The effect of anaemia and abnormalities of erythrocyte indices on HbA1c analysis: a systematic review

Association between the haemoglobin glycation index (HGI) and clinical outcomes in patients with acute decompensated heart failure

BACKGROUND

A growing number of studies show that people with similar blood glucose levels have different levels of glycosylated haemoglobin (HbA1c), and relying only on HbA1c may lead to clinical decision-making errors. The haemoglobin glycation index (HGI) quantifies the difference in HbA1c among individuals and is strongly linked to the risk of cardiovascular disease. However, the connection between this phenomenon and the poor outcomes of patients with acute decompensated heart failure (ADHF) is currently unknown.

PATIENTS AND METHODS

This retrospective, single-centre-based cohort study included 1531 hospitalized patients with ADHF from September 2010 to January 2020. The HGI is calculated from the difference between the observed and predicted HbA1c values [predicted HbA1c = 0.024 × fasting plasma glucose (FPG) (mg/dL)+3.1]. The endpoints examined in the study included all-cause death, cardiovascular (CV) death, and major adverse cardiac events (MACE). We fitted multivariable-adjusted Cox proportional hazard models to investigate the association between the HGI and clinical outcomes.

RESULTS

During the five-year follow-up, 427 (27.9%) patients died from all causes, 232 (15.6%) from CV death, and 848 (55.4%) from MACE. The restricted cubic spline analysis also showed that the cumulative risk of all-cause and CV deaths decreased linearly with increasing HGI. According to multivariate Cox proportional hazard models, the highest tertile of the HGI was associated with a lower incidence of all-cause and cardiovascular deaths [all-cause death, adjusted hazard ratio (HR): 0.720, 95% confidence interval (CI): 0.563-0.921, p = 0.009; CV death, adjusted HR: 0.619, 95% CI: 0.445-0.861, p = 0.004]. A 1% increase in the HGI was associated with a 12.5% reduction in the risk of all-cause death and a 20.8% reduction in the risk of CV death.

CONCLUSIONS

A high HGI was directly associated with a reduction in all-cause and CV deaths but was not associated with MACE. These findings may be helpful in the management of patients with ADHF.

Endocrinopathies in beta thalassemia: a narrative review

Beta thalassemia is the most common genetic blood disorder, characterized by reduced production or complete absence of beta-globin chains. The combination of systematic red blood cell transfusion and iron chelation therapy is the most readily available supportive treatment and one that has considerably prolonged the survival of thalassemia patients. Despite this, the development of endocrine abnormalities correlated with beta thalassemia still exists and is mostly associated with iron overload, chronic anemia, and hypoxia. A multifactorial approach has been employed to investigate other factors involved in the pathogenesis of endocrinopathies, including genotype, liver disease, HCV, splenectomy, socioeconomic factors, chelation therapy, and deficiency of elements. The development of specific biomarkers for predicting endocrinopathy risk has been the subject of extensive discussion. The objective of the present narrative review is to present recent data on endocrinopathies in beta thalassemia patients, including the prevalence, the proposed pathogenetic mechanisms, the risk factors, the diagnostic methods applied, and finally the recommended treatment options.

Diabetes mellitus in older persons with neurocognitive disorder: overtreatment prevalence and associated structural brain MRI findings

BACKGROUND

Tight diabetes control is often applied in older persons with neurocognitive disorder resulting in increased hypoglycemic episodes but little is known about the pattern of brain injury in these overtreated patients. This study aims to: (a) quantify the prevalence of diabetes overtreatment in cognitively impaired older adults in a clinical population followed in an academic memory clinic (b) identify risk factors contributing to overtreatment; and (c) explore the association between diabetes overtreatment and specific brain region volume changes.

METHODS

Retrospective study of older patients with type 2 diabetes and cognitive impairment who were diagnosed in a memory clinic from 2013 to 2020. Patients were classified into vulnerable and dependent according to their health profile. Overtreatment was defined when glycated hemoglobin was under 7% for vulnerable and 7.6% for dependent patients. Characteristics associated to overtreatment were examined in multivariable analysis. Grey matter volume in defined brain regions was measured from MRI using voxel-based morphometry and compared in patients over- vs. adequately treated.

RESULTS

Among 161 patients included (median age 76.8 years, range 60.8-93.3 years, 32.9% women), 29.8% were considered as adequately treated, 54.0% as overtreated, and 16.2% as undertreated. In multivariable analyses, no association was observed between diabetes overtreatment and age or the severity of cognitive impairment. Among patients with neuroimaging data (N = 71), associations between overtreatment and grey matter loss were observed in several brain regions. Specifically, significant reductions in grey matter were found in the caudate (adj β coeff: -0.217, 95%CI: [-0.416 to -0.018], p = .033), the precentral gyri (adj βcoeff:-0.277, 95%CI: [-0.482 to -0.073], p = .009), the superior frontal gyri (adj βcoeff: -0.244, 95%CI: [-0.458 to -0.030], p = .026), the calcarine cortex (adj βcoeff:-0.193, 95%CI: [-0.386 to -0.001], p = .049), the superior occipital gyri (adj βcoeff: -0.291, 95%CI: [-0.521 to -0.061], p = .014) and the inferior occipital gyri (adj βcoeff: -0.236, 95%CI: [-0.456 to - 0.015], p = .036).

CONCLUSION

A significant proportion of older patients with diabetes and neurocognitive disorder were subjected to excessively intensive treatment. The association identified with volume loss in several specific brain regions highlights the need to further investigate the potential cerebral damages associated with overtreatment and related hypoglycemia in larger sample.

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.

Application and management of continuous glucose monitoring in diabetic kidney disease

Diabetic kidney disease (DKD) is a common complication of diabetes mellitus that contributes to the risk of end-stage kidney disease (ESKD). Wide glycemic var-iations, such as hypoglycemia and hyperglycemia, are broadly found in diabetic patients with DKD and especially ESKD, as a result of impaired renal metabolism. It is essential to monitor glycemia for effective management of DKD. Hemoglobin A1c (HbA1c) has long been considered as the gold standard for monitoring glycemia for > 3 months. However, assessment of HbA1c has some bias as it is susceptible to factors such as anemia and liver or kidney dysfunction. Continuous glucose monitoring (CGM) has provided new insights on glycemic assessment and management. CGM directly measures glucose level in interstitial fluid, reports real-time or retrospective glucose concentration, and provides multiple glycemic metrics. It avoids the pitfalls of HbA1c in some contexts, and may serve as a precise alternative to estimation of mean glucose and glycemic variability. Emerging studies have demonstrated the merits of CGM for precise monitoring, which allows fine-tuning of glycemic management in diabetic patients. Therefore, CGM technology has the potential for better glycemic monitoring in DKD patients. More research is needed to explore its application and management in different stages of DKD, including hemodialysis, peritoneal dialysis and kidney transplantation.

The Glycemic Ratio Is Strongly and Independently Associated With Mortality in the Critically Ill

BACKGROUND

Interventional studies investigating blood glucose (BG) management in intensive care units (ICU) have been inconclusive. New insights are needed. We assessed the ability of a new metric, the Glycemic Ratio (GR), to determine the relationship of ICU glucose control relative to preadmission glycemia and mortality.

METHODS

Retrospective cohort investigation (n = 4790) in an adult medical-surgical ICU included patients with minimum four BGs, hemoglobin (Hgb), and hemoglobin A1c (HbA1c). The GR is the quotient of mean ICU BGs (mBG) and estimated preadmission BG, derived from HbA1c.

RESULTS

Mortality displayed a J-shaped curve with GR (nadir GR 0.9), independent of background glycemia, consistent for HbA1c <6.5% vs >6.5%, and Hgb >10 g/dL vs <10 g/dL and medical versus surgical. An optimal range of GR 0.80 to 0.99 was associated with decreased mortality compared with GR above and below this range. The mBG displayed a linear relationship with mortality at lower HbA1c but diminished for HbA1c >6.5%, and dependent on preadmission glycemia. In adjusted analysis, GR remained associated with mortality (odds ratio = 2.61, 95% confidence interval = 1.48-4.62, P = .0012), but mBG did not (1.004, 1.000-1.009, .059). A single value on admission was not independently associated with mortality.

