Ion-exchange High-performance Liquid Research Articles

An incidental finding of a hemoglobin E variant in a diabetic patient with an abnormal glycated hemoglobin level: a case report

BackgroundGlycated hemoglobin is a well-known marker for evaluating long-term glycemic control. However, the accuracy of glycated hemoglobin measurement can be affected by the presence of hemoglobin variants, which makes the determination and interpretation of glycated hemoglobin values in terms of glycemic control not only difficult but also misleading. Here we present the first ever case of a patient with type 2 diabetes with hemoglobin E from Nepal, diagnosed incidentally because of spurious glycated hemoglobin levels.Case presentationA 45-year-old Hindu Mongolian female with a history of type 2 diabetes for around 9 years but not very compliant with follow-ups was referred to our facility for plasma fasting and postprandial blood glucose levels and glycated hemoglobin. Fasting and postprandial blood sugars were found to be high. A consistent very low glycated hemoglobin by two different high-performance liquid chromatography (HPLC) methods compelled us to call the patient for a detailed clinical history and for the records of investigations done in the past. The patient has been a known case of type 2 diabetes for around 9 years and presented irregularly for follow-up visits. Around 4 years ago, she presented to a healthcare facility with fatigue, severe headaches, pain in the abdomen, discomfort, and dizziness for a couple of months, where she was shown to have high blood glucose. She was referred to a tertiary-level hospital in Kathmandu, where she was prescribed metformin 500 mg once daily (OD). Due to her abnormal hemoglobin A1c reports, she was then sent to the National Public Health Laboratory for repeat investigations. Her blood and urine investigations were sent. Complete blood count findings revealed high red blood cell and white blood cell counts, a low mean corpuscular volume, and a high red cell distribution width-coefficient of variation. Other parameters, including serum electrolytes, renal function tests, liver function tests, and urine routine examinations, were within normal limits. A peripheral blood smear revealed microcytic hypochromic red cells with some target cells. Hemoglobin electrophoresis showed a very high percentage of hemoglobin E, a very low percentage of hemoglobin A2, and normal proportions of hemoglobin A and hemoglobin F. A diagnosis of homozygous hemoglobin E was made, and family screening was advised.ConclusionsClinicians should be aware of the limitations of glycated hemoglobin estimation by ion exchange high-performance liquid chromatography in patients with hemoglobin E and other hemoglobin variants. If the clinical impression and glycated hemoglobin test results do not match, glycated hemoglobin values should be determined with a second method based on a different principle, and glycemic status should be confirmed through alternative investigations, preferably those that are not influenced by the presence of hemoglobin variants (for example, boronate affinity chromatography, fructosamine test, glycated albumin test, the oral glucose tolerance test, continuous glucose monitoring, etc.). Consistent or even doubtful results should also raise the suspicion of a hemoglobin variant, which should be confirmed through further evaluation and investigations.

Association of Glycated Hemoglobin With Acute Ischemic Stroke in a Tertiary Care Center in a Tribal Region of Jharkhand.

