weekly doses in combination with metformin. Significant reductions in HbA_1c occurred across the full-dose range tested, with minimal transaminase elevations at lower doses. Furthermore, novel results suggest that despite inhibition of glycogenolysis after GCGR antagonism, IONIS-GCGR_Rx did not increase hepatic glycogen content.

A Retrospective Cohort Study of Patients with Type 2 Diabetes in China: Associations of Hypoglycemia with Health Care Resource Utilization and Associated Costs

INTRODUCTION

This study aimed to examine the associations of hypoglycemia with health care resource utilization (HCRU) and health care costs among patients with type 2 diabetes mellitus (T2DM) in China.

METHODS

This retrospective cohort study was conducted with 23,680 T2DM patients >18 years old who visited the Second Affiliated Hospital of Nanchang University between 1 January 2011 and 31 December 2015. Univariate descriptive statistics were used to relate the HCRU and associated costs to patient characteristics, and regression analysis was used to examine the association between hypoglycemia and HCRU, controlling for other confounding factors.

RESULTS

In the T2DM patients with or without insulin treatment, when compared with nonhypoglycemic patients, hypoglycemia was associated with more medical visits (all T2DM patients 19.48 vs. 10.46, insulin users 23.45 vs. 14.12) and higher diabetes-related medical costs (all T2DM patients ¥5187.54 vs. ¥3525.00, insulin users ¥6948.84 vs. ¥3401.15) and medication costs (T2DM patients ¥1349.40 vs. ¥641.92, insulin users: ¥1363.87 vs. ¥853.96). Controlling for age, gender, and Charlson comorbidity index (CCI) score, hypoglycemia and insulin intake were associated with greater health care resource utilization. As compared to nonhypoglycemic patients, hypoglycemic T2DM patients and those on insulin therapy performed more outpatient visits (proportions of hypoglycemic vs nonhypoglycemic T2DM patients performing 3+ visits: 72.69% vs. 65.49%; proportions of hypoglycemic vs nonhypoglycemic patients on insulin therapy performing 3+ visits: 78.26% vs. 71.73%) and were hospitalized more often (proportions of hypoglycemic vs nonhypoglycemic T2DM patients with 3+ admissions 75.90% vs. 50.24%; proportions of hypoglycemic vs nonhypoglycemic patients on insulin therapy with 3+ admissions: 83.19% vs. 58.51%).

CONCLUSION

Hypoglycemia in diabetes patients was associated with increased healthcare resource utilization and health-related expenditure, especially for patients on insulin treatment. Insulin treatment regimens should be more individualized and account for hypoglycemia risk.

Coronary artery disease severity modifies associations between glycemic control and both mortality and myocardial infarction

AIMS

This study examined whether the association between hemoglobin A1c (HbA1c) and short-term clinical outcomes is moderated by CAD severity.

METHODS

We studied 17,394 US Veterans with type 2 diabetes who underwent elective cardiac catheterization between 2005 and 2013. CAD severity was categorized as obstructive, non-obstructive, or no CAD. Using multivariable Cox proportional hazards regression, we assessed associations between time-varying HbA1c and two-year all-cause mortality and non-fatal MI, with an interaction term between HbA1c and CAD severity.

RESULTS

61%, 22%, and 17% of participants had obstructive, non-obstructive, and no CAD, respectively. CAD severity modified the relationship between HbA1c and each outcome (interaction p-value 0.0005 for mortality and <0.0001 for MI). Low HbA1c (<42 mmol/mol) was associated with increased mortality, relative to HbA1c of 48-52 mmol/mol, in individuals with obstructive CAD (HR 1.52 [1.17, 1.97]) and non-obstructive CAD (HR 2.61 [1.61, 4.23]), but not in those with no CAD (HR 0.91 [0.46, 1.79]). In contrast, higher HbA1c levels (≥53 mmol/mol) were associated with increased MI risk only in individuals with obstructive CAD.

CONCLUSIONS

The associations between HbA1c and mortality and MI were moderated by CAD severity. Measures of cardiovascular disease severity may inform optimal individualized diabetes management.