Hypoglycemia unawareness and autonomic dysfunction in diabetes: Lessons learned and roles of diabetes technologies

Immunoprotection Strategies in β-Cell Replacement Therapy: A Closer Look at Porcine Islet Xenotransplantation

Type 1 diabetes mellitus (T1DM) is characterized by absolute insulin deficiency primarily due to autoimmune destruction of pancreatic β-cells. The prevailing treatment for T1DM involves daily subcutaneous insulin injections, but a substantial proportion of patients face challenges such as severe hypoglycemic episodes and poorly controlled hyperglycemia. For T1DM patients, a more effective therapeutic option involves the replacement of β-cells through allogeneic transplantation of either the entire pancreas or isolated pancreatic islets. Unfortunately, the scarcity of transplantable human organs has led to a growing list of patients waiting for an islet transplant. One potential alternative is xenotransplantation of porcine pancreatic islets. However, due to inter-species molecular incompatibilities, porcine tissues trigger a robust immune response in humans, leading to xenograft rejection. Several promising strategies aim to overcome this challenge and enhance the long-term survival and functionality of xenogeneic islet grafts. These strategies include the use of islets derived from genetically modified pigs, immunoisolation of islets by encapsulation in biocompatible materials, and the creation of an immunomodulatory microenvironment by co-transplanting islets with accessory cells or utilizing immunomodulatory biomaterials. This review concentrates on delineating the primary obstacles in islet xenotransplantation and elucidates the fundamental principles and recent breakthroughs aimed at addressing these challenges.

Heterogeneity of glycaemic phenotypes in type 1 diabetes

AIMS/HYPOTHESIS

Our study aims to uncover glycaemic phenotype heterogeneity in type 1 diabetes.

METHODS

In the Study of the French-speaking Society of Type 1 Diabetes (SFDT1), we characterised glycaemic heterogeneity thanks to a set of complementary metrics: HbA1c, time in range (TIR), time below range (TBR), CV, Gold score and glycaemia risk index (GRI). Applying the Discriminative Dimensionality Reduction with Trees (DDRTree) algorithm, we created a phenotypic tree, i.e. a 2D visual mapping. We also carried out a clustering analysis for comparison.

RESULTS

We included 618 participants with type 1 diabetes (52.9% men, mean age 40.6 years [SD 14.1]). Our phenotypic tree identified seven glycaemic phenotypes. The 2D phenotypic tree comprised a main branch in the proximal region and glycaemic phenotypes in the distal areas. Dimension 1, the horizontal dimension, was positively associated with GRI (coefficient [95% CI]) (0.54 [0.52, 0.57]), HbA1c (0.39 [0.35, 0.42]), CV (0.24 [0.19, 0.28]) and TBR (0.11 [0.06, 0.15]), and negatively with TIR (-0.52 [-0.54, -0.49]). The vertical dimension was positively associated with TBR (0.41 [0.38, 0.44]), CV (0.40 [0.37, 0.43]), TIR (0.16 [0.12, 0.20]), Gold score (0.10 [0.06, 0.15]) and GRI (0.06 [0.02, 0.11]), and negatively with HbA1c (-0.21 [-0.25, -0.17]). Notably, socioeconomic factors, cardiovascular risk indicators, retinopathy and treatment strategy were significant determinants of glycaemic phenotype diversity. The phenotypic tree enabled more granularity than traditional clustering in revealing clinically relevant subgroups of people with type 1 diabetes.

CONCLUSIONS/INTERPRETATION

Our study advances the current understanding of the complex glycaemic profile in people with type 1 diabetes and suggests that strategies based on isolated glycaemic metrics might not capture the complexity of the glycaemic phenotypes in real life. Relying on these phenotypes could improve patient stratification in type 1 diabetes care and personalise disease management.

Ultra-stable insulin-glucagon fusion protein exploits an endogenous hepatic switch to mitigate hypoglycemic risk

The risk of hypoglycemia and its serious medical sequelae restrict insulin replacement therapy for diabetes mellitus. Such adverse clinical impact has motivated development of diverse glucose-responsive technologies, including algorithm-controlled insulin pumps linked to continuous glucose monitors ("closed-loop systems") and glucose-sensing ("smart") insulins. These technologies seek to optimize glycemic control while minimizing hypoglycemic risk. Here, we describe an alternative approach that exploits an endogenous glucose-dependent switch in hepatic physiology: preferential insulin signaling (under hyperglycemic conditions) versus preferential counter-regulatory glucagon signaling (during hypoglycemia). Motivated by prior reports of glucagon-insulin co-infusion, we designed and tested an ultra-stable glucagon-insulin fusion protein whose relative hormonal activities were calibrated by respective modifications; physical stability was concurrently augmented to facilitate formulation, enhance shelf life and expand access. An N-terminal glucagon moiety was stabilized by an α-helix-compatible Lys 13 -Glu 17 lactam bridge; A C-terminal insulin moiety was stabilized as a single chain with foreshortened C domain. Studies in vitro demonstrated (a) resistance to fibrillation on prolonged agitation at 37 °C and (b) dual hormonal signaling activities with appropriate balance. Glucodynamic responses were monitored in rats relative to control fusion proteins lacking one or the other hormonal activity, and continuous intravenous infusion emulated basal subcutaneous therapy. Whereas efficacy in mitigating hyperglycemia was unaffected by the glucagon moiety, the fusion protein enhanced endogenous glucose production under hypoglycemic conditions. Together, these findings provide proof of principle toward a basal glucose-responsive insulin biotechnology of striking simplicity. The fusion protein's augmented stability promises to circumvent the costly cold chain presently constraining global insulin access.

Significance Statement

The therapeutic goal of insulin replacement therapy in diabetes is normalization of blood-glucose concentration, which prevents or delays long-term complications. A critical barrier is posed by recurrent hypoglycemic events that results in short- and long-term morbidities. An innovative approach envisions co-injection of glucagon (a counter-regulatory hormone) to exploit a glycemia-dependent hepatic switch in relative hormone responsiveness. To provide an enabling technology, we describe an ultra-stable fusion protein containing insulin- and glucagon moieties. Proof of principle was obtained in rats. A single-chain insulin moiety provides glycemic control whereas a lactam-stabilized glucagon extension mitigates hypoglycemia. This dual-hormone fusion protein promises to provide a basal formulation with reduced risk of hypoglycemia. Resistance to fibrillation may circumvent the cold chain required for global access.