Increased glycated hemoglobin (HbA1c) levels have shown an association with an increased risk of stroke in patients admitted to a tertiary care center in Jharkhand. To find out and estimate the risk of acute ischemic stroke in patients with increased HbA1c levels compared with controls. This observational case-control study was conducted on patients admitted to the department of general medicine at a tertiary care center in Ranchi from June 2021 to November 2022. The patients included in this study were those aged 18 years or older and who were clinically and radiologically diagnosed with acute ischemic stroke. Only patients with a first episode of stroke were included, and patients with hemorrhagic stroke or transient ischemic attack were excluded from this study. An equal number of control participants were also included. Ion exchange high-performance liquid chromatography was used to perform the HbA1c tests. The same method was used to measure HbA1c levels in the controls. All findings were recorded in aMicrosoft Excel sheet (Microsoft Corporation, Redmond, WA), and the data were analyzed using SPSS version 22.0software (IBM Corp., Armonk, NY). After performing a descriptive statistical analysis, the findings were classified over a range of values and described accordingly. For each variable, an independent t-test was performed to compare the cases with the controls. A multivariable logistic regression analysis was used to choose the appropriate potential factors to determine the association in the multivariable analysis. A total of 185 cases and 185 controls were included. The mean age of the cases with ischemic stroke was 63.77 ± 10.312, and that of the controls was 53.18 ± 11.35 (p < 0.01). The mean HbA1c level in the patients of acute ischemic stroke was 6.97 ± 1.84, and that of the controls was 5.99 ± 1.69 (p < 0.01). The mean random blood sugar (RBS) value in the ischemic stroke cases was 170.21 ± 84.16, and that of the controls was 150.03 ± 82.25 (p = 0.02). To compare the factors that were determined to be statistically significant between ischemic stroke cases and controls, a multivariable logistic regression analysis was performed. The HbA1c p-value was 0.01, the odds ratio (OR) was 1.280, and the 95% CI was 1.11-1.48. The other variables apart from HbA1c that were statistically significant between the ischemic stroke cases and the controls were age (p < 0.01, OR: 1.280, 95% CI: 1.06-1.11), hypertension (p = 0.618, OR: 1.130, 95% CI: 0.70-1.83), and high-density lipoprotein (p = 0.055, OR: 0.975, 95% CI: 0.95-1.00). When other cofounders were considered, it was concluded that with a 1% increase in HbA1c, the risk of stroke increases by 28% (OR: 1.28, 95% CI: 1.11-1.48). To compare the variables that were determined to be statistically significant between the control and ischemic stroke case groups, a multivariable logistic regression was used. The area under the receiver operating characteristic curve for HbA1c was 0.773and RBS was 0.600. This study shows that higher HbA1c levels in patients increase the risk of ischemic stroke. This study brings to light the need to screen the population periodically for diabetes by routinely testing for Hba1c in those who are at high risk of diabetes. Stroke risk can be reduced with early management and intervention. This study also concludes that HbA1c is a better predictor for assessing the risk of ischemic stroke than RBS levels.

HbA1c As Diabetes Mellitus Biomarker and Its Methods Evolution

This literature aims to review various aspects of HbA1c as a Diabetes Mellitus (DM) biomarker and various HbA1c examination methods and their respective advantages and limitations. Diabetes mellitus is a condition characterized by chronic hyperglycemia and can lead to microvascular and macrovascular complications in the future. HbA1c has been used extensively over the last few decades to monitor glycemic control and assess microvascular and macrovascular risk. It has also been used as one of the diagnostic criteria for DM. HbA1c is hemoglobin A, which is glycated at the N terminal of its valine beta-globin chain and provides an overview of glycemic control over the past three months. HbA1c is often reported using % or mmol/mol units and can be adjusted to assess the average blood glucose level over the past three months. Various methods developed for HbA1c examination include immunoassay, boronate affinity, enzymatic, capillary electrophoresis, and Ion-Exchange High-Performance Liquid Chromatography (IE-HPLC), and each has its advantages and limitations. In addition to their advantages in detecting HbA1c, the capillary electrophoresis and IE-HPLC methods can also detect other types of hemoglobin and the presence of hemoglobin variants.

Uncommon causes of hemoglobin E flags identified during measurement of hemoglobin A1c by ion-exchange high-performance liquid chromatography.

We present 3 cases of discordant results from screening hemoglobin A1c (HbA1c) measured by ion-exchange high-performance liquid chromatography (HPLC) all due to various forms of interference and flagged by the instrument as "suspected hemoglobin E (HbE)." The first case was due to a rare hemoglobin variant, later confirmed to be hemoglobin Hoshida, the second due to "true" heterozygous HbE, and the third a result of analytical artifact causing splitting of the HbA1c peak without an underlying variant hemoglobin. We examine the similarities in these cases along with the laboratory work-up to classify each cause of interference to demonstrate the wide array of potential causes for the suspected HbE flag and why it warrants proper work-up. Because there is no standardized method of reporting out hemoglobin variant interference in HbA1c measurement, we discuss our laboratory's process of investigating discordant HbA1c measurements and reporting results in cases with variant interference as 1 possible model to follow, along with discussing the associated laboratory, ethical, and clinical considerations. We also examine the structure of hemoglobin Hoshida, HbE, and conduct a brief literature review of previous reports.

Quantification of polyprenyl diphosphates in Escherichia coli cells using high-performance liquid chromatography.

