Influence of iron deficiency on Hb A1c levels in type 2 diabetic patients

Exploring the Impact of Iron Deficiency Anaemia on Glycated Haemoglobin A1c Levels in Pregnant and Non-Pregnant Women: A Systematic Review

Haemoglobin A1C (HbA1c) is fundamental in monitoring glycaemic control during pregnancy. However, several conditions could affect this test's accuracy, including iron deficiency anaemia (IDA). Hence, this systematic review delves into the underexplored connection between IDA, iron replacement therapy (IRT), and haemoglobin A1C (HbA1c) during pregnancy. An electronic search of the Cochrane, MEDLINE, and Embase databases was conducted by six authors. From a comprehensive search strategy, 968 records were obtained. After applying the inclusion and exclusion criteria, seven studies were included, comprising 365 women selected for analysis. Six studies indicated a positive correlation between IDA and HbA1c levels, while one found no correlation. The average HbA1c level of the included studies in pregnant women was 5.64%. In comparison, it was found that non-pregnant women had lower HbA1c levels. Among the included studies, the mean HbA1c levels decreased from 5.1% to 4.89% after treating pregnant women with IRT. The review emphasises the complexity of interpreting HbA1c levels in pregnant women with IDA, highlighting the influence of pregnancy-induced physiological changes. In addition, this suggests that HbA1c should not be the sole criterion for diabetes management in pregnant women with IDA. Future research should focus on alternative glycaemic monitoring methods unaffected by IDA.

Serum Iron Levels, Dietary Iron Intake, and Supplement Use in Relation to Metabolic Syndrome in Adolescents: A Cross-Sectional Study

The objective of this study was to investigate the potential associations between serum iron levels, dietary iron intake, and iron supplementation, and the prevalence of metabolic syndrome (MetS) in adolescents A cross-sectional analysis was conducted, utilizing data from adolescents participating in the 2003-2018 cycle of the National Health and Nutrition Examination Survey (NHANES). Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) pertaining to serum iron, dietary iron, and iron supplementation were derived through multivariate logistic regression models. Additionally, a restricted cubic spline (RCS) regression model was applied to explore the nonlinear relationship between dietary iron and serum iron concerning MetS. The study encompassed 4858 American adolescents aged 12 to 19, among whom 413 (8.5%) manifested MetS. The study cohort exhibited an average age of 15.52 years, comprising 2551 males (52.51%) and 2307 females (47.49%). Relative to individuals in the lowest serum iron quartile, those in the highest quartile for serum iron (OR = 0.33, 95% CI 0.21-0.50), the highest quartile for dietary iron (OR = 0.53, 95% CI 0.32-0.89), and those utilizing iron supplements (OR = 0.61, 95% CI 0.37-0.99) evinced a diminished prevalence of MetS, even post adjustment for potential confounding variables. A non-linear relationship was discerned between serum iron and MetS, exhibiting a statistically significant negative correlation when serum iron concentrations exceeded the inflection point (serum iron = 8.66 µmol/L, P for nonlinear < 0.001). This investigation reveals that higher levels of serum iron, increased dietary iron intake, and the use of iron supplements are linked to a lower prevalence of MetS in US adolescents. These findings suggest that dietary modifications could play a role in promoting the health of adolescents.

The Effect of Iron Replacement Therapy on HbA1c Levels in Diabetic and Nondiabetic Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies have reported that iron-deficiency anemia (IDA) and its treatment might lead to a distorted reading of glycated hemoglobin (HbA1c) value. Hence, this review aims to systematically investigate the effect of iron replacement therapy (IRT) on HbA1c levels, as the literature is deficient in assessing this clinical phenomenon.

METHODS

An electronic search of the Cochrane, MEDLINE, and Embase databases was conducted by four independent authors.

RESULTS

Among the 8332 articles identified using the search strategy, 10 records (with a total of 2113 participants) met the inclusion criteria and were analyzed. In nine of the studies, IRT was found to decrease HbA1c levels; in the remaining study, IRT was found to increase HbA1c levels. The effect size of the pooled standardized mean difference in HbA1c levels between the treatment and control groups with IDA was 1.8 (95% CI = -0.5, 2.31). Heterogeneity was assessed using the I2 and χ2 tests, and the resultant values were 98.46% and p = 0.09, respectively. Additionally, the mean difference between the HbA1c levels (pre-IRT and post-IRT) showed a drop in the HbA1c levels which ranged from 1.20 to 0.43 mg/dL.

