Red cell transfusion decreases hemoglobin A1c in patients with diabetes

Fertility and Pregnancy in Women with Transfusion-Dependent Thalassemia

Because women with transfusion-dependent thalassemia are seeking pregnancy, ensuring the best outcomes for both mother and baby require concerted and collaborative efforts between the hematologist, obstetrician, cardiologist, hepatologist, and genetic counselor among others. Proactive counseling, early fertility evaluation, optimal management of iron overload and organ function, and application of advances in reproductive technology and prenatal screening are important in ensuring a healthy outcome. Many unanswered questions remain requiring further study, including fertility preservation, non-invasive prenatal diagnosis, chelation therapy during pregnancy, and indications and duration of anticoagulation.

Impact of Hyperglycemia and Diabetes Mellitus on Breakthrough Mucormycosis Outcomes in Patients with Hematologic Malignancies-Complex and Intriguing Associations

Mucormycosis (MCR) is frequently associated with diabetic ketoacidosis and hyperglycemia, as well as hematologic malignancies (HMs) and hematopoietic stem cell transplantation (HSCT). However, little is known about the effect of hyperglycemia on MCR outcomes in patients with HMs. We therefore conducted a retrospective cohort study of adult patients hospitalized with MCR and HM or HSCT (n = 103) at MD Anderson Cancer Center from April 2000 through to April 2020. Twenty-three patients (22%) had documented episodes of severe hyperglycemia. Sixty patients had >5 serum glucose measurements within 28 days prior to MCR symptom onset; of those, 14 (23%) met the criteria for persistent hyperglycemia. Sixteen patients (16%) received insulin prior to admission. The crude mortality 42 days from the onset of MCR symptoms in our cohort was 31%. Neither severe nor persistent hyperglycemia were associated with excess mortality. Insulin use prior to index admission was associated with decreased 42-day mortality on univariate analysis (p = 0.031). In conclusion, in a setting of high crude mortality, severe and/or persistent hyperglycemia do not appear to be associated with excess mortality in patients with HM or HSCT developing MCR. Insulin use prior to MCR diagnosis may be associated with decreased mortality, although further research is needed to validate this effect and to study its mechanistic underpinnings.

Effect of glycated hemoglobin A1c on the survival of patients with oral squamous cell carcinoma: A multi-institutional database cohort study

Objectives

Few studies have evaluated the impact of blood glucose levels on cancer prognosis. We investigated the association between hemoglobin A1c (HbA1c) and survival in oral squamous cell carcinoma (OSCC) patients.

Materials and Methods

A 19-year retrospective cohort study of OSCC patients was performed using the Chang Gung Research Database to identify and enroll 7279 patients diagnosed with OSCC between January 2001 and June 2020. A total of 3600 patients were recruited after performing 1:2 frequency-matching between patients with DM and non-DM. A Cox’s regression model was used to evaluate the relative hazards of all-cause mortality (ACM) and disease-specific mortality (DSM) in relation to HbA1c.

Results

An unadjusted Cox’s regression model indicated that DM, in addition to high levels of HbA1c, were statistically prognostic of poor survival. An adjusted hazard ratio (aHR) of HbA1c ≥ 8% interval at the initial diagnosis of OSCC was statistically higher for DSM (1.25 to 2.24) compared to the non-DM group in different regression models. Considering the effect of sustained HbA1c control in 699 patients, the aHR of mean HbA1c ≥ 9% interval was statistically higher for ACM (1.78 to 2.13) compared to the reference group (7% ≤ HbA1c< 8%). In addition, increased hazards of ACM (2.09 to 2.18) and DSM (2.20 to 2.41) were consistently observed in the highest quartiles of average real variability of HbA1c.

Conclusion

Poor and unstable control of HbA1c could strongly predict the risks of mortality in OSCC patients with DM.

Patterns and Effects of Admission Hyperglycemia and Inflammatory Response in Trauma Patients: A Prospective Clinical Study

BACKGROUND

The constellation of the initial hyperglycemia, proinflammatory cytokines and severity of injury among trauma patients is understudied. We aimed to evaluate the patterns and effects of on-admission hyperglycemia and inflammatory response in a level 1 trauma center. We hypothesized that higher initial readings of blood glucose and cytokines are associated with severe injuries and worse in-hospital outcomes in trauma patients.