Dephosphorylation of undecaprenyl diphosphate is a crucial step in the synthesis of undecaprenyl phosphate, which is essential for cell wall synthesis. We have developed a method for the quantification of intracellular polyprenyl diphosphates, which have never before been measured directly. Polyprenyl phosphates and diphosphates prepared by chemical phosphorylation of polyprenols from Staphylococcus aureus were used to establish the conditions for fractionation by ion-exchange chromatography and high-performance liquid chromatography (HPLC). By using an elution solvent containing tetraethylammonium phosphate as an ion-pair reagent for HPLC, polyprenyl phosphate and polyprenyl diphosphate with carbon numbers from 40 to 55 could be detected as separate peaks from the reversed-phase column. This analytical method was applied to lipids extracted from Escherichia coli to determine the intracellular levels of octaprenyl phosphate, undecaprenyl phosphate, octaprenyl diphosphate, and undecaprenyl diphosphate. This is the first report of separate measurement of cellular levels of polyprenyl phosphates and polyprenyl diphosphates.

The Diabetic Issues Related to a Familial Case of Hemoglobin Wayne: A Case Report and Review

Diabetes is a common disorder of carbohydrate metabolism that produces significant complications when either poorly treated or overtreated. Before 1978, the HgbA1c modality was not available to diagnose or monitor diabetes but now has become the standard of care. The results from this laboratory test are proportional to the glycosylation of hemoglobin and represents an accepted measure of glycemic control. Effects of hemoglobinopathies depend on their quaternary structure and have been shown to have impact HgbA1c results. Hgb Wayne is a rare hemoglobinopathy that occurs from a frameshift mutation in which either an asparagine (Hgb Wayne 1) or aspartic acid (Hgb Wayne 2) is located at residue 139 of the HBA2 gene. When separated by electrophoresis, this peak appears very close to that of the HgbA1c. Most HgbA1c monitoring equipment is either electrophoresis or ion exchange high-performance liquid chromatography which combine these two peaks together as one, falsely elevating the patient’s HgbA1c level. This co-elution can create an incongruity between HgbA1c levels and those of random glucose readings. Acting upon a falsely elevated HgbA1c with medication risks life-threatening hypoglycemia. In these following cases, this is explored with two related patients diagnosed independently by separate physicians in the same practice.

In-use stability of ready-to-administer daratumumab subcutaneous injection solution in plastic syringes

ObjectiveIn multiple myeloma patients, daratumumab is preferably injected subcutaneously. The summary of product characteristics of daratumumab subcutaneous injection solution specifies physicochemical stability for the prepared syringe for 24 hours at...

Association of Glycosylated Hemoglobin with Left Ventricular Diastolic Dysfunction in Type 2 Diabetes Mellitus

Abstract Background: Diabetes is the leading cause of death and disability among cardiovascular disease patients. By 2025, India will have people with diabetes to one in every five diabetics worldwide. Aim: The study examines the relationship between glycosylated hemoglobin (HbA1c) levels and left ventricular diastolic dysfunction (LVDD) in type 2 diabetes patients. Settings and Design: This was a cross-sectional observational study. Materials and Methods: Over 2 years, 345 subjects with type 2 diabetes mellitus who gave informed consent and met the inclusion criteria were studied. The HbA1c test was performed using ion-exchange high-performance liquid chromatography. Electrocardiogram and two-dimensional echocardiography were used to evaluate cardiac dysfunctions. The relationship between potential variables and outcomes was determined using logistic regression. Statistical Analysis: All statistical analyses were carried out using STATA version 13 (College Station, TX: Stata Corp LP). Results: Mean HbA1c levels were found to be higher in patients with LVDD (10.40% ± 4.25%) compared to normal LVDD (7.51% ±3.18%) (P = 0.004) in the current study. The predicted left ventricular (LV) function with an area under the receiver operating characteristic curve of 0.883. Conclusions: LVDD is a common finding in people with type 2 diabetes. LVDD causes various cardiac complications, including LV hypertrophy, which is concerning. The current findings suggest that HbA1c is a reliable predictor of LVDD that can be used for screening in resource-limited areas where echocardiography is unavailable. In addition, regular HbA1c screening and blood sugar control can help prevent cardiovascular complications caused by LVDD in type 2 diabetic patients.