Neurological dysfunction screening in a cohort of adolescents with type 1 diabetes: a six-year follow-up

Aims

Diabetic neuropathy (DN) is one of the most insidious microvascular complications in patients with type 1 diabetes (T1DM) and initial signs may appear during childhood. The aim of this study is to evaluate associations between the Nerve Conduction Studies (NCS) outcomes at enrollment with neuropathy screening questionnaires performed six years later in a cohort of asymptomatic adolescents followed up until early adulthood, affected by T1DM.

Methods

We performed NCS in a cohort of seventy-two adolescents with T1DM and eighteen healthy controls. Six years later, screening questionnaires for DN were proposed: Michigan Neuropathy Screening Instrument (MNSI, specific for symptoms of somatic dysfunction), Composite Autonomic Symptom Score 31 (COMPASS 31, specific for abnormalities of the autonomic component) and Clarke questionnaire (perception of hypoglycemia). Thirty-two TD1M subjects agreed to participate in the follow-up; main clinical-metabolic parameters, including the number of episodes of hypoglycemia in the past twelve months, were collected.

Results

11.8% of subjects showed changes compatible with DN through the MNSI questionnaire, while 41% declared a reduced perception of hypoglycemia on the Clarke questionnaire. No significant correlation was observed between the clinical-metabolic parameters or altered response to NCS and scores of MNSI and COMPASS 31 questionnaires. On the other hand, an association was observed between NCS abnormalities and a high number of hypoglycemic events after six years (97-fold increased risk, p = 0.009).

Conclusion

The frequency of somatic alterations in the study population is 11.8%, whereas the frequency of symptoms correlated with autonomic damage is about 41%. An autonomic impairment recorded at NCS may represent a six-year risk factor for increased hypoglycemic episodes, even if more extensive studies are needed to investigate this possible relationship further.

Innovations in bio-engineering and cell-based approaches to address immunological challenges in islet transplantation

Human allogeneic pancreatic islet transplantation is a life-changing treatment for patients with severe Type 1 Diabetes (T1D) who suffer from hypoglycemia unawareness and high risk of severe hypoglycemia. However, intensive immunosuppression is required to prevent immune rejection of the graft, that may in turn lead to undesirable side effects such as toxicity to the islet cells, kidney toxicity, occurrence of opportunistic infections, and malignancies. The shortage of cadaveric human islet donors further limits islet transplantation as a treatment option for widespread adoption. Alternatively, porcine islets have been considered as another source of insulin-secreting cells for transplantation in T1D patients, though xeno-transplants raise concerns over the risk of endogenous retrovirus transmission and immunological incompatibility. As a result, technological advancements have been made to protect transplanted islets from immune rejection and inflammation, ideally in the absence of chronic immunosuppression, to improve the outcomes and accessibility of allogeneic islet cell replacement therapies. These include the use of microencapsulation or macroencapsulation devices designed to provide an immunoprotective environment using a cell-impermeable layer, preventing immune cell attack of the transplanted cells. Other up and coming advancements are based on the use of stem cells as the starting source material for generating islet cells 'on-demand'. These starting stem cell sources include human induced pluripotent stem cells (hiPSCs) that have been genetically engineered to avoid the host immune response, curated HLA-selected donor hiPSCs that can be matched with recipients within a given population, and multipotent stem cells with natural immune privilege properties. These strategies are developed to provide an immune-evasive cell resource for allogeneic cell therapy. This review will summarize the immunological challenges facing islet transplantation and highlight recent bio-engineering and cell-based approaches aimed at avoiding immune rejection, to improve the accessibility of islet cell therapy and enhance treatment outcomes. Better understanding of the different approaches and their limitations can guide future research endeavors towards developing more comprehensive and targeted strategies for creating a more tolerogenic microenvironment, and improve the effectiveness and sustainability of islet transplantation to benefit more patients.

Hypoimmune islets achieve insulin independence after allogeneic transplantation in a fully immunocompetent non-human primate

Allogeneic transplantation of pancreatic islets for patients with difficult-to-control diabetes mellitus is severely hampered by the requirement for continuous immunosuppression and its associated morbidity. We report that allogeneic transplantation of genetically engineered (B2M-/-, CIITA-/-, CD47+), primary, hypoimmune, pseudo-islets (p-islets) results in their engraftment into a fully immunocompetent, diabetic non-human primate wherein they provide stable endocrine function and enable insulin independence without inducing any detectable immune response in the absence of immunosuppression. Hypoimmune primary p-islets may provide a curative cell therapy for type 1 diabetes mellitus.

Relationships of hypoglycemia awareness, hypoglycemia beliefs, and continuous glucose monitoring glycemic profiles with anxiety and depression symptoms in adults with type 1 diabetes using continuous glucose monitoring systems

AIMS

To evaluate relationships of hypoglycemia awareness, hypoglycemia beliefs, and continuous glucose monitoring (CGM) glycemic profiles with anxiety and depression symptoms in adults with type 1 diabetes (T1D) who use CGM.

METHODS

A cross-sectional survey and data collections were completed with 196 T1D adults who used CGM (59% also used automated insulin delivery devices (AIDs)). We assessed hypoglycemia awareness (Gold instrument), hypoglycemia beliefs (Attitudes to Awareness of Hypoglycemia instrument), CGM glycemic profiles, demographics, and anxiety and depression symptoms (Hospital Anxiety and Depression Scale). Analysis included simple and multiple linear regression analyses.

RESULTS

Lower hypoglycemia awareness, weaker "hypoglycemia concerns minimized" beliefs, stronger "hyperglycemia avoidance prioritized" beliefs were independently associated with higher anxiety symptoms (P < 0.05), with similar trends in both subgroups using and not using AIDs. Lower hypoglycemia awareness were independently associated with greater depression symptoms (P < 0.05). In participants not using AIDs, more time in hypoglycemia was related to less anxiety and depression symptoms (P < 0.05). Being female and younger were independently associated with higher anxiety symptoms, while being younger was also independently associated with greater depression symptoms (P < 0.05).

CONCLUSION

Our findings revealed relationships of impaired hypoglycemia awareness, hypoglycemia beliefs, CGM-detected hypoglycemia with anxiety and depression symptoms in T1D adults who use CGMs.