METHODS

A prospective, observational study was conducted for adult trauma patients who were admitted and tested for on-admission blood glucose, hemoglobin A1c, interleukin (IL)-6, IL-18 and hs-CRP. Patients were categorized into four groups [non-diabetic normoglycemic, diabetic normoglycemic, diabetic hyperglycemic (DH) and stress-induced hyperglycemic (SIH)]. The inflammatory markers were measured on three time points (admission, 24 h and 48 h). Generalized estimating equations (GEE) were used to account for the correlation for the inflammatory markers. Pearson's correlation test and logistic regression analysis were also performed.

RESULTS

During the study period, 250 adult trauma patients were enrolled. Almost 13% of patients presented with hyperglycemia (50% had SIH and 50% had DH). Patients with SIH were younger, had significantly higher Injury Severity Score (ISS), higher IL-6 readings, prolonged hospital length of stay and higher mortality. The SIH group had lower Revised Trauma Score (p = 0.005), lower Trauma Injury Severity Score (p = 0.01) and lower GCS (p = 0.001). Patients with hyperglycemia had higher in-hospital mortality than the normoglycemia group (12.5% vs 3.7%; p = 0.02). A significant correlation was identified between the initial blood glucose level and serum lactate, IL-6, ISS and hospital length of stay. Overall rate of change in slope 88.54 (95% CI:-143.39-33.68) points was found more in hyperglycemia than normoglycemia group (p = 0.002) for IL-6 values, whereas there was no statistical significant change in slopes of age, gender and their interaction. The initial IL-6 levels correlated with ISS (r = 0.40, p = 0.001). On-admission hyperglycemia had an adjusted odds ratio 2.42 (95% CI: 1.076-5.447, p = 0.03) for severe injury (ISS > 12) after adjusting for age, shock index and blood transfusion.

CONCLUSIONS

In trauma patients, on-admission hyperglycemia correlates well with the initial serum IL-6 level and is associated with more severe injuries. Therefore, it could be a simple marker of injury severity and useful tool for patient triage and risk assessment.

TRIAL REGISTRATION

This study was registered at the ClinicalTrials.gov (Identifier: NCT02999386), retrospectively Registered on December 21, 2016. https://clinicaltrials.gov/ct2/show/NCT02999386 .

Do We Store Packed Red Blood Cells under "Quasi-Diabetic" Conditions?

Red blood cell (RBC) transfusion is one of the most common therapeutic procedures in modern medicine. Although frequently lifesaving, it often has deleterious side effects. RBC quality is one of the critical factors for transfusion efficacy and safety. The role of various factors in the cells’ ability to maintain their functionality during storage is widely discussed in professional literature. Thus, the extra- and intracellular factors inducing an accelerated RBC aging need to be identified and therapeutically modified. Despite the extensively studied in vivo effect of chronic hyperglycemia on RBC hemodynamic and metabolic properties, as well as on their lifespan, only limited attention has been directed at the high sugar concentration in RBCs storage media, a possible cause of damage to red blood cells. This mini-review aims to compare the biophysical and biochemical changes observed in the red blood cells during cold storage and in patients with non-insulin-dependent diabetes mellitus (NIDDM). Given the well-described corresponding RBC alterations in NIDDM and during cold storage, we may regard the stored (especially long-stored) RBCs as “quasi-diabetic”. Keeping in mind that these RBC modifications may be crucial for the initial steps of microvascular pathogenesis, suitable preventive care for the transfused patients should be considered. We hope that our hypothesis will stimulate targeted experimental research to establish a relationship between a high sugar concentration in a storage medium and a deterioration in cells’ functional properties during storage.

Beyond A1C: A Practical Approach to Interpreting and Optimizing Continuous Glucose Data in Youth

Despite significant pharmacological and technological advances in the treatment of type 1 diabetes, the majority of youth in the United States do not meet the American Diabetes Association's recommended A1C goal. Understanding and managing glycemic variability is important in children and adolescents. Because A1C provides an incomplete picture of day-to-day glycemic fluctuations, continuous glucose monitoring (CGM)-derived metrics are a promising addition to address glycemic management challenges in youth with diabetes. In this article, we discuss how to develop practical strategies to optimize the use of CGM in the pediatric population, interpret the valuable data it provides, and develop personalized and actionable treatment goals.