Biomarkers of seafood intake during pregnancy – Pollutants versus fatty acids and micronutrients

Intake of fish and seafood during pregnancy may have certain beneficial effects on fetal development, but measurement of intake using questionnaires is unreliable. Here, we assessed several candidate biomarkers of seafood intake, including long-chain omega 3 fatty acids (n-3 LCPUFA), selenium, iodine, methylmercury, and different arsenic compounds, in 549 pregnant women (gestational week 29) in the prospective birth cohort NICE (Nutritional impact on Immunological maturation during Childhood in relation to the Environment). Proportions of the fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in erythrocytes were measured using gas chromatography with flame ionization detector. Selenium was measured in blood plasma and erythrocytes, mercury and arsenic in erythrocytes, and iodine and several arsenic compounds in urine, using inductively coupled plasma mass spectrometry, arsenic compounds after first being separated by ion exchange high-performance liquid chromatography (HPLC). Each biomarker was related to intake of total seafood and to intake of fatty and lean fish, and shellfish in third trimester, estimated from a semi-quantitative food frequency questionnaire filled out in gestational week 34. The pregnant women reported a median total seafood intake of 184 g/week (5th-95th percentiles: 34–465 g/week). This intake correlated most strongly with erythrocyte mercury concentrations (rho = 0.49, p < 0.001), consisting essentially of methylmercury, followed by total arsenic in erythrocytes (rho = 0.34, p < 0.001), and arsenobetaine in urine (rho = 0.33, p < 0.001), the main form of urinary arsenic. These biomarkers correlated well with intake of both fatty fish, lean fish, and shellfish. Erythrocyte DHA and plasma selenium correlated, although weakly, mainly with fatty fish (rho = 0.25 and 0.22, respectively, both p < 0.001). In conclusion, elevated concentrations of erythrocyte mercury and urinary arsenobetaine can be useful indicators of seafood intake, more so than the n-3 LCPUFAs. However, the relative importance of the biomarkers may differ depending on the type and amount of seafood consumed.

Structural Analysis of Phosphorylation Proteoforms in a Dynamic Heterogeneous System Using Flash Oxidation Coupled In-Line with Ion Exchange Chromatography.

Protein posttranslational modifications (PTMs) are key modulators of protein structure and function that often change in a dynamic fashion in response to cellular stimuli. Dynamic PTMs are very challenging to structurally characterize using modern techniques, including covalent labeling methods, due to the presence of multiple proteoforms and conformers together in solution. We have coupled an ion exchange high-performance liquid chromatography separation with a flash oxidation system [ion exchange chromatography liquid chromatography-flash oxidation (IEX LC-FOX)] to successfully elucidate structural changes among three phosphoproteoforms of ovalbumin (OVA) during dephosphorylation with alkaline phosphatase. Real-time dosimetry indicates no difference in the effective radical dose between peaks or across the peak, demonstrating both the lack of scavenging of the NaCl gradient and the lack of a concentration effect on radical dose between peaks of different intensities. The use of IEX LC-FOX allows us to structurally probe into each phosphoproteoform as it elutes from the column, capturing structural data before the dynamics of the system to reintroduce heterogeneity. We found significant differences in the residue-level oxidation between the hydroxyl radical footprint of nonphosphorylated, monophosphorylated, and diphosphorylated OVA. Not only were our data consistent with the previously reported stabilization of OVA structure by phosphorylation, but local structural changes were also consistent with the measured order of dephosphorylation of Ser344 being removed first. These results demonstrate the utility of IEX LC-FOX for measuring the structural effects of PTMs, even in dynamic systems.

The Effect of Storage at -20°C and -80°C on HbA1c Measurements in Whole Blood Samples Analysed Using Bio-Rad D-10

Introduction: Glycated haemoglobin (HbA1c) is a test commonly measured in many clinical laboratories to monitor and diagnose diabetes mellitus (DM). The laboratory in Hospital Tengku Ampuan Afzan (HTAA) receives HbA1c samples internally and from several other hospitals and clinics in the state of Pahang, at which, before transportation and analysis, the samples are often stored. This study determined the stability of HbA1c samples following different storage temperatures and duration for up to 30 days. Method: Whole blood samples for HbA1c analysis were collected from 222 healthy blood donors and type 2 DM (T2DM) patients. Each sample was prepared into four aliquots, which were then stored at temperatures -20°C and -80°C. HbA1c analyses were performed at baseline, days 15 and 30 using ion-exchange high-performance liquid chromatography (HPLC) assay technique on Bio-Rad D-10 analyser. HbA1c levels following sample storage were compared to the levels at baseline. Results: The baseline HbA1c (mean±SD) was 6.6±2.2%. At -20°C of storage, the HbA1c levels decreased with a mean difference of 0.1% and 0.3% on days 15 and 30, respectively. Storage at -80°C resulted in a mean difference of 0.1% on day 15 whilst no change was noted on day 30. The number of samples that showed clinically significant HbA1c change (defined as a change of &gt;0.5%) was less for the samples stored at -80°C (4.5%) as compared to -20°C (23%). Conclusion: HbA1c concentration is affected by temperature and duration of sample storage. In instances where prolonged storage of HbA1c samples is expected, storage at -80°C is preferable.

