Association between the presence of iron deficiency anemia and hemoglobin A1c in Korean adults: the 2011-2012 Korea National Health and Nutrition Examination Survey

Obesity modifies the association between diabetes and iron biomarkers and red cell indices in reproductive-aged women in the United States

Obesity and diabetes are associated with impaired iron metabolism. We aimed to examine the independent relationship between diabetes and iron after controlling for body weight (or obesity) in women aged 20-49 years. The National Health and Nutrition Examination Survey data from 2015 to 2018 were used in this investigation. Body composition data, HbAc1, iron biomarkers (serum ferritin (SF), soluble transferrin receptor (sTfR), and body iron index (BII)), mean corpuscular volume (MCV), mean hemoglobin concentration (MCH), red cell distribution width (RDW), and hemoglobin were used. Linear regression models were used to examine how and to what extent body mass index (BMI) modified the relationship between diabetes and iron status biomarkers. A total of 1834 women aged 20-49 were included in the analysis with a mean (SD) age of 32 .2 ± 6.1 years and BMI of 29.5 ± 6.9 kg/m2. The mean SF (p = 0.014) and BII (p < 0.001) were lower, while sTfR (p < 0.001) was higher in women with diabetes than those with no diabetes. Mean estimates for MCV and MCH were lower, while RDW (p = 0.001) was higher in diabetes patients (all p < 0.001). Women with diabetes were more likely to have iron deficiency, anemia, and iron deficiency anemia than those without diabetes (18.1% vs 8.6%, p < 0.001), (24.4% vs 8.4%, p < 0.001), and (14.8% vs 5.2%, p < 0.001), respectively. Among women with obesity, those with diabetes had lower predicted ferritin (β = -0.19, p = 0.016), BII (β = -0.99, p = 0.016), and hemoglobin (β = -0.27, p = 0.042) than those without diabetes. The study shows that diabetes is linked to lower iron stores; this is exacerbated in those with obesity.

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.

Correlation of HbA1c with Serum Iron & Transferrin Saturation in Non-Diabetic Patients with Iron Deficiency

Objective

To determine correlation of HbA1c with serum iron and transferrin saturation in non-diabetic patients with iron deficiency.

Methods

This cross-sectional comparative study was conducted at Dr Ruth KM Pfau Civil Hospital Karachi from 15th September 2021 to 14th March 2022, on non-diabetic patients based on fasting blood sugar (FBS) of <100 mg/dl. Patients were divided into two groups. Group one included patients having iron deficiency anemia (ID), whereas group two included same number of age and sex matched healthy subjects taken as controls, without ID. Blood sample was taken for HbA1c, CBC, serum iron and total iron binding capacity. Transferrin saturation (TSAT) was calculated. Comparison of quantitative variables with ID and non-ID group was done by Student's t-test. Correlation of HbA1c with iron &TSAT was done in both groups using Kendal tau-b test, as data was not normally distributed.

Results

Out of 230 patients, 83 (36.1%) were males while 147(63.9%) were females. Mean age of patients was 43.7±13.28 years. Mean HbA1c level was significantly high in ID group (5.89±0.43) as compared to non-ID group (5.52±0.50) with a p-value <.001. The HbA1c levels correlated negatively with hemoglobin, serum iron levels and transferrin saturation with a p-value <.001.

Conclusion

Low serum Iron and TSAT was related to elevation in HbA1c value. Iron deficiency needs to be corrected before HbA1c interpretation.

