Differences in A1C by race and ethnicity among patients with impaired glucose tolerance in the Diabetes Prevention Program

The relationship between HbA1C levels and clinical outcome in patients with traumatic train injury: A prospective study

Introduction/Aim: Recently, hemoglobin A1c (HbA1c) has been suggested as a predictor of mortality and poor clinical outcome in patients with trauma. The aim of this study was to evaluate the relationship between HbA1c values and clinical outcome in patients with traumatic brain injury (TBI). Methods: In a cross-sectional study, a total of 133 TBI patients referred to the emergency department of Imam Khomeini Hospital in Sari, Mazandaran, Iran were evaluated. After transferring the patients to the neurosurgery ward, their HbA1c, fasting blood glucose (FBG) and postprandial glucose (PPG) were measured. Also, patients' Glasgow Coma Scale (GCS) score was recorded at the time of admission, 24 hours after admission and at the time of discharge from the hospital. Results: The mean of GCS score of patients at the time of admission, 24 hours after admission, and at the time of discharge were 9.02 (2.09), 10.07 (2.16), and 12.98 (1.82), respectively. The mean GCS score of patients with HbA1c < 5.7% was significantly lower than of patients with HbA1c = 5.7 - 6.5% at the time of admission (p < 0.05). At 24 hours after admission, the mean GCS score of patients with HbA1c < 5.7% was significantly lower than in other groups (p < 0.05). However, at the time of discharge, the mean GCS score of patients with HbA1c > 6.5% was significantly lower than in patients with HbA1c = 5.7 - 6.5% (p < 0.05). Over time, the mean of GCS scores in all patients significantly increased (p < 0.001). Conclusion: According to the results of this study it seems that HbA1c measurements cannot provide clear information about the clinical outcome of patients with TBI.

2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Prediabetes Burden in Nigeria: A Systematic Review and Meta-Analysis

Prediabetes is a borderline glycemic status associated with both higher incidence of cardiovascular disease as well as higher risk of progression to diabetes. There is a rising burden of diabetes and prediabetes globally. This study aims to estimate the burden of prediabetes in Nigeria. Online searches of Google Scholar, PubMed, and Scopus were conducted and studies were selected based on predefined criteria. A total of 15 studies consisting of 14,206 individuals conducted between 2000 and 2019 were included in the meta-analysis with studies using American Diabetic Association (ADA) and World Health Organization (WHO) criteria pooled separately. The pooled prevalence of prediabetes in Nigeria was found to be 13.2% (95% CI: 5.6-23.2%, I2 = 98.4%) using the ADA criteria and 10.4% (95% CI: 4.3-18.9%, I2 = 99.2%) using the WHO criteria. According to the latest data by the United Nations, this translates to an estimated 15.8 and 12.5 million adult prediabetic individuals in Nigeria using the ADA and WHO criteria, respectively. The prevalence rates for women and men were similar at 12.1% (95% CI: 5-21%). The pooled prevalence rates for urban and rural settlements were also similar at 9% (95% CI: 2-22%). In conclusion, the prevalence of prediabetes in Nigeria was almost two times higher than the 7.3% estimate by the International Diabetes Federation in 2003. The similar rates of prediabetes between men and women and between urban and rural settlements points toward narrowing of cardiovascular risk burden between the two sexes and the two settlements. This represents higher future cardiovascular disease burden in the country further pressurizing the overstretched healthcare system.

Definition and Classification of Diabetes and Prediabetes and Emerging Data on Phenotypes

Diabetes diagnosis has important implications for individuals. Diagnostic criteria for fasting and 2-hour plasma glucose and HbA1c are universally agreed. Intermediate hyperglycemia/prediabetes is a risk factor for diabetes and cardiovascular disease. Because risk is a continuum, determining cut-point is problematic and reflected in significant differences in recommended fasting glucose and HbA1c criteria. Many types of diabetes are recognized. Diabetes classification systems are limited by a lack of understanding of etiopathogenetic pathways leading to diminished β-cell function. The World Health Organization classification system is designed to assist clinical care decisions. Newly recognized phenotypic clusters of diabetes might inform future classification systems.

Implementation of a community-based low-calorie dietary intervention for the induction of type-2 diabetes and pre-diabetes remission: a feasibility study utilising a type 2 hybrid design

Objectives

The aims of this feasibility study were to (1) examine the implementation of a community-based health advocate (CHA) training programme to develop the clinical skills needed to support a diabetes remission protocol based on a low-calorie diet (LCD) and (2) investigate if participant weight loss can be achieved and diabetes remission induced under these conditions.

Methods

This tripartite study followed a type 2 implementation-effectiveness design. Three faith-based organisations (FBOs) were purposively selected as study sites. Implementation outcomes were guided by the Consolidated Framework for Implementation Research. During the pre-implementation phase, site ‘readiness’ to facilitate the intervention was determined from a site visit and an interview with the FBOs’ leadership. During the implementation phase, congregants could volunteer for the 10-week CHA training which included practical exercises in weight, glucose and blood pressure (BP) measurement, and a summative practical assessment. Acceptability and implementation effectiveness were assessed via survey. During the intervention phase, other congregants and community members with T2DM or pre-diabetes and overweight were invited to participate in the 12-week LCD. Anti-diabetic medication was discontinued on day 1 of the intervention. Clinical effectiveness was determined from the change in weight, fasting blood glucose (FBG) and BP which were monitored weekly at the FBO by the CHA. HbA1C was performed at weeks 1 and 12.

Results

The FBOs were found to be ready as determined by their adequate resources and engagement in health-related matters. Twenty-nine CHAs completed the training; all attained a passing grade at ≥1 clinical station, indicating implementation effectiveness. CHA feedback indicated that the programme structure was acceptable and provided sufficient access to intervention-related material. Thirty-one persons participated in the LCD (11 T2DM:20 pre-diabetes). Mean (95%CI) weight loss was 6.0 kg (3.7 to 8.2), 7.9 kg in males vs 5.7 kg in females; A1C (%) decreased from 6.6 to 6.1, with a greater reduction in those with T2DM when compared to pre-diabetes. FBG decreased from 6.4 to 6.0mmol/L. T2DM remission rates were 60% and 90% by A1C<6.5% and FBG<7mmol/L respectively. Pre-diabetes remission was 18% and 40% by A1C<5.7% and FBG<5.6 respectively.

Conclusion

Implementation of a community-based diabetes remission protocol is both feasible and clinically effective. Its sustainability is to be determined. Adaptability to other disorders or other settings should be investigated.

Trial registration

NCT03536377 registered on 24 May 2018.

Who should return for an oral glucose tolerance test? A proposed clinical pathway based on retrospective analysis of 332 children

OBJECTIVES

Fasting plasma glucose or oral glucose tolerance test (OGTT) is the traditional diagnostic tool for type 2 diabetes (T2DM). However, fasting is required and implementation in all overweight/obese subjects is not practical. This study aimed to formulate a clinical pathway to stratify subjects according to their risk of abnormal OGTT.

METHODS

This retrospective study included patients with overweight or obesity who had undergone OGTT in a tertiary paediatric unit from 2012 to 2018. The optimal haemoglobin A1c (HbA1c) cutoff that predicts abnormal OGTT was evaluated. Other non-fasting parameters, in combination with this HbA1c cutoff, were also explored as predictors of abnormal OGTT.

RESULTS

Three hundred and thirty-two patients (boys: 54.2%, Chinese: 97.3%) were included for analysis, of which, 272 (81.9%) patients had normal OGTT while 60 (18.0%) patients had abnormal OGTT (prediabetes or T2DM). Optimal HbA1c predicting abnormal OGTT was 5.5% (AUC 0.71; sensitivity of 66.7% and specificity of 71%). When HbA1c≥5.5% was combined with positive family history and abnormal alanine transaminase (ALT) level, the positive predictive value for abnormal OGTT was increased from 33.6 to 61.6%.

CONCLUSIONS

HbA1c, family history of T2DM and ALT level could be used to derive a clinical pathway to stratify children who have high risk of abnormal OGTT.

Emerging Diabetic Novel Biomarkers of the 21st Century

Diabetes is a growing epidemic with estimated prevalence of infected to reach ~592 million by the year 2035. An effective way to approach is to detect the disease at a very early stage to reduce the complications and improve lifestyle management. Although several traditional biomarkers including glucated hemoglobin, glucated albumin, fructosamine, and 1,5-anhydroglucitol have helped in ease of diagnosis, there is lack of sensitivity and specificity and are inaccurate in certain clinical settings. Thus, search for new and effective biomarkers is a continuous process with an aim of accurate and timely diagnosis. Several novel biomarkers have surged in the present century that are helpful in timely detection of the disease condition. Although it is accepted that a single biomarker will have its inherent limitations, combining several markers will help to identify individuals at high risk of developing prediabetes and eventually its progression to frank diabetes. This review describes the novel biomarkers of the 21st century, both in type 1 and type 2 diabetes mellitus, and their present potential for assessing risk stratification due to insulin resistance that will pave the way for improved clinical outcome.