Clinical implications, diagnosis, and management of diabetes in patients with chronic liver diseases

Diabetes mellitus (DM) negatively affects the development and progression of chronic liver diseases (CLD) of various etiologies. Concurrent DM and CLD are also associated with worse clinical outcomes with respect to mortality, the occurrence of hepatic decompensation, and the development of hepatocellular carcinoma (HCC). Unfortunately, early diagnosis and optimal treatment of DM can be challenging, due to the lack of established clinical guidelines as well as the medical complexity of this patient population. We conducted an exploratory review of relevant literature to provide an up-to-date review for internists and hepatologists caring for this patient population. We reviewed the epidemiological and pathophysiological associations between DM and CLD, the impact of insulin resistance on the progression and manifestations of CLD, the pathogenesis of hepatogenic diabetes, as well as the practical challenges in diagnosis and monitoring of DM in this patient population. We also reviewed the latest clinical evidence on various pharmacological antihyperglycemic therapies with an emphasis on liver disease-related clinical outcomes. Finally, we proposed an algorithm for managing DM in patients with CLD and discussed the clinical and research questions that remain to be addressed.

HbA1C as a marker of retrograde glycaemic control in diabetes patient with co-existed beta-thalassaemia: A case report and a literature review

WHAT IS KNOWN AND OBJECTIVE

The HbA1C marker used in assessing diabetes control quality is not sufficient in diabetes patients with thalassaemia.

CASE DESCRIPTION

A male diabetic patient with thalassaemia was hospitalized due to distal neuropathic pain, right toe trophic ulcer, unacceptable five-point glycaemic profile and recommended HbA1C value. After simultaneously initiated insulin therapy and management of ulcer by hyperbaric oxygen, the patient showed improved glycaemic control and ulcer healing, which led to the patient's discharge.

WHAT IS NEW AND CONCLUSION

In thalassaemia and haemoglobinopathies, due to discrepancies in the five-point glycaemic profile and HbA1C values, it is necessary to measure HbA1C with a different method or to determine HbA1C and fructosamine simultaneously.

Islets for Research: Nothing Is Perfect, but We Can Do Better

In December 2018, Diabetes and Diabetologia began requiring authors of papers reporting data obtained from studies on human islets to report critical characteristics of the human islets used for research. The islet community was asked to provide feedback on it. Here is the contribution by the European Consortium for Islet Transplantation.

Evaluation of continuous glucose monitoring system for detection of alterations in glucose homeostasis in pediatric patients with β-thalassemia major

BACKGROUND

Disturbances of glucose metabolism are common in β-thalassemia major (β-TM).

AIM

This study was conducted to assess the pattern of glucose homeostasis in pediatric β-TM patients comparing oral glucose tolerance test (OGTT) and continuous glucose monitoring system (CGMS).

METHODS

Two-hundred β-TM patients were studied and those with random blood glucose (RBG) ≥7.8 mmol/L (140 mg/dL) were subjected to OGTT, insertion of CGMS and measurement of fasting C peptide, fasting insulin, and hemoglobin A1c (HbA1c).

RESULTS

Twenty patients (10%) had RBG ≥ 7.8 mmol/L. Using OGTT, 6 out of 20 patients (30%) had impaired glucose tolerance (IGT) while 7 (35%) patients were in the diabetic range. CGMS showed that 7/20 (35%) patients had IGT and 13 (65%) patients had diabetes mellitus (DM); 10 of the latter group had HbA1c readings within diabetic range. The percentage of diabetic patients diagnosed by CGMS was significantly higher than that with OGTT (P = 0.012). Serum ferritin was the only independent variable related to elevated RBG. All β-TM patients with DM were non-compliant to chelation therapy.

CONCLUSIONS

The use of CGMS in the diagnosis of early glycemic abnormalities among pediatric patients with β-TM appears to be superior to other known diagnostic modalities.

Fertility and Pregnancy in Women with Transfusion-Dependent Thalassemia

As more women with transfusion-dependent thalassemia are seeking pregnancy, ensuring the best outcomes for both the mother and baby requires concerted, collaborative efforts between practitioners and the family. Proactive counseling, early fertility evaluation, recent developments in reproductive technology, and optimal management of iron overload, have resulted in more successful pregnancies and the birth of healthy newborns. With advances in technology for prenatal screening and increased awareness to perform screening for hemoglobinopathies, healthy pregnancy outcomes have become the expectation. Topics that require further study include management that allows fertility preservation, improved non-invasive prenatal diagnosis methods for affected fetuses, the use of chelation therapy during pregnancy, and indications for and duration of anticoagulation.