Rubrometabolic Syndrome

Metabolic syndrome (MS), a conglomeration of several conditions including obesity, type 2 diabetes mellitus (T2DM), insulin resistance, elevated blood pressure, and dyslipidemia is reaching epidemic proportions. Anemia is caused by iron deficiency or dysregulation of iron homeostasis, leading to tissue hypoxia. Coexistence of anemia and MS or its components has been reported in the literature. The term "rubrometabolic syndrome" acts as a unifying entity linking the importance of blood in health and anemia in MS; it justifies two principles - redness of blood and low-grade inflammation. Chronic low-grade inflammation in MS affects iron metabolism leading to anemia. Tissue hypoxia that results from the anemic condition seems to be a major causative factor for the exacerbation of several microvascular and macrovascular components of T2DM, which include diabetic neuropathy, nephropathy, retinopathy, and cardiovascular complications. In obesity, anemia leads to malabsorption of micronutrients and can complicate the management of the condition by bariatric surgery. Anemia interferes with the diagnosis and management of T2DM, obesity, dyslipidemia, or hypertension due to its effect on pathological tests as well as medications. Since anemia in MS is multifaceted, the management of anemia is challenging as overcorrection of anemia with erythropoietin-stimulating agents can cause detrimental effects. These limitations necessitate availability of an effective and safe therapy that can maintain and elevate the hemoglobin levels along with maintaining the physiological balance of other systems. This review discusses the physiological links between anemia and MS along with diagnosis and management strategies in patients with coexistence of anemia and MS.

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.

Random forest approach for determining risk prediction and predictive factors of type 2 diabetes: large-scale health check-up data in Japan

Introduction

Early intervention in type 2 diabetes can prevent exacerbation of insulin resistance. More effective interventions can be implemented by early and precise prediction of the change in glycated haemoglobin A1c (HbA1c). Artificial intelligence (AI), which has been introduced into various medical fields, may be useful in predicting changes in HbA1c. However, the inability to explain the predictive factors has been a problem in the use of deep learning, the leading AI technology. Therefore, we applied a highly interpretable AI method, random forest (RF), to large-scale health check-up data and examined whether there was an advantage over a conventional prediction model.

Research design and methods

This study included a cumulative total of 42 908 subjects not receiving treatment for diabetes with an HbA1c <6.5%. The objective variable was the change in HbA1c in the next year. Each prediction model was created with 51 health-check items and part of their change values from the previous year. We used two analytical methods to compare the predictive powers: RF as a new model and multivariate logistic regression (MLR) as a conventional model. We also created models excluding the change values to determine whether it positively affected the predictions. In addition, variable importance was calculated in the RF analysis, and standard regression coefficients were calculated in the MLR analysis to identify the predictors.

Results

The RF model showed a higher predictive power for the change in HbA1c than MLR in all models. The RF model including change values showed the highest predictive power. In the RF prediction model, HbA1c, fasting blood glucose, body weight, alkaline phosphatase and platelet count were factors with high predictive power.

Conclusions

Correct use of the RF method may enable highly accurate risk prediction for the change in HbA1c and may allow the identification of new diabetes risk predictors.

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.

Associations of anemia and hemoglobin with hemoglobin A1c among non-diabetic workers in Japan

AIMS/INTRODUCTION

We examined the association between hemoglobin A1c (HbA1c) and anemia, which was categorized into three groups according to mean corpuscular volume (MCV), as well as the association between hemoglobin in the non-anemic range and HbA1c.

MATERIALS AND METHODS

We used the 2016 health checkup data from 36,422 workers without diabetes. Anemic people were divided into three groups based on MCV: <80, 80-90 and >90 fL. Non-anemic people were divided into four groups based on their hemoglobin levels. We carried out multiple linear regression models to estimate the means and 95% confidence intervals (CIs) of HbA1c.

RESULTS

For men, 0.2% had anemia with MCV <80 fL, 0.5% had anemia with MCV 80-90 fL, 0.9% had anemia with MCV >90 fL and 98.4% had no anemia. For women, the corresponding values were 6.1, 6.4, 2.8 and 84.7%, respectively. The adjusted mean HbA1c (%) values for men with anemia with MCV <80, 80-90 and >90 fL were 5.67 (95% CI 5.60-5.74), 5.58 (95% CI 5.54-5.62) and 5.41 (95% CI 5.37-5.44), respectively. Among men without anemia, HbA1c (%) increased from 5.36 (95% CI 5.34-5.39) in those with hemoglobin ≥17.5 mg/dL to 5.45 (95% CI 5.45-5.46) in those with hemoglobin 13.0 to <14.5 mg/dL (P for trend <0.001). The HbA1c values were higher in men with anemia with MCV <80 fL or MCV 80-90 fL, but lower in men with MCV >90 fL, compared with non-anemic men with hemoglobin 13.0 to <14.5 mg/dL (All P < 0.001). Similar findings were observed in women.