A Review on Research Progress in the Application of Glycosylated Hemoglobin and Glycated Albumin in the Screening and Monitoring of Gestational Diabetes

Glycosylated hemoglobin (HbA1C) and glycated albumin (GA) can be used for blood glucose management of a person with diabetes as a result of their convenience and stability. However, there is no corresponding standard for the application of glycosylated hemoglobin and glycosylated albumin in gestational diabetes mellitus (GDM). In this review, we summarize the published research and discuss three aspects of the significance of HBA1C and GA in GDM patients: screening of gestational diabetes mellitus, blood glucose monitoring and the relationship with pregnancy outcome. At present, studies suggest that HBA1C can be used as a screening indicator for pregnant women, but it cannot completely replace OGTT. HbA1C and GA can be used for blood glucose management in patients with GDM to reduce the incidence of GDM complications. However, the application of HBA1C and GA in GDM still needs more research and clinical practice support.

Evaluation of Hemoglobin A1c before and after initiation of continuous glucose monitoring in children with type 1 diabetes mellitus

OBJECTIVES

The development of continuous glucose monitoring (CGM) systems has allowed for identification of blood sugar variations and trends in real-time that is not feasible with conventional self-monitoring of blood glucose. However, there is inconsistent data to show that the use of CGM leads to better glycemic control as measured by Hemoglobin A1c (HbA1c) in pediatric patients with type 1 diabetes mellitus. Our study aimed to compare the average HbA1c level in the 1-2 years prior to starting a CGM to the average HbA1c level in the 1-2 years immediately following CGM initiation in a sample of 1-20 year olds with type 1 diabetes mellitus.

METHODS

Participants were 90 youth (ages 1-20) followed for type 1 diabetes care at our institution who used a CGM for at least a 6 month time period. We performed a retrospective chart review to obtain up to four HbA1c values pre and post-CGM initiation each. We evaluated pre- and post-CGM initiation changes in mean HbA1c via dependent samples t-tests using IBM SPSS 24.0.

RESULTS

The mean HbA1c was 8.7% pre-CGM and decreased to 8.27% 9-12 months after CGM initiation in the overall sample. A statistically significant decrease in HbA1c was seen in patients who used multiple daily injections (p=0.02), those with a pre-CGM HbA1c greater than 9% (p=0.01), and those with a diabetes duration of 5-10 years (p=0.02).

CONCLUSION

CGM use was associated with a decrease in HbA1c over time which was statistically significant in some subgroups.

Knowledge of Hemoglobin A1c and Glycemic Control in an Urban Population

AIM

Our study aims to assess the knowledge of hemoglobin A1c (HbA1c) and glycemic control in patients with diabetes mellitus (DM) at an urban academic institution.

METHODS

This was a retrospective cross-sectional study that included a survey of 100 adult patients with DM. Our patient cohort was divided into those with recent HbA1c < 8.0% and those with HbA1c ≥ 8.0% for subgroup analysis.

RESULTS

The majority (71%) of patients correctly defined HbA1c and half were aware of their HbA1c target, but they were unable to correlate the correct average blood glucose for an HbA1c level of 7%. Worse control, defined as an HbA1c level of ≥ 8%, was associated with co-morbid disease, but was not associated with understanding HbA1c definition, target or socioeconomic disparities. Perceived glycemic control was congruent with the actual control in 46% of our patients. Ninety percent of those with HbA1c ≥ 8% perceived their control to be better than it actually was, and 97% of those with HbA1c < 8% perceived their control worse than it actually was (P < 0.00001).

CONCLUSION

Although most patients knew the definition of HbA1c, they were unable to correlate HbA1c with average blood sugar. There remain opportunities to increase education for this vulnerable population with co-morbid disease on the use of the HbA1c disease marker as an education tool.

The utility of diagnostic tests in the detection and prediction of glucose intolerance in the early and late postpartum period in women after gestational diabetes: a longitudinal cohort study

BACKGROUND

Due to diverging international recommendations, the unclear role of HbA1c and the lack of longitudinal data, we investigated the accuracy of diagnostic tests in the early and late postpartum in women with gestational diabetes (GDM) especially to predict future glucose-intolerance.

METHODS

This longitudinal cohort included 967 women with GDM from 2011 to 2020. A 75-g oGTT and HbA1c were performed at 4-12 weeks (early) postpartum. FPG and HbA1c were measured at 1 and 3-year (late) postpartum. ADA criteria were used as gold standards. At all time-points (4-12 weeks, 1-year and 3-year postpartum) women with diabetes and prediabetes were grouped together and referred to as glucose-intolerant, because at most 3% of the entire cohort population had diabetes at any time-point.

RESULTS

The prevalence of glucose-intolerance in the early postpartum was higher using FPG and HbA1c (27.5%) than oGTT criteria (18.2%). Only 48-80% of women diagnosed with glucose-intolerance in the early postpartum actually remained intolerant. This was especially low when FPG or oGTT were combined with HbA1c (1-year: ≤ 62% and 3-years: ≤ 50%). Regardless of the test used, 1/3 of women with initially normal glucose-tolerance became glucose-intolerant in the late postpartum. HbA1c was unrelated to iron status/intake, remained stable throughout, but poorly predicted future glucose-intolerance. In the longitudinal analyses, all diagnostic tests in the early postpartum showed acceptable specificities (74-96%) but poor sensitivities (all < 38%) to predict glucose-intolerance after only 10-months. At 1-year postpartum however, the combination of FPG and HbA1c could best predict glucose-intolerance 2-years later.

CONCLUSIONS

Combining FPG with HbA1c at 1-year postpartum represents a reliable choice to predict future glucose-intolerance. Given the poor prediction of tests including oGTT in the early postpartum, focus should rather be on continuous long-term screening.

Postchallenge glucose increment was associated with hemoglobin glycation index in subjects with no history of diabetes

We investigated the association between postchallenge glucose increment and hemoglobin glycation index (HGI), the difference between observed and predicted glycated hemoglobin (HbA1c), in subjects with no history of diabetes. We enrolled 1381 subjects who attended our outpatient clinic for an oral glucose tolerance test (OGTT) to screen for diabetes. HGI was defined as observed HbA1c minus predicted HbA1c. The predicted HbA1c was calculated by entering fasting plasma glucose (FPG) level into an equation [HbA1c(%)=FPG(mg/dL)*0.029+2.9686] determined from an HbA1c versus FPG regression analysis using data from an independent cohort of 2734 subjects with no history of diabetes. The association between 2-hour glucose increment and HGI was analyzed using linear regression analyses with adjustment of relevant parameters. Overall, the proportions of subjects with normal glucose tolerance, pre-diabetes, and newly diagnosed diabetes were 42.3%, 41.3%, and 16.4%, respectively. Compared with subjects who had an HGI≤0, subjects with an HGI>0 had a lower FPG (95.0±13.3 vs 98.5±15.3 mg/dL, p<0.001) but a higher 2-hour plasma glucose (151.1±52.8 vs 144.6±51.4 mg/dL, p=0.027) and 2-hour glucose increment (56.1±46.1 vs 46.1±45.0 mg/dL, p<0.001). The 2-hour glucose increment after an OGTT was independently associated with HGI (β coefficient 0.003, 95% CI 0.002 to 0.003, p<0.001). Our findings suggested that postchallenge glucose increment was independently associated with HGI in subjects with no history of diabetes.

The Impact of Race on Short-term Treatment Response to Bevacizumab in Diabetic Macular Edema

PURPOSE

To determine the impact of race and ethnicity on efficacy of intravitreal bevacizumab for diabetic macular edema in anti-vascular endothelial growth factor (VEGF) treatment-naive patients.

DESIGN

Retrospective cohort study.

METHODS

Setting: Urban-based academic institution with affiliated private offices.

STUDY POPULATION

Intravitreal anti-VEGF naïve patients seen between 2010 and 2019 of White (W) race, Black (B) race, or Hispanic (H) ethnicity aged 18 years and older with diabetic macular edema who received intravitreal injections of bevacizumab. Exclusion criteria were prior intravitreal anti-VEGF treatment, invasive ophthalmologic interventions, and laser treatments within 3 months prior to first injection through the duration of the study. Exposures: Intravitreal bevacizumab.

MAIN OUTCOMES MEASURES

Percentage of patients with visual acuity (VA) improvement and mean percentage reduction in central macular thickness (CMT).

