Use Of HbA1c Research Articles

Prediabetes and cardiovascular diseases: a serious but overlooked issue

The elevated risk of cardiovascular diseases and prediabetes is a practical area of concern although there is dearth of data coming from across the globe despite epidemiological studies connecting the duo. Recent meta-analysis in BMJ reported relative risk of 1.15 for a composite of cardiovascular disease and 1.16 for ischaemic heart disease in the prediabetic population as opposed to that in the population with normal sugar levels. A recent research placed a 25% elevated risk of myocardial infarction in the prediabetic population along with greater chances of undergoing various forms of revascularization. Prediabetes although defined by numbers and classified as IFG (Impaired fasting glucose) and IGT (Impaired glucose tolerance), debates still exit on the cutoffs to be used and also on use of HbA1C to define prediabetes. Recent Chinese study looked at age specific cut offs for the interplay between prediabetes and elevated cardiovascular disease risk and found family history as an important pointer in the younger age group and life style factors to be of importance in older age group. More research and studies encompassing the global population at large needs to be done to eliminate the population bias involved in a nationwide studies, with insights into the Sirtuin proteins SRT1- 7 and its modulators, whose impact on cardiovascular disease is well established.

Vector of glycated hemoglobin in the formation of dysglycemia in postmenopause: Emphasis on early diagnosis and therapy

Introduction. The close relationship of postmenopause with insulin resistance (IR) and metabolic syndrome (MetS) marks a high cardiometabolic risk of dysglycemia, determining the need for its early diagnosis and therapy. Pathogenetically substantiated criteria for the diagnosis of prediabetes and the nature of early drug therapy for type 2 diabetes mellitus (T2DM) are debated. Information on the relationship between glucose homeostasis parameters and menopausal MetS is fragmentary.Aim. To evaluate the associations of glycated hemoglobin (HbA1c) levels with indices of IR, β-cell function and MetS character- istics in a cohort of postmenopausal women with different carbohydrate metabolic states.Materials and methods. In 94 Caucasian postmenopausal women 58.0 (53.0; 63.0) years old the following were determined: HbA1c, fasting glycemia (FG), TyG and HOMA2 indices, C-peptid, BMI, waist circumference (WC), blood pressure (BP), triglycerides (TG), HDL-C levels. When classifying women by HbA1c (ADA criteria), 15 had normoglycemia, 24 prediabetes, 55 T2DM. ME (25–75%) was assessed using SPSS (version 17); intergroup differences according to the Mann – Whitney test; Spearman and partial correlation analysis were performed.Results. HbA1c age independently correlated with IR parameters: TyG (R = 0.590; p < 0.001), HOMA2-IR (R = 0.318; p < 0.05) and beta cell function: HOMA2-B (R = -0.355; p < 0.001); with lipid markers of MetS (TG, HDL-C, respectively R = 0.382; -0.448; p < 0.001), anthropometric and blood pressure levels.Conclusion. Associations of HbA1c in postmenopausal women with a spectrum of glucose homeostasis parameters and MetS mark it as a vector of formation and progression of dysglycemia due to a close connection with the functional state of β-cells and the importance of lipoglucotoxicity in the dynamics of postmenopausal IR. The obtained data pathogenetically determine the use of HbA1c in the verification of dysglycemia and the early administration of combined antihyperglycemic therapy aimed at preserving β-cell function. The potential of dipeptidyl peptidase-4 inhibitors in slowing the progression of type 2 diabetes mellitus is considered

Maternal periconception hyperglycemia, preconception diabetes, and risk of major congenital malformations in offspring.