CONCLUSIONS

The GR provided new insight into malglycemia that was not apparent using mBG, or an admission value. Mortality was associated with acute change from preadmission glycemia (GR). Further assessment of the impact of GR deviations from the nadir in mortality at GR 0.80 to 0.99, as both relative hypo- and hyperglycemia, and as duration of exposure and intensity, may further define the multifaceted nature of malglycemia.

Association of iron homeostasis biomarkers in type 2 diabetes and glycaemic traits: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Mendelian randomization (MR) studies show iron positively associated with type 2 diabetes (T2D) but included potentially biasing hereditary haemochromatosis variants and did not assess reverse causality.

METHODS

We assessed the relation of iron homeostasis with T2D and glycaemic traits bidirectionally, using genome-wide association studies (GWAS) of iron homeostasis biomarkers [ferritin, serum iron, total iron-binding capacity (TIBC), transferrin saturation (TSAT) (n ≤ 246 139)], T2D (DIAMANTE n = 933 970 and FinnGen n = 300 483), and glycaemic traits [fasting glucose (FG), 2-h glucose, glycated haemoglobin (HbA1c) and fasting insulin (FI) (n ≤ 209 605)]. Inverse variance weighting (IVW) was the main analysis, supplemented with sensitivity analyses and assessment of mediation by hepcidin.

RESULTS

Iron homeostasis biomarkers were largely unrelated to T2D, although serum iron was potentially associated with higher T2D [odds ratio: 1.07 per standard deviation; 95% confidence interval (CI): 0.99 to 1.16; P-value: 0.078) in DIAMANTE only. Higher ferritin, serum iron, TSAT and lower TIBC likely decreased HbA1c, but were not associated with other glycaemic traits. Liability to T2D likely increased TIBC (0.03 per log odds; 95% CI: 0.01 to 0.05; P-value: 0.005), FI likely increased ferritin (0.29 per log pmol/L; 95% CI: 0.12 to 0.47; P-value: 8.72 x 10-4). FG likely increased serum iron (0.06 per mmol/L; 95% CI: 0.001 to 0.12; P-value: 0.046). Hepcidin did not mediate these associations.

CONCLUSION

It is unlikely that ferritin, TSAT and TIBC cause T2D although an association for serum iron could not be excluded. Glycaemic traits and liability to T2D may affect iron homeostasis, but mediation by hepcidin is unlikely. Corresponding mechanistic studies are warranted.

Impact of stress hyperglycemia ratio, derived from glycated albumin or hemoglobin A1c, on mortality among ST-segment elevation myocardial infarction patients

BACKGROUND

Stress hyperglycemia ratio (SHR), associated with adverse outcomes in patients with ST-segment elevation myocardial infarction (STEMI), has several definitions. This study aims to assess the prognostic value of SHR, derived from hemoglobin A1c (HbA1c) or glycated albumin (GA), to mortality.

METHODS

The study comprised 1,643 STEMI patients who underwent percutaneous coronary intervention (PCI) in two centers. SHR1 was calculated using fasting blood glucose (FBG)/GA, while SHR2 was calculated using the formula FBG/(1.59*HbA1c-2.59). The primary endpoints were in-hospital death and all-cause mortality, with a median follow-up duration of 1.56 years.

RESULTS

Higher SHR1 and SHR2 values are associated with increased risks of in-hospital death and all-cause mortality. Each standard deviation increase in SHR1 corresponded to a 39% and 22% escalation in in-hospital death and all-cause mortality, respectively. The respective increases for SHR2 were 51% and 26%. Further examinations validated these relationships as linear. Additionally, the areas under the curve (AUC) for in-hospital death were not significantly different between SHR1 and SHR2 (p > 0.05). Incorporating SHR1 or SHR2 into the base model significantly improved the discrimination and risk reclassification for in-hospital and all-cause mortality. A subgroup analysis revealed that the effects of SHR1 and SHR2 were more pronounced in patients with hypercholesteremia.

CONCLUSION

SHR1 and SHR2 have emerged as robust and independent prognostic markers for STEMI patients undergoing PCI. The SHR calculation based on either HbA1c or GA can provide additional predictive value for mortality beyond traditional risk factors, helping to identify high-risk STEMI patients.

Implications of Iron Deficiency Anaemia on Glycemic Dynamics in Diabetes Mellitus: A Critical Risk Factor in Cardiovascular Disease

BACKGROUND

Iron deficiency anemia (IDA) is a highly prevalent comorbidity in patients with diabetes, with rates estimated between 13% and 47% across studies. Iron deficiency anemia may potentially influence hemoglobin A1c (HbA1c) values, which are routinely measured to monitor long-term glycemic control in diabetes. Some evidence suggests that HbA1c may be lower in diabetics with IDA due to increased red blood cell turnover. However, current evidence elucidating the effects of IDA on HbA1c and diabetes outcomes remains inconsistent and inconclusive.

OBJECTIVE

This cross-sectional study aimed to evaluate the relationship between IDA, HbA1c levels, and glycemic dynamics in patients with diabetes mellitus.

METHODS

The study sample included 143 adult patients diagnosed with diabetes, recruited from outpatient clinics in Saudi Arabia. Iron deficiency anemia was identified through serum ferritin <100 ng/mL, transferrin saturation <20%, and hematologic parameters. The HbA1c levels were measured using standardized laboratory methods. Daily glucose profiles were obtained by continuous glucose monitoring (CGM) in a subset of patients to assess glycemic dynamics.

RESULTS

The prevalence of IDA was 39.9% among the diabetic cohort. Patients with IDA had a numerically higher mean HbA1c of 7.2% compared to 6.8% in non-anemic diabetics, suggesting a potential effect of IDA on HbA1c. Those with IDA also spent more time in hyperglycemic ranges, along with greater glucose variability based on CGM data. Iron deficiency measures, including low ferritin and high red cell distribution width (RDW), showed weak positive correlations with HbA1c levels.

CONCLUSION

Iron deficiency anemia is highly prevalent among Saudi diabetic patients and is potentially associated with inaccurate HbA1c values and poor short-term glycemic control. However, larger controlled studies are warranted to conclusively investigate mechanisms linking IDA to alterations in HbA1c and glycemic dynamics. Optimized screening and treatment of IDA may lead to more accurate diabetes monitoring and improved outcomes.

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance.

The evolving continuum of dysglycaemia: Non-diabetic hyperglycaemia in older adults

Identifying non-diabetic hyperglycaemia (NDH) and intervening to halt the progression to type 2 diabetes has become an essential component of cardiovascular and cerebrovascular risk reduction. Diabetes prevention programs have been instigated to address the increasing prevalence of NDH and type 2 diabetes by targeting lifestyle modifications. Evidence suggests that the risk of progression from NDH to type 2 diabetes declines with age, and that a diagnosis of type 2 diabetes in older adults is not associated with the same risk of adverse consequences as it is in younger age groups. The current definition of NDH is not adjusted based on a person's age. Therefore, there is debate about the emphasis that should be placed upon a diagnosis of NDH in older adults. This article will explore the evidence and current clinical practice surrounding dysglycaemia through the spectrum of different age ranges, and the potential implications this has for older adults.

Use of Continuous Glucose Monitoring in Patients Following Bariatric Surgery: A Scoping Review

The objective of this scoping review was to summarize the emerging literature on the use of continuous glucose monitoring (CGM) in post-bariatric surgery patients, with a focus on its features (e.g., device, mode, and accuracy), as well as purposes and outcomes of utilization. Three databases (PubMed, EMBASE, and Web of Science) were searched to obtain relevant studies. Results suggested that most studies used CGM for 3-7 days under blinded mode. Accuracy data were available in only one study, which reported a mean absolute relative difference of 21.7% for Freestyle Libre. The primary applications of CGM were for elucidating glucose patterns and assessing glycemic treatment outcomes. No study has tested the effect of CGM as an intervention strategy to enhance glucose control.