Intestinal permeability in patients with IgA nephropathy and other glomerular diseases: an observational study

BackgroundA dysregulated ‘gut-kidney axis’ may contribute to immunoglobulin A nephropathy (IgAN). We studied whether IgAN patients have disturbed intestinal permeability.MethodsIn a prospective, cross sectional, pilot study we assessed intestinal permeability in 35 IgAN patients, 18 patients with non-IgAN glomerulonephritides (GNs) and 19 healthy controls. After an overnight fast, trial participants ingested a multi-sugar solution and samples were obtained from 0 to 2, 2 to 5- and 5 to 24-h urine portions. Urinary sugar concentrations were quantified using isocratic ion-exchange high performance liquid chromatography. Indices of small intestinal permeability (0–2-h lactulose/L-rhamnose (L/R) ratio), distal small intestinal and proximal colonic permeability (2–5-h sucralose/erythritol (S/E) ratio) and colonic permeability (5–24-h sucralose/erythritol (S/E) ratio) were evaluated. Associations between groups and indices of intestinal permeability were investigated by a linear mixed model.ResultsSmall intestinal permeability (0–2 h L/R-ratio) was significantly increased in patients with glomerular diseases versus healthy controls. More precisely, increased small intestinal permeability was exclusively noted in non-IgAN GN patients, whereas IgAN patients exhibited a trend towards elevated small intestinal permeability. In total, 54% of patients with IgAN and 67% of non-IgAN GN patients had increased small intestinal permeability. Neither distal small intestinal and proximal colonic permeability nor colonic gut permeability indices (i.e., 2–5 h and 5–24 h S/E ratios) were significantly different between controls and any of the GN patient groups.ConclusionThe present single center pilot study suggests that disturbed intestinal permeability is common in patients with glomerular diseases and is not specific for IgAN.Trial registration numberGerman Clinical Trials Register DRKS00021533, Date: 24.04.2020.Graphical abstract

Arsenic species in mesopelagic organisms and their fate during aquafeed processing.

A responsible harvest of mesopelagic species as aquafeed ingredients has the potential to address the United Nations Sustainable Development Goal 14, which calls for sustainable use of marine resources. Prior to utilization, the levels of undesirable substances need to be examined, and earlier studies on mesopelagic species have reported on total arsenic (As) content. However, the total As content does not give a complete basis for risk assessment since As can occur in different chemical species with varying toxicity. In this work, As speciation was conducted in single-species samples of the five most abundant mesopelagic organisms in Norwegian fjords. In addition, As species were studied in mesopelagic mixed biomass and in the resulting oil and meal feed ingredients after lab-scale feed processing. Water-soluble As species were determined based on ion-exchange high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). This was supplemented by extracting arsenolipids (AsLipids) and determining total As in this fraction. The non-toxic arsenobetaine (AB) was the dominant form in mesopelagic crustaceans and fish species, accounting for approximately 70% and 50% of total As, respectively. Other water-soluble species were present in minor fractions, including carcinogenic inorganic As, which, in most samples, was below limit of quantification. The fish species had a higher proportion of AsLipids, approximately 35% of total As, compared to crustaceans which contained 20% on average. The feed processing simulation revealed generally low levels of water-soluble As species besides AB, but considerable fractions of potentially toxic AsLipids were found in the biomass, and transferred to the mesopelagic meal and oil. This study is the first to report occurrence data of at least 12 As species in mesopelagic organisms, thereby providing valuable information for future risk assessments on the feasibility of harnessing mesopelagic biomass as feed ingredients.

Identification of a New Antifungal Peptide W1 From a Marine Bacillus amyloliquefaciens Reveals Its Potential in Controlling Fungal Plant Diseases.