CONCLUSIONS

We observed elevated HbA1c among anemic people with MCV <80 fL or MCV 80-90 fL, and decreased HbA1c among anemic people with MCV >90 fL, suggesting that different types of anemia might influence HbA1c differently. In addition, non-anemic people with lower hemoglobin levels had higher HbA1c levels, suggesting that hemoglobin levels are in need of consideration when interpreting HbA1c values among non-anemic people.

Increased Levels of Glycated Hemoglobin A1c and Iron Deficiency Anemia: A Review

Worldwide, the prevalence of diabetes remains high. Studies have shown that iron deficiency anemia (IDA) is associated with increased levels of glycated hemoglobin A1c (HbA1c), but the mechanism remains unclear. Hematological changes, iron metabolism, study methodology, and other factors could affect the results of diagnostic investigations, leading to false results. Red blood cell turnover in the bone marrow and the quality and heterogeneity of erythrocytes may influence the rate of hemoglobin glycation. By changing the structure of hemoglobin and inducing peroxidation, iron deficiency accelerates glycation. This review aims to discuss the possible causes of the association between increased levels of HbA1c and IDA.

Accuracy of diabetes screening methods used for people with tuberculosis, Indonesia, Peru, Romania, South Africa

Objective

To evaluate the performance of diagnostic tools for diabetes mellitus, including laboratory methods and clinical risk scores, in newly-diagnosed pulmonary tuberculosis patients from four middle-income countries.

Methods

In a multicentre, prospective study, we recruited 2185 patients with pulmonary tuberculosis from sites in Indonesia, Peru, Romania and South Africa from January 2014 to September 2016. Using laboratory-measured glycated haemoglobin (HbA1c) as the gold standard, we measured the diagnostic accuracy of random plasma glucose, point-of-care HbA1c, fasting blood glucose, urine dipstick, published and newly derived diabetes mellitus risk scores and anthropometric measurements. We also analysed combinations of tests, including a two-step test using point-of-care HbA1cwhen initial random plasma glucose was ≥ 6.1 mmol/L.

Findings

The overall crude prevalence of diabetes mellitus among newly diagnosed tuberculosis patients was 283/2185 (13.0%; 95% confidence interval, CI: 11.6–14.4). The marker with the best diagnostic accuracy was point-of-care HbA1c (area under receiver operating characteristic curve: 0.81; 95% CI: 0.75–0.86). A risk score derived using age, point-of-care HbA1c and random plasma glucose had the best overall diagnostic accuracy (area under curve: 0.85; 95% CI: 0.81–0.90). There was substantial heterogeneity between sites for all markers, but the two-step combination test performed well in Indonesia and Peru.

Conclusion

Random plasma glucose followed by point-of-care HbA1c testing can accurately diagnose diabetes in tuberculosis patients, particularly those with substantial hyperglycaemia, while reducing the need for more expensive point-of-care HbA1c testing. Risk scores with or without biochemical data may be useful but require validation.

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.

Prevalence of non-communicable disease risk factors among poor shantytown residents in Dhaka, Bangladesh: a community-based cross-sectional survey

OBJECTIVES

This study aims to describe the prevalence of non-communicable disease (NCD) risk factors among the urban poor in Bangladesh.

DESIGN

We conducted a community-based cross-sectional epidemiological study.

SETTING

The study was conducted in a shantytown in the city of Dhaka. There were 8604 households with 34 170 residents in the community. Those households were categorised into two wealth strata based on the housing structure.