Prevalence and associations of impaired awareness of hypoglycemia in a pediatric type 1 diabetes population - The Norwegian Childhood Diabetes Registry

AIMS

To determine the prevalence and associations of impaired awareness of hypoglycemia (IAH) in pediatric type 1 diabetes.

METHODS

Nationwide, population-based cross-sectional study with 51 % participation. Participants (n = 1329; 53 % males) aged 2-19 years (median 13.3) with type 1 diabetes ≥ 6 months (median 4.6 years) self-assessed hypoglycemia awareness with a validated questionnaire ('Clarke'). Parents responded for children aged < 9 years (n = 235). We estimated associations between IAH and clinical data in the Norwegian Childhood Diabetes Registry.

RESULTS

The overall prevalence of IAH was 22 %, but gradually decreased from 53 % in preschoolers to 12 % in adolescents aged ≥ 16 years. IAH was associated (adjusted OR; 95 %CI) with episodes of severe hypoglycemia (6.0; 3.04, 11.8) and diabetic ketoacidosis (3.45; 1.37, 8.68) the preceding year, increased fear of hypoglycemia (highest quartile vs. lowest: 2.27; 1.51, 3.40), female sex (1.41; 1.05, 1.90), and HbA1c ≥ 8.5 % (69 mmol/mol) vs. 7.5-8.4 % (58-68 mmol/mol) (1.48; 1.01, 2.18), but not with disease duration, use of insulin pump or continuous glucose monitoring, or HbA1c < 7.5 % (58 mmol/mol).

CONCLUSIONS

IAH is prevalent in pediatric diabetes and more likely reported in young children. IAH is associated with severe hypoglycemia and fear of hypoglycemia, but good metabolic control seems achievable without increased risk of IAH.

Insulin therapy among diabetic patients in rural communities of Sub-Saharan Africa: a perspective review

In this perspective review, we describe a brief background on the status quo of diabetes mellitus-related therapies and glycemic control among patients in rural communities in sub-Saharan Africa. The article discusses insulin therapy as well as the difficulties in obtaining insulin and oral hypoglycemic medications for diabetic patients living in sub-Saharan Africa. We wrap up our discussion with suggestions on solutions and opportunities for future research to tackle this health challenge in these impoverished communities. We conducted a literature search from PubMed and Google Scholar up until August 2023. Key words were used to generate search terms used to retrieve the required information. All types of literature with pertinent information on the current topic were included in the study. Diabetes mellitus is on the rise in sub-Saharan Africa. Several studies have reported poor glycemic control, low screening rates for diabetes mellitus, cigarette smoking, high alcohol consumption, prescription of antidiabetic therapy, and associated costs as contributors to the uptake of antidiabetic treatment. Although there is paucity of data on the extent of insulin therapy uptake and its possible modifiable contributors among the diabetic patients in the region, the anticipated increase in the number of people with diabetes on the continent makes it critical for global leaders to address the research gaps in insulin therapy among rural communities of sub-Saharan Africa, thus reducing the burden of diabetes in these populations.

Associations Between Hypoglycemia Awareness, Hypoglycemia Beliefs, and Continuous Glucose Monitoring Glycemic Profiles and Anxiety and Depression Symptoms in Adults with Type 1 Diabetes Using Advanced Diabetes Technologies

AIMS

To evaluate relationships between hypoglycemia awareness, hypoglycemia beliefs, and continuous glucose monitoring (CGM) glycemic profiles and anxiety and depression symptoms in adults with type 1 diabetes (T1D) who use CGM or automated insulin delivery devices.

METHODS

A cross-sectional survey and data collections were completed with 196 T1D adults who used advanced diabetes technologies. We assessed hypoglycemia awareness (Gold instrument), hypoglycemia beliefs (Attitudes to Awareness of Hypoglycemia instrument), CGM glycemic profiles, demographics, and anxiety and depression symptoms (Hospital Anxiety and Depression Scale). Data were processed via regression analyses and receiver operating characteristic analyses.

RESULTS

Lower hypoglycemia awareness, weaker "hypoglycemia concerns minimized" beliefs, stronger "hyperglycemia avoidance prioritized" beliefs, female, and younger age were independently associated with higher anxiety symptoms (P<0.05). Lower hypoglycemia awareness, less time in hypoglycemia, and younger age were independently associated with greater depression symptoms (P<0.05). Age of <50 years had 77.8% sensitivity and 48.8% specificity in detecting elevated anxiety symptoms. Spending ≥35% of time with glucose levels >180 mg/dL on CGMs had 85.7% sensitivity and 54.3% specificity in detecting elevated depression symptoms.

CONCLUSION

Our findings revealed relationships between impaired hypoglycemia awareness, hypoglycemia beliefs, CGM-detected hypoglycemia and anxiety and depression symptoms in T1D adults who use advanced diabetes technologies.

Challenges of CRISPR/Cas-Based Cell Therapy for Type 1 Diabetes: How Not to Engineer a "Trojan Horse"

Type 1 diabetes mellitus (T1D) is an autoimmune disease caused by the destruction of insulin-producing β-cells in the pancreas by cytotoxic T-cells. To date, there are no drugs that can prevent the development of T1D. Insulin replacement therapy is the standard care for patients with T1D. This treatment is life-saving, but is expensive, can lead to acute and long-term complications, and results in reduced overall life expectancy. This has stimulated the research and development of alternative treatments for T1D. In this review, we consider potential therapies for T1D using cellular regenerative medicine approaches with a focus on CRISPR/Cas-engineered cellular products. However, CRISPR/Cas as a genome editing tool has several drawbacks that should be considered for safe and efficient cell engineering. In addition, cellular engineering approaches themselves pose a hidden threat. The purpose of this review is to critically discuss novel strategies for the treatment of T1D using genome editing technology. A well-designed approach to β-cell derivation using CRISPR/Cas-based genome editing technology will significantly reduce the risk of incorrectly engineered cell products that could behave as a "Trojan horse".

Effect of hypoglycemia on baroreflex sensitivity in individuals with type 2 diabetes: implications for autonomic control of cardiovascular function in diabetes

PURPOSE

Hypoglycemia is associated with increased mortality, though the mechanisms underlying this association are not established. Hypoglycemia impairs the counterregulatory hormonal and autonomic responses to subsequent hypoglycemia. It is unknown whether hypoglycemia elicits a generalized impairment in autonomic control of cardiovascular function in individuals with type 2 diabetes. We tested the hypothesis that in individuals with type 2 diabetes, hypoglycemia impairs a key measure of cardiovascular autonomic homeostasis, baroreflex sensitivity.