A bacterium, Bacillus amyloliquefaciens W0101, isolated from the Arctic Ocean, showed potent antifungal activity against several plant pathogenic fungi. An antifungal peptide W1, with a molecular weight of approximately 2.4 kDa, was purified from the culture supernatant of the strain W0101 using ion-exchange chromatography and high-performance liquid chromatography. By analysis of Liquid Chromatograph-Mass Spectrometer, the peptide W1 was identified as a new antifungal peptide derived from the fragment of preprotein translocase subunit YajC. Further analysis revealed that W1 could disrupt the hyphae and spores of Sclerotinia sclerotiorum and inhibit its growth. W1 suppressed S. sclerotiorum and Fusarium oxysporum at a minimum inhibitory concentration of 140 and 58 μg/ml, respectively. The antifungal activity of W1 remained stable at 20–80°C or pH 6–11, with reduced activity at 100–110°C and pH 4–5, and under three protease treatments. Additionally, W1 also had a certain extent of metal ion resistance. These results therefore suggest that the peptide W1 from marine B. amyloliquefaciens W0101 may represent a new antifungal peptide with potential application in the biocontrol of plant diseases.

Association between depression and HbA1c levels in the elderly population with type 2 diabetes mellitus during COVID-19 pandemic.

Diabetes mellitus is a chronic progressive disease affecting the metabolic hormonal system and its prevalence in the elderly population is high. Depression is one of the psychiatric disorders in diabetic patients in particular during the coronavirus disease 2019 (COVID-19) pandemic. People with depression are more susceptible to leading an unhealthy lifestyle; therefore, depression and diabetes have a negative influence on life quality and aggravate complications and symptoms. The aim of this study was to determine the association between depression and hemoglobin A1c (HbA1c) levels in elderly with type 2 diabetes mellitus patients. A cross-sectional study was conducted where a total of 42 diabetic patients from the Puskesmas Belakang Padang, Batam of Indonesia was recruited. The HbA1c level, the main determinant of optimum glycemic control, was measured using ion-exchange high-performance liquid chromatography while the level of depression was assessed using Geriatric Depression Scale-15 (GDS-15). The association between depression and HbA1c levels was analyzed using the chi-squared test. Our study found that that 69% of the elderly with diabetes experienced a depression, classified as mild (40.5%), moderate (21.4%) and severe (7.1%). There were 61.9% of the subjects had poor HbA1c control. Our data suggested that the depression level was associated with HbA1c (p = 0.002). In conclusion, there is a significant association between depression and HbA1c levels in the elderly with type 2 diabetes mellitus.

Influence of RBC Indices on HbA1c Measurement by Capillary Electrophoresis and HPLC Methods.

HbA1c is the gold standard of diabetic surveys to monitor the long-term glycemic control. Anemia is cited as a major confounder to HbA1c analysis; however, the effect of RBC indices influences on HbA1c analysis is not known. The aim of this study is to compare ion-exchange high-performance liquid chromatography, and capillary electrophoresis to evaluate the influence of RBC parameters on HbA1c values in anemia patients. Erythrocyte parameters were collected from the 307 randomly selected specimens from the Hematology division. HbA1c was measured on the same specimen using Tosoh G8 and Capillarys 2 Flex Piercing on the same day. There is acceptable concordance between the results of capillary electrophoresis and HPLC methods (R2 = 0.953, p < 0.001). However, significant differences in HbA1c value between the two assay methods were obtained in the patients with abnormal RBC indices (p < 0.001). Our results demonstrated HbA1c differences were significantly different in the patients with low Hb (≤ 8 g/dL) and high RDW-CV (≥ 13.7%). It is suggested that in the analysis of HbA1c level in anemia patients, simultaneous testing for hemoglobin level is needed. In addition, development of a new reference value of HBA1c for patients with severe anemia should be considered.

INTERFERENCES OF HbA1c ANALYSIS IN HOSPITAL UNIVERSITI SAINS MALAYSIA – 3 YEARS STUDY

Haemoglobin A1c (HbA1c) is used to monitor glycaemic control and predict diabetic complications. Measurement of HbA1c can be interfered by haemoglobin (Hb) variant and other Hb derivatives include carbamylated Hb and elevated labile A1c. This study is to determine the percentages and type of interferences during HbA1c analysis and the percentages of non- reportable HbA1c results. This is a cross-sectional study using retrospective data of HbA1c. The HbA1c is measured on Biorad D10 using the ion-exchange high-performance liquid chromatography method. The data were analyzed using descriptive statistics. A total of 26,560 patients were included. The result showed the presence of interferences of 2269 (8.56%). The most common causes of the interferences were the Hb variant (8.48%) followed by carbamylated Hb and labile A1c (0.03% each). The non-reportable HbA1c results were 0.46% with the Hb variant contributed most of the causes. By knowing the presence of interferences particularly the Hb variant, the HbA1c results hopefully are interpreted with caution and correct management can be given to the patients.