Glycated hemoglobin concentrations of red blood cells minimally increase during storage under standard blood banking conditions

BACKGROUND

Few and inconsistent data exist describing the effect of storage duration on glycated hemoglobin (HbA1c) concentrations of red blood cells (RBCs), impeding interpretation of HbA1c values in transfused diabetic patients. Hence the aim of this study was to evaluate to what extent HbA1c concentrations of RBCs change during the maximum allowed storage period of 42 days.

STUDY DESIGN AND METHODS

Blood was drawn from 16 volunteers, leukofiltered, and stored under standard blood banking conditions. HbA1c concentrations of RBCs were measured on Days 1 and 42 of storage using three different validated devices (ion‐exchange high‐performance liquid chromatography Method A1 and A2, turbidimetric immunoassay Method B).

RESULTS

Mean HbA1c concentrations of RBCs on Day 1 were 5.3 ± 0.3% (Method A1), 5.4 ± 0.4% (Method A2), and 5.1 ± 0.4% (Method B). HbA1c concentrations increased to 5.6 ± 0.3% (A1, p < 0.0001), 5.7 ± 0.3% (A2, p = 0.004), and 5.5 ± 0.4% (B, p < 0.0001) on Day 42, respectively, corresponding to a 1.06‐fold increase across all methods. Glucose concentrations in the storage solution of RBCs decreased from 495 ± 27 to 225 ± 55 mg/dL (p < 0.0001), confirming that stored RBCs were metabolically active.

CONCLUSION

These results suggest a significant, albeit minor, and most likely clinically insignificant increase in HbA1c concentrations during storage of RBCs for 42 days.

Glucose Homeostasis Markers in Beta-Thalassemia

BACKGROUND

Glycosylated hemoglobin (HbA1c) has been a well-recognized marker of glucose homeostasis among thalassemics. Recently some studies have proposed the role of fructosamine as a better marker as compared with HbA1c. Hence, the study was carried out to find out which marker holds promise among Indian beta-thalassemic children.

METHODS

In this case-control study, 60 diagnosed cases of beta-thalassemia major and equal number of normal controls who were ≥8 years of age were enrolled. HbA1c, fructosamine, and fasting insulin levels were measured in all. Oral glucose tolerance test was done as a gold standard and the measured parameters were compared.

RESULTS

HbA1c was significantly higher in cases (7.10% [±0.47%]) than in controls (5.15% [±0.19%]) (P<0.001). Thalassemics with abnormal glucose tolerance had higher HbA1c level (7.34% [±0.57%]) than those with normal glucose tolerance (7.05% [±0.43%]) (P=0.05). Insulin resistance was noticed among thalassemics with abnormal glucose tolerance as compared with their normal counterparts (P=0.04). No significant difference was found in fructosamine levels between cases (239.80 [±31.80] μmol/L) and controls (234.10 [±21.34] μmol/L) (P=0.25) or between thalassemics with abnormal glucose tolerance (243.92 [±21.94] μmol/L) and their normal counterparts (238.77 [±33.93] μmol/L) (P=0.62).

CONCLUSIONS

The use of HbA1c as a diagnostic marker for diabetes in hemolytic anemias has to be done with caution as its baseline values are higher in them. Despite this finding, HbA1c continues to be a good marker for worsening glucose homeostasis in thalassemics as higher values were found in thalassemics with abnormal glucose tolerance compared with their normal counterparts. The present study did not find any relationship of fructosamine levels with impaired glucose tolerance in beta-thalassemia.

Identifying Prediabetes and Type 2 Diabetes in Asymptomatic Youth: Should HbA1c Be Used as a Diagnostic Approach?

PURPOSE OF REVIEW

Because the incidence of type 2 diabetes and prediabetes in children is rising, routine screening of those at risk is recommended. In 2010, the ADA made the recommendation to include hemoglobin A1c (HbA1c) as a diagnostic test for diabetes, in addition to the oral glucose tolerance test or fasting plasma glucose. Our objective was to assess the pediatric literature with regard to HbA1c test performance and discuss advantages and disadvantages of use of the test for diagnostic purposes.