METHODS

Sixteen individuals with well-controlled type 2 diabetes and without known cardiovascular disease were exposed to two 90-min episodes of experimental hypoglycemia (2.8 mmol/L, 50 mg/dL) on the same day. All individuals experienced a hypoglycemic-hyperinsulinemic clamp in the morning (AM clamp) and again in the afternoon (PM clamp). Baroreflex sensitivity was assessed using the modified Oxford method before the initiation of each hypoglycemic-hyperinsulinemic clamp, during the last 30 min of hypoglycemia, and the following morning. A mixed effects model adjusting for sex, age, BMI, and insulin level, demonstrated a significant effect of hypoglycemia on baroreflex sensitivity. The study is registered at ClinicalTrials.gov (NCT03422471).

RESULTS

Baroreflex sensitivity during PM hypoglycemia was reduced compared to baseline, during AM hypoglycemia, and the next day. Insulin levels positively correlated with baroreflex sensitivity at baseline and during AM hypoglycemia.

CONCLUSION

Exposure to hypoglycemia impairs a key measure of autonomic control of cardiovascular function and, thus, may increase the risk of cardiac arrhythmias and blood pressure lability in individuals with type 2 diabetes. This effect is attenuated in part by increased insulin levels.

Current and future therapies to treat impaired awareness of hypoglycemia

In order to achieve optimal glycemic control, intensive insulin regimes are needed for individuals with Type 1 Diabetes (T1D) and insulin-dependent Type 2 Diabetes (T2D). Unfortunately, intensive glycemic control often results in insulin-induced hypoglycemia. Moreover, recurrent episodes of hypoglycemia result in both the loss of the characteristic warning symptoms associated with hypoglycemia and an attenuated counterregulatory hormone responses. The blunting of warning symptoms is known as impaired awareness of hypoglycemia (IAH). Together, IAH and the loss of the hormonal response is termed hypoglycemia associated autonomic failure (HAAF). IAH is prevalent in up to 25% in people with T1D and up to 10% in people with T2D. IAH and HAAF increase the risk of severe hypoglycemia 6-fold and 25-fold, respectively. To reduce this risk for severe hypoglycemia, multiple different therapeutic approaches are being explored that could improve awareness of hypoglycemia. Current therapies to improve awareness of hypoglycemia include patient education and psychoeducation, the use of novel glycemic control technology, pancreas/islet transplantation, and drug therapy. This review examines both existing therapies and potential therapies that are in pre-clinical testing. Novel treatments that improve awareness of hypoglycemia, via improving the counterregulatory hormone responses or improving hypoglycemic symptom recognition, would also shed light on the possible neurological mechanisms that lead to the development of IAH. To reduce the risk of severe hypoglycemia in people with diabetes, elucidating the mechanism behind IAH, as well as developing targeted therapies is currently an unmet need for those that suffer from IAH.

An mHealth Text Messaging Program Providing Symptom Detection Training and Psychoeducation to Improve Hypoglycemia Self-Management: Intervention Development Study

BACKGROUND

Hypoglycemia remains a challenge for roughly 25% of people with type 1 diabetes (T1D) despite using advanced technologies such as continuous glucose monitors (CGMs) or automated insulin delivery systems. Factors impacting hypoglycemia self-management behaviors (including reduced ability to detect hypoglycemia symptoms and unhelpful hypoglycemia beliefs) can lead to hypoglycemia development in people with T1D who use advanced diabetes technology.

OBJECTIVE

This study aims to develop a scalable, personalized mobile health (mHealth) behavioral intervention program to improve hypoglycemia self-management and ultimately reduce hypoglycemia in people with T1D who use advanced diabetes technology.

METHODS

We (a multidisciplinary team, including clinical and health psychologists, diabetes care and education specialists, endocrinologists, mHealth interventionists and computer engineers, qualitative researchers, and patient partners) jointly developed an mHealth text messaging hypoglycemia behavioral intervention program based on user-centered design principles. The following five iterative steps were taken: (1) conceptualization of hypoglycemia self-management processes and relevant interventions; (2) identification of text message themes and message content development; (3) message revision; (4) patient partner assessments for message readability, language acceptability, and trustworthiness; and (5) message finalization and integration with a CGM data-connected mHealth SMS text message delivery platform. An mHealth web-based SMS text message delivery platform that communicates with a CGM glucose information-sharing platform was also developed.

RESULTS

The mHealth SMS text messaging hypoglycemia behavioral intervention program HypoPals, directed by patients' own CGM data, delivers personalized intervention messages to (1) improve hypoglycemia symptom detection and (2) elicit self-reflection, provide fact-based education, and suggest practical health behaviors to address unhelpful hypoglycemia beliefs and promote hypoglycemia self-management. The program is designed to message patients up to 4 times per day over a 10-week period.

CONCLUSIONS

A rigorous conceptual framework, a multidisciplinary team (including patient partners), and behavior change techniques were incorporated to create a scalable, personalized mHealth SMS text messaging behavioral intervention. This program was systematically developed to improve hypoglycemia self-management in advanced diabetes technology users with T1D. A clinical trial is needed to evaluate the program's efficacy for future clinical implementation.

The Effect of Exercise on Cardiovascular Autonomic Nervous Function in Patients with Diabetes: A Systematic Review

BACKGROUND

Diabetic neuropathy, including autonomic neuropathy, is a severe complication in patients with poorly controlled diabetes. Specifically, cardiovascular autonomic neuropathy (CAN) plays a significant prognostic role in cardiovascular morbidity and mortality. Exercise, an essential component of diabetes treatment, may have a therapeutic effect on patients with diabetes complicated by CAN. However, it remains unclear whether exercise has a therapeutic or protective effect in diabetes patients with CAN.

METHODS

The author conducted a systematic search of PubMed/MEDLINE, Embase, and The Cochrane Library, resulting in the identification of eight eligible randomized controlled trials for this review.

RESULTS

Exercise, including aerobic exercise combined with resistance training (RT), high-intensity interval training, and progressive RT, has shown a beneficial effect on cardiac autonomic function (CAF) in patients with type 2 diabetes, as measured by heart rate variability, heart rate recovery, and baroreflex sensitivity. However, most studies had low quality. Moreover, there were no relevant studies examining the effect of exercise on CAF in older patients, patients with poorly controlled diabetes, and patients with type 1 diabetes.