Age and gender differences in the prevalence of chronic diseases and atherosclerotic cardiovascular disease risk scores in adults in Riyadh city, Saudi Arabia.

Objectives:To evaluate age and gender differences in the prevalence of chronic diseases and to calculate atherosclerotic cardiovascular disease (ASCVD) risk scores in adults aged 30-75 years in Riyadh city, Saudi Arabia.Methods:This cross-sectional, interview-based study was conducted with 2997 men and women, visiting primary health care centers in Riyadh, during the years 2015 to 2016. Serum glycosylated hemoglobin and lipid levels were measured by ion-exchange high-performance liquid chromatography and fully automated analyzer using enzymatic methods, respectively. The 10-year and lifetime ASCVD risk scores were calculated using an online calculator.Results:The mean age of men was 43.1 (±11.7) and women was 43.8 (± 10.9) years. Prevalence rates of diabetes mellitus, hypertension, hypercholesterolemia, and obesity in men versus women were 20.3% versus 24.8% (p=0.006), 15% versus 19.5% (p=0.003), 50.7% versus 53.4% (p=0.16), and 41.2% versus 56.7% (p<0.001), respectively. Majority of men and women with chronic diseases belonged to the age groups 30-39 and 50-59 years, respectively. High 10-year ASCVD risk was found in 32% men and 7.6% women, whereas lifetime risk was present in 67% and 51%, respectively.Conclusion:Women in the age group 50-59 years, with multiple risk factors are at a greater risk of developing cardiovascular diseases than men of same age. Young adults were at more risk for lifetime ASCVD, whereas the 10-year ASCVD risk increased with increasing age.

Direct determination of cellulosic glucan content in starch-containing samples

A simple and highly selective analytical procedure is presented for the determination of cellulosic glucan content in samples that contain both cellulose and starch. This method eliminates the unacceptably large compounding errors of current two-measurement methods. If both starch and cellulose are present before analytical hydrolysis, both will be hydrolyzed to glucose causing bias and inaccuracy in the method. To prevent this interference, the removal of starch prior to cellulosic quantification is crucial. The method presented here is a concise in-series procedure with minimal measurements, eliminating large compounding errors. Sample preparation consists of a starch extraction employing enzymatic hydrolysis followed by a simple filtration and wash. The samples are then subjected to a two-stage acid hydrolysis. The concentration of glucose is determined by ion exchange high-performance liquid chromatography with a Pb2+ column and a refractive index detector. The cellulosic glucan content is calculated based on the initial dry weight of the starting material. Data for the native biomass materials studied show excellent reproducibility, with coefficients of variance of 3.0% or less associated with the method. This selectivity for cellulosic glucan by the procedure was validated with several analytical techniques such as liquid chromatography coupled with mass spectrometry (LC–MS), Raman spectroscopy, and nuclear magnetic resonance.

High peak of carbamylated hemoglobin discordant with urea level: a case report

ABSTRACT Hemoglobin A1c (HbA1c) measurement is commonly performed in diabetes mellitus patients to monitor glycemic control over the last three to four months. Carbamylated hemoglobin, which is the hemoglobin that binds to isocyanic acid derived from urea, is one of the possible analytical interference in the uremic patient. When measured by ion-exchange high-performance liquid chromatography (HPLC), carbamylated hemoglobin forms a peak that overlaps the peak of HbA1c, causing a falsely elevated HbA1c result. We report a case of a 60-years-old man who had a spurious increase in HbA1c, with a high carbamylated hemoglobin peak disproportionate to the urea value. Subsequent hemoglobin analysis using hemoglobin electrophoresis and HPLC hemoglobin testing system suggested hemoglobin J (Hb J) variant. Our case highlighted the possibility of misleading HbA1c interpretation in the presence of a high carbamylated hemoglobin peak, but not proportionate to urea value. In this study, Hb J was detected. A method free from hemoglobin variant interference should be used ideally, and monitoring glycemic control should be performed using alternative methods, such as serum fructosamine or continuous glucose monitoring.