RESULTS

Percentage with VA improvement was 27% vs 39% vs 50% after 1 injection (n = 314), and 34% vs 55% vs 59% after 3 injections (n = 150) for B, H, and W cohorts, respectively. Black patients experienced lower odds of VA improvement compared with White and Hispanic patients after 1 injection (odds of 0.480, CI 0.284-0.814, P = .006) and 3 injections (odds of 0.342, CI 0.149-0.782, P = .008) while controlling for age, sex, baseline glycated hemoglobin (HbA_1c), baseline CMT, baseline VA, laser history, injection time course, and follow-up delay.

CONCLUSIONS

Black patients had a significantly lower likelihood of visual acuity improvement following intravitreal bevacizumab treatment compared with White and Hispanic patients. Further research is warranted to understand the effect of race and ethnicity on anti-VEGF efficacy to ensure optimal treatment for each individual.

COVID-19 pandemic: Can fasting plasma glucose and HbA1c replace the oral glucose tolerance test to screen for hyperglycaemia in pregnancy?

AIMS

To evaluate proposals considering HbA1c and fasting plasma glucose (FPG) measurement as a substitute for oral glucose tolerance test (OGTT) to diagnose hyperglycaemia in pregnancy (HIP) during COVID-19 pandemic.

METHODS

Of the 7,334 women who underwent the OGTT between 22 and 30 weeks gestation, 966 had HIP (WHO diagnostic criteria, reference standard). The 467 women who had an available HbA1c were used for analysis. French-speaking Society of Diabetes (SFD) proposal to diagnose HIP during COVID-19 pandemic was retrospectively applied: HbA1c ≥5.7% (39 mmol/mol) and/or FPG level ≥5.1 mmol/l. SFD proposal sensitivity for HIP diagnosis and the occurrence of HIP-related events (preeclampsia, large for gestational age infant, shoulder dystocia or neonatal hypoglycaemia) in women with false negative (FN) and true positive (TP) HIP-diagnoses were evaluated.

RESULTS

The sensitivity was 57% [95% confidence interval 52-62]. FN women had globally lower plasma glucose levels during OGTT, lower HbA1c and body mass index than those TP. The percentage of HIP-related events was similar in FN (who were cared) and TP cases, respectively 19.5 and 16.9% (p = 0.48). We observed similar results when women at high risk for HIP only were considered.

CONCLUSION

The SFD proposal has a poor sensitivity to detect HIP. Furthermore, it fails to have any advantages in predicting adverse outcomes.

Association of Baseline Characteristics With Insulin Sensitivity and β-Cell Function in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) Study Cohort

OBJECTIVE

We investigated sex and racial differences in insulin sensitivity, β-cell function, and glycated hemoglobin (HbA1c) and the associations with selected phenotypic characteristics.

RESEARCH DESIGN AND METHODS

This is a cross-sectional analysis of baseline data from 3,108 GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) participants. All had type 2 diabetes diagnosed <10 years earlier and were on metformin monotherapy. Insulin sensitivity and β-cell function were evaluated using the HOMA of insulin sensitivity and estimates from oral glucose tolerance tests, including the Matsuda Index, insulinogenic index, C-peptide index, and oral disposition index (DI).

RESULTS

The cohort was 56.6 ± 10 years of age (mean ± SD), 63.8% male, with BMI 34.2 ± 6.7 kg/m2, HbA1c 7.5 ± 0.5%, and type 2 diabetes duration 4.0 ± 2.8 years. Women had higher DI than men but similar insulin sensitivity. DI was the highest in Black/African Americans, followed by American Indians/Alaska Natives, Asians, and Whites in descending order. Compared with Whites, American Indians/Alaska Natives had significantly higher HbA1c, but Black/African Americans and Asians had lower HbA1c. However, when adjusted for glucose levels, Black/African Americans had higher HbA1c than Whites. Insulin sensitivity correlated inversely with BMI, waist-to-hip ratio, triglyceride-to-HDL-cholesterol ratio (TG/HDL-C), and the presence of metabolic syndrome, whereas DI was associated directly with age and inversely with BMI, HbA1c, and TG/HDL-C.

CONCLUSIONS

In the GRADE cohort, β-cell function differed by sex and race and was associated with the concurrent level of HbA1c. HbA1c also differed among the races, but not by sex. Age, BMI, and TG/HDL-C were associated with multiple measures of β-cell function and insulin sensitivity.

Prevalence and impact of chronic dysglycemia in intensive care unit patients-A retrospective cohort study

BACKGROUND

The prevalence of chronic dysglycemia (diabetes and prediabetes) in patients admitted to Swedish intensive care units (ICUs) is unknown. We aimed to determine the prevalence of such chronic dysglycemia and asses its impact on blood glucose control and patient-centered outcomes in critically ill patients.

METHODS

In this retrospective observational cohort study, we obtained glycated hemoglobin A1c (HbA1c) in patients admitted to four tertiary ICUs in Sweden between March and August 2016. Based on previous diabetes history and HbA1c we determined the prevalence of chronic dysglycemia. We used multivariable regression analyses to study the association of chronic dysglycemia with the time-weighted average blood glucose concentration, glycemic lability index (GLI), and development of hypoglycemia (co-primary outcomes), and with ICU length of stay, mechanical ventilation duration, renal replacement therapy (RRT) use, vasopressor use, ICU-acquired infections, and mortality (exploratory clinical outcomes).

RESULTS

Of 943 patients, 312 (33%) had chronic dysglycemia. Of these 312 patients, 84 (27%) had prediabetes, 43 (14%) had undiagnosed diabetes and 185 (59%) had known diabetes. Chronic dysglycemia was independently associated with higher time-weighted average blood glucose concentration (P < .001), higher GLI (P < .001), and hypoglycemia (P < .001). Chronic dysglycemia was independently associated with RRT use (adjusted odds ratio 1.97, 95% CI 1.24-3.13, P = .004) but not with other exploratory clinical outcomes.

CONCLUSIONS

In four tertiary Swedish ICUs, measurement of HbA1c showed that one-third of patients had chronic dysglycemia. Chronic dysglycemia was associated with marked derangements in glycemic control, and a greater need for renal replacement therapy.

2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

The Compatibility of Hemoglobin A1c with Oral Glucose Tolerance Test and Fasting Plasma Glucose

Objectives:

Diabetes mellitus (DM) is a chronic metabolic disease requiring lifelong medical care, and its prevalence is increasing worldwide. Early diagnosis of prediabetes and diabetes is significant in view of the mortality, morbidity and cost associated with them. Because of the difficulties in application and reproducibility of oral glucose tolerance test (OGTT), which is considered to be the gold standard in the diagnosis of DM, more feasible diagnostic tests are needed. This study aims to evaluate the validity of hemoglobin A1c (HbA1c) in predicting prediabetes and diabetes in the Turkish population and to evaluate the compatibility of HbA1c with other diagnostic tests.

Methods:

The patients who were admitted to Health Sciences University Sisli Hamidiye Etfal Training and Research Hospital internal diseases and endocrinology outpatient clinics between 01.01.2013 and 30.06.2014 enrolled in this study. The participants were >18 years of age and were not diagnosed with prediabetes or DM earlier. The results of OGTT, fasting plasma glucose (FPG) and HbA1c tests were retrospectively screened, and the correlation of them was analyzed.

Results:

In this study, 201 participants enrolled. Of these cases, 127 were women and 74 were men. Mean age of the group was 49.3±10.4 years. HbA1c was observed <5.7% in the 15%, 5.7-6.4% in the 60%, and ≥ 6.5% in the 25% of the cases. While FPG was <100 mg/dL in 24% of the participants, it was found to be between 100-126 mg/dL in 71% and ≥126 mg/dL in 5% of the participants. According to the OGTT data, 23% of the cases were healthy, 59% were prediabetic and 18% were diabetic. The sensitivity and specificity of HbA1c were calculated as 50% and 80%, respectively. While the sensitivity of FPG was 17% and specificity was 97%.

Conclusion:

The data obtained from our study show that HbA1c is a more sensitive test compared to FPG in the diagnosis of DM. Prospective studies with broad participation at national and international levels are needed to redefine HbA1c cut-off points for the diagnosis of DM and prediabetes. Thus, it will be possible to revise the diagnostic guidelines accordingly.

The trials and tribulations of determining HbA1c targets for diabetes mellitus

Glycated haemoglobin (HbA_1c) is considered the gold standard for predicting glycaemia-associated risks for the microvascular and macrovascular complications of diabetes mellitus over 5-10 years. The value of HbA_1c in the care of patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) is unassailable, yet HbA_1c targets remain contentious. Guidelines from diabetes care organizations recommend conflicting HbA_1c targets - generally between 6.5% and 8%. However, all such organizations advocate for individualization of HbA_1c targets, leaving both health-care providers and their patients confused about what HbA_1c target is appropriate in an individual patient. In this Review, we outline the landmark T1DM and T2DM trials that informed the current guidelines, we discuss the evidence that drives individualized HbA_1c targets, we examine the limitations of HbA_1c, and we consider alternatives for monitoring glycaemic control. Ultimately, in synthesizing this literature, we argue for an HbA_1c target of <7% for most individuals, but emphasize the importance of helping patients determine their own personal goals and determinants of quality of life that are independent of a particular glycaemic target. We also recognize that as newer technologies and anti-hyperglycaemic therapies emerge, glycaemic targets will continue to evolve.