What are the roles of maternal preconception diabetes and related periconceptional hyperglycemia on the risk of major congenital malformations (MCMs) in offspring? Maternal periconceptional glycated hemoglobin (HbA1c) levels over 5.6% were associated with an increased risk of congenital heart defects (CHD) in the offspring, and maternal preconception diabetes was associated with an increased risk of CHD, including when HbA1c levels were within euglycemic ranges. Maternal preconception diabetes has been linked with MCMs in the offspring. However, evidence concerning associations with specific periconception serum measures of hyperglycemia, and susceptibility of different organ systems, is inconsistent. Moreover, limited evidence exists concerning the effectiveness of antidiabetic medications in mitigating diabetes-related teratogenic risks. A large Israeli birth cohort of 46534 children born in 2001-2020. Maternal HbA1c test results were obtained from 90 days before conception to mid-pregnancy. Maternal diabetes, other cardiometabolic conditions, and MCMs in newborns were ascertained based on clinical diagnoses, medication dispensing records, and laboratory test results using previously validated algorithms. Associations were modeled using generalized additive logistic regression models with thin plate penalized splines. Maternal periconceptional HbA1c value was associated with CHD in newborns, with the risk starting to increase at HbA1c values exceeding 5.6%. The association between HbA1c and CHD was stronger among mothers with type 2 diabetes mellitus (T2DM) compared to the other diabetes groups. Maternal pre-existing T2DM was associated with CHD even after accounting for HbA1C levels and other cardiometabolic comorbidities (odds ratio (OR)=1.89, 95% CI 1.18, 3.03); and the OR was materially unchanged when only mothers with pre-existing T2DM who had high adherence to antidiabetic medications and normal HbA1c levels were considered. The rarity of some specific malformation groups limited the ability to conduct more granular analyses. The use of HbA1c as a time-aggregated measure of glycemic control may miss transient glycemic dysregulation that could be clinically meaningful for teratogenic risks. The observed association between pre-existing diabetes and the risk of malformations within HbA1c levels suggests underlying causal pathways that are partly independent of maternal glucose control. Therefore, treatments for hyperglycemia might not completely mitigate the teratogenic risk associated with maternal preconception diabetes. The work was supported by NIH grants K99ES035433, R01HD097778, and P30ES000002. None of the authors reports competing interests. N/A.

6547 Glycated Hemoglobin is a Better Glycemic Indicator than Glycated Albumin in Mothers with Pregestational Diabetes: Preliminary Results of a CGM study in the 2nd and 3rd Trimesters

Abstract Disclosure: M. Md Amin: None. J. Ratnasingam: None. S.S. Paramasivam: None. L. Ibrahim: None. L. Lim: None. Q. Lim: None. N. Hee Ken Yoong: None. M. Hamdan: None. S. Ganapathy: None. P. Sthaneshwar: None. S.R. Vethakkan: None. Glycemic control is strongly associated with maternofetal outcomes in mothers with pregestational diabetes. Glycated Hemoglobin (HbA1c) is most accurate in the first trimester. The use of HbA1c to monitor glycemia in pregnancy however is controversial, as altered red-cell kinetics and iron deficiency render it less accurate than in the nongravid state, especially in the 2nd or 3rd trimester. Glycated albumin (GA) is an alternative measure of intermediate-term glycemia (2-3 weeks) which is unaffected by red-cell survival that has been used to monitor glycemia in CKD and pregnancy. However, the accuracy of HbA1c as opposed to GA is unclear, especially in later pregnancy and there are no published data comparing it with CGM (Continuous Glucose Monitoring) metrics in pregnancy. We compared the accuracy of HbA1c and GA as a glycemic indicator in later pregnancy using mean glucose from a 6-day CGM as reference, hypothesizing that GA would correlate more strongly with CGM metrics.Twelve pregnant Malaysian mothers with pregestational Type 1 (n=2) and Type 2 DM(n=10) were enrolled in this prospective observational study. Mothers with known hemoglobinopathy, nephrotic syndrome and liver cirrhosis were excluded. Patients underwent blinded 6-day CGM (Medtronic iPro2) followed by blood sampling for GA, HbA1c, albumin and hemoglobin on Day 7 at standardized timepoints in the 2nd and 3rd trimester (20-28 weeks, 30-36 weeks). Mean pre-pregnancy BMI was 28kg/m2(±5). Mean Hb was 12.3g/dL (±1.5), 16.7% of mothers had anemia, while 62.5% had serum albumin < 35g/L. GA did not correlate with mean CGM glucose (2nd trimester: r=0.180 [n=10], 3rd trimester r=0.493 [n=8], p=NS). After excluding obese women (pre-pregnancy BMI>30kg/m2) however, GA correlated well with mean CGM glucose in the 3rd trimester (r=0.870, p<0.05). HbA1c correlated significantly and strongly with mean CGM glucose in later pregnancy (2nd trimester: r=0.621 [n=11], 3rd trimester r=0.718[n=8], p<0.05) and correlated with estimated A1c from CGM (r=0.548, p=0.01). Unexpectedly, our data indicate that HbA1c correlates well with gold standard mean CGM glucose with a strength approximating that observed in the nongravid population with diabetes, thus validating its use as a complementary secondary measure of glycemia to fingerstick-glucose for therapeutic decision-making in later, as well as early pregnancy. Obesity is a known confounder of accuracy of GA, our findings corroborate this. Therefore, utility of GA as an alternative glycemic measure in pregnancy is potentially limited by the increasing prevalence of obesity worldwide and impact of gestational weight gain. A larger sample is needed to confirm these preliminary findings. Presentation: 6/2/2024