RECENT FINDINGS

HbA1c has a number of advantages, including elimination of the need for fasting, lower variability, assay standardization, and long-term association with future development of diabetes. It also has many drawbacks. It can be affected by a number of non-glycemic factors, including red blood cell turnover, hemoglobinopathies, medications, race, and age. In particular, it performs differently in children compared with adults, generally with lower sensitivity for prediabetes (as low as 0-5% in children vs 23-27% in adults) and lower area under the receiver operating characteristic curve (AUC) (0.53 vs 0.73 for prediabetes), and it has lower efficacy at a higher cost, compared with other tests of glycemia. Finally, HbA1c may perform very differently across diverse populations according to race/ethnicity; in Chinese populations, the proportion of individuals classified with prediabetes based on HbA1c predominates compared with IFG (77% for HbA1c vs 27.7% for IFG), whereas in US populations, it is the opposite (24.8% for HbA1c vs 80.1% for FPG). HbA1c is controversial because although it is convenient, it is not a true measure of glycemia. The interpretation of HbA1c results requires a nuanced understanding that many primary care physicians who are ordering the test in greater numbers do not possess. Alternative markers of glycemia may hold promise for the future but are not yet endorsed for use in practice. Further studies are needed to determine appropriate thresholds for screening tests and the long-term impact of screening and identification.

Changes in hemoglobin profile reflect autologous blood transfusion misuse in sports

The changes in hemoglobin (Hb) profile following autologous blood transfusion (ABT) for the first time were studied for anti-doping purposes. Twenty-four healthy, trained male subjects (aged 18‒40) were enrolled and randomized into either the transfusion (T) or control (C) groups. Blood samples were taken from the T subjects at baseline, after withdrawal and reinfusion of 450 ml of refrigerated or cryopreserved blood, and from C subjects at the same time points. Hematological variables (Complete blood count, Reticulocytes, Immature Reticulocytes Fraction, Red-cell Distribution Width, OFF-hr score) were measured. The Hb types were analyzed by high-performance liquid chromatography and the Hemoglobin Profile Index (HbPI) arbitrarily calculated. Between-group differences were observed for red blood cells and reticulocytes. Unlike C, the T group, after withdrawal and reinfusion, showed a significant trend analysis for both hematological variables (Hemoglobin concentration, reticulocytes, OFF-hr score) and Hb types (glycated hemoglobin-HbA1c, HbPI). The control charts highlighted samples with abnormal values (> 3-SD above/below the population mean) after reinfusion for hematological variables in one subject versus five subjects for HbA1c and HbPI. A significant ROC-curve analysis (area = 0.649, p = 0.015) identified a HbA1c cut-off value ≤ 2.7% associated to 100% specificity of blood reinfusion (sensitivity 25%). Hemoglobin profile changed in trained subjects after ABT, with abnormal values of HbA1c and HbPI in 42% of subjects after reinfusion. Future studies will confirm the usefulness of these biomarkers in the anti-doping field.

Hyperglycemia and Cancer: An Algorithm to Guide Oncology Nurses

BACKGROUND

A dual diagnosis of cancer and hyperglycemia has demonstrated untoward effects on patients' cancer treatment, prognosis, and survival. 
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OBJECTIVES

The purpose of this evidence-based project is to improve knowledge and awareness of the consequences of hyperglycemia in patients with cancer, increasing nurses' capability to effectively intervene. In addition, a clinical algorithm based on current evidence was developed and is presented.
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METHODS

An educational program was developed and pilot tested. The program addressed the etiology of hyperglycemia and its effects on patients with cancer. Knowledge of hyperglycemia in patients with cancer was assessed with a pre- and post-test.
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FINDINGS

All participants found the educational program effective and deemed the clinical algorithm useful. Results improved significantly after participation in the educational intervention.

Diabetic Kidney Disease: Is There a Role for Glycemic Variability?

PURPOSE OF REVIEW

Diabetes is the leading cause of kidney disease globally. Diabetic kidney disease (DKD) is a heterogeneous disorder manifested as albuminuria and/or decreasing GFR. Hyperglycemic burden is the major contributor to the development of DKD. In this article, we review the evidence for the contribution of glycemic variability and the pitfalls associated with use of hemoglobin A1c (A1C), the gold standard for assessment of glucose control, in the setting of DKD.