PARTICIPANTS

The study targeted residents aged 18-64 years. A total of 2986 eligible households with one eligible individual were selected by simple random sampling stratified by household wealth status. A total of 2551 residents completed the questionnaire survey, and 2009 participated in the subsequent physical and biochemical measurements.

OUTCOME MEASURES

A modified WHO survey instrument was used for assessing behavioural risk factors and physical and biochemical measurements, including glycated haemoglobin (HbA1c). The prevalence of NCD risk factors, such as tobacco use, fruit and vegetable intake, overweight/obesity, hypertension, diabetes (HbA1c ≥6.5%) and dyslipidaemia, was described according to household wealth status and gender differences.

RESULTS

The prevalence of current tobacco use was 60.4% in men and 23.5% in women. Most of them (90.8%) consumed more than 1 serving of fruits and vegetables per day; however, only 2.1% consumed more than 5 servings. Overweight/obesity was more common in women (39.2%) than in men (18.9%), while underweight was more common in men (21.0%) than in women (7.1%). The prevalence of hypertension was 18.6% in men and 20.7% in women. The prevalence of diabetes was 15.6% in men and 22.5% in women, which was much higher than the estimated national prevalence (7%). The prevalence of raised total cholesterol (≥190 mg/dL) was 25.7% in men and 34.0% in women.

CONCLUSION

The study identified that tobacco use, both overweight and underweight, diabetes, hypertension and dyslipidaemia were prevalent among the urban poor in Bangladesh.

The prevalence of and factors associated with high-risk alcohol consumption in Korean adults: The 2009-2011 Korea National Health and Nutrition Examination Survey

Background

The consequences of alcohol consumption on health outcomes are largely determined by two separate, but related, dimensions of drinking: the total volume of alcohol consumed and the pattern of drinking. Most epidemiological studies focus on the amount of alcohol consumed and do not consider the pattern of drinking.

Objectives

This study evaluated the prevalence of and factors associated with high-risk and heavy alcohol drinking in Korean adults.

Methods

This study analyzed 15,215 of the 28,009 participants in the 2009–2011 Korea National Health and Nutrition Examination Survey (KNHANES). High-risk alcohol drinking was defined as Alcohol Use Disorders Identification Test (AUDIT) scores ≥16, which provides a framework for intervention to identify hazardous and harmful drinking patterns as the cause of alcohol-use disorders, according to World Health Organization guidelines.

Results

The prevalence of high-risk drinking was 15.1%, with the highest prevalence of 17.2% in middle-aged adults (45–64 years). In men, the prevalence of high-risk alcohol drinking was 23.7%, with the highest prevalence found in middle-aged adults. In women, the prevalence of high-risk alcohol drinking was 4.2%, with the highest prevalence found in younger adults. Men had higher weighted mean AUDIT scores than women (10.0 vs. 4.0, P<0.001), and age was negatively associated with the AUDIT score (P<0.001). Elementary school graduates had higher mean AUDIT scores than senior high school (P = 0.003) or college (P<0.001) graduates. Regarding occupation, clerical support workers (P = 0.002) and service and sales workers (P<0.001) had higher mean AUDIT scores than managers and professionals. Logistic regression analyses of high-risk alcohol drinking using sex, age, education level, number of family members, household income, and occupation as covariates was performed. Women had a lower risk of high-risk alcohol drinking (odds ratio (OR) 0.14, 95% CI: 0.13–0.16, P<0.001) than men. Regarding age, compared to control subjects aged 19–29 years, adults aged 60–69 and older than 70 years had 0.67- (95% CI: 0.51–0.89, P = 0.005) and 0.29-fold (95% CI: 0.20–0.70, P<0.001) lower risks, respectively, of high-risk alcohol drinking, whereas adults aged 30–59 had an increased risk of high-risk alcohol drinking. Using elementary school graduates as controls, senior high school (OR: 0.70, 95% CI: 0.55–0.87, P = 0.002) and college (OR: 0.54, 95% CI: 0.42–0. 70, P<0.001) graduates had lower risks of high-risk alcohol drinking. Regarding occupation, compared to managers and professionals as controls, service and sales workers had a greater risk of high-risk alcohol drinking (OR: 1.36, 95% CI: 1.07–1.73, P = 0.011). The number of family members and household income did not influence high-risk alcohol drinking.