CONCLUSIONS

The results suggest that IRT decreases HbA1c levels, and it is helpful in treating IDA patients with poor glycemic control. Accordingly, the results provide an added perspective on antidiabetic medication dosing and physicians' interpretation of initially elevated HbA1c values.

Analytical evaluation and quality assessment of the ARKRAY ADAMS A1c Lite HA-8380V for HbA1c

INTRODUCTION

ARKRAY ADAMS A1c Lite HA-8380V is a fully automated high- performance liquid chromatography system for the measurement of HbA1c. We aimed to evaluate its analytical performance using the Variant Mode.

METHODS

Carry-over, linearity, imprecision, trueness, interferences and comparison against ARKRAY ADAMS A1c HA-8180V and HA-8180T analyzers were studied.

RESULTS

Total CVs 0.93% (IFCC units), 0.63% (NGSP units) at low concentration and 1.01% (IFCC) 0.74% (NGSP), at high concentration. Mean difference with the target values was -0.44 mmol/mol (IFCC) -0.04% (NGSP). Carry-over, linearity and method comparison were excellent.The results were not affected in the range of total Hb 39-199 g/L, labile fraction 5.7%, carbamylated Hb 9.1% nor acetylated Hb 7.8%, effect of common variants was negligible.

CONCLUSIONS

the analyzer demonstrated very good analytical performances, according to the consensus criteria established for HbA1c; it is adequate for laboratories with medium-low workloads.

Analytical evaluation and quality assessment of the ARKRAY ADAMS A1c HA-8190V for Hb A1c

ARKRAY ADAMS A1c HA-8190V is a fully automated high-pressure liquid chromatography (HPLC) system for the measurement of HbA1c. The runtime is 58 s per sample in the Variant mode and 24 s per sample in the Fast mode. We evaluated the analytical performance of this analyzer in the Variant mode, to verify the quality of analysis, according to the consensus criteria established for this measurand. Reproducibility, trueness, carry-over, linearity, interferences and comparison with ARKRAY ADAMS A1c HA-8180V and HA-8180T analyzers were evaluated. Total CVs were 0.76% (IFCC units) 0.55 (NGSP units) at low HbA1c concentration and 0.85% (IFCC units) 0.68 (NGSP units) at high HbA1c concentration. Mean difference with the target values was -1.25 mmol/mol (-0.119%) and total error at medium level was 2.83% (IFCC units), 2.46% (NGSP units) Carry-over was 0%. Linearity was shown in the range 27-122 mmol/mol (4.6-13.3%). The results were not affected in the range of total Hb 59-199 g/L, labile fraction up to 5.5%, carbamylated up to Hb 6.3% nor acetylated Hb up to 5.3%. Method comparison demonstrated good concordance between the methods. The analyzer demonstrated a high analytical performance adequate for routine clinical use in laboratories with high workloads.

Frequency of iron deficiency anemia in type 2 diabetes - Insights from tertiary diabetes care centres across India

AIM

To study the frequency of iron deficiency anemia (IDA) in individuals with type 2 diabetes mellitus (T2DM) seen at tertiary diabetes care centres across India.

METHODS

This is a retrospective study (January 1, 2017-December 31, 2019), which included 1137 individuals with T2DM, aged ≥18 years, for whom data on glycemic, lipid and haematological parameters were available. Anthropometric measurements were done using standardized techniques. Biochemical investigations included fasting plasma glucose[FPG], post prandial plasma glucose, HbA1c, lipids and serum ferritin and iron wherever feasible.