Use of HbA1c as index of glycemic control and lipid profile in diabetic individuals

Use of HbA1c as index of glycemic control and lipid profile in diabetic individuals

When is HbA1c useful and what do the numbers mean – do they help or hinder?

Background: Glycated haemoglobin (HbA1c) measurement is used for diagnosis, management and remission of type 2 diabetes (T2DM), with measurements comparable worldwide and the World Health Organization listing medical conditions that affect its accuracy. Admission glucose is in the ‘diabetes’ range in 5% of emergency hospital admissions without prior diagnosis, with literature searches indicating inconsistent practice on using HbA1c to confirm diagnosis. As oral glucose tolerance tests (OGTT) were not possible during the COVID-19 pandemic, guidance was issued by the Royal College of Obstetrics and Gynaecology on using HbA1c for gestational diabetes mellitus. Aims: This study explores use of HbA1c at Queen Elizabeth Hospital Birmingham, a large university hospital serving a multi- ethnic adult population. Methods: Information is presented on comparability, clinical audits, research studies and current practice, and is illustrated by case reports. Results: Data from the National Glycohemoglobin Standardization Program show comparability of laboratoryHbA1c and point-of-care testing methods from 1993 to 2023. Although HbA1c was used to diagnose gestational diabetes during the COVID-19 pandemic, hospitals have reverted to OGTT post pandemic. In contrast, HbA1c is now being used to assess T2DM remission. Case reports illustrate these scenarios and highlight the complexity of decision-making when the accuracy of the HbA1c reading is affected by multiple co- morbidities. Conclusions: This wider use of HbA1c includes remission of T2DM but the diagnosis of gestational diabetes has reverted to OGTT post pandemic. A pictorial representation of HbA1c range is presented to aid understanding of this test. It is suitable for diagnosis of diabetes in most people except those with some variant haemoglobins or abnormal red blood cell turnover.

Longitudinal impact of COVID-19 pandemic on the utilization of hemoglobin A1c testing in outpatients

BackgroundDuring the COVID-19 pandemic, concerns arose about disparate access to health care and laboratory testing. There is limited information about the pandemic’s impact on the frequency of diabetic laboratory testing across demographic subgroups (e.g., sex, age over 65 y, and race). MethodsThis retrospective study examined outpatient hemoglobin A1c (HbA1c) testing in a large academic medical center in Upstate New York between March 2019 and March 2021. Multivariate Poisson regression models were used to evaluate the pandemic’s effects on HbA1c utilization. ResultsOver 190,000 HbA1c results from predominately white (76.1 %) and older (mean age, 60.6 y) outpatients were analyzed. Compared to pre-pandemic time period, the average number of HbA1c tests per patient during COVID time period experienced a small, though significant, drop (1.3 to 1.2; p < 0.001) on aggregate and in outpatients, males, females, and seniors. The modest reduction was not significant by race except for the white seniors (p < 0.001). However, the testing frequency remained within recommendations from the American Diabetes Association for monitoring prediabetic patients and patients with stable glycemic control. ConclusionGiven the propensity for healthcare disruptions to widen disparities, it is reassuring that we did not observe a worsening of disparities in rates of HbA1c testing during the COVID-19 pandemic.

HbA1c: an independent risk factor for dysthyroid optic neuropathy.