The risk of clinical misinterpretation of HbA1c: Modelling the impact of biological variation and analytical performance on HbA1c used for diagnosis and monitoring of diabetes

BACKGROUND

The validity of clinical interpretation of HbA1c depends on the analytical performance of the method and the biological variation of HbA1c in patients. The contribution of non-glucose related factors to the biological variation of HbA1c (NGBVA1c) is not known. This paper explores the cumulative impact of analytical errors and NGBVA1c on the risk of misinterpretation.

METHODS

A model has been developed to predict the risk of misinterpretation of HbA1c for diagnosis and monitoring with variables for analytical performance and levels of NGBVA1c.

RESULTS

The model results in probabilities of misinterpretation for a given HbA1c.

EXAMPLE

for an HbA1c 43 mmol/mol (6.1%), bias 1 mmol/mol (0.09%), CV 3% (2%) used for diagnosis, the probabilities of misinterpretation range from 1 to 19% depending on the contribution of NGBVA1c to the biological variation of HbA1c.

CONCLUSIONS

In addition to analytical bias and imprecision, NGBVA1c contributes to the risk of misinterpretation, but the relative impact is different per clinical application of HbA1c. For monitoring, imprecision is the predominating factor, for diagnosis both biological variation and analytical bias. Given the increasing use of HbA1c for diagnosis, increase of knowledge on NGBVA1c, decrease of analytical bias, and awareness of the risk of misinterpretation are required.

Iron status and cardiometabolic risk in children

AIM

We aimed to evaluate associations between serum ferritin and transferrin and variables related to the metabolic syndrome (MetS) in children.

METHODS

Cross-sectional and longitudinal study in prepubertal children(n=832) aged 3-14 years. A subset(n=203) were re-examined after a mean follow-up of 3.7±0.8 years[range 2-6]. Outcomes were MetS and MetS components scores, glycosylated haemoglobin (HbA1c), and their follow-up change.

RESULTS

Children with low ferritin had increased HbA1c Z scores (ANCOVA,P=0.003). Ferritin was inversely associated with glycaemia [fully adjusted β (95% confidence interval): -2.35(-4.36 to -0.34)]. Transferrin was associated with diastolic blood pressure[β: 0.02(0.01-0.04)] and log-HOMA-IR [β:0.001(0.0005-0.002)]. MetS risk score worsened during follow-up in children with the lowest baseline ferritin levels. In contrast, at baseline ferritin was positively associated with all (except glycaemia) the MetS-related variables but adjustments for inflammatory, hepatic function, and body mass markers attenuated those associations(P>0.05).

CONCLUSIONS

Lower iron status was independently associated with glycaemic markers and MetS in children, whereas higher ferritin levels were related to other cardiometabolic risk markers under the influence of inflammation, hepatic injury and body mass. Research is required to study whether this mixed pattern is part of an early risk or would be explained by a normal transition during growth and development.

Malglycemia in the critical care setting. Part I: Defining hyperglycemia in the critical care setting using the glycemic ratio

INTRODUCTION

Stress-induced hyperglycemia (SIH) is conventionally represented by Blood Glucose (BG) although recent evidence indicates the Glycemic Ratio (GR, quotient of mean BG and estimated preadmission BG) is a superior prognostic marker. We assessed the association between in-hospital mortality and SIH, using BG and GR in an adult medical-surgical ICU.

METHODS

We included patients with hemoglobin A1c (HbA1c) and minimum four BGs in a retrospective cohort investigation (n = 4790).

RESULTS

A critical SIH threshold of GR 1.1 was identified. Mortality increased with increasing exposure to GR ≥ 1.1 (r² = 0.94, p = 0.0007). Duration of exposure to BG ≥ 180 mg/dL demonstrated a less robust association with mortality (r² = 0.75, p = 0.059). In risk-adjusted analyses, hours GR ≥ 1.1 (OR 1.0014, 95%CI (1.0003-1.0026), p = 0.0161) and hours BG ≥ 180 mg/dL (OR 1.0080, 95%CI (1.0034-1.0126), p = 0.0006) were associated with mortality. In the cohort with no exposure to hypoglycemia however, only hours GR ≥ 1.1 was associated with mortality (OR 1.0027, 95%CI (1.0012-1.0043), p = 0.0007), not BG ≥ 180 mg/dL (OR 1.0031, 95%CI (0.9949-1.0114), p = 0.50) and this relationship remained intact for those who never experienced BG outside the 70-180 mg/dL range (n = 2494).

CONCLUSIONS

Clinically significant SIH commenced above GR 1.1. Mortality was associated with hours of exposure to GR ≥ 1.1 which was a superior marker of SIH compared to BG.

Prevalence of anemia and its associated factors among patients with type 2 diabetes mellitus in a referral diabetic clinic in the north of Iran

BACKGROUND

PURPOSE: This study intended to investigate the prevalence of anemia and its associated factors among patients with type 2 diabetes mellitus (T2DM) in Gorgan, Iran.

METHODS

This cross-sectional study was conducted on 415 (109 men) patients with T2DM referred to the referral diabetes clinic of Sayad Shirazi Hospital in Gorgan in 2021. Demographic information, anthropometric indices, past medical history,  and some laboratory data on cell counts, serum blood glucose, HbA1c, creatinine, lipid/iron profiles, and urinary albumin were collected. The univariable and multivariable logistic regression analysis was applied to compute odds ratios (ORs) and 95% confidence intervals (CI) for potential associated factors, using SPSS version 21. The multivariable Model was adjusted for obesity, Hb A1c, T2DM duration, using glucose-lowering drugs (GLDs), chronic kidney disease (CKD), albuminuria, hypertriglyceridemia, and hypercholesterolemia.  RESULTS: The prevalence of anemia was 21.5% [95%CI: 17.6-25.7] among our total participants. The corresponding values for men and women were 20.2 (13.1-29.0) and 21.9 (17.4-27.0), respectively.The adjusted model revealed that obesity (OR, 1.94 [95% CI, 1.17-3.23]), T2DM duration for more than five years (OR, 3.12 [1.78-5.47]), albuminuria (OR, 6.37 [3.13-10.91]), chronic kidney disease (OR, 4.30 [ 2.83-7.29]) and hypertriglyceridemia (OR, 1.72 [ 1.21-2.77]) were significantly associated with prevalent anemia among patients with T2DM. Moreover, using insulin separately or in combination with oral GLDs associated positively with the prevalence of anemia with ORs of 2.60 [1.42-6.42] and 1.87 [1.30-4.37] , respectively.

CONCLUSION

Anemia had a high prevalence among patients with T2DM in the north of Iran (about 22%), which is associated with obesity, hypertriglyceridemia, duration of T2DM, and diabetic kidney disease.

Glycosylated haemoglobin as an indicator of diabetes control in pregnancy: A 10-year review of the relationship between HbA1c trends and delivery outcome in type I and type II diabetes

BACKGROUND

Pregestational diabetes mellitus (PGDM) confers an increased risk of adverse maternal and neonatal outcomes [1,2]. Glycaemic control in the medium and long term is commonly evaluated by examining glycosylated haemoglobin (HbA1c) levels. However, the value of HbA1c in pregnancy may be diminished by increased level of red cell turnover characteristic of pregnancy [3,4]. We sought to examine the impact of HbA1c in the first trimester and pre-delivery, and the within-patient change throughout gestation on mode of delivery and birthweight in pregnancies complicated by a pre-pregnancy diagnosis of type I or type II diabetes.

METHODS

A 10-year consecutive cohort of pregnancies complicated by PGDM, from Jan 2010 until Dec 2019, was examined for HbA1c data in the first trimester and within 6 weeks of delivery. Perinatal outcome data, including gestational age at delivery, mode of delivery and birthweight centile, were obtained from hospital records. The Spearman Rank correlation was used to correlate HcA1c levels in the first trimester with birthweight centiles. Non-parametric summaries and rank-based tests, Signed-rank test and Kruskal-Wallis test, were used to compare Hba1c levels.