Association of Adipose Tissue Distribution With Type 2 Diabetes in Breast Cancer Patients

PURPOSE

We examined the association of adipose tissue distribution with type 2 diabetes (T2D) in breast cancer patients.

METHODS

Participants (N = 238) diagnosed with breast cancer at 20-75 years old who received breast cancer treatment at a major hospital from January 1, 2012, to December 31, 2017, with at least one completed and identifiable abdominal or pelvic computed tomography (CT) scan and data regarding race and ethnicity were included. Thirty-two breast cancer patients were identified as T2D patients after their breast cancer diagnoses. The adipose tissue distribution (visceral fat area [VFA], subcutaneous fat area [SFA], and the ratio of VFA to SFA [VFA/SFA]) was quantified on CT images of the third lumbar vertebra. T2D status was retrieved from patients' electronic medical records. The association of adipose tissue distribution with T2D in women with breast cancer was examined using multivariable logistic regression.

RESULTS

Participants with T2D had significantly smaller SFA compared to those without T2D (odds ratio [OR] = 0.88, 95% confidence interval [95% CI] = 0.81-0.96, per 10 cm2 SFA). A positive association of VFA/SFA ratio with T2D was observed (OR = 19.57, 95% CI = 3.26-117.42, per unit VFA/SFA), although the estimate was imprecise.

CONCLUSIONS

The amount of subcutaneous adipose tissue was inversely associated with T2D, and the ratio of the amount of visceral adipose tissue to the amount of subcutaneous adipose tissue was positively associated with T2D in breast cancer patients.

Association of hemoglobin glycation index and its interaction with obesity/family history of hypertension on hypertension risk: a community-based cross-sectional survey

Background

Hemoglobin glycation index (HGI) is considered to be a convenient measurable indicator to assess the inter-individual variation of HbA1c. In the present study, we tested the relationship between HGI and risk of hypertension, and further explored the possible interacting influences of HGI with other such factors on hypertension risk among Chinese individuals.

Methods

The eligible subjects were chosen from a community-based cross-sectional survey in China. We collected relevant data and clinical indicators for each participant. HGI was calculated as “measured HbA1c-predicted HbA1c” and divided into four categories according to quartile. The following indicators were used to assess interactive effects: (1) relative excess risk due to interaction (RERI); (2) attributable proportion due to interaction (AP); and (3) synergy index (SI). Statistical analysis was performed using R software.

Results

Specifically, 1777 eligible participants were selected in this cross-sectional survey. There were 433 subjects who were identified to have hypertension (24.4%). A significant increase in the prevalence of hypertension from Q1 to Q4 of HGI was observed (p < 0.001). Multivariable logistic model demonstrated that subjects at the highest HGI group had a substantially increased risk of being hypertensive than subjects in the first quartile of HGI, as indicated by the OR value of 1.87 (95% CI 1.26–2.78). Moreover, a significant interaction between family history of hypertension and HGI on hypertension risk was detected (RERI: 1.36, 95% CI 0.11–2.63; AP: 0.43, 95% CI 0.17–0.69; and SI:2.68, 95% CI 1.10–6.48). The interactive effect between HGI and abdominal obesity was also found to be significant, as estimated by the value of RERI (1.04, 95% CI 0.24–1.85), AP (0.33, 95% CI 0.11–0.56) and SI (1.96, 95% CI 1.01–3.79). However, in the analysis of the interaction between HGI and general obesity, only the AP value (0.28, 95% CI 0.01–0.54) was observed to be significant.

Conclusion

High HGI was independently associated with the risk of hypertension. Moreover, HGI significantly shared interactions with obesity and family history of hypertension that influenced the risk of hypertension.

Inducing remission of Type 2 diabetes in the Caribbean: findings from a mixed methods feasibility study of a low-calorie liquid diet-based intervention in Barbados

AIM

In a high proportion of people with recently diagnosed Type 2 diabetes, a short (2-3-month) low-calorie diet is able to restore normal glucose and insulin metabolism. The aim of this study was to determine the feasibility of this approach in Barbados.

METHODS

Twenty-five individuals with Type 2 diabetes diagnosed within past 6 years, not on insulin, BMI ≥ 27 kg/m² were recruited. Hypoglycaemic medication was stopped on commencement of the 8-week liquid (760 calorie) diet. Insulin response was assessed in meal tests at baseline, 8 weeks and 8 months. Semi-structured interviews, analysed thematically, explored participants' experiences. 'Responders' were those with fasting plasma glucose (FPG) < 7 mmol/l at 8 weeks.

RESULTS

Ten men and 15 women (mean age 48, range 26-68 years) participated. Mean (sd) BMI was 34.2 kg/m² (6.0); FPG 9.2 mmol/l (2.2). Mean weight loss at 8 weeks and 8 months was 10.1 kg [95% confidence interval (CI) 8.1, 12.0] and 8.2 kg (95% CI 5.8, 10.6); FPG was lower by 2.2 mmol/l (95% CI 1.2, 3.2) and 1.7 mmol/l (95% CI 0.8, 2.7) respectively. Nine of 11 (82%) of those who lost ≥ 10 kg were 'responders' compared with 6 of 14 (43%) who lost < 10 kg (P = 0.048). The 30-min insulin increment was higher in responders at baseline and follow-up (P ≤ 0.01). A food culture based on starchy foods and pressures to eat large amounts at social events were among the challenges identified by participants.

CONCLUSIONS

The feasibility of this approach to weight loss and diabetes remission in a predominantly black population in Barbados was demonstrated.

Racial differences in prediabetes prevalence by test type for the US pediatric and adult population: NHANES 1999-2016

BACKGROUND

Previous studies have shown that US estimates of prediabetes or diabetes differ depending on test type, fasting plasma glucose (FPG) vs hemoglobin A1c (HbA1c). Given age, race, and test differences reported in the literature, we sought to further examine these differences in prediabetes detection using a nationally representative sample.

METHODS

Using the National Health and Nutrition Examination Survey (NHANES) 1999-2016, individuals were identified as having prediabetes with an HbA1c of 5.7% to 6.4% or a FPG of 100 to 125 mg/dL. We excluded individuals with measurements in the diabetic range. We ran generalized estimating equation logistic regressions to examine the relationship between age, race, and test type with interactions, controlling for sex and body mass index. We compared the difference in predicted prediabetes prevalence detected by impaired fasting glycemia (IFG) vs HbA1c by race/ethnicity among children and adults separately using adjusted Wald tests.

RESULTS

The absolute difference in predicted prediabetes detected by IFG vs HbA1c was 19.9% for white adolescents, 0% for black adolescents, and 20.1% for Hispanic adolescents; 21.4% for white adults, -1.2% for black adults, and 19.2% for Hispanic adults. Using adjusted Wald tests, we found the absolute differences between black vs white and black vs Hispanic individuals to be significant, but, not between Hispanic and white individuals among children and adults separately.

CONCLUSIONS

These observations highlight differences in test performance among racial/ethnic groups. Our findings corroborate the need for further studies to determine appropriate HbA1c cutoff levels for diagnosis of prediabetes by age group and race.

High concordance between chart review adjudication and electronic medical record data to identify prevalent and incident diabetes mellitus among persons with and without HIV

BACKGROUND

Electronic medical records (EMR) represent a rich source of data, but the value of EMR for health research relies on accurate ascertainment of clinical diagnoses. Identifying diabetes in EMR is complicated by the variety of accepted diagnostic criteria, some of which can be confounded by conditions such as HIV infection. We compared EMR-based criteria for estimating diabetes prevalence and incidence in the Veterans Health Administration (VHA), overall and by HIV status, against physician chart review and adjudication.

RESEARCH DESIGN AND METHODS

We used laboratory values (serum glucose and hemoglobin A1c% [HbA1c]), ICD-9 codes, and medication records from the United States Veterans Aging Cohort Study Biomarker Cohort to identify veterans with any indication of diabetes in the EMR for subsequent physician adjudication. Sensitivity, specificity, PPV, NPV, and kappa statistics were used to evaluate agreement of EMR-based diabetes diagnoses with chart review adjudicated diagnoses.

RESULTS

EMR entries were reviewed for 1546 persons with HIV (PWH) and 843 HIV-negative participants through 2015. Agreement was at least moderate overall (kappa ≥ 0.42) for all pre-specified measures and among PWH vs HIV-negative, and African-American vs white sub-groups. Having at least one HbA1c ≥6.5% provided substantial agreement with chart adjudication for prevalent and incident diabetes (kappa = 0.89 and 0.73).