We aimed to explore the frequencies of islet β-cell autoantibodies and insulin resistance (IR) in thyroid-associated ophthalmopathy (TAO) and identify specific diabetes mellitus (DM) indicators as early predictors for dysthyroid optic neuropathy (DON). Ninety-eight TAO patients (57 DON and 41 non-DON patients) and 48 healthy control (HC) participants were recruited for this prospective cross-sectional study. Serum thyroxine, serum thyroid autoantibodies, serum humoral immune markers against islet β-cell, fasting plasma glucose (FPG), fasting serum insulin (FINS), fasting c-peptide (FCP), and glycosylated hemoglobin A1 (HbA1c) were measured. Logistic regression analysis was used to evaluate the correlation of patients' age, body mass index (BMI), FPG, HbA1c, and related indexes of islet β-cell function to the occurrence of DON. The DON group had higher FPG (P<0.001, 0.016) and HbA1c (P<0.0001, P<0.001) levels than the HC and non-DON groups. The homeostasis model assessment (HOMA)-IR level was the highest in the DON group (HC 2.15 ± 0.89, non-DON 2.41 ± 1.24, and DON 2.82 ± 2.65), while the HOMA-β level was the lowest (HC 101.8 ± 44.75%, non-DON 102.9 ± 54.61%, and DON 88.29 ± 52.75%), with no significant differences (P=1, P>0.05). On univariate analysis, age (P=0.006), BMI (P=0.022), history of steroid use (P=0.014), FPG (P=0.013), and HbA1c (P=0.001) levels were significantly associated with the presence/absence of DON. In addition, after adjusting for potential confounds, the HbA1c level was an independent factor associated with DON (P=0.009, OR=4.012). HbA1c is an independent risk factor for DON. Given the interconnected link between thyroid dysfunction and DM, the use of HbA1c as a potential biomarker for DON warrants further investigation.

Usefulness of HbA1C in differentiating Gestational Diabetes Mellitus and preexisting Diabetes Mellitus in the early stages of pregnancy

Introduction: Diabetes mellitus in pregnancy can cause several complications for the mother and the neonate if left untreated. This study identifies the proportion of undiagnosed pre-existing diabetic pregnant women and the necessity of doing an HbA1C test in the first trimester for its diagnosis.Methodology: Pregnant women in the first trimester without a history of hypertensive disorders, Diabetes Mellitus in their previous pregnancies were recruited for the studies. Then blood samples were withdrawn from them to perform OGTT and the HbA1C test on booking visit (8-12 weeks of gestation). The results were used to diagnose and find the proportions of pregnant women with pre-existing diabetes mellitus and gestational diabetes mellitus.Results: The HbA1C test was done for 428 pregnant women and among them, 25 (5.8%) had levels above ≥ 48 mmol/mol (6.5%) and were diagnosed with pre-existing diabetes. Of the 428 pregnant women, only 267 attended the OGTT. Among the 267 pregnant women, 15 had HbA1C levels equal to or more than 6.5% and they were identified to have pre-existing diabetes. Pregnant women diagnosed with gestational diabetes were 34 and the HbA1C of these women was &lt;6.5%. However, the 15 pregnant women who were diagnosed with preexisting diabetes were not identified with gestational diabetes from the OGTT.Conclusion: HbA1C can be used as a useful tool for screening pre-existing diabetes during pregnancy. Due to the high prevalence of pregnant women with pre-existing diabetes (5.8%) found in this study, it can be recommended to perform a HbA1C test at the booking visit to identify high-risk, pregnant women.

The risk of clinical misinterpretation of HbA1c: Modelling the impact of biological variation and analytical performance on HbA1c used for diagnosis and monitoring of diabetes

BackgroundThe validity of clinical interpretation of HbA1c depends on the analytical performance of the method and the biological variation of HbA1c in patients. The contribution of non-glucose related factors to the biological variation of HbA1c (NGBVA1c) is not known. This paper explores the cumulative impact of analytical errors and NGBVA1c on the risk of misinterpretation. MethodsA model has been developed to predict the risk of misinterpretation of HbA1c for diagnosis and monitoring with variables for analytical performance and levels of NGBVA1c. ResultsThe model results in probabilities of misinterpretation for a given HbA1c. Example: for an HbA1c 43 mmol/mol (6.1%), bias 1 mmol/mol (0.09%), CV 3% (2%) used for diagnosis, the probabilities of misinterpretation range from 1 to 19% depending on the contribution of NGBVA1c to the biological variation of HbA1c. ConclusionsIn addition to analytical bias and imprecision, NGBVA1c contributes to the risk of misinterpretation, but the relative impact is different per clinical application of HbA1c. For monitoring, imprecision is the predominating factor, for diagnosis both biological variation and analytical bias. Given the increasing use of HbA1c for diagnosis, increase of knowledge on NGBVA1c, decrease of analytical bias, and awareness of the risk of misinterpretation are required.

