Factors That Interfere With Hba1c Test Results
Information for physicians and patients regarding HbS, HbC, HbE and HbD traits More about hemoglobin variants and HbA1c can also be found at the NIDDK web site: Sickle Cell Trait and Other Hemoglobinopathies and Diabetes: Important Information for Physicians For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests Factors that Interfere with HbA1c Measurement: Genetic variants (e.g. HbS trait, HbC trait), elevated fetal hemoglobin (HbF) and chemically modified derivatives of hemoglobin (e.g. carbamylated Hb in patients with renal failure) can affect the accuracy of HbA1c measurements. The effects vary depending on the specific Hb variant or derivative and the specific HbA1c method. Table 1 contains information for most of the commonly used current HbA1c methods for the four most common Hb variants, elevated HbF and carbamylated Hb. Interferences from less common Hb variants and derivatives are discussed in Bry, et al . All entries in Table 1 are based on published information. In addition, if a product insert indicates clearly that there is inference from a particular factor, then the interference is entered as “yes” and the product insert is cited. When selecting an assay method, laboratories should take into consideration characteristics of the patient population served, (e.g. high prevalence of hemoglobinopathies or renal failure). Factors that affect interpretation of HbA1c Results: Any condition that shortens erythrocyte survival or decreases mean erythrocyte age (e.g., recovery from acute blood loss, hemolytic anemia) will falsely lower HbA1c test results regardless of the assay method used . HbA1c results from patients with HbSS, HbCC, and HbSC must be interpreted with caution given the patholog Continue reading >>
The Diabetes And Anemia Connection
The Diabetes and Iron Deficiency Anemia Connection Its common to see elevation of ferritin, the storage form of iron, in cases of insulin resistance and diabetes. This is because ferritin is also considered an acute phase reactant, which means it spikes in the presence of inflammation. Ferritin is primarily stored in the liver, and its common for it to elevate in cases of fatty liver disease, which is strongly connected to insulin resistance. However, serum iron levels tend to fall in diabetic patientstheres an inverse correlation between iron levels and HbA1c(a measurement of where the glucose has been over the last 3 months). There are several possible reasons for this. Kidney complications. Elevated blood sugar will, over time, damage the tiny blood vessels in the kidneys in the same way that it can damage the vessels anywhere else (leading to cardiovascular disease). Smaller vessels show damage first, which is why kidney damage is one of the side effects of diabetes to watch out for. The significance here: the kidneys produce the hormone erythropoietin, which tells bone marrow to make more red blood cells. Underperforming kidneys will also decrease production of erythropoietin, leading to anemia. This studyshows that diabetics with reduced renal function are more likely to end up with iron deficiency anemia than those with without reduced renal function. Neuropathy. Prolonged elevation of blood sugar can also damage nerves, probably because nerves also require a blood supply, which they receive from tiny arteries. There are several types of neuropathy that can result, one of which is autonomic neuropathy. Unlike the typical symptoms of peripheral neuropathy (tingling and numbness of fingers and toes), this can present with dizziness, fainting, digestive disturbance Continue reading >>
Diabetes And Anemia: Are They Related?