RESULTS

Of the 1137 individuals included for the study, 117 (10.3%) were categorized as no 'iron deficiency' (ID) group [normal hemoglobin: male ≥13 g/dl, female ≥12 g/dl and normal serum ferritin ≥70 μg/L], 123 (10.8%) as ID group [normal hemoglobin and low serum ferritin <70 μg/L)], 447 (39.3%) as IDA group [low haemoglobin: male <13 g/dl, female <12 g/dl and low serum ferritin] and 450 (39.6%) as 'anemia of chronic disease' (ACD) group [low hemoglobin and normal serum ferritin]. The percentage of women having ID (57.7%) and IDA (65.3%) was significantly higher than their male counterparts. ID was most prevalent (61.7%) in the individuals with duration of diabetes <5 years whereas ACD was most prevalent (50.5%) in individuals with long standing diabetes (>10 years). Independent risk factors for IDA were female gender (OR 3.3,95% CI:1.75-6.23, p < 0.001), duration of diabetes (OR 1.05, 95% CI 1.01-1.11, p = 0.028) and FPG (OR 1.01, 95% CI 0.99-1.00, p = 0.018).

CONCLUSIONS

There is a need of identifying and monitoring iron status and anemia in patients with T2DM.

Variation in the hemoglobin glycation index

A high hemoglobin glycation index (HGI) has been repeatedly associated with greater risk for hypoglycemia in people with diabetes and greater risk for chronic vascular disease in people with or without diabetes. This review explores how different sources of analytical and biological variation in HbA1c and blood glucose individually and collectively affect the clinical information value of HGI. We conclude that HGI is a complex quantitative trait that is a clinically practical biomarker of risk for both hypoglycemia and chronic vascular disease.

Sex-Specific Associations of Iron-Anemia Status With Hemoglobin A1C Levels Among Hispanics/Latinos Without Self-Reported Diabetes Mellitus: The Hispanic Community Health Study/Study of Latinos

OBJECTIVE

The objective of this study was to examine the sex-specific associations of mutually exclusive iron-anemia status categories with hemoglobin A1C (HbA1C) levels among U.S. Hispanics/Latinos without self-reported diabetes mellitus.

METHODS

Baseline cross-sectional data (7247 women and 4904 men without self-reported diabetes mellitus) from the Hispanic Community Health Study/Study of Latinos were analyzed. Per the American Diabetes Association's defined criteria, based on HbA1C levels, the participants were categorized as having normoglycemia, prediabetes, or probable diabetes mellitus. The iron-anemia status categories were as follows: no anemia and no iron deficiency (reference), iron deficiency, iron deficiency anemia (IDA), and non-iron deficiency anemia (non-IDA). Survey multinomial logistic regression models were used to examine the sex-specific associations of iron-anemia status with HbA1C levels after adjusting for sociodemographic, lifestyle, and clinical factors.

RESULTS

The age-standardized prevalence of iron-anemia status categories differed by sex. Compared with those with no anemia and no iron deficiency and normoglycemia, women with IDA had higher odds of having prediabetes (odds ratio [OR], 2.18; 95% CI, 1.64-2.89) and probable diabetes mellitus (OR, 3.59; 95% CI, 1.62-7.99) based on HbA1C levels; men with non-IDA had higher odds of having probable diabetes mellitus (OR, 2.97; 95% CI, 1.13-7.78) based on HbA1C levels. All other associations did not reach statistical significance.

CONCLUSION

Among U.S. Hispanics/Latinos without self-reported diabetes mellitus, the age-standardized prevalence of iron deficiency, IDA, and non-IDA is high and varies by sex. Women with IDA had higher odds of having prediabetes and probable diabetes mellitus, defined based on HbA1C levels. Men with non-IDA had higher odds of having probable diabetes mellitus, defined based on HbA1C levels. Iron-anemia status should be considered while interpreting elevated HbA1C levels among U.S. Hispanics/Latinos without self-reported diabetes mellitus.