CONCLUSIONS

Exercise has the potential to manage patients with CAN by balancing sympathetic and parasympathetic nervous system functions; however, further studies are warranted in the future.

Reproducibility of continuous glucose monitoring results under real-life conditions in an adult population: a functional data analysis

Continuous glucose monitoring systems (CGM) are a very useful tool to understand the behaviour of glucose in different situations and populations. Despite the widespread use of CGM systems in both clinical practice and research, our understanding of the reproducibility of CGM data remains limited. The present work examines the reproducibility of the results provided by a CGM system in a random sample of a free-living adult population, from a functional data analysis approach. Functional intraclass correlation coefficients (ICCs) and their 95% confidence intervals (CI) were calculated to assess the reproducibility of CGM results in 581 individuals. 62% were females 581 participants (62% women) mean age 48 years (range 18-87) were included, 12% had previously been diagnosed with diabetes. The inter-day reproducibility of the CGM results was greater for subjects with diabetes (ICC 0.46 [CI 0.39-0.55]) than for normoglycaemic subjects (ICC 0.30 [CI 0.27-0.33]); the value for prediabetic subjects was intermediate (ICC 0.37 [CI 0.31-0.42]). For normoglycaemic subjects, inter-day reproducibility was poorer among the younger (ICC 0.26 [CI 0.21-0.30]) than the older subjects (ICC 0.39 [CI 0.32-0.45]). Inter-day reproducibility was poorest among normoglycaemic subjects, especially younger normoglycaemic subjects, suggesting the need to monitor some patient groups more often than others.

Corneal Confocal Microscopy Identifies Structural Small Fibre Abnormalities in an Adolescent with Type 1 Diabetes and Impaired Awareness of Hypoglycaemia

Impaired awareness of hypoglycaemia (IAH) is present in around 25-40% of individuals with type 1 diabetes mellitus (T1DM). Herein, we present a case of an adolescent with T1DM and IAH who had worse corneal nerve parameters compared to a T1DM adolescent without IAH. Small fibre abnormalities detected by corneal confocal microscopy in an objective easy-to-perform non-invasive test might be a surrogate indicator of underlying autonomic dysfunction in T1DM and IAH.

Cardiovascular autonomic neuropathy is associated with increased glycemic variability driven by hyperglycemia rather than hypoglycemia in patients with diabetes

AIM

Cardiac autonomic neuropathy (CAN) has been suggested to be associated with hypoglycemia and impaired hypoglycemia unawareness. We have assessed the relationship between CAN and extensive measures of glucose variability (GV) in patients with type 1 and type 2 diabetes.

METHODS

Participants with diabetes underwent continuous glucose monitoring (CGM) to obtain measures of GV and the extent of hyperglycemia and hypoglycemia and cardiovascular autonomic reflex testing.

RESULTS

Of the 40 participants (20 T1DM and 20 T2DM) (aged 40.70±13.73 years, diabetes duration 14.43±7.35 years, HbA1c 8.85±1.70%), 23 (57.5%) had CAN. Despite a lower coefficient of variation (CV) (31.26±11.87 vs. 40.33±11.03, P=0.018), they had a higher CONGA (8.42±2.58 vs. 6.68±1.88, P=0.024) with a lower median LBGI (1.60 (range: 0.20-3.50) vs. 4.90 (range: 3.20-7.40), P=0.010) and percentage median time spent in hypoglycemia (4 (range:4-13) vs. 1 (range:0-5), P=0.008), compared to those without CAN. The percentage GRADE_Euglycemia (3.30±2.78 vs. 5.69±3.09, P=0.017) and GRADE_Hypoglycemia (0.3 (range: 0 - 3.80) vs. 1.8 (range: 0.9-6.5), P=0.036) were significantly lower, while the percentage median GRADE_{Hyperglycemia} (95.45 (range:93-98) vs. 91.6 (82.8-95.1), P=0.013) was significantly higher in participants with CAN compared to those without CAN.

CONCLUSION

CAN was associated with increased glycemic variability with less time in euglycemia attributed to a greater time in hyperglycemia but not hypoglycemia.

Protective and risk factors of impaired awareness of hypoglycemia in patients with type 1 diabetes: a cross-sectional analysis of baseline data from the PR-IAH study

BACKGROUND

Hypoglycemia in type 1 diabetes (T1D) is associated with mortality and morbidity, especially when awareness of hypoglycemia is impaired. This study aimed to investigate the protective and risk factors for impaired awareness of hypoglycemia (IAH) in adults with T1D.

METHODS

This cross-sectional study enrolled 288 adults with T1D (mean age, 50.4 ± 14.6 years; male, 36.5%; diabetes duration, 17.6 ± 11.2 years; mean HbA1c level, 7.7 ± 0.9%), who were divided into IAH and non-IAH (control) groups. A survey was conducted to assess hypoglycemia awareness using the Clarke questionnaire. Diabetes histories, complications, fear of hypoglycemia, diabetes distress, hypoglycemia problem-solving abilities, and treatment data were collected.

RESULTS

The prevalence of IAH was 19.1%. Diabetic peripheral neuropathy was associated with an increased risk of IAH (odds ratio [OR] 2.63; 95% confidence interval [CI] 1.13-5.91; P = 0.014), while treatment with continuous subcutaneous insulin infusion and hypoglycemia problem-solving perception scores were associated with a decreased risk of IAH (OR, 0.48; 95% CI, 0.22-0.96; P = 0.030; and OR, 0.54; 95% CI, 0.37-0.78; P = 0.001, respectively). There was no difference in continuous glucose monitoring use between the groups.

CONCLUSION

We identified protective factors in addition to risk factors for IAH in adults with T1D. This information may help manage problematic hypoglycemia.

TRIAL REGISTRATION

University hospital Medical Information Network (UMIN) Center: UMIN000039475). Approval date 13 February 2020.