CONCLUSIONS

Identification of those with diabetes nationally within the VHA can be used in future studies to evaluate treatments, health outcomes, and adjust for diabetes in epidemiologic studies. Our methodology may provide insights for other organizations seeking to use EMR data for accurate determination of diabetes.

Geographic and Racial/Ethnic Variation in Glycemic Control and Treatment in a National Sample of Veterans With Diabetes

OBJECTIVE

Geographic and racial/ethnic disparities related to diabetes control and treatment have not previously been examined at the national level.

RESEARCH DESIGN AND METHODS

A retrospective cohort study was conducted in a national cohort of 1,140,634 veterans with diabetes, defined as two or more diabetes ICD-9 codes (250.xx) across inpatient and outpatient records. Main exposures of interest included 125 Veterans Administration Medical Center (VAMC) catchment areas as well as racial/ethnic group. The main outcome measure was HbA1c level dichotomized at ≥8.0% (≥64 mmol/mol).

RESULTS

After adjustment for age, sex, racial/ethnic group, service-connected disability, marital status, and the van Walraven Elixhauser comorbidity score, the prevalence of uncontrolled diabetes varied by VAMC catchment area, with values ranging from 19.1% to 29.2%. Moreover, these differences largely persisted after further adjusting for medication use and adherence as well as utilization and access metrics. Racial/ethnic differences in diabetes control were also noted. In our final models, compared with non-Hispanic Whites, non-Hispanic Blacks (odds ratio 1.11 [95% credible interval 1.09-1.14]) and Hispanics (1.36 [1.09-1.14]) had a higher odds of uncontrolled HBA1c level.

CONCLUSIONS

In a national cohort of veterans with diabetes, we found geographic as well as racial/ethnic differences in diabetes control rates that were not explained by adjustment for demographics, comorbidity burden, use or type of diabetes medication, health care utilization, access metrics, or medication adherence. Moreover, disparities in suboptimal control appeared consistent across most, but not all, VAMC catchment areas, with non-Hispanic Black and Hispanic veterans having a higher odds of suboptimal diabetes control than non-Hispanic White veterans.

The Sickle Effect: The Silent Titan Affecting Glycated Hemoglobin Reliability

Hemoglobin A1c (HbA1c) is a popular invaluable tool in the diagnosis of Type 2 diabetes for red blood cells (RBCs) with a lifespan of 120 days; however, many factors, including hemoglobinopathies, affect its accuracy. Sickle cell trait, primarily a benign medical condition, is a point mutation in only one of two beta-globin genes on chromosome 11. We performed a traditional review to identify how the sickle cell trait (SCT) affects the interpretation of HbA1c and the further implications it may have on the diagnosis and management of Type 2 diabetes. A literature search was performed using PubMed®/MEDLINE® and Google Scholar with formulated keywords (sickle cell trait, HbAS, HbA1c, glycosylated hemoglobin, diabetes, RBC lifespan, race, and genetics), with the majority of results being mainly observational studies. The National Glycohemoglobin Standardization Program (NGSP) is responsible for standardizing HbA1c results and also highlights factors that can interfere with HbA1c, including hemoglobin variants. Studies that utilize only an NGSP-certified method with no clinically significant interference by HbS in patients with and without SCT showed contrasting results. Additional studies showed that persons of African ancestry, the group to which the majority of SCT patients belong, have a higher HbA1c than non-Hispanic whites (NHWs), just based on race, and a greater probability of having glucose-6-phosphate dehydrogenase (G6PD) deficiency, which lowers HbA1c. The most extensive study investigating the RBC lifespan in SCT patients showed a reduction in the cell lifespan compared to normal patients; however, other smaller studies were contradictory. Our study highlights the need for hemoglobinopathy detection before or during HbA1c measurement in populations with a high degree of African ancestry and the importance of patient notification. It also shows that SCT affects the accuracy of HbA1c, through its likely reduction of RBC lifespan and its increased association with African ancestry and G6PD deficiency. This review recommends that for SCT patients with potential Type 2 diabetes, HbA1c should be used in combination with another diagnostic tool such as fasting blood glucose, fructosamine, or glycated albumin to decrease the chances of a missed diagnosis.

Pitfalls of HbA1c in the Diagnosis of Diabetes

Many health care providers screen high-risk individuals exclusively with an HbA1c despite its insensitivity for detecting dysglycemia. The 2 cases presented describe the inherent caveats of interpreting HbA1c without performing an oral glucose tolerance test (OGTT). The first case reflects the risk of overdiagnosing type 2 diabetes (T2D) in an older African American male in whom HbA1c levels, although variable, were primarily in the mid-prediabetes range (5.7-6.4% [39-46 mmol/mol]) for many years although the initial OGTT demonstrated borderline impaired fasting glucose with a fasting plasma glucose of 102 mg/dL [5.7 mmol/L]) without evidence for impaired glucose tolerance (2-hour glucose ≥140-199 mg/dl ([7.8-11.1 mmol/L]). Because subsequent HbA1c levels were diagnostic of T2D (6.5%-6.6% [48-49 mmol/mol]), a second OGTT performed was normal. The second case illustrates the risk of underdiagnosing T2D in a male with HIV having normal HbA1c levels over many years who underwent an OGTT when mild prediabetes (HbA1c = 5.7% [39 mmol/mol]) developed that was diagnostic of T2D. To avoid inadvertent mistreatment, it is therefore essential to perform an OGTT, despite its limitations, in high-risk individuals, particularly when glucose or fructosamine and HbA1c values are discordant. Innate differences in the relationship between fructosamine or fasting glucose to HbA1c are demonstrated by the glycation gap or hemoglobin glycation index.

Subjective wellbeing as a determinant of glycated hemoglobin in older adults: longitudinal findings from the English Longitudinal Study of Ageing

BACKGROUND

Previous research has shown an association between subjective wellbeing and incident diabetes. Less is known about the role of wellbeing for subclinical disease trajectories as captured via glycated hemoglobin (HbA1c). We aimed to explore the association between subjective wellbeing and future HbA1c levels, and the role of sociodemographic, behavioral and clinical factors in this association.

METHODS

We used data from the English Longitudinal Study of Ageing for this study (N = 2161). Subjective wellbeing (CASP-19) was measured at wave 2 and HbA1c was measured 8 years later at wave 6. Participants were free from diabetes at baseline. We conducted a series of analyses to examine the extent to which the association was accounted for by a range of sociodemographic, behavioral and clinical factors in linear regression models.

RESULTS

Models showed that subjective wellbeing (CASP-19 total score) was inversely associated with HbA1c 8 years later after controlling for depressive symptoms, age, sex, and baseline HbA1c (B = -0.035, 95% CI -0.060 to -0.011, p = 0.005). Inclusion of sociodemographic variables and behavioral factors in models accounted for a large proportion (17.0% and 24.5%, respectively) of the relationship between wellbeing and later HbA1c; clinical risk factors explained a smaller proportion of the relationship (3.4%).

CONCLUSIONS

Poorer subjective wellbeing is associated with greater HbA1c over 8 years of follow-up and this relationship can in part be explained by sociodemographic, behavioral and clinical factors among older adults.

Prevalence of admission plasma glucose in 'diabetes' or 'at risk' ranges in hospital emergencies with no prior diagnosis of diabetes by gender, age and ethnicity

AIMS

To establish the prevalence of admission plasma glucose in 'diabetes' and 'at risk' ranges in emergency hospital admissions with no prior diagnosis of diabetes; characteristics of people with hyperglycaemia; and factors influencing glucose measurement.

METHODS

Electronic patient records for 113 097 hospital admissions over 1 year from 2014 to 2015 included 43 201 emergencies with glucose available for 31 927 (74%) admissions, comprising 22 045 people. Data are presented for 18 965 people with no prior diagnosis of diabetes and glucose available on first attendance.

RESULTS

Three quarters (14 214) were White Europeans aged 62 (43-78) years, median (IQ range); 12% (2241) South Asians 46 (32-64) years; 9% (1726) Unknown/Other ethnicities 43 (29-61) years; and 4% (784) Afro-Caribbeans 49 (33-63) years, P < .001. Overall, 5% (1003) had glucose in the 'diabetes' range (≥11.1 mmol/L) higher at 8% (175) for South Asians; 16% (3042) were 'at risk' (7.8-11.0 mmol/L), that is 17% (2379) White Europeans, 15% (338) South Asians, 14% (236) Unknown/Others and 11% (89) Afro-Caribbeans, P < .001. The prevalence for South Asians aged <30 years was 2.1% and 5.2%, respectively, 2.6% and 8.6% for Afro-Caribbeans <30 years, and 2.0% and 8.4% for White Europeans <40 years. Glucose increased with age and was more often in the 'diabetes' range for South Asians than White Europeans with South Asian men particularly affected. One third of all emergency admissions were for <24 hours with 58% of these having glucose measured compared to 82% with duration >24 hours.