RESULTS

During the 10-year study period, a consecutive cohort of 396 pregnancies that attained a viable gestational age (>24 weeks' gestation) and complicated by pregestational diabetes was identified; representing 81 % of the population of pregestational diabetic pregnancies managed by this service during the study period. The median [IQR] HbA1c levels (mmol/mol) in the first trimester, pre-delivery and the differential across gestation were 51 [19] mmol/mol, 43 [11] mmol/mol and -8 [13] mmol/mol, respectively. A statistically significant reduction in HbA1c levels throughout gestation was observed (p < 0.001). The median [IQR] birthweight centile was 69 [50 - 96]. The distributions in HbA1c levels and birthweight centiles were heavily skewed. No correlation was identified between HbA1c levels and mode of delivery.

CONCLUSION

Neither baseline HbA1c levels, pre-delivery values, nor trends across gestation appear to impact birthweight centile or mode of delivery in PGDM. While optimising glycaemic control can affect the long term health of the mother, these indices cannot be relied upon to reflect the impact of glycaemic control on fetal growth aberrations that influence mode of delivery.

Improving the accuracy of revised cardiac risk index with HbA1C: Hemoglobin ratio (HH ratio) - A retrospective cohort study

Background

The current Lee's Revised cardiac risk index (RCRI) was created in 1999. Validation studies have found RCRI to be only moderately discriminant. The "Diabetes Mellitus on insulin" component of the score does not accurately reflect the severity of the disease. A previously studied HbA1C:Hemoglobin ratio shows an improved association with outcomes than individual components alone.

Study design

A retrospective cohort study was performed in diabetic patients undergoing non-cardiac surgery. Ethics approval was obtained. The study compares the predictive value of RCRI and substitution of the "DM on insulin" component with HH ratio for 30- and 90-day mortality, and postoperative acute myocardial injury (AMI) and acute kidney injury (AKI).

Results

A total of 20,099 adult patients were included in the final analysis. The incidence of 30- and 90-day mortality was at 4.2 and 6.5%, respectively. Substitution of HH ratio in RCRI resulted in 687 more patients being in the moderate to high-risk category. The substituted HH-RCRI score had better prediction for 30-day (AUC 0.66 vs. 0.69, p < 0.001) and 90-day mortality (AUC 0.67 vs. 0.70, p < 0.001), and postoperative AMI (AUC 0.69 vs. 0.71, p < 0.001) and AKI (AUC 0.57 vs. 0.62, p < 0.001).

Conclusion

Although currently not an universal practice, substitution of "DM on insulin" with HbA1C:Hemoglobin ratio in RCRI score improves the accuracy of the RCRI risk prediction model in diabetic patients going for non-cardiac surgery.

HbA1c as a time predictive biomarker for an additional islet autoantibody and type 1 diabetes in seroconverted TEDDY children

OBJECTIVE

Increased level of glycated hemoglobin (HbA1c) is associated with type 1 diabetes onset that in turn is preceded by one to several autoantibodies against the pancreatic islet beta cell autoantigens; insulin (IA), glutamic acid decarboxylase (GAD), islet antigen-2 (IA-2) and zinc transporter 8 (ZnT8). The risk for type 1 diabetes diagnosis increases by autoantibody number. Biomarkers predicting the development of a second or a subsequent autoantibody and type 1 diabetes are needed to predict disease stages and improve secondary prevention trials. This study aimed to investigate whether HbA1c possibly predicts the progression from first to a subsequent autoantibody or type 1 diabetes in healthy children participating in the Environmental Determinants of Diabetes in the Young (TEDDY) study.

RESEARCH DESIGN AND METHODS

A joint model was designed to assess the association of longitudinal HbA1c levels with the development of first (insulin or GAD autoantibodies) to a second, second to third, third to fourth autoantibody or type 1 diabetes in healthy children prospectively followed from birth until 15 years of age.

RESULTS

It was found that increased levels of HbA1c were associated with a higher risk of type 1 diabetes (HR 1.82, 95% CI [1.57-2.10], p < 0.001) regardless of first appearing autoantibody, autoantibody number or type. A decrease in HbA1c levels was associated with the development of IA-2A as a second autoantibody following GADA (HR 0.85, 95% CI [0.75, 0.97], p = 0.017) and a fourth autoantibody following GADA, IAA and ZnT8A (HR 0.90, 95% CI [0.82, 0.99], p = 0.036). HbA1c trajectory analyses showed a significant increase of HbA1c over time (p < 0.001) and that the increase is more rapid as the number of autoantibodies increased from one to three (p < 0.001).

CONCLUSION

In conclusion, increased HbA1c is a reliable time predictive marker for type 1 diabetes onset. The increased rate of increase of HbA1c from first to third autoantibody and the decrease in HbA1c predicting the development of IA-2A are novel findings proving the link between HbA1c and the appearance of autoantibodies.

Sex differences in the association of fasting glucose with HbA1c, and their consequences for mortality: A Mendelian randomization study

BACKGROUND

Hemoglobin A1c (HbA1c) is used for diabetes diagnosis and management. HbA1c also represents iron-related erythrocyte properties which differ by sex. We investigated erythrocyte properties on HbA1c and glucose, and whether corresponding consequences for mortality differed by sex.

METHODS

In this two-sample Mendelian randomization study using the largest publicly available European descent summary statistics, we assessed sex-specific associations of iron (n=163,511) and hemoglobin (188,076 women/162,398 men) with HbA1c (185,022 women/159,160 men) and fasting glucose (73,089 women/67,506 men), of fasting glucose with HbA1c and diabetes (cases=6,589 women/10,686 men, controls=187,137 women/155,780 men), and of fasting glucose (n=140,595), HbA1c (n=146,806) and liability to diabetes (74,124 cases/824,006 controls) with parental attained age (412,937 mothers/415,311 fathers).

FINDINGS

Iron and hemoglobin were inversely associated with HbA1c but not fasting glucose. Fasting glucose was more strongly associated with HbA1c and diabetes in women (1.65 standard deviation (SD) per mmol/L [95% confidence interval 1.58, 1.72]; odds ratio (OR) 7.36 per mmol/L [4.12, 10.98]) than men (0.89 [0.81, 0.98]; OR 2.79 [1.96, 4.98]). The inverse associations of HbA1c and liability to diabetes with lifespan were possibly stronger in men (-1.80 years per percentage [-2.77, -0.42]; -0.93 years per logOR [-1.23, -0.59]) than women (-0.80 [-2.69, 0.66]; -0.44 [-0.62, -0.26]).

INTERPRETATION

HbA1c underestimates fasting glucose in men compared with women, possibly due to erythrocyte properties. Whether HbA1c and liability to diabetes reduce lifespan more in men than women because diagnostic and management criteria involving HbA1c mean that glycemia in men is under-treated compared to women needs urgent investigation.

FUNDING

None.

Quantification of stress-induced hyperglycaemia associated with key diagnostic categories using the stress hyperglycaemia ratio

AIM

Stress-induced hyperglycaemia (SIH) is the acute increase from preadmission glycaemia and is associated with poor outcomes. Early recognition of SIH and subsequent blood glucose (BG) management improves outcomes, but the degree of SIH provoked by distinct diagnostic categories remains unknown. Quantification of SIH is now possible using the stress hyperglycaemia ratio (SHR), which measures the proportional change from preadmission glycaemia, based on haemoglobin A_1c (HbA_1c ).

METHODS

We identified eligible patients for eight medical (n = 892) and eight surgical (n = 347) categories. Maximum BG from the first 24 h of admission for medical, or postoperatively for surgical patients was used to calculate SHR.

RESULTS

Analysis of variance indicated differing SHR and BG within both the medical (p < 0.0001 for both) and surgical cohort (p < 0.0001 for both). Diagnostic categories were associated with signature levels of SHR that varied between groups. Medically, SHR was greatest for ST-elevation myocardial infarction (1.22 ± 0.33) and sepsis (1.37 ± 0.43). Surgically, SHR was greatest for colectomy (1.62 ± 0.48) and cardiac surgeries (coronary artery graft 1.56 ± 0.43, aortic valve replacement 1.71 ± 0.33, and mitral valve replacement 1.75 ± 0.34). SHR values remained independent of HbA_1c , with no difference for those with HbA_1c above or below 6.5% (p > 0.11 for each). BG however was highly dependent on HbA_1c , invariably elevated in those with HbA_1c  ≥ 6.5% (p < 0.001 for each), and unreliably reflected SIH.