Human hypoimmune primary pancreatic islets avoid rejection and autoimmunity and alleviate diabetes in allogeneic humanized mice

Transplantation of allogeneic pancreatic donor islets has successfully been performed in selected patients with difficult-to-control insulin-dependent diabetes and impaired awareness of hypoglycemia (IAH). However, the required systemic immunosuppression associated with this procedure prevents this cell replacement therapy from more widespread adoption in larger patient populations. We report the editing of primary human islet cells to the hypoimmune HLA class I- and class II-negative and CD47-overexpressing phenotype and their reaggregation into human HIP pseudoislets (p-islets). Human HIP p-islets were shown to survive, engraft, and ameliorate diabetes in immunocompetent, allogeneic, diabetic humanized mice. HIP p-islet cells were further shown to avoid autoimmune killing in autologous, diabetic humanized autoimmune mice. The survival and endocrine function of HIP p-islet cells were not impaired by contamination of unedited or partially edited cells within the p-islets. HIP p-islet cells were eliminated quickly and reliably in this model using a CD47-targeting antibody, thus providing a safety strategy in case HIP cells exert toxicity in a future clinical setting. Transplantation of human HIP p-islets for which no immunosuppression is required has the potential to lead to wider adoption of this therapy and help more diabetes patients with IAH and history of severe hypoglycemic events to achieve insulin independence.

Improved Effectiveness of Immediate Continuous Glucose Monitoring in Hypoglycemia-Prone People with Type 1 Diabetes Compared with Hypoglycemia-Focused Psychoeducation Following a Previous Structured Education: A Randomized Controlled Trial

Objective: Stepped-care has been suggested in the management of patients with problematic hypoglycemia and impaired awareness of hypoglycemia (IAH), initially with psychoeducational programs based on blood glucose awareness training, progressing to diabetes technology in those with persisting need. We examined the clinical effectiveness of stepped-care starting with HypoAware and adding continuous glucose monitoring (CGM) as needed, versus immediate CGM in type 1 diabetes patients with problematic hypoglycemia despite previous structured education in insulin adjustment. Research Design and Methods: A randomized controlled trial (N = 52, mean age 53, 56% females). The stepped-care group attended HypoAware. If a severe hypoglycemic event (SHE) had occurred or IAH was still present after 6 months, CGM was initiated. The control group started immediate CGM. Primary endpoint was the number of participants with self-reported SHE. Secondary outcomes, evaluated at 6 and 12 months, were glycated hemoglobin (HbA1c), the number of participants with IAH time below range (TBR; <54 mg/dL), and patient-reported outcomes (PROs). Results: At 6 months, the number of patients reporting SHE had decreased significantly more in the CGM group: -39% (P < 0.05). HbA1c decreased more in the CGM group (-0.47 percentage-points, P < 0.05). IAH was restored in 31% of patients in both groups. TBR (<54 mg/dL) was lower in the CGM group (-2.4 percentage-points, P < 0.05). In the stepped-care group, 93% started CGM/intermittently scanned CGM. At 12 months, the number of patients reporting SHE was still higher in the stepped-care group. No differences were found in PROs. Conclusions: Immediate start of CGM is more effective than a hypoglycemia-focused reeducation program in reducing SHE risk and attaining glycemic targets in individuals with problematic hypoglycemia and IAH despite previous education in insulin dose adjustment. Trial registration: Netherlands Trial Register, NL64474.029.18.

Pathophysiology and management of hypoglycemia in diabetes

In the century since the discovery of insulin, diabetes has changed from an early death sentence to a manageable chronic disease. This change in longevity and duration of diabetes coupled with significant advances in therapeutic options for patients has fundamentally changed the landscape of diabetes management, particularly in patients with type 1 diabetes mellitus. However, hypoglycemia remains a major barrier to achieving optimal glycemic control. Current understanding of the mechanisms of hypoglycemia has expanded to include not only counter-regulatory hormonal responses but also direct changes in brain glucose, fuel sensing, and utilization, as well as changes in neural networks that modulate behavior, mood, and cognition. Different strategies to prevent and treat hypoglycemia have been developed, including educational strategies, new insulin formulations, delivery devices, novel technologies, and pharmacologic targets. This review article will discuss current literature contributing to our understanding of the myriad of factors that lead to the development of clinically meaningful hypoglycemia and review established and novel therapies for the prevention and treatment of hypoglycemia.

Predictors of change in hypoglycemia unawareness among patients with type 1 diabetes

AIMS

To analyse predictors of hypoglycemia unawareness (HU) and improvement in Clarke score in clinical practice.

MATERIALS AND METHODS

We retrospectively identified patients with type 1 diabetes (T1D) at an academic T1D clinic who completed HU surveys 6-12 months apart. HU (Clarke score ≥4) and improvement in Clarke score (decrease by ≥1 point or more clinically relevant ≥2 point) were assessed in univariable relationships and using multivariable logistic regression.

RESULTS

Of the 300 participants, median diabetes duration was 19 years, 47 had HU at baseline, and 91 had an improvement by 1 point while 21 had an improvement by 2 points. Patients with baseline Clarke score ≥4 who had ≥1 or ≥2 point improvement had lower filtration rate (eGFR) than those who did not. After adjustment for other variables, gender (male OR 0.33, 95% CI 0.15, 0.74), log diabetes duration (OR 6.40, 95% CI 2.84, 14.5), and eGFR <60 ml/min/1.73 m² (5.56, 95% CI 1.98, 15.6) were independent predictors of baseline HU. Continuous glucose monitoring use (OR 2.04, 95% CI 1.20, 3.48) and log diabetes duration (OR 1.78, 95% CI 1.22, 2.60) were independent predictors of 1 point improvement and eGFR <60 ml/min/1.73 m² (OR 10.5, 95% CI 3.64, 30.0) and an education visit (OR 2.64, 95% CI 1.01, 6.89) were independent predictors of 2 point improvement in Clarke score.

CONCLUSIONS

Diabetes duration, gender, and eGFR were independent predictors of HU. Improvement in Clarke score is possible in patients with long-standing T1D, underscoring the need for additional study.

Progress in islet transplantation is more important than ever

It is increasingly clear that pancreatic islet replacement is needed to provide a comprehensive treatment for the growing numbers of patients with type 1 diabetes mellitus. Advances from the past year suggest that this goal might now be within reach.

Understanding Hypoglycemia in the Real World

PURPOSE

The purpose of this study was to gain a better understanding of real-world hypoglycemia experiences from people living with diabetes.

METHODS

An exploratory cross-sectional study of a convenience sample of 374 English-speaking adults affected by diabetes using an online survey was conducted.