Beyond A1C: exploring continuous glucose monitoring metrics in managing diabetes.

Hemoglobin A1c (HbA1c) has long been considered a cornerstone of diabetes mellitus (DM) management, as both an indicator of average glycemia and a predictor of long-term complications among people with DM. However, HbA1c is subject to non-glycemic influences which confound interpretation and as a measure of average glycemia does not provide information regarding glucose trends or about the occurrence of hypoglycemia and/or hyperglycemia episodes. As such, solitary use of HbA1c, without accompanying glucose data, does not confer actionable information that can be harnessed to guide targeted therapy in many patients with DM. While conventional capillary blood glucose monitoring (BGM) sheds light on momentary glucose levels, in practical use the inherent infrequency of measurement precludes elucidation of glycemic trends or reliable detection of hypoglycemia or hyperglycemia episodes. In contrast, continuous glucose monitoring (CGM) data reveal glucose trends and potentially undetected hypo- and hyperglycemia patterns that can occur between discrete BGM measurements. The use of CGM has grown significantly over the past decades as an ever-expanding body of literature demonstrates a multitude of clinical benefits for people with DM. Continually improving CGM accuracy and ease of use have further fueled the widespread adoption of CGM. Furthermore, percent time in range correlates well with HbA1c, is accepted as a validated indicator of glycemia, and is associated with the risk of several DM complications. We explore the benefits and limitations of CGM use, the use of CGM in clinical practice, and the application of CGM to advanced diabetes technologies.

Prediction of Fetal Macrosomia in Patients with Gestational Diabetes Mellitus through measuring the umbilical cord thickness and glycated hemoglobin (HbA1c) levels

Background: One of the most prevalent medical issues, diabetes mellitus, has emerged as a serious concern to pregnant women. It is linked to a number of maternal and fetal issues, including delivery traumas, perinatal death, shoulder dystocia, macrosomia, and operating room interference. Early prediction of fatal complications will improve outcome and reduce perinatal mortality. Aim and objectives; to determine if pregnant diabetes women's use of HbA1c and umbilical cord thickness may accurately predict fetus's macrosomia. Subjects and methods; At Al-Hussein University Hospital, six-month prospective observational research on 100 pregnant women with gestational diabetes who were 28 to 29 weeks along was conducted. Patients had a thorough medical history review, an ultrasound assessment, and an ultrasonography examination. Result: HbA1c and UCA at 27-28 weeks and 36-37 weeks of gestation are substantially different across the three groups that were examined. Conclusion: The severe obstetric problems, including shoulder dystocia and postpartum hemorrhage, are caused by macrosomia. There are times when it is difficult to foresee shoulder dystocia. The group most at risk for these issues may be found, however, using macrosomia prediction. There have been documented studies using sonographic measurement for predicting fetal macrosomia. Fetal macrosomia is well predicted by the thickness of the umbilical cord and the fetal fat layer.

Use of HbA1c for new diagnosis of diabetes in those with hyperglycaemia on admission to or attendance at hospital urgently requires research

The prevalence of diabetes in Birmingham is 11% but it is 22% in hospital inpatients. Queen Elizabeth Hospital in Birmingham (QEHB) serves a multi-ethnic population with 6% Afro-Caribbean, 19% South Asian and 70% White European. A clinical audit of 18,965 emergency admissions to QEHB showed that 5% were undiagnosed but had admission glucose in the ‘diabetes’ range and 16% were in the ‘at risk’ range. The proportion of Afro-Caribbeans (7%) and South Asians (8%) in the ‘diabetes’ range was higher than White Europeans (5%). Given the magnitude of the problem, this paper explores the issues concerning the use of reflex HbA1c testing in the UK for diagnosis of diabetes in hospital admissions. HbA1c testing is suitable for most patients but conditions affecting red blood cell turnover invalidate the results in a small number of people. However, there are pertinent questions relating to the introduction of such testing in the NHS on a routine basis. Literature searches on a topical question ‘Is hyperglycaemia identified during emergency admission/attendance acted upon?’, were performed from 2016 to 2021 and 2016 to 2022. They identified 21 different, relevant, research papers - 5 from Australia, 9 from Europe including 4 from the UK, 5 from America and 1 each from Canada and Africa. These papers revealed an absence of established procedures for the management and follow-up of routinely detected hyperglycaemia using HbA1c when no previous diabetes diagnosis was recorded. Further work is required to determine the role of reflex HbA1c testing for diagnosis of diabetes in admissions with hyperglycaemia, and the cost-effectiveness and role of point-of-care HbA1c testing.