Serum iron is negatively correlated with the HbA1c level in children and adolescents with type 1 diabetes mellitus

Although mainly affected by the blood glucose levels, the level of HbA1c could be influenced by other important factors, such as an iron deficiency, which is commonly found in children with type 1 diabetes mellitus (T1DM). However, a clinical judgment could not be established, as previous studies still reported conflicting results and lack of data regarding Indonesia. We aimed to evaluate the correlation between the serum iron and HbA1c levels in children with T1DM. This single-center cross-sectional study was conducted from February to October 2020 at Sanglah Hospital, Bali, Indonesia. Patients aged 1–18 yr were included in this study. The HbA1c and serum iron levels were evaluated in the blood samples. Spearman and partial correlation analyses were used to analyze the correlations between variables. The statistical significance was set at P < 0.05. Thirty-three subjects were analyzed, with a mean age of 11.24 ± 3.76 yr. Low serum iron and poor glycemic index were found in 54.5% and 69.7% of the subjects, respectively. Spearman correlation analysis revealed a low negative correlation between the serum iron and HbA1c levels (Spearman’s rho = –0.376, P = 0.031). A partial correlation showed a moderate negative correlation (r = –0.473, P = 0.013) after adjusting for confounding variables. This study found a moderate negative correlation between the serum iron and HbA1c level in children and adolescents with T1DM.

The Effect of Anemia and the Goal of Optimal HbA1c Control in Diabetes and Non-Diabetes

Hemoglobin A1c (HbA1c) is the gold standard for the diagnosis of diabetes; however, many clinical conditions affect the HbA1c level, including anemia. And, the most common causes of anemia worldwide include iron deficiency anemia (IDA). We performed a systematic search using different combinations of MeSH words from the electronic database for the last 10 years (2011 to 2020). Articles included in the study were observational, randomized controlled trial (RCT), and review/systematic review. A total of 18 articles were included in the study. The majority of the studies showed the association between hemoglobin (Hb) and HbA1c. Large-scale studies showed that the HbA1c level increases in IDA and some studies showed its correction after the treatment with oral iron supplementation. Our study indicates the need for screening for anemia in patients before commencing the treatment of diabetes diagnosed via the HbA1c level. Furthermore, anemia should be corrected before setting the treatment goal of optimal HbA1c control, especially when the level is in the diagnostic threshold. Also, the purpose of strict HbA1c control is not recommended in the anemic patient before it is corrected. However, further large-scale interventional studies are needed to know precisely the goal of optimal HbA1c control in diabetic and non-diabetic individuals.

Mean blood glucose-independent HbA1c racial disparity and iron status in youth with Type 1 DM

INTRODUCTION

Black patients have higher HbA1c than Whites even after adjustment for mean blood glucose (MBG). Decreased iron status has been associated with increased HbA1c independently of glucose. We hypothesized that decreased iron status might account for higher HbA1c in Black patients.

METHODS

Pediatric patients with T1D in the Diabetes Center at Children's Hospital of New Orleans who self-identified as either Black or White were recruited for the study. At the time of their clinic visit labs were obtained for ferritin (Fer), soluble transferrin receptor (sTfR), HbA1c, and CBC. MBG was derived from patient's home glucose meter records over the last 30 days. Total body iron (TBI) and sTfr/log₁₀ Fer (R/lFer) were calculated.

RESULTS

A total of 80 (35 Blacks/45 Whites; 41 female/39 male) patients were recruited. Unadjusted levels of HbA1c, MBG, sTfR, Fer, RDW-CV, and RDW-SD were all higher in Blacks than Whites. TBI and R/lFer were not different between groups. Fer was correlated with Hb, MBG but not HbA1c. sTfR was correlated with HbA1c, MCV, MCH, and RDW-SD. In multiple variable analysis with HbA1c as the dependent variable, race and MBG were statistically significant in the model. However, measures of iron status: Fer, sTfR, R/lFer and TBI were not statistically influential.

CONCLUSION

After adjustment for race, MBG and RDW-CV, iron indices were not statistically significant independent predictors of HbA1c levels. These observations indicate that factors besides iron status and CBC indices contribute to MBG-independent racial disparity in HbA1c.