CONCLUSIONS

Hyperglycaemia was evident in 21% of adults admitted as an emergency; various aspects related to follow-up and initial testing, age and ethnicity need to be considered by professional bodies addressing undiagnosed diabetes in hospital admissions.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

Estimation of Hemoglobin A1c from Continuous Glucose Monitoring Data in Individuals with Type 1 Diabetes: Is Time In Range All We Need?

Objective: To bridge the gap between laboratory-measured hemoglobin A1c (HbA1c) and continuous glucose monitoring (CGM)-derived time in target range (TIR), introducing TIR-driven estimated A1c (eA1c). Methods: Data from Protocol 1 (training data set) and Protocol 3 (testing data set) of the International Diabetes Closed-Loop Trial were used. Training data included 3 months of CGM recordings from 125 individuals with type 1 diabetes, and HbA1c at 3 months; testing data included 9 months of CGM recordings from 168 individuals, and HbA1c at 3, 6, and 9 months. Hemoglobin glycation was modeled by a first-order differential equation driven by TIR. Three model parameters were estimated in the training data set and fixed thereafter. A fourth parameter was estimated in the testing data set, to individualize the model by calibration with month 3 HbA1c. The accuracy of eA1c was assessed on months 6 and 9 HbA1c. Results: eA1c was tracked for each individual in the testing data set for 6 months after calibration. Mean absolute differences between HbA1c and eA1c 3- and 6-month postcalibration were 0.25% and 0.24%; Pearson's correlation coefficients were 0.93 and 0.93; percentages of eA1c within 10% from reference HbA1c were 97.6% and 96.3%, respectively. Conclusions: HbA1c and TIR are reflections of the same underlying process of glycemic fluctuation. Using a model individualized with one HbA1c measurement, TIR provides an accurate approximation of HbA1c for at least 6 months, reflecting blood glucose fluctuations and nonglycemic biological factors. Thus, eA1c is an intermediate metric that mathematically adjusts a CGM-based assessment of glycemic control to individual glycation rates.

Retinopathy develops at similar glucose levels but higher HbA1c levels in people with black African ancestry compared to white European ancestry: evidence for the need to individualize HbA1c interpretation

AIMS

To examine the association of HbA_1c and glucose levels with incident diabetic retinopathy according to black African or white European ancestry.

METHODS

In this retrospective cohort study of 202 500 US Veterans with diabetes (2000-2014), measures included HbA_1c , outpatient random serum/plasma glucose, and incident retinopathy [conversion from negative to ≥2 positive evaluations (ICD-9 codes), without a subsequent negative].

RESULTS

At baseline, the study population had a mean age of 59.3 years, their mean BMI was 31.9 kg/m² , HbA_1c level was 57 mmol/mol (7.4%) and glucose level was 8.8 mmol/l, and 77% were of white European ancestry (white individuals) and 21% of black African ancestry (black individuals). HbA_1c was 0.3% higher in black vs white individuals (P < 0.001), adjusting for baseline age, sex, BMI, estimated glomerular filtration rate (eGFR), haemoglobin, and average systolic blood pressure and glucose. Over 11 years, incident retinopathy occurred in 9% of black and 7% of white individuals, but black individuals had higher HbA_1c , glucose, and systolic blood pressure (all P < 0.001); adjusted for these factors, incident retinopathy was reduced in black vs white individuals (P < 0.001). The population incidence of retinopathy (7%) was associated with higher mean baseline HbA_1c in individuals with black vs white ancestry [63 mmol/mol (7.9%) vs 58 mmol/mol (7.5%); P < 0.001)], but with similar baseline glucose levels (9.0 vs 9.0 mmol/l; P = 0.660, all adjusted for baseline age, sex and BMI).

CONCLUSIONS

Since retinopathy occurs at higher HbA_1c levels in black people for a given level of average plasma glucose, strategies may be needed to individualize the interpretation of HbA_1c measurements.

Association Between Maternal Normal Range HbA1c Values and Adverse Birth Outcomes

CONTEXT

Higher blood glucose level during gestational periods has been consistently associated with increased risk of adverse birth outcomes. Evidence regarding the association between higher glycated hemoglobin A1c (HbA1c) within the normal range and adverse birth outcomes is limited.

OBJECTIVE

We aimed to examine the association between HbA1c within the normal range and the risk of adverse birth outcomes.

DESIGN AND SETTING

The data were abstracted from the Information System of Guangdong Women and Children Hospital, China, from September 2014 to March 2018.

PATIENTS

A total of 5658 pregnant women with normal gestational HbA1c were included in this analysis.

MAIN OUTCOME MEASURES

The adverse birth outcomes include preterm birth, macrosomia, and large for gestational age (LGA).

RESULTS

Among 5658 subjects, the rates of preterm birth, macrosomia, and LGA were 4.6% (261/5658), 3.5% (200/5658), and 5.7% (325/5658), respectively. The results of multivariate logistic regression model showed that each 1% increase in maternal HbA1c was positively associated with increased risks of preterm birth (OR 1.58; 95% CI, 1.08-2.31), macrosomia (OR 1.70; 95% CI, 1.10-2.64), and LGA (OR 1.38; 95% CI, 0.98-1.96). The association between gestational HbA1c and preterm birth was more evident among women with prepregnancy body mass index (BMI) ≤ 24 kg/m2.

CONCLUSIONS

Gestational higher HbA1c level within the normal range is an independent risk factor for preterm birth, macrosomia, and LGA. Intervention for reducing HbAc1 may help to prevent adverse birth outcomes.

Racial/Ethnic Differences in Glycemic Control in Older Adults with Type 2 Diabetes: United States 2003-2014

The aim of this study was to determine whether racial differences in HbA1c persist in older adults (≥65 years) living with type 2 diabetes. Data from The National Health and Nutrition Examination Survey (NHANES) 2003–2014 were used to examine the association between HbA1c and older adults (≥65 years) over time. Compared to non-Hispanic Whites, Mexican Americans had the greatest difference in average HbA1c among minority groups, followed by those with unspecified/mixed ethnicities and non-Hispanic Blacks. In the adjusted linear model, racial minorities had a statistically significant relationship with HbA1c. There was no relationship between HbA1c and older age and insulin use. Trends in mean HbA1c over time increased for non-Hispanic Blacks and Mexican Americans and decreased for non-Hispanic Whites. The findings suggest that racial differences in HbA1c persist into older age and compared to non-Hispanic Whites, non-Hispanic Blacks and Mexican Americans are at an increased risk of morbidity, mortality, and disability due to high HbA1c. Furthermore, alternate measures of glycemic control may be needed to screen and manage T2DM in racial minorities.

Glycated haemoglobin as a screening test for abnormal glucose homeostasis in childhood obesity

AIM

To estimate the proportion of type 2 diabetes mellitus and abnormal glucose homeostasis in childhood obesity and assess the predictive role of HbA_1c as a diagnostic marker compared with oral glucose tolerance testing (OGTT).

METHODS

A retrospective study in a tertiary paediatric hospital. Data were collected on all overweight or obese children who underwent routine OGTT between 2012 and 2016. Ethnicity, anthropometry, comorbidities and other risk factors associated with diabetes were recorded systematically. Fasting venous glucose, insulin and HbA_1c values, along with 120-min venous glucose were recorded. Receiver operating characteristic (ROC) curve analysis was performed to derive optimum thresholds of HbA_1c for detection of type 2 diabetes, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Predictive HbA_1c thresholds for the detection of abnormal glucose homeostasis in children with obesity were calculated.

RESULTS

Of 156 children, 13 (8%, 10 female, 10 Asian) had type 2 diabetes, 95 (61%) had normal glucose tolerance, 18 (12%) had isolated IFG, 19 (12%) had isolated IGT, and another 11 (7%) had both IFG and IGT. The proportion of abnormal glucose homeostasis was 39%. ROC curve analysis demonstrated that HbA_1c ≥ 42 mmol/mol (6.0%) predicted type 2 diabetes (specificity 95%, sensitivity 85%) but performed moderately for IFG (specificity 46%, sensitivity 78%) and IGT (specificity 78%, sensitivity 55%).

CONCLUSION

Despite HbA_1c being a less-sensitive diagnostic tool compared with OGTT for children with IFG and IGT, it is reliable in detecting type 2 diabetes in asymptomatic children with obesity, instead of the labour- and cost-intensive OGTT.

Prevalence of Prediabetes Among Adolescents and Young Adults in the United States, 2005-2016

IMPORTANCE

Individuals with prediabetes are at increased risk of developing type 2 diabetes, chronic kidney disease, and cardiovascular disease. The incidence and prevalence of type 2 diabetes in the US adolescent population have increased in the last decade. Therefore, it is important to monitor the prevalence of prediabetes and varying levels of glucose tolerance to assess the future risk of type 2 diabetes in the youngest segment of the population.