Someone’s anemic if they have an abnormally low amount of red blood cells – and when there are too few red blood cells, body organs don’t get the oxygen they need. This not only strains and damages organs, but it also decreases a person’s quality of life by causing fatigue, weakness, and headaches. Red blood cells can transport oxygen because they’re full of a complex molecule called hemoglobin, which can grab, hold, and release oxygen as needed in different part of the body. A doctor may an anemic person as having “too little hemoglobin” or “a low hematocrit”. The first statement refers to the amount of concentration of hemoglobin molecules in your blood, and the second refers to the concentration of red blood cells in your blood. If that sounds redundant, you’re right! They’re both describing the same thing. That’s why it’s best to pay attention to one or the other (not both) to avoid confusion. Types of anemia There are quite a few different types of anemia (over 400 to be exact!). The most common ones are summarized below. It is very important to know the type of anemia and the cause. Without knowing the cause, you cannot treat the disease! Iron Deficiency. This is the most common type. It is caused by lack of absorption, intake, or by blood loss. Aplastic. This occurs when the body stops making new red blood cells. It is rare, but very serious. Hemolytic. This type happens when red blood cells are destroyed faster than they can be produced. Vitamin Deficiency. Poor nutrition, or impaired vitamin absorption causes this type. Pernicious. With this, the B-12 intake is okay, but the body cannot process it correctly. Fragile Red Cell. Some people inherit abnormal red blood cells that die earlier than normal, like in sickle cell or thalassemia. Continue reading >>
Pernicious Anemia: Practice Essentials, Pathophysiology, Etiology
The term pernicious anemia is an anachronismit dates from the era when treatment had not yet been discovered, and the disease was fatalbut it remains in use for megaloblastic anemia resulting from vitamin B12 deficiency due to lack of intrinsic factor (IF). [ 1 ] Impaired IF production can occur in adults due to autoimmune destruction of parietal cells, which secrete IF. Gastrectomy can significantly reduce the production of IF. A rare congenital autosomal recessive disorder can result in deficiency of IF without gastric atrophy. Several conditions other than impaired Intrinsic Factor production can cause a megaloblastic anemia such as: folic acid deficiency, altered pH in the small intestine, and lack of absorption of B12 complexes in the terminal ileum. Thus, pernicious anemia must be differentiated from other disorders that interfere with the absorption and metabolism of vitamin B-12 (see DDx and Workup ). The following goals are the most important in establishing care for patients with pernicious anemia: To establish that the patient has cobalamin deficiency Treat with cobalamin. Higher doses of cobalamin are administered in patients with B12-related mental or neurological impairment. If there is evidence for folic acid deficiency but pernicious anemia remains a possibility, treat with both folic acid and cobalamin until pernicious anemia has been ruled out. The reason is that folic acid restores blood counts but does not prevent the development of subacute combined system degeneration in patients with pernicious anemia. Monitor therapy to confirm that that therapy has been effective Administration of adequate quantities of cobalamin for the remainder of the patient's life Periodic evaluation to rule out gastric carcinoma For further discussion, see Treatment and M Continue reading >>
Glycated Hemoglobin Levels In Patients With Decompensated Cirrhosis
Copyright © 2016 Jeffrey Nadelson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Introduction. Aim of this study is to determine if HbA1c levels are a reliable predictor of glycemic control in patients with decompensated cirrhosis. Methods. 200 unique patients referred for liver transplantation at University of Tennessee/Methodist University Transplant Institute with a HbA1c result were included. Three glucose levels prior to the “measured” A1c (MA1c) were input into an HbA1c calculator from the American Diabetes Association website to determine the “calculated” A1c (CA1c). The differences between MA1c and CA1c levels were computed. Patients were divided into three groups: group A, difference of <0.5; group B, 0.51–1.5; and group C, >1.5. Results. 97 (49%) patients had hemoglobin A1c of less than 5%. Discordance between calculated and measured HbA1c of >0.5% was seen in 47% (). Higher level of discordance of greater than >1.5 was in 12% of patients (). Hemoglobin was an independent predictor for higher discordance (odds ratio 0.77 95%, CI 0.60–0.99, and value 0.04). HbA1c was an independent predictor of occurrence of HCC (OR 2.69 955, CI 1.38–5.43, and value 0.008). Conclusion. HbA1c is not a reliable predictor of glycemic control in patients with decompensated cirrhosis, especially in those with severe anemia. 1. Introduction Hemoglobin A1c (HbA1c) is the gold standard for the measurement of long-range glycemic control in patients with diabetes mellitus. Many studies have reported diabetes mellitus to be a risk factor in patients with alcoholic liver disease and nonalcoholi Continue reading >>
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What Clinical Laboratorians Should Do In Response To Extremely Low Hemoglobin A1c Results
Extremely low hemoglobin A1c (HbA1c) results below reference range are rare, and the causes and clinical implications associated with low HbA1c results are not well understood among clinical laboratorians. A case of extremely low HbA1c results was reported, in which liver cirrhosis, subacute hemorrhage and recent transfusion all contributed to the low result. This case illustrates when HbA1c should not be used as a clinically relevant diabetes marker. However, low or extremely low HbA1c (<5.0% or <4.0%) may occur in apparently healthy individuals. When this occurs, it is an independent risk factor associated with liver diseases, hospitalization, and all-cause mortality. From the clinical laboratory perspective, the clinical cause of extremely low HbA1c should be determined, and suggestions of different test utilization or increased health surveillance should be given to care providers. Continue reading >>
Anemia And Hemoglobin A1c Level: Is There A Case For Redefining Reference Ranges And Therapeutic Goals?