Conclusions

In a representative sample of Korean adults, the prevalence of high-risk alcohol drinking was 15.1%, with the highest prevalence of 28.3% found in middle-aged men (45–64 years). This study suggests that younger age, male sex, low education level, and service and sales workers are at risk for a high-risk drinking pattern.

Is an Oral Glucose Tolerance Test Still Valid for Diagnosing Diabetes Mellitus?

BACKGROUND

We evaluated the diagnostic rate of diabetes using fasting plasma glucose (FPG), 2-hour plasma glucose (2h PG) after 75 g oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c) levels, and we elucidated the pathophysiologic characteristics and risk factors that give rise to diabetes in patients with prediabetes.

METHODS

The data of 236 patients who had the OGTT at Konkuk University Hospital were analyzed. Fasting, 30, and 120 minutes blood glucose levels and insulin levels were measured. The diagnostic rate of diabetes was assessed using FPG, 2h PG, and HbA1c levels. The clinical data and insulin resistance and secretion evaluations were compared using indexes according to the fasting glucose level.

RESULTS

Among 236 subjects, 97 (41.1%) were diabetics and 102 (43.2%) were prediabetics. The rate of diabetes diagnosis by one of the individual criteria was 56.7%, 53.6%, and 84.5% for FPG, HbA1c, and 2h PG, respectively. When two criteria were used to diagnose diabetes, 72.2% of the diabetic patients were identified by FPG and HbA1c, while 100% were identified by FPG and 2h PG, and 91.7% were identified by 2h PG and HbA1c. The HbA1c cut-off value for 2h PG ≥200 mg/dL was 6.1%, and the FPG cut-off value was 115 mg/dL. In impaired fasting glucose subjects, the HbA1c level, Matsuda index, and insulinogenic index were associated with risk of occurrence of overt diabetes (P<0.01).

CONCLUSION

This study suggests that performing additional OGTT for patients with FPG ≥110 mg/dL or HbA1c ≥6.1% is helpful to reclassify their glucose tolerance status and evaluate their potential for progressing to overt diabetes.

Led Astray by Hemoglobin A1c: A Case of Misdiagnosis of Diabetes by Falsely Elevated Hemoglobin A1c

Hemoglobin A1c (A1c) is used frequently to diagnose and treat diabetes mellitus. Therefore, it is important be aware of factors that may interfere with the accuracy of A1c measurements. This is a case of a rare hemoglobin variant that falsely elevated a nondiabetic patient’s A1c level and led to a misdiagnosis of diabetes. A 67-year-old male presented to endocrine clinic for further management after he was diagnosed with diabetes based on an elevated A1c of 10.7%, which is approximately equivalent to an average blood glucose of 260 mg/dL. Multiple repeat A1c levels remained >10%, but his home fasting and random glucose monitoring ranged from 92 to 130 mg/dL. Hemoglobin electrophoresis and subsequent genetic analysis diagnosed the patient with hemoglobin Wayne, a rare hemoglobin variant. This variant falsely elevates A1c levels when A1c is measured using cation-exchange high-performance liquid chromatography. When the boronate affinity method was applied instead, the patient’s A1c level was actually 4.7%. Though hemoglobin Wayne is clinically silent, this patient was erroneously diagnosed with diabetes and started on an antiglycemic medication. Due to this misdiagnosis, the patient was at risk of escalation in his “diabetes management” and hypoglycemia. Therefore, it is important that providers are aware of factors that may result in hemoglobin A1c inaccuracy including hemoglobin variants.