CONCLUSION

The acute stress response associated with various medical and surgical categories is associated with signature levels of SIH. Those with higher expected SHR are more likely to benefit from early SIH management, especially major surgery, which induced SIH typically 40% greater than medical cohorts. SHR equally recognised the acute change in BG from baseline across the full HbA_1c spectrum while BG did not and poorly reflected SIH.

Glycated albumin and continuous glucose monitoring metrics across pregnancy in women with pre-gestational diabetes

INTRODUCTION

Glycated albumin (GA), a biomarker reflecting short-term glycaemia, may be useful to assess glycaemic control in pregnancy. We examined the association between GA and continuous glucose monitoring (CGM) metrics across gestation.

METHODS

In this prospective cohort study including 40 women with pre-gestational diabetes, blood samples for analysis of GA and glycated haemoglobin A1c (HbA1c) were collected at pregnancy week 12, 20, 24, 28, 32 and 36. In the CGM-group (n = 19), CGM data were collected from first trimester until pregnancy week 36. Receiver operating characteristic (ROC) curves were used to assess the accuracy of GA and HbA1c to detect poor glycaemic control, using CGM metrics as the reference standard. This study was conducted at Stavanger University Hospital, Norway, in 2016-2018.

RESULTS

Glycaemic control improved across gestation with more time spent in target range, coinciding with decreased glycaemic variability and lower mean GA level. There was statistically significant correlation between GA and most CGM metrics. The area under the ROC curves (AUC) for detecting time in range <70% and time above range >25% for the pregnancy glucose target 63-140 mg/dl (3.5-7.8 mmol/L) were 0.78 and 0.82 for GA, whereas AUCs of 0.60 and 0.72 were found for HbA1c, respectively.

CONCLUSIONS

Higher GA levels were associated with less time spent in target range, more time spent in the above range area and increased glycaemic variability. GA was more accurate than HbA1c to detect time above range >25% and time in range <70%.

HbA1c at term delivery and adverse pregnancy outcome

Background

There are no obvious thresholds at which the risk of adverse pregnancy outcomes increases as a result of maternal hyperglycemia. HbA1c level which is representative of average blood glucose levels over the last 2–3 months is not as strongly predictive of adverse outcome compared to blood glucose values of oral glucose tolerance test. Data is sparse on the predictive value of HbA1c at term just prior to delivery on adverse outcome. We sought to evaluate HbA1c taken on admission for delivery at term on adverse outcomes of Cesarean delivery and large (≥ 90^th centile) for gestational age (LGA) infants.

Methods

A prospective cross-sectional study was conducted in a university hospital in Malaysia from December 2017-August 2018. 1000 women at term whose deliveries were imminent were enrolled. Blood were drawn and immediately sent for HbA1c analysis at our hospital laboratory. Primary outcomes were Cesarean delivery and LGA.

Results

On crude analyses, Cesarean births (vs. vaginal births) were associated with significantly higher HbA1c (%) levels 5.4[5.2–5.7] vs. 5.3[5.1–5.6] P =  < 0.001 but not for LGA vs. non-LGA 5.4[5.1–5.6] vs. 5.3[5.1–5.6] P = 0.17. After controlling for significant confounders identified on crude analysis (diabetes in pregnancy, parity, ethnicity, body mass index (BMI), previous cesarean, labor induction, Group B streptococcus (GBS) carriage and birth weight), HbA1c is independently predictive of Cesarean birth, adjusted odds ratio (AOR) 1.47 95% CI 1.06–2.06 P = 0.023 per HbA1c 1% increase. Following adjustment for significant confounders (BMI, predelivery anemia [hemoglobin < 11 g/dl] and GBS carriage), the impact of raised HbA1c level on LGA is AOR 1.43 95% CI 0.93–2.18 P = 0.101 per HbA1c 1% increase and non-significant.

Conclusion

Raised HbA1c level at term births in the general pregnant population is independently predictive of Cesarean delivery after adjustment for potential confounders including diabetes in pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05000-7.

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.

Identification of Hemoglobin Variants Prevalent in China and Their Effects on Hemoglobin A1c Measurements

OBJECTIVES

We aimed to evaluate the effects of hemoglobin (Hb) variants prevalent in China on HbA1c measurements and to identify them during HbA1c measurements.

METHODS

We evaluated a cation-exchange high-performance liquid chromatography (HPLC) method (Bio-Rad D-100), a capillary electrophoresis (CE) method (Capillarys 3 TERA), an immunoassay (Cobas c501), and a boronate affinity method (Premier Hb9210, as a comparative method) for HbA1c measurements in the presence of Hb variants prevalent in China.

RESULTS

The Bio-Rad D-100 and Capillarys 3 TERA gave specific retention times and numeric migration positions for each Hb variant, respectively, showing excellent interindividual reproducibility. All methods showed statistically significant differences (P < .01) for several variants. Clinically significant effects were observed for the Bio-Rad D-100 (Hb New York and Hb J-Bangkok), Capillarys 3 TERA (Hb New York and Hb J-Bangkok), and Cobas c501 (Hb New York). Among 297 samples with Hb variants, there were 75 (25.3%) unacceptable results for Bio-Rad D-100, 28 (9.4%) for Capillarys 3 TERA, and 19 (6.4%) for Cobas c501 compared with the results from Premier Hb9210.

CONCLUSIONS

Some Hb variants prevalent in China affect HbA1c measurements. The HPLC retention time and CE migration position can aid in the presumptive identification of Hb variants.

Does optimal HbA1c in diabetes differ according to drug treatment? An evaluation of national electronic database in Malta

BACKGROUND AND AIMS

A J-shaped relationship between HbA_1c and mortality has been reported in subjects with type 2 diabetes. The postulated mechanism linking low HbA_1c with increased mortality is increased hypoglycaemia risk. We tested this hypothesis by comparing the relationship between low HbA_1c to mortality in patients on therapies with different hypoglycaemia risk.

METHODS

We selected patients on any type of treatment for diabetes from a national electronic database (n = 25,743) and linked to other databases, including laboratory database and the national mortality register.

RESULTS

We observed a J-shaped or U-shaped association between HbA_1c and all-cause mortality in the whole type 2 diabetes patient cohort as well as in patients on metformin monotherapy and in those on metformin-sulphonylurea combination therapy, but not in subjects on sulphonylurea monotherapy or in those on insulin.

CONCLUSIONS

Our data confirm the J-shaped relationship between HbA_1c and mortality in type 2 diabetes, but suggest that a low HbA_1c is deleterious even in absence of hypoglycaemia and that subjects with type 2 diabetes might require a slightly elevated blood glucose for optimal outcome. Our data also suggest that the increased mortality associated with sulphonylureas cannot be mediated solely through increased hypoglycaemia risk.

Hemoglobin within normal range is negatively related to hemoglobin A1c in a nondiabetic American population aged 16 years and older

BACKGROUND

Protein glycosylated hemoglobin, hemoglobin A1c (HbA1c) binds hemoglobin (Hb) in red blood cells to blood glucose. However, the relationship between Hb and HbA1c remains unclear.

AIM

To elucidate their relationship in a nondiabetic population aged ≥ 16 years in the United States, using data from the 1999-2018 National Health and Nutrition Examination Survey.

METHODS

This study was based on data from 44560 adults aged ≥ 16 years, excluding those with diabetes. The relationship was estimated using a multivariate regression. We also used piecewise linear regression for subgroup analysis based on age and sex stratification and analysis of the threshold effects of Hb on HbA1c.

RESULTS

Hb and HbA1c levels were negatively correlated in the unadjusted model (β = -0.01; 95%CI: -0.01, -0.01). The correlation was significantly negative when the regression model was minimally regulated and stratified by age and sex, and remained negative when the model was further regulated (more than 10%) to identify covariates with the HbA1c level influence estimates. In subgroup analyses based on age and sex stratification, the association remained negative when the covariates were controlled. A nonlinear relationship was observed between them when the Hb levels reached the tipping point (13.2 g/dL) (adjusted odds ratio, -0.04; 95%CI: -0.05, -0.03) and when the Hb levels exceeded 13.2 g/dL (adjusted odds ratio, -0.10; 95%CI: -0.10, -0.09).