Segun Adeoye, Sherly Abraham, Irina Erlikh, Sylvester Sarfraz, Tomas Borda and Lap Yeung. Abstract Background: Hemoglobin A1c (HbA1c) has been adopted by physicians as a surrogate for monitoring glycemic control. There exists concern that other factors beyond serum glucose concentration may affect glycation rates and by extrapolation HbA1c levels. Study Objectives: The study attempts to discern clinical differences in HbA1c levels in patients with anaemia compared to patients without anemia, quantifying and showing the direction of such differences. Study Design: Using a convenient sampling method and a set of inclusion and exclusion criteria, it examined (retrospectively) patterns in [Hb] and HbA1c in non-diabetics with and without anemia. Results: The study observed a statistically significant 0.4units (8%) difference in the mean HbA1c in anaemia vs. non-anaemic populations. Reference ranges of HbA1c for non-anaemic population and anaemia subtypes was computed. Computed ranges for anaemia group and its subgroups were significantly wider compared to non-anaemia population. Modest but statistically significant correction of anaemia did not result in significant changes in HbA1c. Discussion: i. The linear relationship between [Hb] and HbA1c holds true for anaemic and non-anaemia populations. ii. Non-diabetic, anaemic have a significantly lower mean HbA1c (5.3% vs. 5.7%), but a similar upper limit of reference range due to a higher variance. iii. The variance and proposed reference ranges for anaemia group and its subtypes was greater than in non-anaemia group, perhaps due to homogenization of clinically heterogeneous entities. iv. Modest correction anaemia did not cause significant change in HbAIc, perhaps the increase in [Hb] was too modest or persistence of correction Continue reading >>
- A Novel Intervention Including Individualized Nutritional Recommendations Reduces Hemoglobin A1c Level, Medication Use, and Weight in Type 2 Diabetes
- A Novel Intervention Including Individualized Nutritional Recommendations Reduces Hemoglobin A1c Level, Medication Use, and Weight in Type 2 Diabetes
- Elderly A1C Targets: Should Older People Have More Relaxed Glucose Goals?