RECENT FINDINGS

Glycemic variability, characterized by swings in blood glucose levels, can result in generation of mitochondrial reactive oxygen species, a putative inciting factor for hyperglycemia-induced alterations in intracellular metabolic pathways. While there is indirect evidence supporting the role of glycemic variability in the pathogenesis of DKD, definitive data are lacking. A1C has many limitations and is a particularly suboptimal measure in patients with kidney disease, because its accuracy is compromised by variables affecting RBC survival and other factors. Continuous glucose monitoring (CGM) technology has the potential to enable us to use glucose as a more important clinical tool, for a more definitive understanding of glucose variability and its role in DKD. Glycemic variability may be a factor in the development of DKD, but definitive evidence is lacking. Currently, all available glycemic biomarkers, including A1C, have limitations and in the setting of DKD and should be used cautiously. Emerging data suggest that personal and professional CGM will play an important role in managing diabetes in patients with DKD, where risk of hypoglycemia is high.

The Importance and Utility of Hemoglobin A1c Levels in the Assessment of Donor Pancreas Allografts

BACKGROUND

Hemoglobin A1C (HbA1c) levels are often obtained in potential pancreas graft donors to assess the overall long-term functional glycemic control or the possibility of unrecognized diabetes. Although routinely measured, the impact of donor HbA1c levels on pancreas graft outcomes has not been reported. Here, we researched the relationship between donor HbA1c levels and postoperative pancreas graft survival.

METHODS

Data from 266 pancreas transplant patients including 182 simultaneous kidney-pancreas and 84 pancreas alone transplants were reviewed for the study. The patients were separated into groups according to their HbA1c levels (5 groups: HbA1c < 5.0, 5.0-5.4, 5.5-5.9, ≥6.0 % and not available, or 2 groups: HbA1c <5.7, ≥5.7%). Overall, death-censored and technically successful pancreas graft survival and rejection rates of each group were compared. In the case of technically successful graft survival, graft losses due to technical problems in the first 60 days were excluded.

RESULTS

All groups were similar with regard to donor variables including age, sex, ABO blood type, ethnicity, donor type and recipient variables including recipient age, sex, induction agents and maintenance treatment. Mean follow-up time was 4.2 ± 1.97 years. The overall graft survivals and death censored graft survivals among groups were not statistically different from one other (P > 0.05). Additionally, excluding early technical losses in 18 patients did not reveal any differences in graft survivals. Patient survival and biopsy-proven acute rejections were statistically similar among HbA1c strata.

CONCLUSIONS

This univariate retrospective analysis of a single center/organ procurement organization use of HbA1c shows that donor HbA1c levels between 3.5 and 6.2 in otherwise transplantable pancreata are not associated with different short-term outcomes.

Pregnancy in women with thalassemia: challenges and solutions

Advances in treatment of thalassemia have led to the aging of thalassemic patients, and consequently concern about successful reproductive outcome is augmented. Although women with thalassemia intermedia only were considered competent of achieving pregnancy, case series reveal the willingness of both thalassemia major and thalassemia intermedia women to have a family. Pregnancy in general is characterized by dynamic multiple-system changes and increased susceptibility to oxidative stress, while homozygous, transfusion-dependent, β-thalassemia patients manifest cardiac, hepatic, endocrine, and metabolic disorders attributable to chronic anoxia and iron overload and thalassemia intermedia, usually nontransfused, is associated with augmented risk of thromboembolic events. Pregnancy in thalassemia should be considered a high risk for both mother and fetus, and favorable outcomes are the result of continuous preconception, antenatal, and postpartum assessment and management by a team of thalassemia experts.

An Elevated Glycemic Gap is Associated with Adverse Outcomes in Diabetic Patients with Acute Myocardial Infarction

Acute hyperglycemia is a frequent finding in patients presenting to the emergency department (ED) with acute myocardial infarction (AMI). The prognostic role of hyperglycemia in diabetic patients with AMI remains controversial. We retrospectively reviewed patients' medical records to obtain demographic data, clinical presentation, major adverse cardiac events (MACEs), several clinical scores and laboratory data, including the plasma glucose level at initial presentation and HbA1c levels. The glycemic gap, which represents changes in serum glucose levels during the index event, was calculated from the glucose level upon ED admission minus the HbA1c-derived average glucose (ADAG). We enrolled 331 patients after the review of medical records. An elevated glycemic gap between admission serum glucose levels and ADAG were associated with an increased risk of mortality in patients. The glycemic gap showed superior discriminative power regarding the development of MACEs when compared with the admission glucose level. The calculation of the glycemic gap may increase the discriminative powers of established clinical scoring systems in diabetic patients presenting to the ED with AMI. In conclusion, the glycemic gap could be used as an adjunct parameter to assess the severity and prognosis of diabetic patients presenting with AMI. However, the usefulness of the glycemic gap should be further explored in prospective longitudinal studies.