CONCLUSION

Our study shows that normal Hb levels are negatively correlated with HbA1c in nondiabetic Americans aged ≥ 16 years.

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.

Glycated albumin in pregnancy: LC-MS/MS-based reference interval in healthy, nulliparous Scandinavian women and its diagnostic accuracy in gestational diabetes mellitus

Glycated albumin (GA) may be a useful biomarker of glycemia in pregnancy. The aim of this study was to establish the reference interval (RI) for GA, analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), in healthy, nulliparous pregnant women. In addition, we assessed the accuracy of GA and glycated hemoglobin A1c (HbA1c) in the diagnosis of gestational diabetes mellitus (GDM). Finally, we explored the prevalence of GDM in healthy nulliparas, comparing three diagnostic guidelines (WHO-1999, WHO-2013 and the Norwegian guideline). The study was carried out at Stavanger University Hospital, Norway, and included a study population of 147 pregnant nulliparous women. An oral glucose tolerance test (OGTT) was performed and used as the gold standard for GDM diagnosis. Blood samples for analysis of GA and HbA1c were collected at pregnancy week 24-28. A nonparametric approach was chosen for RI calculation, and receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of GA and HbA1c. The established RI for GA in 121 pregnant women was 7.1-11.6%. The area under the ROC curves (AUCs) were 0.531 (GA) and 0.627 (HbA1c). According to the WHO-1999, WHO-2013 and the Norwegian guideline, respectively, 24 (16%), 36 (24%) and 21 (14%) women were diagnosed with GDM. Only nine women (6%) fulfilled the GDM-criteria of all guidelines. In conclusion, we established the first LC-MS/MS-based RI for GA in pregnant women. At pregnancy weeks 24-28, neither GA nor HbA1c discriminated between those with and without GDM. Different women were diagnosed with GDM using the three guidelines.

Time in range, assessed with continuous glucose monitoring, is associated with brachial-ankle pulse wave velocity in type 2 diabetes: A retrospective single-center analysis

AIMS

The aim of this retrospective single-center is to research the relationship between time in range(TIR), an important novel metric of glycemic control, assessed with continuous glucose monitoring(CGM) and brachial-ankle pulse wave velocity(BaPWV), a unique index of systemic arterial stiffness in type 2 diabetes.

METHODS

Study participants included 469 hospitalized patients with type 2 diabetes and no history of serious cardiovascular disease who underwent CGM and BaPWV measurements. TIR of 3.9-10.0 mmol/L was evaluated with CGM. BaPWV was measured by non-invasive arteriosclerosis detector and high baPWV was defined as a mean baPWV≧1800m/s. The spearman correlation and the partial correlation analysis were applied to analyze the correlation between TIR and baPWV. The binary logistic regression was used to examine the independent association of TIR and high BaPWV.

RESULTS

The presence of high baPWV was 32.2%. Compared with patients of low baPWV, those with high baPWV had significantly reduced TIR(P<0.001). With the increase of TIR tertiles, the prevalence of high BaPWV progressively decreased. Correlation analysis showed that TIR is inversely correlated with BaPWV. In a fully adjusted model controlling for traditional risk factor of CVD, TIR is associated with the presence of high BaPWV independent of HbA1c.

CONCLUSION

TIR is correlated with BaPWV independent of HbA1c in patients with type 2 diabetes, confirming a link between TIR and arterial stiffness.

Mothers' high glycemic levels and the association between periodontitis and low birth weight

BACKGROUND

Maternal hyperglycemia, periodontitis, and adverse gestational outcomes are important health problems. The present study investigated the hypothesis that periodontitis and the glycemic level of mothers may have opposing influences on birth weight (BW). This study evaluated the effect of high glycemic levels, albeit within the normal range, on the association between periodontitis and low birth weight (LBW).

METHODS

732 women took part in this case-control study; 172 were mothers of children with LBW <2,500g, and 560 were mothers of children with BW ≥2,500g. The BW of newborns was obtained from medical records, and information on socioeconomic-demographic, lifestyle behavior were obtained through interviews. Glycated hemoglobin (HbA1c) levels were evaluated, and full-mouth periodontal examination was carried out within seven days postpartum. Hierarchical and logistic regression analysis evaluated the effect of glycemic levels on the association between periodontitis and LBW by subgroups, estimating Odds Ratios (OR) with 95% confidence intervals (95%CI).

RESULTS

In the group with HbA1c levels <5.6%, a statistically significant relationship existed between periodontitis and LBW. Using the Centre for Disease Control/American Academy of Periodontics criteria, the OR_adjusted was 1.55; 95%CI: 1.04-2.31; using the Gomes-Filho et al. criteria the OR_adjusted was 1.91; 95%CI: 1.06-3.45. In the group with higher HbA1c levels but still within the normal range (≥5.6% and <6.5%), the findings showed no association between periodontitis and LBW.

CONCLUSION

Higher maternal glycemic levels within the normal range, inferior to those indicative of gestational diabetes, diabetes mellitus, or hyperglycemia, and periodontitis have opposing effects on BW, altering the association magnitude. This article is protected by copyright. All rights reserved.

Body Composition, Anemia, and Kidney Function among Guatemalan Sugarcane Workers

Rates of anemia among agricultural workers, who are also at risk for kidney injury and chronic kidney disease of unknown cause (CKDu), are unknown. We evaluated body composition through the sum of three skinfolds among 203 male sugarcane cutters and assessed the relationship of variables related to nutrition, anemia (hemoglobin < 13 g/dL), and elevated hemoglobin A1c (HbA1c ≥ 5.7%) with estimated glomerular filtration rate (eGFR) using linear regression. Eleven percent of workers were at the level of essential body fat (2-5%). Anemia was present among 13% of workers, 70% of which were normochromic normocytic, a type of anemia suggesting potential underlying chronic disease. Anemia was more common among those with lower BMI and fat free mass. The prevalence of elevated HbA1c was 21%. A moderate negative correlation was found between hemoglobin and HbA1c (Pearson's r = -0.32, p <0.01) which suggests that HbA1c values should be interpreted with caution in populations that have high rates of anemia. Twelve percent of workers had reduced kidney function with an eGFR < 90 mL/min/1.73 m². On average, the eGFR was 18 mL/min per 1.73 m² lower [(95% CI:-24, -12), p <0.01)] for those with anemia than those without, and 8 mL/min per 1.73 m² lower among those with elevated HbA1c [(95% CI: -13, -2), p < 0.01]. Results will inform future studies examining the role of anemia in the evaluation of CKDu and interventions to improve nutrition for workers in low-resource settings.

HIV infection and anaemia do not affect HbA1c for the detection of diabetes in black South Africans: Evidence from the Durban Diabetes Study

OBJECTIVE

South Africa has a high burden of HIV infection and anaemia. These conditions may cause HbA_1c to over- or underestimate glycaemia; however, this has not been comprehensively investigated in African populations. We assessed the association of anaemia, HIV infection and antiretroviral therapy (ART) with HbA_1c , and implications for the detection and diagnosis of diabetes, in a black South African population.

RESEARCH DESIGN AND METHODS

In this population-based cross-sectional study in eThekwini municipality (Durban), South Africa, we assessed HbA_1c and conducted oral glucose tolerance tests (OGTTs), HIV diagnostic tests and full blood count measurements among 1067 participants without a history of diabetes diagnosis. Linear regression was used to examine differences in HbA_1c by anaemia (comparator: no anaemia), or HIV and ART (comparator: no HIV) status. HbA_1c -based diabetes prevalence was compared with OGTT-based prevalence among individuals with anaemia and with untreated and ART-treated HIV.