Intrinsic peroxidase-like activity of 4-amino hippuric acid reduced/stabilized gold nanoparticles and its application in the selective determination of mercury and iron in ground water

Herein, we report a method for the synthesis of 4-aminohippuric acid (4-AHA) reduced/stabilized gold nanoparticles and their peroxidase mimicking properties for the colorimetric detection of Fe³⁺ and Hg²⁺. The synthesis of nanoparticles was evidenced by appearance of bright red color and an absorption peak at 518 nm. Transmission electron microscopic (TEM) characterization revealed the nanoparticles to be spherical with average size of about 5.9 ± 1.7 nm. X-ray diffraction (XRD) analysis established highly crystalline nature of the nanoparticles. The synthesized nanoparticles have shown very good peroxidase mimicking property; exhibiting the catalytic oxidation of the chromogen 3,3',5,5'-tetramethyl benzidine (TMB) to a blue color product, in the presence of hydrogen peroxide. The peroxidase mimicking activity of the nanoparticles was found to be selectivity enhanced in the presence of Fe³⁺ and Hg²⁺ while there was no change in the activity in the presence of other concomitant ions. The mechanism studies revealed that the synthesized gold nanoparticles assisted in electron transfer during the catalytic process however the stimulation of peroxidase-like activity in the presence of Fe³⁺ and Hg²⁺ is owed to both generation of hydroxyl radical and accelerated electron transfer. The assay was made selective for iron by the addition of cysteine in acetate buffer; whereas the selective detection of mercury was achieved by carrying out the assay in citrate buffer. The linear ranges for the determination of Fe³⁺ and Hg²⁺ in deionized water were found to be: 5-50 ppb and 5-200 ppb respectively. The limits of quantification (LOQ) for Fe³⁺ and Hg²⁺ were 4.0 and 2.5 ppb respectively. The assay was applied for the determination of Fe³⁺ and Hg²⁺ in drinking and ground water samples. The method holds potential for the on-field screening of these metal ions in real environmental samples.

High prevalence and heterogeneity of Dysglycemia in patients with tuberculosis from Peru: a prospective cohort study

BACKGROUND

The accuracy of different laboratory tests for diagnosis of diabetes mellitus (DM) and prediabetes (preDM) in populations exposed to tuberculosis (TB) remains poorly understood. Here, we examined the prevalence of DM and preDM in TB affected people in Lima, Peru.

METHODS

A prospective cohort study of patients affected TB and their household contacts (HHC), was conducted between February and November 2017 in Lima, Peru. Fasting plasma glucose (FPG), HbA1c and oral glucose tolerance test (OGTT) were used to detect DM and preDM in a prospective cohort of TB patients (n = 136) and household contacts (n = 138). Diagnostic performance of the laboratory tests was analyzed. Potential effects of sociodemographic and clinical factors on detection of dysglycemia were analyzed.

RESULTS

In TB patients, prevalence of DM and preDM was 13.97 and 30.88% respectively. Lower prevalence of both DM (6.52%) and preDM (28.99%) were observed in contacts. FPG, HbA1c and OGTT had poor agreement in detection of preDM in either TB cases or contacts. TB-DM patients had substantially lower hemoglobin levels, which resulted in low accuracy of HbA1c-based diagnosis. Classic sociodemographic and clinical characteristics were not different between TB patients with or without dysglycemia.

CONCLUSION

High prevalence of DM and preDM was found in both TB patients and contacts in Lima. Anemia was strongly associated with TB-DM, which directly affected the diagnostic performance of HbA1c in such population.

Ironing out the Details: Untangling Dietary Iron and Genetic Background in Diabetes

The search for genetic risk factors in type-II diabetes has been hindered by a failure to consider dietary variables. Dietary nutrients impact metabolic disease risk and severity and are essential to maintaining metabolic health. Genetic variation between individuals confers differences in metabolism, which directly impacts response to diet. Most studies attempting to identify genetic risk factors in disease fail to incorporate dietary components, and thus are ill-equipped to capture the breadth of the genome's impact on metabolism. Understanding how genetic background interacts with nutrients holds the key to predicting and preventing metabolic diseases through the implementation of personalized nutrition. Dysregulation of iron homeostasis is associated with type-II diabetes, but the link between dietary iron and metabolic dysfunction is poorly defined. High iron burden in adipose tissue induces insulin resistance, but the mechanisms underlying adipose iron accumulation remain unknown. Hepcidin controls dietary iron absorption and distribution in metabolic tissues, but it is unknown whether genetic variation influencing hepcidin expression modifies susceptibility to dietary iron-induced insulin resistance. This review highlights discoveries concerning the axis of iron homeostasis and adipose function and suggests that genetic variation underlying dietary iron metabolism is an understudied component of metabolic disease.