Differences in Hemoglobin A1c Between Hispanics/Latinos and Non-Hispanic Whites: An Analysis of the Hispanic Community Health Study/Study of Latinos and the 2007-2012 National Health and Nutrition Examination Survey

OBJECTIVE

To determine whether, after adjustment for glycemia and other selected covariates, hemoglobin A1c (HbA1c) differed among adults from six Hispanic/Latino heritage groups (Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American) and between Hispanic/Latino and non-Hispanic white adults without self-reported diabetes.

RESEARCH DESIGN AND METHODS

We performed a cross-sectional analysis of data from 13,083 individuals without self-reported diabetes from six Hispanic/Latino heritage groups, enrolled from 2008 to 2011 in the Hispanic Community Health Study/Study of Latinos, and 2,242 non-Hispanic white adults enrolled during the 2007-2012 cycles of the National Health and Nutrition Examination Survey. We compared HbA1c levels among Hispanics/Latinos and between Hispanics/Latinos and non-Hispanic whites before and after adjustment for age, sex, fasting (FPG) and 2-h post-oral glucose tolerance test (2hPG) glucose, anthropometric measurements, and selected biochemical and hematologic variables and after stratification by diabetes status: unrecognized diabetes (FPG ≥7.1 mmol/L or 2hPG ≥11.2 mmol/L), prediabetes (FPG 5.6-7.0 mmol/L or 2hPG 7.8-11.1 mmol/L), and normal glucose tolerance (FPG <5.6 mmol/L and 2hPG <7.8 mmol/L).

RESULTS

Adjusted mean HbA1c differed significantly across all seven groups (P < 0.001). Non-Hispanic whites had significantly lower HbA1c (P < 0.05) than each individual Hispanic/Latino heritage group. Upon stratification by diabetes status, statistically significant differences (P < 0.001) in adjusted mean HbA1c persisted across all seven groups.

CONCLUSIONS

HbA1c differs among Hispanics/Latinos of diverse heritage groups and between non-Hispanic whites and Hispanics/Latinos after adjustment for glycemia and other covariates. The clinical significance of these differences is unknown.

Role of glycated hemoglobin in the screening and diagnosis of posttransplantation diabetes mellitus after renal transplantation: A diagnostic accuracy study

BACKGROUND

The role of glycated hemoglobin (A1C) in the screening and diagnosis of posttransplantation diabetes mellitus (PTDM) is still not entirely understood. We evaluated the use of A1C test in renal transplant recipients at four months after transplantation.

METHODS

A total of 122 out of 274 patients without previous diabetes that underwent kidney transplantation were enrolled. ROC curve was used to analyze the performance of A1C to diagnose PTDM considering OGTT as the reference standard.

RESULTS

OGTT identified 32 (26.2%) patients with PTDM, whereas A1C≥6.5% (48 mmol/mol) identified only 16 patients. A1C showed moderate accuracy to detect PTDM in the ROC curve [AUC 0.832 (95% CI 0.740-0.924, p<0.001)]. A1C of 5.8% (40 mmol/mol) was the equilibrium point (sensitivity 75% and specificity 72.2%) and A1C≥6.2% (44 mmol/mol) showed high specificity of 93.3%.

CONCLUSIONS

A1C≥6.5% (48 mmol/mol) is not enough to be used alone in the diagnosis of PTDM. The combined use of A1C cut-off points of ≤5.8% (40 mmol/mol) and ≥6.2% (44 mmol/mol) would reduce the number of OGTT by 85%. The use of an algorithm with A1C test in combination with FPG and/or 2h-PG proved to be the most efficient strategy to diagnose or rule out PTDM.

Application of smoothed continuous labile haemoglobin A1c reference intervals for identification of potentially spurious HbA1c results

Aims

We aim to develop smoothed continuous 2.5th and 97.5th percentile values for labile glycated haemoglobin A1c to glycated haemoglobin A1c (LHbA1c:HbA1c) ratio against HbA1c, and apply them on our patient population for identification of potentially spurious HbA1c measurements.