RESULTS

In adjusted analyses, normocytic and microcytic anaemia were associated with higher HbA_1c compared with no anaemia, whereas macrocytic anaemia and ART-treated HIV were associated with lower HbA_1c compared with no anaemia and no HIV, respectively. However, magnitudes of association were small (range: β  = -3.4 mmol/mol or -0.31%, p < 0.001 [macrocytic anaemia] to β = 2.1 mmol/mol or 0.19%, p < 0.001 [microcytic anaemia]). There was no significant difference in diabetes prevalence based on HbA_1c or OGTT among individuals with anaemia (2.9% vs. 3.3%, p = 0.69), untreated HIV (1.6% vs. 1.6% p = 1.00) or ART-treated HIV (2.9% vs. 1.2%, p = 0.08).

CONCLUSIONS

Our results suggest that anaemia and HIV status appear unlikely to materially affect the utility of HbA_1c for diabetes detection and diagnosis in this population. Further studies are needed to examine these associations in sub-Saharan African populations.

Influence of red blood cell indices on HbA1c performance in detecting dysglycaemia in a Singapore preconception cohort study

Abnormalities of red blood cell (RBC) indices may affect glycated haemoglobin (HbA1c) levels. We assessed the influence of haemoglobin (Hb) and mean corpuscular volume (MCV) on the performance of HbA1c in detecting dysglycaemia among reproductive aged women planning to conceive. Women aged 18-45 years (n = 985) were classified as normal (12 ≤ Hb ≤ 16 g/dL and 80 ≤ MCV ≤ 100 fL) and abnormal (Hb < 12 g/dL and/or MCV < 80 fL). The Area Under the Receiver Operating Characteristic (AUROC) curve was used to determine the performance of HbA1c in detecting dysglycaemic status (prediabetes and diabetes). There were 771 (78.3%) women with normal RBC indices. The AUROCs for the normal and abnormal groups were 0.75 (95% confidence interval 0.69, 0.81) and 0.80 (0.70, 0.90), respectively, and were not statistically different from one another [difference 0.04 (- 0.16, 0.08)]. Further stratification by ethnicity showed no difference between the two groups among Chinese and Indian women. However, Malay women with normal RBC indices displayed lower AUROC compared to those with abnormal RBC indices (0.71 (0.55, 0.87) vs. 0.98 (0.93, 1.00), p = 0.002). The results suggest that the performance of HbA1c in detecting dysglycaemia was not influenced by abnormal RBC indices based on low Hb and/or low MCV. However, there may be ethnic variations among them.

Levels of inter-alpha-trypsin inhibitor heavy chain H4 urinary polypeptide in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) can cause a variety of adverse maternal and fetal complications. The purpose of this study was to screen and identify the urinary polypeptides related to the severity of GDM and to analyze the correlation between urinary peptide levels and neonatal metabolic indices. A total of 31 normal pregnant women (N group) and 74 patients with GDM (GDM group) were randomly selected between February 2018 and August 2019. Patients with GDM were divided into two groups according to their fasting plasma glucose (FPG) levels. The urine samples were enriched using weak cation-exchange magnetic beads (MB-WCX), and eight different urine polypeptides were screened and analyzed. The peptide spectra were obtained using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The urinary peptide signatures of the two groups were compared using the BioExplorer software. The difference analysis of the eight urinary polypeptides between the normal pregnant (N) group and GDM group showed that two polypeptides with mass-to- charge ratios (m/z) of 2175.7 and 2318.8, respectively, were significantly different between the two groups (P < 0.01). The m/z 2175.7 polypeptide was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS), and the corresponding name of the molecule was inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4). The changes in ITIH4 levels correlated with those in the neonatal metabolic indices. By establishing the Fisher discriminant function equation for the GDM group, the difference in sample distribution and mean value of the two groups could be observed directly.Abbreviations: GDM: gestational diabetes mellitus; FPG: fasting plasma glucose; MB-WCX: weak cation exchange magnetic beads; MALDI-TOF MS: matrix-assisted laser desorption ionization time-of-flight mass spectrometry; m/z: mass charge ratio; LC-MS: liquid chromatography-tandem mass spectrometry; glycosylated hemoglobin (HbA1c); PPG: postprandial plasma glucose; ITIH4: inter-alpha-trypsin inhibitor heavy chain H4; IR: insulin resistance; NFPG: neonatal fasting plasma glucose; NH: neonatal height; NW: neonatal weight; BMI: body mass index; RPL: recurrent pregnancy loss; OGTT: oral glucose tolerance test; ADA: American Diabetes Association; LIS: Laboratory Information System.

The glycemic status determines the direction of the relationship between red cell distribution width and HbA1c

AIMS

Available studies conducted on heterogenous populations on the association between the erythrocyte distribution width (RDW) and HbA1c have reported a positive, negative or neutral relationship. The aim of the present study is to investigate the debated relationship between RDW and HbA1c among hematologically healthy individuals with and without type 2 diabetes mellitus (T2DM).

METHODS

Paired measurements of RDW and HbA1c of 183 hematologically healthy individuals (100 without DM, 83 with T2DM) were obtained. The association of HbA1c with a) hematologic parameters (hemoglobin, log[ferritin], RDW) and b) factors related to glycemia (BMI, fructosamine, FPG) was examined within each group separately and in the sum of the study sample.

RESULTS

There was a significant positive correlation of RDW with HbA1c among those without DM while the opposite was true among individuals with T2DM (r = 0.315, p = 0.001 and r = -0.275, p = 0.011). In the T2DM group a significant negative correlation with fructosamine was noted (r = -0.274, p = 0.012) which was absent among normoglycemic individuals. Among those without DM the association between HbA1c and RDW remained significant after adjustment for all tested parameters. In the population with T2DM the significance was attenuated after including glycemia-related factors values. In multivariable regression in the sum of the study sample, the interaction between diabetes status and RDW as regards HbA1c was significant [unstandardized correlation coefficient - 0.397 (-0.646 to -0.147), p = 0.002] and remained significant after adjustment for multiple potential confounders.

CONCLUSIONS

Among individuals without DM, the RDW likely reflects the non-glycemic interference on HbA1c values, while in T2DM RDW may serve as an indirect index of glycemia and dysmetabolism.

HbA1c performs well in monitoring glucose control even in populations with high prevalence of medical conditions that may alter its reliability: the OPTIMAL observational multicenter study

INTRODUCTION

The utility of HbA1c (glycosylated hemoglobin) to estimate glycemic control in populations of African and other low-resource countries has been questioned because of high prevalence of other medical conditions that may affect its reliability. Using continuous glucose monitoring (CGM), we aimed to determine the comparative performance of HbA1c, fasting plasma glucose (FPG) (within 5 hours of a meal) and random non-fasting glucose (RPG) in assessing glycemic burden.

RESEARCH DESIGN AND METHODS

We assessed the performance of HbA1c, FPG and RPG in comparison to CGM mean glucose in 192 Ugandan participants with type 2 diabetes. Analysis was undertaken in all participants, and in subgroups with and without medical conditions reported to affect HbA1c reliability. We then assessed the performance of FPG and RPG, and optimal thresholds, in comparison to HbA1c in participants without medical conditions thought to alter HbA1c reliability.

RESULTS

32.8% (63/192) of participants had medical conditions that may affect HbA1c reliability: anemia 9.4% (18/192), sickle cell trait and/or hemoglobin C (HbC) 22.4% (43/192), or renal impairment 6.3% (12/192). Despite high prevalence of medical conditions thought to affect HbA1c reliability, HbA1c had the strongest correlation with CGM measured glucose in day-to-day living (0.88, 95% CI 0.84 to 0.91), followed by FPG (0.82, 95% CI 0.76 to 0.86) and RPG (0.76, 95% CI 0.69 to 0.81). Among participants without conditions thought to affect HbA1c reliability, FPG and RPG had a similar diagnostic performance in identifying poor glycemic control defined by a range of HbA1c thresholds. FPG of ≥7.1 mmol/L and RPG of ≥10.5 mmol/L correctly identified 78.2% and 78.8%, respectively, of patients with an HbA1c of ≥7.0%.

CONCLUSIONS

HbA1c is the optimal test for monitoring glucose control even in low-income and middle-income countries where medical conditions that may alter its reliability are prevalent; FPG and RPG are valuable alternatives where HbA1c is not available.