Falsely Decreased Hba1c In A Type 2 Diabetic Patient Treated With Dapsone - Sciencedirect
Volume 111, Issue 2 , February 2012, Pages 109-112 Author links open overlay panel Ying-ChuenLaia Chou-ShiangWangb Yi-ChingWangb Yu-LingHsub Lee-MingChuangb Glycated hemoglobin A1c (HbA1c) is an important indicator of glycemic control. The current recommendation for glycemic control based on HbA1c values has been widely accepted. However, HbA1c values depend on the lifespan of erythrocytes and the assay methods used. Here, we report the case of a patient with type 2 diabetes with unusual falling of HbA1c due to interference from dapsone treatment for leukocytoclastic vasculitis. He was a 52-year-old man, who was diagnosed with type 2 diabetes mellitus 5 years previously and who had been treated in our hospital in the past 3 years. Glycemia was controlled by sulfonylurea and metformin. During the 3-years follow-up period, HbA1c dropped significantly during the addition of dapsone treatment, although plasma glucose levels remained stable. HbA1c levels were raised after discontinuation of dapsone. With rechallenge of dapsone usage, HbA1c decreased again. We conclude that dapsone may be the cause of artificially low HbA1c. Other measurements to monitor glycemic control should be considered when dapsone is used for the treatment of concurrent disorders, such as autoimmune disease and pneumocystis jiroveci pneumonia. Continue reading >>
Artefactually Low Hemoglobin A1c In A Patient With Hemolytic Anemia
HbA1c concentrations are affected by several factors including red blood cell turnover. The International Expert Committee has highlighted this observation for the benefit of physicians who evaluate HbA1c in diabetics. There are many types of anaemia that affect glycated haemoglobin (HbA1c) values but iron deficiency anaemia, one of the most common, has been proved to show higher than true values of HbA1c. The mechanism of how iron deficiency anaemia affects HbA1c has yet to be understood. Several studies have been conducted in order to unravel the mechanisms but there still remains a dearth of information. Future research needs to focus on the mechanistic reasons why HbA1c is higher in patients with iron deficiency anaemia in particular. This can pave the way for possible large scale studies to address the HbA1c enhancing effect and the mechanism of increased HbA glycation in iron deficiency properly. Human Serum Albumin (HSA) has been suggested to be an alternate biomarker to the existing Hemoglobin-A1c (HbA1c) marker for glycemic monitoring. Development and usage of HSA as an alternate biomarker requires the identification of glycation sites, or equivalently, glucose-binding pockets. In this work we combine molecular dynamics simulations of HSA and the state-of-art machine learning method Support Vector Machine (SVM) to predict glucose-binding pockets in HSA. SVM uses the three dimensional arrangement of atoms and their chemical properties to predict glucose-binding ability of a pocket. Feature selection reveals that the arrangement of atoms and their chemical properties within the first 4 from the centroid of the pocket play an important role in the binding of glucose. With a 10-fold cross validation accuracy of 84%, our SVM model reveals seven new potential glucos Continue reading >>
Why Hemoglobin A1c Is Not A Reliable Marker
i was recently tested for Hemoglobin A1c because i presented to an endocrinologist with extremely low blood glucose on lab test and some scary symptoms, not the ordinary hypoglycemia symptoms. My A1c was 4.7 which registered as low (L) on the lab print out–it was only slightly low. Does a low score on this suggest a possibility of short-lived RBCs? Does it have any relationship with extremely low blood glucose? my result at the lab, fasting, was 32mg/dL. Not long after that i got a home glucometer and i get the same kind of results on that as the lab got, in the 20s and 30s first thing in the morning, every day. did not know i had hypoglycemia until i had that lab test, though i had had one episode where i woke up with ataxia, i fell while walking to the bathroom first thing in the morning, i got up and immediately fell again. I soon found that i had very impaired coordination. i did not know why and i was very worried. Eventually i wanted to have breakfast but had great difficulty holding the measuring cup under the faucet, to get some water to heat, to make instant oatmeal, i lacked the coordination to get the water