Methods

The LHbA1c and HbA1c were measured using Bio-rad Variant II high-performance liquid chromatography system. We recorded the LHbA1c and HbA1c values of 1555 patients who had normal chromatograms. Using these results, the 2.5th and 97.5th percentile reference limits of the LHbA1c:HbA1c ratio were described by LHbA1c:HbA1c=−0.0072×HbA1c +0.2925 and LHbA1c:HbA1c=−0.0132×HbA1c +0.5327, respectively.

Results

When the reference intervals were applied on a separate 1000 patients, 34 and 29 of them had abnormally high and low LHbA1c:HbA1c ratios, respectively. Most of the observed high ratios were associated concurrently with elevated plasma glucose, anaemia, chronic liver and kidney diseases. A suppressed ratio was mostly associated with haemoglobin variants. Patients with heterozygous HbE or HbS variants tend to have lower LHbA1c:HbA1c ratios while the converse is true for heterozygous HbJ.

Conclusions

The continuous LHbA1c:HbA1c ratio may be used to detect confounding factors or spurious HbA1c results, but its performance is confounded and reduced by the ambient plasma glucose.

Pitfalls in hemoglobin A1c measurement: when results may be misleading

Since the beginning of clinical use in the 1970s, hemoglobin A1c (A1c) has become the standard tool for monitoring glycemic control in patients with diabetes. The role of the A1c test was broadened in 2010, when the American Diabetes Association added A1c as a diagnostic criterion for diabetes. Because of hemoglobin A1c's integral role in diagnosis and treatment, it is important to recognize clinical scenarios and interfering factors that yield false results. The purpose of this review is to describe the A1c measurement, outline clinical scenarios or factors that may yield false results, and describe alternative laboratory biomarkers.

Haemoglobin glycation (Hb1Ac) increases during red blood cell storage: a MALDI-TOF mass-spectrometry-based investigation

Haemoglobin A1c (HbA1c ) represents a key biomarker in diabetes diagnosis and management, as it is indicative of recent blood glucose concentrations. Glycation of haemoglobin is a non-enzymatic irreversible process that is promoted by the prolonged exposure of erythrocytes to high glucose concentrations, a condition that is known to occur under blood banking conditions. However, controversial data indicate no clear hint as to whether and to which extent HbA1c accumulates during red blood cell storage. Hereby, we propose the application of a validated MALDI-TOF mass-spectrometry-based method to this issue and report the observation about HbA1c levels apparently increasing over storage progression.

Decreased serum glucose and glycosylated hemoglobin levels in patients with Chuvash polycythemia: a role for HIF in glucose metabolism

In Chuvash polycythemia, a homozygous 598C>T mutation in the von Hippel-Lindau gene (VHL) leads to an R200W substitution in VHL protein, impaired degradation of α-subunits of hypoxia-inducible factor (HIF)-1 and HIF-2, and augmented hypoxic responses during normoxia. Chronic hypoxia of high altitude is associated with decreased serum glucose and insulin concentrations. Other investigators reported that HIF-1 promotes cellular glucose uptake by increased expression of GLUT1 and increased glycolysis by increased expression of enzymes such as PDK. On the other hand, inactivation of Vhl in murine liver leads to hypoglycemia associated with a HIF-2-related decrease in the expression of the gluconeogenic enzyme genes Pepck, G6pc, and Glut2. We therefore hypothesized that glucose concentrations are decreased in individuals with Chuvash polycythemia. We found that 88 Chuvash VHL ( R200W ) homozygotes had lower random glucose and glycosylated hemoglobin A1c levels than 52 Chuvash subjects with wild-type VHL alleles. Serum metabolomics revealed higher glycerol and citrate levels in the VHL ( R200W ) homozygotes. We expanded these observations in VHL ( R200W ) homozygote mice and found that they had lower fasting glucose values and lower glucose excursions than wild-type control mice but no change in fasting insulin concentrations. Hepatic expression of Glut2 and G6pc, but not Pdk2, was decreased, and skeletal muscle expression of Glut1, Pdk1, and Pdk4 was increased. These results suggest that both decreased hepatic gluconeogenesis and increased skeletal uptake and glycolysis contribute to the decreased glucose concentrations. Further study is needed to determine whether pharmacologically manipulating HIF expression might be beneficial for treatment of diabetic patients.