PSUN219 Increasing Frequency of Hemoglobin A1c (Hba1c) Measurements in Hospitalized Patients With Diabetes: A Quality Improvement Project Using Lean Six Sigma

Abstract Background Studies have shown the predictive value of hemoglobin A1c (HbA1c) on inpatient glycemic control, and its value for discharge planning. There is little data on HbA1c testing adherence to American Diabetes Association (ADA) guidelines among inpatient providers, and anecdotal evidence suggests that most inpatient providers do not have a standardized approach to HbA1c measurement. The Lean Six Sigma method is a management system that originated in the automobile industry and has become widely used in healthcare to improve the efficiency of processes. The objective of this study was to determine the impact utilizing Lean Six Sigma methodology to increase frequency of HbA1c measurements among hospitalized patients with a known history of diabetes, in line with ADA guidelines. Methods This was a quality improvement study performed in a 240-bed community hospital, evaluating inpatients (≥16 years) consecutively admitted with a diagnosis of diabetes (ICD-10 code E8-E13 and O24) between January 2016-June 2021. Patients were excluded if they had a HbA1c in the health system electronic health record (EHR) in the prior 3 months. The Lean Six Sigma approach was utilized to define the problem and implement solutions. The intervention bundle delivered between November 2017 and February 2018 included 1) provider and nursing education on the utility of HbA1c in patient care, 2) change in laboratory protocols for more rapid turnaround of HbA1c, 3) modifications to the EHR including a glucose management tab and insulin order set that included HbA1c. Hospital encounter and patient-level data were extracted from the EHR via bulk query. Demographic characteristics were calculated. Frequency of HbA1c lab sent while inpatient was compared pre- (Jan 2016-Nov 2017) and post-intervention (March 2018-June 2021) using chi-square analysis. Results 17,869 patients were included (7,332 pre- and 10,537 post-intervention). Demographics did not differ between pre and post intervention periods (mean age [range]: 78.1 [16-106] years, sex: 52.3% male, race: 52.1% White, 25.1% Black). Only 53.5% of patients who met criteria had a HbA1c measured during hospitalization before intervention. This frequency increased to 70.2% postintervention. The improvement in the frequency of HbA1c measurement was sustained more than two years following the initial interventions and continued to improve over time. Conclusion This novel approach was successful in improving adherence to guideline-based measurement of HbA1c in hospitalized patients. This is the first quality improvement project in a community hospital utilizing the Lean Six Sigma process for this purpose and may represent a valuable methodology for community hospitals to improve inpatient diabetes care. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Audit of the use of HbA1c in children and young people without a prior diagnosis of diabetes mellitus

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Glycated haemoglobin and the association with long-term survival among patients evaluated for stable angina – a prospective Norwegian cohort