into the cup. I persisted and did make the instant oatmeal (pour hot water onto flakes and it’s done), and i got my lap top and was eating the oatmeal and i suddenly was aware that the symptoms were going away. Previously i had been unable to type. While eating the small amount of oatmeal, i realized i could type. That was about a month before the lab test. Since it only happened that once, i put it out of my mind. About 5 days after the lab test, i had the second episode, worse than the first, i woke falling out of bed to the floor, couldn’t use my arm to break the fall, i didn’t have the coordination. i sat on the floor, i could not get up and wa Continue reading >>
Influence Of Iron Deficiency Anemia On Hemoglobin A1c Levels In Diabetic Individuals With Controlled Plasma Glucose Levels
Go to: Introduction: Hemoglobin A1C (HbA1c) reflects patient’s glycemic status over the previous 3 months. Previous studies have reported that iron deficiency may elevate A1C concentrations, independent of glycemia. This study is aimed to analyze the effect of iron deficiency anemia on HbA1c levels in diabetic population having plasma glucose levels in control. Methods: Totally, 120 diabetic, iron-deficient anemic individuals (70 females and 50 males) having controlled plasma glucose levels with same number of iron-sufficient non-anemic individuals were streamlined for the study. Their data of HbA1c (Bio-Rad D-10 HPLC analyzer), ferritin (cobas e411 ECLIA hormone analyzer), fasting plasma glucose (FPG, Roche Hitachi P800/917 chemistry analyzer), hemoglobin (Beckman Coulter LH780), peripheral smear examination, red cell indices, and medical history were recorded. Statistical analysis was carried out by student’s t-test, Chi-square test, and Pearson’s coefficient of regression. Results: We found elevated HbA1c (6.8 ± 1.4%) in iron-deficient individuals as compared to controls, and elevation was more in women (7.02 ± 1.58%). On further classification on the basis of FPG levels, A1C was elevated more in group having fasting glucose levels between 100-126 mg/dl (7.33 ± 1.55%) compared to the those with normal plasma glucose levels (<100 mg/dl). No significant correlation was found between HbA1c and ferritin and hemoglobin. Conclusion: This study found a positive correlation between iron deficiency anemia and increased A1C levels, especially in the controlled diabetic women and individuals having FPG between 100-126 mg/dl. Hence, before altering the treatment regimen for diabetic patient, presence of iron deficiency anemia should be considered. Key Words: Iron defici Continue reading >>
What Is A Complete Blood Count (cbc)?
The CBC is used as a broad screening test to check for such disorders as anemia, infection, and many other diseases. It is actually a panel of tests that examines different parts of the blood and includes the following: • White blood cell (WBC) count is a count of the actual number of white blood cells per volume of blood. Both increases and decreases can be significant. • White blood cell differential looks at the types of white blood cells present. There are five different types of white blood cells, each with its own function in protecting us from infection. The differential classifies a person’s white blood cells into each type: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. • Red blood cell (RBC) count is a count of the actual number of red blood cells per volume of blood. Both increases and decreases can point to abnormal conditions. • Hemoglobin measures the amount of oxygen-carrying protein in the blood. • Hematocrit measures the percentage of red blood cells in a given volume of whole blood. • The platelet count is the number of platelets in a given volume of blood. Both increases and decreases can point to abnormal conditions of excess bleeding or clotting. Mean platelet volume (MPV) is a machine-calculated measurement of the average size of your platelets. New platelets are larger, and an increased MPV occurs when increased numbers of platelets are being produced. MPV gives your doctor information about platelet production in your bone marrow. • Mean corpuscular volume (MCV) is a measurement of the average size of your RBCs. The MCV is elevated when your RBCs are larger than normal (macrocytic), for example in anemia caused by vitamin B-12 deficiency. When the MCV is decreased, your RBCs are smaller than normal (microcytic) a Continue reading >>
When Is Hemoglobin A1c Inaccurate In Assessing Glycemic Control?