RESULTS

Participant mean age was 37 years with an average diabetes duration of 21 years. On average, participants reported feeling hypoglycemia at 64 mg/dL (3.6 mmol/L), worrying about hypoglycemia at 63 mg/dL (3.5 mmol/L), and treating hypoglycemia at 72 mg/dL (4 mmol/L). Terminology used by study participants did not match the current classifications of hypoglycemia used in clinical research. Participants who have been told they have hypoglycemia unawareness treat at a significantly lower level compared to those without hypoglycemia unawareness. Only 58% always carry hypoglycemia treatment; there was a relationship with increasing age and always carrying hypoglycemia treatment. Thirty-eight percent of participants treat hypoglycemia with the recommended 15 g of carbohydrate (CHO). Survey respondents who wore continuous glucose monitors reported using significantly less CHO to treat hypoglycemia.

CONCLUSIONS

In the real world, experiences related to feeling, worrying about, and treating hypoglycemia trend higher than what is noted in the standardized hypoglycemia classifications. Study findings have implications for teaching and supporting people with diabetes who experience hypoglycemia. Consuming less CHO to treat hypoglycemia could lead to fewer episodes of rebound hyperglycemia and less weight gain. Increased support for continuous glucose monitoring is warranted.

Hypoglycemia unawareness in type 1 diabetes patients using intermittent continuous glucose monitoring: Identification of risk factors and glycemic patterns

BACKGROUND

Hypoglycemia unawareness designates failure to detect eminent hypoglycemia. Clarke's questionnaire is one of the most used systems to evaluate this problem.

AIMS

To relate Clarke's questionnaire (QQ) results with continuous glucose monitoring data.

METHODS

Application of the questionnaire in a sample of type 1 diabetes mellitus (T1DM) patients using intermittent continuous glucose monitoring (iCGM).

RESULTS

111 T1DM patients were evaluated, 56.8% female, mean age 35.0 ± 12.4 years and mean disease duration 18.8 ± 10.5 years. According to CQ, 13.5% had unawareness, 76.6% awareness and 9.9% indeterminate awareness to hypoglycemia. Those with unawareness had longer disease duration (25.1 ± 10.4 vs 18.2 ± 10.3 for awareness and 14.9 ± 9.9 for indeterminate awareness, p = 0.047), more time below range (10.3 ± 4.9% vs 6.3 ± 5.1 and 6.3 ± 4.8; p = 0.009) and higher mean duration of hypoglycemia (131.7 ± 38.6 vs 116.6 ± 49.6 and 131.7 ± 38.6; p = 0.008). In multivariate analysis, mean duration of hypoglycemia was an independent predictor of CQ results. In a receiver operating curve (AUC 0.746; p = 0.004) a mean duration of hypoglycemia ≥106.5 min showed 84.6% sensitivity/64.4% specificity for unawareness.

CONCLUSIONS

Our sample had a significative prevalence of hypoglycemia unawareness which increased with longer diabetes duration. iCGM data can be indicative of this problem, with a mean hypoglycemia duration ≥106.5 min being suggestive, albeit unspecific.

Evaluating the Incidence and Risk Factors Associated With Mild and Severe Hypoglycemia in Insulin-Treated Type 2 Diabetes

OBJECTIVES

This study to assess the incidence rates and risk factors of hypoglycemia in a wide real-life sample of patients with insulin-treated type 2 diabetes mellitus.

METHODS

In a prospective epidemiological study, data from 817 subjects were collected from medical records and via interviews. Over a 3-month period, hypoglycemic episodes were recorded via self-measurement of glucose levels at least twice daily. Cox proportional and negative binomial multivariable models were applied to estimate adjusted and unadjusted hazard ratios and incidence rate ratios of hypoglycemic events.

RESULTS

Of the 817 patients, 52.9% experienced hypoglycemia, 38.1% had only nonsevere episodes, and 14.8% had at least 1 severe episode. Total events per patient-year were estimated at 13.3 (±24.8), with 11.8 (±21.6) and 1.4 (±4.7) being nonsevere and severe, respectively. History of hypoglycemia and severe hypoglycemia were consistent risk factors of hypoglycemia. Intensification of therapy was associated with higher incidence rates, whereas the effect on the hazard rates was more moderate. Longer duration of insulin therapy and the presence of congestive heart failure were associated with a higher risk of developing and frequency of hypoglycemia. Hypoglycemia awareness was found to independently affect only mild hypoglycemia.

CONCLUSIONS

Hypoglycemia is a common complication in patients with insulin-treated type 2 diabetes mellitus. The risk factors of developing hypoglycemia are to some extent different from those of the frequency of hypoglycemic episodes. Particular attention is required for patients with recurrent hypoglycemic events and on intensive antidiabetic therapy.

The management of type 1 diabetes in adults. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) convened a writing group to develop a consensus statement on the management of type 1 diabetes in adults. The writing group has considered the rapid development of new treatments and technologies and addressed the following topics: diagnosis, aims of management, schedule of care, diabetes self-management education and support, glucose monitoring, insulin therapy, hypoglycaemia, behavioural considerations, psychosocial care, diabetic ketoacidosis, pancreas and islet transplantation, adjunctive therapies, special populations, inpatient management and future perspectives. Although we discuss the schedule for follow-up examinations and testing, we have not included the evaluation and treatment of the chronic microvascular and macrovascular complications of diabetes as these are well-reviewed and discussed elsewhere. The writing group was aware of both national and international guidance on type 1 diabetes and did not seek to replicate this but rather aimed to highlight the major areas that healthcare professionals should consider when managing adults with type 1 diabetes. Though evidence-based where possible, the recommendations in the report represent the consensus opinion of the authors. Graphical abstract.

The Management of Type 1 Diabetes in Adults. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) convened a writing group to develop a consensus statement on the management of type 1 diabetes in adults. The writing group has considered the rapid development of new treatments and technologies and addressed the following topics: diagnosis, aims of management, schedule of care, diabetes self-management education and support, glucose monitoring, insulin therapy, hypoglycemia, behavioral considerations, psychosocial care, diabetic ketoacidosis, pancreas and islet transplantation, adjunctive therapies, special populations, inpatient management, and future perspectives. Although we discuss the schedule for follow-up examinations and testing, we have not included the evaluation and treatment of the chronic microvascular and macrovascular complications of diabetes as these are well-reviewed and discussed elsewhere. The writing group was aware of both national and international guidance on type 1 diabetes and did not seek to replicate this but rather aimed to highlight the major areas that health care professionals should consider when managing adults with type 1 diabetes. Though evidence-based where possible, the recommendations in the report represent the consensus opinion of the authors.