Abstract Background and methods Recent guidelines have included glycated haemoglobin (HbA1c) ≥48 mmol/L as a diagnostic criterion for diabetes mellitus (DM) in addition to plasma glucose (PG) concentrations, mainly based on the relationship between hyperglycemia and microvascular disease [1]. However, increased HbA1c may stem not only from hyperglycemia, and the risk association between HbA1c and long-term survival in patients with stable coronary heart disease and HbA1c ≥48 mmol/L but no previous DM according to PG is uncertain. We explored the relationship between HbA1c and survival among patients with and without DM who were evaluated for stable angina in the period 2000–2004. Endpoints were obtained from the Norwegian Cause of Death Registry. Results In total, 4164 patients were evaluated by cardiac cathetherization, of whom 576 patients (13.8%) had DM (median HbA1c 55 mmol/L) according to self-report and/or baseline PG concentrations. Of the remaining 3588 patients 1026 had HbA1c ≥48 mmol/L; however, HbA1c did not correlate with the HOMA2 insulin resistance index or fasting PG in these patients. During median (25–75 percentile) follow-up time of 14.0 (12.1–15.4) years a total of 1328 patients (31.9%) died, of whom 582 from cardiovascular causes. In patients with DM according to PG, HbA1c trended towards positive associations with all-cause and CVD mortality when adjusted for age and gender (HRs (95% CIs) 1.13 (0.99–1.28) and 1.16 (0.98–1.39) per 1SD, respectively). However, HbA1c was not associated with survival in either the group of patients without DM and HbA1c &amp;lt;48 mmol/L (median HbA1c 38 mmol/L) (HRs (95% CIs) 0.99 (0.92–1.06) and 0.96 (0.86–1.08) for all-cause and CVD mortality, respectively) or patients without DM but having HbA1c ≥48 mmol/L (median HbA1c 53 mmol/L) (HRs (95% CIs) 0.99 (0.88–1.12) and 1.04 (0.88–1.22)). Conclusion In patients evaluated for stable angina pectoris about two decades ago, almost a third of patients with no history of DM according to PG still had HbA1c concentrations indicating DM according to current guidelines. Including these patients in the DM category yielded similar percentages of patients with DM as observed in recent populations with stable coronary disease [2]. However, as opposed to what we observed in patients with DM, HbA1c did not show any association with very long-term survival among patients without DM. Our findings therefore question the use of HbA1c in the diagnosis of DM, especially in terms of risk assessment for longevity among patients with chronic coronary syndrome. Funding Acknowledgement Type of funding sources: None.

94-OR: CGM Metrics, HbA1c, and Retinopathy Are Differentially Associated by Disease Duration in Long-Duration Type 1 Diabetes

Continuous glucose monitor (CGM) -derived metrics provide measures of glycemic variability that are not captured with the use of HbA1c alone. However, they have not been evaluated in long-duration type 1 diabetes (T1D) subjects, in whom the greater risk of glycemic excursions and comorbidities highlight the need for other glycemic markers apart from HbA1c. Among the Joslin “Medalists” with T1D≥50 years, a single consecutive 14-day block of CGM data was remotely obtained from a subset of CGM users (n=64) after a period of routine activities. Using linear regression, mean historical HbA1c associated with mean glucose (β= 17.54, p&amp;lt;0.0001) , glucose management indicator (GMI; β= 0.42, p&amp;lt;0.0001) , and time above range (TAR) &amp;gt;250 mg/dL (β= 3.31, p=0.0003) ; and inversely with time in range (TIR) 70-180 mg/dL (β= -8.08, p=0.0003) and time below range (TBR) &amp;lt;70 mg/dL (β= -2.11, p=0.0006) . While no associations were found between CGM metrics and complications in the overall subset, tertile analysis by T1D duration (tertile 1, 51-61 years; tertile 2, 62-69 years; tertile 3, 70-85 years) revealed that T1D duration modified the effect of CGM metrics on proliferative retinopathy (PDR) even after adjusting for HbA1c (p for interaction &amp;lt;0.05) . In subjects with the longest T1D duration (tertile 3) , PDR associated with mean glucose (β= 26.92, p=0.02) , GMI (β= 0.64, p=0.02) , and TAR (β= 6.81, p=0.03) ; and inversely with TIR (β= -12.57, p=0.04) . Tertile analysis of HbA1c and complications in the overall Medalist cohort (n=952) showed that HbA1c associated with PDR in tertile 1 (p=0.03) . Our results suggest that while HbA1c and CGM metrics are closely linked in long-duration T1D subjects, they may provide differential contributions to the temporal onset of microvascular complications, independent of each other. Additionally, as development to PDR has been demonstrated to stabilize in Medalists with the longest T1D duration, favorable values of CGM metrics may contribute to this protection. Disclosure M.Yu: None. T.Boumenna: None. J.Gauthier: None. R.Tham: None. W.Fickweiler: None. J.Sun: Consultant; American Diabetes Association, American Medical Association, Research Support; Adaptive Sensory Technology, Boehringer Ingelheim International GmbH, Genentech, Inc., Jaeb Center for Health Research, Janssen Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk, Optovue, Incorporated, Physical Sciences, Inc, Roche Pharmaceuticals. H.Shah: None. G.L.King: Advisory Panel; Medtronic, Research Support; Janssen Pharmaceuticals, Inc. Funding American Diabetes Association (9-18-CVD1-005) ; Mary K. Iacocca Family Foundation, Thomas Beatson Jr. Foundation, National Eye Institute (R01EY026080-01)