Hemoglobin A1C (HbA1c) is an invaluable tool for monitoring long-term glycemic control in diabetic patients. However, many clinicians managing diabetics have encountered the problem of HbA1c values that do not agree with fingerstick glucose logs. Before suspecting an improperly calibrated glucometer or poor patient record keeping, it is useful to consider the situations in which HbA1c may be spuriously elevated or depressed. These issues are best understood after reviewing how HbA1c is defined and measuredtopics fraught with considerable confusion. Glycosylation is a non-enzymatic, time-dependent chemical reaction in which glucose binds to the amino groups of proteins. Historically, and long before its precise chemistry was discovered, glycosylated Hb was defined as an area of an elution chromatogram containing hemoglobin glycosylation products. This elution peak was labeled as HbA1, in keeping with the existing nomenclature (HbA, HbA2, HbF, etc. had been identified previously). Later it was recognized that the chromatographic HbA1 region is not homogeneous and consists of several component peaks, designated A1a, A1b and A1c, with HbA1c being the dominant one. The HbA1c fraction also turned out to correlate best with mean serum glucose concentrations, ie, to be a better index of long-term glycemia. Relatively recently HbA1c was redefined chemically: now glycohemoglobin refers to hemoglobin glycosylated at any of its amino groups, while HbA1c is defined as glycohemoglobin with glucose bound specifically to the terminal valine of the beta-globin chain. Consequently, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has developed a standard reference method for HbA1c in which hemoglobin is cleaved with a specific peptidase into multip Continue reading >>
Pernicious Anemia - Diabetes Self-management
A condition in which the body cannot make enough red blood cells due to a deficiency in vitamin B12. Pernicious anemia is somewhat more common in people with Type 1 diabetes than it is in the general population. Pernicious anemia is most commonly caused by an autoimmune attack on the parietal cells of the stomach. Ordinarily, the parietal cells make a protein called intrinsic factor, which helps the body absorb vitamin B12. When the parietal cells get destroyed by the immune system, they can no longer make intrinsic factor, and vitamin B12 cannot be absorbed properly. Lack of vitamin B12 keeps red blood cells from dividing normally and causes them to become too large, so that they have difficulty getting out of the bone marrow. Vitamin B12 is also necessary for the nervous system to work properly. Pernicious anemia can cause multiple problems throughout the body. In people with pernicious anemia, the heart has to work harder to pump enough blood to nourish the bodys tissues. This can lead to cardiac arrhythmias (fast or irregular heartbeats), an enlarged heart, and even heart failure (in which the heart cannot pump blood efficiently enough to meet the bodys needs). It may also raise the risk of heart attacks and strokes . Related damage to the nervous system can cause such diverse symptoms as numbness and tingling in the hands and feet, difficulty with balance, vision changes, memory loss, and confusion. Other symptoms include fatigue, loss of appetite, and diarrhea. Fortunately, pernicious anemia is usually easy to treat with vitamin B12 injections, although some people develop permanent nerve damage before the condition is diagnosed and treated. In addition to pernicious anemia, there are a number of other autoimmune diseases that tend to run in clusters in people wi Continue reading >>
Microcytic Anemia Elevates Hemoglobin A1c Levels In The Subjects With Normal Fasting Plasma Glucose
Microcytic Anemia Elevates Hemoglobin A1c Levels in the Subjects with Normal Fasting Plasma Glucose [bold]Background and Aims:[/bo [bold]Background and Aims:[/bold] HbA1c is used world-wide as a control marker of diabetes mellitus. HbA1c is known to be affected not only by plasma glucose level but also by life span of red blood cell. However whether microcytic anemia has an influence on HbA1c in subjects with normal fasting plasma glucose is unclear. The purpose of this study is to elucidate how hemoglobin A1c (HbA1c) is affected by microcytic anemia.[br][bold]Material and Methods:[/bold] The study subjects consisted of 1874 men and 1529 women who underwent health checkups including fasting plasma glucose, HbA1c, CBC. All subjects had FPG levels bellow 100mg/dl and took therapy neither for diabetes nor anemia. We investigated whether microcytic anemia has an influence on HbA1c and the attribute of discrepant cases between FPG and HbA1c.[br][bold]Results:[/bold] The subjects were divided into three groups by tertiles of hemoglobin concentration(Hb) and MCV :,the micocytic group(MC) with low MCV, the microcytic anemia(MCA) with low MCV and low Hb and the control . [br]The HbA1c levels in MCA were 2.0% higher than those in the control in men and 4.7% higher in women.[br]We defined discrepant cases between FPG and HbA1c as those with HbA1c more than 5.5%. More discrepancies between FPG and HbA1c were found in MC and MCA than in the control group. In men, the proportions of discrepant cases were 5.4%, 9.9%, 16.5% in the control group, MC and MCA, respectively. In women, the proportions were 6.2%, 24.5% and 31.5%, respectively.[br]Multiple regression analysis revealed that FPG and age were the positive independent factors for HbA1c, and Hb and MCV were the negative independen Continue reading >>