Benefits of a Switch from Intermittently Scanned Continuous Glucose Monitoring (isCGM) to Real-Time (rt) CGM in Diabetes Type 1 Suboptimal Controlled Patients in Real-Life: A One-Year Prospective Study §

The switch from intermittently scanned continuous glucose monitoring (isCGM) to real-time (rt) CGM could improve glycemic management in suboptimal controlled type 1 diabetes patients, but long-term study is lacking. We evaluated retrospectively the ambulatory glucose profile (AGP) in such patients after switching from Free Style Libre 1 (FSL1) to Dexcom G4 (DG4) biosensors over 1 year. Patients (n = 21, 43 ± 15 years, BMI 25 ± 5, HbA1c 8.1 ± 1.0%) had severe hypoglycemia and/or HbA1c ≥ 8%. AGP metrics (time-in-range (TIR) 70–180 mg/dL, time-below-range (TBR) <70 mg/dL or <54 mg/dL, glucose coefficient of variation (%CV), time-above-range (TAR) >180 mg/dL or >250 mg/dL, glucose management indicator (GMI), average glucose) were collected the last 3 months of FSL1 use (M0) and of DG4 for 3, 6 (M6) and 12 (M12) months of use. Values were means ± standard deviation or medians [Q1;Q3]. At M12 versus M0, the higher TIR (50 ± 17 vs. 45 ± 16, p = 0.036), and lower TBR < 70 mg/dL (2.5 [1.6;5.5] vs. 7.0 [4.5;12.5], p = 0.0007), TBR < 54 mg/dL (0.7 [0.4;0.8] vs. 2.3 [0.8;7.0], p = 0.007) and %CV (39 ± 5 vs. 45 ± 8, p = 0.0009), evidenced a long-term effectiveness of the switch. Compared to M6, TBR < 70 mg/dL decreased, %CV remained stable, while the improvement on hyperglycemia exposure decreased (higher GMI, TAR and average glucose). This switch was a relevant therapeutic option, though a loss of benefit on hyperglycemia stressed the need for optimized management of threshold alarms. Nevertheless, few patients attained the recommended values for AGP metrics, and the reasons why some patients are “responders” vs. “non-responders” warrant to be investigated.

Perceptions and Understanding of Diabetes Mellitus Technology in Adults with Type 1 or Type 2 DM: A Pilot Survey from Pakistan

INTRODUCTION

Diabetes mellitus technology (DMT) is increasingly used for routine management in developed countries, yet its uptake in developing countries is not as consistent. Multiple factors may influence this, including country specific patient perception regarding DMT. We conducted a pilot study in Pakistan to understand this important question which has not been studied yet.

METHODS

A cross-sectional pilot study was conducted in Pakistan. An anonymous survey exploring perceptions of diabetes technology was circulated on social media platforms, collecting responses over 2 weeks. Target population included adults (≥18 years) living in Pakistan, with DM1 or 2.

RESULTS

A total of 40 responses were received. The majority (36/40) reported using conventional glucometers. Nine used continuous glucose monitoring (CGM). Thirty-two of 40 patients believed DMT improved diabetes care, 22 felt it helped decreased risk of Diabetes-related complications. 15/40 stated that DMT results in increased cost of care. Sixteen reported their diabetes care teams had never discussed wearable DMT options whereas 11 disliked them because they did not want a device on their self.

CONCLUSION

In our pilot study we have identified broad themes of opportunity and challenges to DMT use in Pakistan. Patients' perceptions regarding DMT were generally positive but significant barriers to its acceptance included high cost, lack of discussion between doctor and patient about available technology and personal hesitation. Limitations of our study include sampling bias (online survey) and small sample size, but this data can help inform larger studies, to look at this important topic in greater detail.

Validation of the Korean version of the Boston Autonomic Symptom Questionnaire

BACKGROUND AND PURPOSE

The Boston Autonomic Symptom Questionnaire (BASQ) is a quantitative tool using a numeric rating scale to assess the symptoms of systemic dysautonomia, including cardiovascular, gastrointestinal, urinary, sudomotor, vasomotor, and sexual functions. The aim of this study was to validate the Korean version of the BASQ (KBASQ).

METHODS

Prospectively enrolled subjects who submitted to autonomic function tests, including tests for cardiovagal, adrenergic, and sudomotor functions, also completed the KBASQ and the Korean version of the Orthostatic Grading Scale (KOGS), a validated questionnaire or assessing orthostatic symptoms.Twenty-eight subjects completed the KBASQ twice to assess test-retest reliability. We classified the subjects to dysautonomia or normal control group according to dysautonomic symptoms and the results of autonomic function tests.

RESULTS

This study enrolled 225 subjects aged 54.0±18.1 years (mean±standard deviation), with a male/female ratio of 1/1.03. The internal validity of the KBASQ was excellent (Cronbach's α=0.922), and that of each of its subscales ranged from excellent to acceptable (Cronbach's α=0.709-0.952). The test-retest reliability was good, with correlation coefficients ranging from 0.354 to 0.917. The subcategory scores for the KBASQ were significantly higher in the dysautonomia group than in the normal control group. There were significant correlations among the items in the KBASQ and KOGS. There was also a significant correlation between KBASQ scores and the results of the autonomic function tests.

CONCLUSIONS

The internal validity and reliability of the KBASQ were good, indicating that it may be a useful screening tool for the systematic evaluation of autonomic symptoms in patients with dysautonomia.

The Prevalence of Diabetic Microvascular Complications in China and the USA

PURPOSE OF REVIEW

Diabetes can lead to development of devastating microvascular complications, such as nephropathy, retinopathy, and peripheral sensory and autonomic neuropathy. While China and the USA both face the threat of this major public health challenge, the literature is limited in describing similarities and differences in the prevalence, and risk factors for the development, of diabetic microvascular complications between these two countries.

RECENT FINDINGS

The current review discusses the following: (1) the most recent evidence on prevalence of diabetic microvascular complications in China and the USA (including downtrends of diabetes retinopathy and neuropathy in the USA); (2) differences in patient risk factors of these complications; (3) challenges and current knowledge gaps (such as lacking national epidemiological data of diabetic complications in China); and (4) potential future clinical and research opportunities (including needs in diabetes evaluation and management in remote areas and standardization of methods in evaluating diabetic complications across countries). Diabetic microvascular complications remain to be health threats in both China and the USA. Further investigations are needed for comprehensive understanding and effect prevention and management of these complications.