Correlation between Glycosylated Haemoglobin and serum lipid profile in patients with type 2 diabetes

Introduction: Dyslipidaemia is one of the major risk factor for cardiovascular disease in Type 2 Diabetes mellitus, characterized by elevated Total cholesterol (TC), Triglycerides (TG), Low density lipoprotein (LDL) and decreased High density lipoprotein (HDL). Haemoglobin A1c (HbA1c) is widely used as an index of mean glycaemia, a measure of risk for the development of diabetes complications and a measure of the quality of diabetes care. The aim of this study was to determine the impact of glycaemic control on lipid profile and to know utility of HbA1c as an indirect indicator of dyslipidaemia. Objectives: To assess the relationship between glycemic control (HbA1c) and serum lipid profile as well as to evaluate the importance of HbA1c as an indicator of dyslipidemia in patients with T2DM. Materials and Methods: The present study is a prospective, observational study which is conducted in the Department of General Medicine at Surabhi Institute of Medical Sciences over a period of 6 months. A total of 65 T2DM patients with dyslipidemia who had visited the hospital. Inclusion criteria: Adults aged above 30 years and having Type 2 Diabetes Mellitus with dyslipidaemia.

Relationship between HbA1c, fructosamine and clinical assessment of glycemic control in dogs.

BackgroundSerum fructosamine is a routine test used for clinical monitoring of diabetes mellitus (DM) but the usefulness of HbA1c for this purpose has not been extensively studied.HypothesisThe study aimed to compare the ability of blood HbA1c and serum fructosamine tests to correctly classify DM control determined using a clinically-based assessment.Animals28 client-owned dogs with naturally-occurring diabetes mellitus.MethodsCross-sectional observational study. Ability of fructosamine and HbA1c tests to classify diabetes control in dogs was determined.ResultsClinical assessment classified 50% of dogs as having good diabetic control and 82% as having acceptable diabetic control. Analysis using Cohen’s kappa test showed that agreements between fructosamine and HbA1c results and the clinical assessment ranged from poor to fair. Fructosamine and HbA1c results from each dog showed a moderate correlation. Overall, the HbA1c test showed the best agreement with the clinical assessment when diabetes control was considered either acceptable or unacceptable, although the strength of agreement was considered fair (kappa = 0.27).Conclusions and clinical importanceThe HbA1c concentration was found to be more consistent with clinical evaluation of diabetes control than was the serum fructosamine concentration. The HbA1c level is a useful tool for assessment of glycemic status in diabetic dogs but should be used alongside other tests for outpatient monitoring of clinically stable diabetic dogs.

The role of first-trimester HbA1c in the early detection of gestational diabetes

BackgroundWe aimed to assess the utility of HbA1c in the early detection of gestational diabetes (GDM) in the first trimester.MethodsThis prospective study was performed on 700 pregnant women in the perinatology clinic at a tertiary university hospital from March 2018 to March 2020. For all pregnant women, HbA1c and fasting blood glucose (FBG) levels were examined during the first trimester. Then, a GDM screening test was done within 24–28 weeks of pregnancy using a 100 g oral glucose tolerance test (OGTT) as the gold standard test. The GDM diagnosis was made according to the American Diabetes Association (ADA) criteria. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of HbA1c and FBG were calculated using the receiver operating characteristic (ROC) curve.ResultsOf 700 participants, one hundred and fifteen (16.4%) women had GDM. The GDM patients were significantly older and had a higher pre-gestational body mass index and pregnancy weight gain compared to the non-GDM participants. The sensitivity and specificity for ruling out GDM at an HbA1c cut-off value of 4.85% was 92.2 and 32.8%, respectively, with a 95.5% NPV and a 21.2% PPV. Furthermore, sensitivity and specificity for diagnosing GDM at an HbA1c cut-off value of 5.45% was 54.8 and 96.8%, respectively, with a 91.5% NPV and a 76.8% PPV. Using HbA1c could decline OGTT in 40.4% of the pregnant women (28.7% with HbA1c < 4.85 and 11.7% with HbA1c ≥ 5.45%).ConclusionIt seems that the first-trimester HbA1c cannot replace OGTT for the diagnosis of GDM because of its insufficient sensitivity and specificity. However, women with higher first-trimester HbA1c had a high risk for GDM incidence.