OBJECTIVE

To examine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and increased glycated hemoglobin A1c (HbA1c) levels in US adolescents (aged 12-18 years) and young adults (aged 19-34 years) without diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analyses of the 2005-2016 National Health and Nutrition Examination Survey assessed a population-based sample of adolescents and young adults who were not pregnant, did not have diabetes, and had measured fasting plasma glucose, 2-hour plasma glucose after a 75-g oral glucose tolerance test, and HbA1c levels. Analysis began in April 2017.

MAIN OUTCOMES AND MEASURES

Impaired fasting glucose was defined as fasting plasma glucose of 100 mg/dL to less than 126 mg/dL, IGT as 2-hour plasma glucose of 140 mg/dL to less than 200 mg/dL, and increased HbA1c level as HbA1c level between 5.7% and 6.4%. The prevalence of IFG, isolated IFG, IGT, isolated IGT, increased HbA1c level, isolated increased HbA1c level, and prediabetes (defined as having IFG, IGT, or increased HbA1c level) were estimated. Fasting insulin levels and cardiometabolic risk factors across glycemic abnormality phenotypes were also compared. Obesity was defined as having age- and sex-specific body mass index (calculated as weight in kilograms divided by height in meters squared) in the 95th percentile or higher in adolescents or 30 or higher in young adults.

RESULTS

Of 5786 individuals, 2606 (45%) were adolescents and 3180 (55%) were young adults. Of adolescents, 50.6% (95% CI, 47.6%-53.6%) were boys, and 50.6% (95% CI, 48.8%-52.4%) of young adults were men. Among adolescents, the prevalence of prediabetes was 18.0% (95% CI, 16.0%-20.1%) and among young adults was 24.0% (95% CI, 22.0%-26.1%). Impaired fasting glucose constituted the largest proportion of prediabetes, with prevalence of 11.1% (95% CI, 9.5%-13.0%) in adolescents and 15.8% (95% CI, 14.0%-17.9%) in young adults. In multivariable logistic models including age, sex, race/ethnicity, and body mass index, the predictive marginal prevalence of prediabetes was significantly higher in male than in female individuals (22.5% [95% CI, 19.5%-25.4%] vs 13.4% [95% CI, 10.8%-16.5%] in adolescents and 29.1% [95% CI, 26.4%-32.1%] vs 18.8% [95% CI, 16.5%-21.3%] in young adults). Prediabetes prevalence was significantly higher in individuals with obesity than in those with normal weight (25.7% [95% CI, 20.0%-32.4%] vs 16.4% [95% CI, 14.3%-18.7%] in adolescents and 36.9% [95% CI, 32.9%-41.1%] vs 16.6% [95% CI, 14.2%-19.4%] in young adults). Compared with persons with normal glucose tolerance, adolescents and young adults with prediabetes had significantly higher non-high-density lipoprotein cholesterol levels, systolic blood pressure, central adiposity, and lower insulin sensitivity (P < .05 for all).

CONCLUSIONS AND RELEVANCE

In the United States, about 1 of 5 adolescents and 1 of 4 young adults have prediabetes. The adjusted prevalence of prediabetes is higher in male individuals and in people with obesity. Adolescents and young adults with prediabetes also present an unfavorable cardiometabolic risk profile, putting them both at increased risk of type 2 diabetes and cardiovascular diseases.

2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes-2020

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee (https://doi.org/10.2337/dc20-SPPC), a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc20-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Rationale and Design for a GRADE Substudy of Continuous Glucose Monitoring

Background: The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) study has enrolled a racially and ethnically diverse population with type 2 diabetes, performed extensive phenotyping, and randomly assigned the participants to one of four second-line diabetes medications. The continuous glucose monitoring (CGM) substudy has been added to determine whether there are racial/ethnic differences in the relationship between average glucose (AG) and hemoglobin A1c (HbA1c). CGM will also be used to compare time in target range, glucose variability, and the frequency and duration of hypoglycemia across study groups. Methods: The observational CGM substudy will enroll up to 1800 of the 5047 GRADE study participants from the four treatment groups, including as many as 450 participants from each of 4 racial/ethnic minority groups to be compared: Hispanic White, non-Hispanic White, non-Hispanic African American, and non-Hispanic Other. CGM will be performed for 2 weeks in proximity to a GRADE annual visit, during which an oral glucose tolerance test will be performed and HbA1c and glycated albumin measured. Indicators of interindividual variation in red blood cell turnover, based on specialized erythrocyte measurements, will also be measured to explore the potential causes of interindividual HbA1c variations. Conclusions: The GRADE CGM substudy will provide new insights into whether differences exist in the relationship between HbA1c and AG among different racial/ethnic groups and whether glycemic profiles differ among frequently used diabetes medications and their potential clinical implications. Understanding such differences is important for clinical care and adjustment of diabetes medications in patients of different races or ethnicities.

Inequalities in glycemic control in childhood onset type 2 diabetes in England and Wales-A national population-based longitudinal study

BACKGROUND

Not much is known about glycaemic-control trajectories in childhood-onset type 2 diabetes (T2D). We investigated characteristics of children and young people (CYP) with T2D and inequalities in glycemic control.

METHODS

We studied 747 CYP with T2D, <19 years of age in 2009-2016 (from the total population-based National Pediatric Diabetes Audit [>95% diabetes cases in England/Wales]). Linear mixed-effects modeling was used to assess socioeconomic and ethnic differences in longitudinal glycated hemoglobin (HbA_1c ) trajectories during 4 years post-diagnosis (3326 HbA_1c data points, mean 4.5 data points/subject). Self-identified ethnicity was grouped into six categories. Index of Multiple Deprivation (a small geographical area-level deprivation measure) was grouped into SES quintiles for analysis.

RESULTS

Fifty-eight percent were non-White, 66% were female, and 41% were in the most disadvantaged SES quintile. Mean age and HbA_1c at diagnosis were 13.4 years and 68 mmol/mol, respectively. Following an initial decrease between diagnosis and end of year 1 (-15.2 mmol/mol 95%CI, -19.2, -11.2), HbA_1c trajectories increased between years 1 and 3 (10 mmol/mol, 7.6, 12.4), followed by slight gradual decrease subsequently (-1.6 mmol/mol, -2, -1.1). Compared to White CYP, Pakistani children had higher HbA_1c at diagnosis (13.2 mmol/mol, 5.6-20.9). During follow-up, mixed-ethnicity and Pakistani CYP had poorer glycemic control. Compared to children in the most disadvantaged quintile, those in the most advantaged had lower HbA_1c at diagnosis (-6.3 mmol, -12.6, -0.1). Differences by SES remained during follow-up. Mutual adjustment for SES and ethnicity did not substantially alter the above estimates.

CONCLUSIONS

About two-thirds of children with childhood-onset T2D were non-White, female adolescents, just under half of whom live in the most disadvantaged areas of England and Wales. Additionally, there are substantial socioeconomic and ethnic inequalities in diabetes control.

Mechanisms of Collagen Crosslinking in Diabetes and Keratoconus

Collagen crosslinking provides the mechanical strength required for physiological maintenance of the extracellular matrix in most tissues in the human body, including the cornea. Aging and diabetes mellitus (DM) are processes that are both associated with increased collagen crosslinking that leads to increased corneal rigidity. By contrast, keratoconus (KC) is a corneal thinning disease associated with decreased mechanical stiffness leading to ectasia of the central cornea. Studies have suggested that crosslinking mediated by reactive advanced glycation end products during DM may protect the cornea from KC development. Parallel to this hypothesis, riboflavin-mediated photoreactive corneal crosslinking has been proposed as a therapeutic option to halt the progression of corneal thinning by inducing intra- and intermolecular crosslink formation within the collagen fibrils of the stroma, leading to stabilization of the disease. Here, we review the pathobiology of DM and KC in the context of corneal structure, the epidemiology behind the inverse correlation of DM and KC development, and the chemical mechanisms of lysyl oxidase-mediated crosslinking, advanced glycation end product-mediated crosslinking, and photoreactive riboflavin-mediated corneal crosslinking. The goal of this review is to define the biological and chemical pathways important in physiological and pathological processes related to collagen crosslinking in DM and KC.

Racial differences in performance of HbA1c for the classification of diabetes and prediabetes among US adults of non-Hispanic black and white race

AIM

To characterize differences between black and white people in optimal HbA_1c thresholds for diagnoses of diabetes and prediabetes.

METHODS

Data were included from the National Health and Nutrition Examination Survey, 2005-2014. Black and white adults (age 18-70 years) who underwent an oral glucose tolerance test and had available fasting plasma glucose, 2-h plasma glucose and HbA_1c measurements were eligible for inclusion. Diabetes or prediabetes status was defined by fasting plasma glucose and 2-h plasma glucose using American Diabetes Association criteria. Classification of diabetes, prediabetes and dysglycaemia by HbA_1c was evaluated for a range of HbA_1c thresholds, with optimal thresholds defined as those values that maximized the sum of sensitivity and specificity (Youden's index).

RESULTS

In 5324 black (32.3%) and white (67.7%) individuals, Youden's index (optimal) thresholds for HbA_1c were ≥42 mmol/mol (6.0%) and ≥39 mmol/mol (5.7%) for discriminating diabetes vs non-diabetes, ≥ 44 mmol/mol (6.2%) and ≥39 mmol/mol (5.7%) for discriminating diabetes vs prediabetes (excluding normoglycaemia), ≥39 mmol/mol (5.7%) and ≥37 mmol/mol (5.5%) for discriminating dysglycaemia vs normoglycaemia, and ≥39 mmol/mol (5.7%) and ≥37 mmol/mol (5.5%) for discriminating prediabetes vs normoglycaemia (excluding diabetes), in black and white people, respectively.

CONCLUSIONS

Consistently higher optimal HbA_1c thresholds in black people than in white people suggest a need to individualize HbA_1c relative to glucose levels if HbA_1c is used to diagnose diabetes and prediabetes.

A labile form of hemoglobin A1c is higher in African-American youth with type 1 diabetes compared to Caucasian patients at similar glucose levels

BACKGROUND

Hemoglobin A1c (HbA1c) levels are higher in African-American (AA) individuals compared to Caucasians (EA) even after adjustment for blood glucose levels. To better understand the mechanism of this disparity we examined the relationship of an unstable (labile) form of HbA1c (L-HbA1c) with race and glucose.

METHODS

Samples for HbA1c were collected from pediatric patients self-identified as either AA (15F, 12M, age 13.4 ± 3.5 years) or EA (22F, 30M, age 14.6 ± 3.4 years) with type 1 diabetes at the time of a clinic visit. Clinic HbA1c (HbA1c) was performed by immunoassay. L-HbA1c equaled the difference in the HbA1c fraction by dynamic capillary isoelectric focusing before and after incubation in a low pH buffer. A capillary glucose (Clinic-BG) was measured at clinic visit. Mean blood glucose (MBG) was calculated from the last 30 days of the patient's glucose meter data. The influence of race on L-HbA1c was assessed in a multiple variable regression model adjusted for Clinic-BG.

RESULTS

The groups were similar for age and duration of diabetes. L-HbA1c was correlated with Clinic-BG, MBG, and HbA1c. The mean levels of L-HbA1c, HbA1c, MBG, but not Clinic-BG were higher in AA patients compared to EA. After adjustment for Clinic-BG, L-HbA1c was still higher in AA (2.8 ± 0.7% AA vs 2.1 ± 0.7% EA, P < .0001).

CONCLUSIONS

L-HbA1c is correlated with Clinic-BG. At any given level of Clinic-BG, AA patients have higher levels of L-HbA1c than EA. This preliminary study suggests that early factors prior to the formation of stable HbA1c may contribute to the observed glucose-independent racial disparity.

Self-Management as a Mediator of the Relationship between Social Support Dimensions and Health Outcomes of African American Adults with Type 2 Diabetes

Social support promotes behavior change and self-management that leads to improved health outcomes. The purpose of this study was to evaluate the role of self-management in mediating the relationship between social support dimensions and health outcomes of African Americans with type 2 diabetes (T2D). Cross-sectional data were collected from 102 African Americans with T2D at an outpatient clinic. The majority of the participants were female, single, unemployed, and having low income. Functional support, the quality of the primary intimate relationship, and the number of support persons were negatively correlated with depression. Functional support and satisfaction with support explained a significant small amount of the variance in self-management. However, self-management did not mediate the relationships between social support dimensions and the health outcomes. The results of this study shed the light on the unique relationships of social support dimensions with health outcomes of African Americans with T2D.

Total hemoglobin count has significant impact on A1C - Data from National Health and Nutrition Examination Survey 1999-2014

BACKGROUND

Previous study showed A1C was affected by hemoglobin and gender in non-anemic Koreans. However, there was no other data to support those important findings.

METHODS

Participants from National Health and Nutrition Examination Survey (NHANES) - 1999 to 2014 with age over 12 years were examined. After excluding participants with hypoglycemia and moderate to severe anemia, 22,974 participants were included in analysis. Both female and male were divided into three groups based on their hemoglobin level. Linear regression and multivariate regression analyses were conducted to assess the relationship between A1C and hemoglobin in three fasting plasma glucose (FPG) intervals.

RESULTS

For both female and male, A1C was significantly negatively correlated with hemoglobin in the FPG interval range between 80 to 126mg/dl, p<0.0001. A1C was not significantly associated with hemoglobin over the other two intervals (70≤FPG<80mg/dl and FPG≥126mg/dl, p>0.05). In addition, over FPG interval between 80 to 126mg/dl, after adjusting age and fasting glucose level, A1C still significantly negatively correlated with hemoglobin (regression coefficient=-0.052, p<0.0001 in females, regression coefficient=-0.050, p<0.0001 in males).

CONCLUSIONS

A1C would decrease by 0.05% (about 0.5mmol/mol) as a result of each 1g/dl increase in total hemoglobin count when plasma glucose level in normal or prediabetes range. The mechanism behind this finding is unclear. Further study should be conducted and hemoglobin count may need be taken into consideration when applying A1C for the diagnosis of diabetes or to screen for prediabetes.

Importance of early elevated maternal HbA1c levels in identifying adverse fetal and neonatal events

AIMS

The aims of this study were to explore factors that associated with gestational diabetes mellitus (GDM), and to determine the relationship between early maternal HbA1c levels and adverse fetal or neonatal events, and to determine an optimal maternal glucose testing method in order to decrease the potential health risk for their offspring.

METHODS

From December 2015 to May 2016, a total of 6744 pregnant women were enrolled from Shanghai First Maternal and Infant Hospital affiliated to Tongji University prospectively in the nested case-control study. Each GDM case was matched with a healthy pregnant woman and followed up. Outcome analyses were conducted between GDM case and control groups, as well as elevated and normal maternal HbA1c levels, respectively.

RESULTS

A total of 1836 women were included in the adverse fetal and neonatal events examination. For pregnant women with early HbA1c ≥ 5.2%, the adjusted risk ratios (RR) of respiratory distress syndrome (RDS), pneumonia and jaundice were 4.37 (95%CI 1.54-12.35), 2.03 (95%CI 1.24-3.33) and 1.49 (95%CI 1.01-2.20), respectively. After treatments, the frequency for the majority of events in GDM group was similar to that of healthy pregnant women. Moreover, the area under the curve (AUC) of early maternal HbA1c in predicting potential RDS is 0.734. HbA1c ≤ 4.9% excluded for RDS.

CONCLUSIONS

Compared with women with normal HbA1c, those with an early elevated HbA1c level were more likely to develop adverse events, including RDS, pneumonia and jaundice. Early HbA1c testing can be used as an auxiliary method identifying potential RDS.

Cardiovascular Health Among Non-Hispanic Asian Americans: NHANES, 2011-2016

Background Asian Americans are the fastest growing population in the United States, but little is known about their cardiovascular health (CVH). The objective of this study was to assess CVH among non-Hispanic Asian Americans (NHAAs) and to compare these estimates to those of non-Hispanic white (NHW) participants. Methods and Results Merging NHANES (National Health and Nutrition Examination Survey) data from 2011 to 2016, we examined 7 metrics (smoking, weight, physical activity, diet, blood cholesterol, blood glucose, and blood pressure) to assess CVH among 5278 NHW and 1486 NHAA participants aged ≥20 years. We assessed (1) the percentage meeting 6 to 7 metrics (ideal CVH), (2) the percentage meeting only 0 to 2 metrics (poor CVH), and (3) the overall mean CVH score. We compared these estimates between NHAAs and NHWs and among foreign-born NHAAs by birthplace and number of years living in the United States. The adjusted prevalence of ideal CVH was 8.7% among NHAAs and 5.9% among NHWs ( P<0.001). NHAAs were significantly more likely to have ideal CVH (adjusted prevalence ratio: 1.42; 95% CI, 1.29-1.55) compared with NHWs. Among NHAAs, there was no significant difference in ideal CVH between US- and foreign-born participants, nor by number of years living in the United States. With lower body mass index thresholds (<23, normal weight) for NHAAs, there were no statistically significant differences in the adjusted prevalence of ideal CVH (6.5% versus 5.9%, P=0.216) between NHAAs and NHWs. Conclusions NHAAs had a higher prevalence of overall ideal CVH compared with NHWs. However, when using a lower body mass index threshold for NHAAs, there was no difference in ideal CVH between the groups.