In a cohort of individuals with type 2 diabetes using the drug sulfasalazine, HbA1c lowering is associated with haematological changes

OBJECTIVES

Several small studies indicate the sulphonamide component of the drug sulfasalazine lowers HbA_1c. We investigated reduction of HbA_1c following incident prescription of sulfasalazine and related aminosalicylates, lacking the sulphonamide group, in an observational cohort.

RESEARCH DESIGN AND METHODS

Individuals in the Scottish Care Information Diabetes Collaboration (SCI-Diabetes) with type 2 diabetes and incident prescription for an aminosalicylate drug (sulfasalazine, mesalazine, olsalazine or balsalazide) were identified. Baseline and 6-month HbA_1c were required for eligibility, to calculate HbA_1c response. To investigate association with haemolysis, change in components of full blood count was assessed. Paired t-tests compared difference in baseline and treatment HbA_1c measures and other clinical variables.

RESULTS

In all, 113 individuals treated with sulfasalazine and 103 with mesalazine (lacking the sulphonamide group) were eligible, with no eligible individuals treated with olsalazine or balsalazide. Baseline characteristics were similar. Mean (SD) HbA_1c reduction at 6 months was -9 ± 16 mmol/mol (-0.9 ± 1.4%) (p < 0.0001) in those taking sulfasalazine with no reduction in those taking mesalazine (2 ± 16 mmol/mol (0.2 ± 1.4%). Sulfasalazine but not mesalazine was associated with a mean (SD) increase in mean cell volume of 3.7 ± 5.6 fl (p < 0.0001) and decrease in red cell count of -0.2 ± 0.4 × 10^-12 /L (p < 0.0001).

CONCLUSIONS

In this observational, population-based study, sulfasalazine initiation was associated with a 6-month reduction in HbA_1c . This correlated with haematological changes suggesting haemolytic effects of sulfasalazine. Haemolysis is proposed to contribute to HbA_1c lowering through the sulphonamide pharmacophore. This suggests that HbA_1c is not a reliable measure of glycaemia in individuals prescribed sulfasalazine.

Comparison of Turbidimetric Inhibition Immunoassay, High-Performance Liquid Chromatography, and Capillary Electrophoresis Methods for Glycated Hemoglobin Determination

OBJECTIVE

The purpose of this study was to compare the performances of and evaluate the agreement among glycated hemoglobin values analyzed by using National Glycohemoglobin Standardization Program-certified and International Federation of Clinical Chemistry-standardized analyzers.

THIS CROSS-SECTIONAL STUDY WAS CONDUCTED AT THE

Armed Forces Institute of Pathology, Department of Chemical Pathology from March 2019 to May 2019.

METHODS

Glycated hemoglobin (HbA1c) was measured in the blood specimens from 100 patients on an ADVIA 1800 by a turbidimetric inhibitory immunoassay (TINIA), Sebia instrument by electrophoresis, and Bio-Rad Variant II Turbo system by high-performance liquid chromatography (HPLC). Quantitative variables were calculated as the mean ± standard deviation (SD). Precision and method comparisons were carried out according to Clinical and Laboratory Standards Institute recommendations. The results obtained from each analyzer were compared by correlation analysis. Method comparison was done by linear regression and Bland-Altman plots using the SPSS software version 24.

RESULTS

The mean ± SD HbA1c values from TINIA, electrophoresis, and HPLC were 7.188% ± 1.89%, 7.164% ± 1.866%, and 7.160% ± 1.85%, respectively. The between-run coefficients of variation for TINIA, electrophoresis, and HPLC were 0.64%, 0.61%, and 0.60%, respectively. All 3 showed good correlation (TINIA, R2 = .994, P = .00; electrophoresis, R2 = .992, P = 0.00; and HPLC, R2 = .994, P = 0.00).

CONCLUSION

The good clinical agreements of HbA1c and strong correlations between analyzers indicate that these analyzers can be used interchangeably.

Interpreting HbA1c in Presence of Deficiency Anemias

HbA1c is used extensively for the diagnosis and management of diabetes mellitus. It constitutes 80% of glycated HbA1(Glycated haemoglobin(GHb)A), and depends upon blood glucose and RBC life span. RBC life span varies with anemia, leading to a consequent alteration in the HbA1c value irrespective of the circulating blood glucose concentration. But to the best of our knowledge no Hb cut offs have been derived for appropriate interpretation of HbA1c. The prevalence of anemia in Indian population is nearly 40% as per its definition by WHO-Hb < 12 g/dL in females and < 13 g/dL in males-with most cases attributable to nutritional deficiencies. Hence, we aimed to identify Hb cut-off for accurate interpretation of HbA_1c in presence of deficiency anemias. Partial correlation between random blood glucose (RBG) and HbA_1c was studied in 1312 subjects, 470 of whom had deficiency-related anemia]. The data was adjusted for age, sex and Hb. Partial correlation between RBG and HbA1c was highly significant (p < 0.0001) till Hb of 8.1 gm/dL. Significance reduced to p = 0.003 and p = 0.006 as the cut off of Hb reduced to 7.1 gm/dL and 5.0 gm/dL, respectively, but was not lost. Hence, caution in interpretation of HbA_1c is not required till an Hb of 5 g/dL.

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

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

Complete blood counts with red blood cell determinants associate with reduced beta-cell function in seroconverted Swedish TEDDY children

OBJECTIVES

To investigate whether changes in complete blood count (CBC) in islet autoantibody positive children with increased genetic risk for type 1 diabetes are associated with oral glucose tolerance tests (OGTT) and HbA1c over time.

METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study follows children with increased risk for type 1 diabetes in the United States, Germany, Sweden and Finland. In the current study, 89 Swedish TEDDY children (median age 8.8 years) positive for one or multiple islet autoantibodies were followed up to 5 (median 2.3) years for CBC, OGTT and HbA1c. A statistical mixed effect model was used to investigate the association between CBC and OGTT or HbA1c.

RESULTS

HbA1c over time increased by the number of autoantibodies (p < .001). Reduction in mean corpuscular haemoglobin (MCH) and mean cell volume (MCV) was both associated with an increase in HbA1c (p < .001). A reduction in red blood cell (RBC) counts (p = .003), haemoglobin (p = .002) and haematocrit (p = .006) levels was associated with increased fasting glucose. Increased red blood cells, haemoglobin, haematocrit and MCH but decreased levels of red blood cell distribution widths (RDW) were all associated with increased fasting insulin.

CONCLUSIONS

The decrease in RBC indices with increasing HbA1c and the decrease in RBC and its parameters with increasing fasting glucose in seroconverted children may reflect an insidious deterioration in glucose metabolism associated with islet beta-cell autoimmunity.

Prevalence and co-existence of cardiometabolic risk factors and associations with nutrition-related and socioeconomic indicators in a national sample of Gambian women

Cardiovascular diseases (CVD) are on the rise in Sub-Saharan Africa, and a large proportion of the adult population is thought to suffer from at least one cardiometabolic risk factor. This study assessed cardiometabolic risk factors and the contribution of nutrition-related indicators in Gambian women. The prevalence and co-existence of diabetes (elevated glycated hemoglobin (HbA1c ≥ 6.5%) or prediabetes (HbA1c ≥ 5.7% to < 6.5%), hypertension (systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg), obesity (body mass index (BMI) ≥ 30.0) and inflammation (C-reactive protein (CRP) > 3 mg/L or alpha-1-acid glycoprotein (AGP) > 1 g/L) and the contribution of nutrition related and socioeconomic indicators were measured in non-pregnant women 15-49 years of age in the Gambia using data from a nationally representative cross-sectional stratified survey. Nationally, 54.5% (95% CI: 47.4, 61.4) of 1407 women had elevated HbA1c. Of these, 14.9% were diabetic and 85.1% were prediabetic. Moreover, 20.8% (95% CI 17.8, 20.0) of 1685 women had hypertension, 11.1% (95% CI 9.0, 13.7) of 1651 were obese and 17.2% (95% CI 5.1, 19.6) of 1401 had inflammation. At least one of the aforementioned cardiometabolic risk factor was present in 68.3% (95% CI 63.0, 73.1) of women. Obesity increased the risk of hypertension (aRR 1.84; 95% CI 1.40, 2.41), diabetes (aRR 1.91; 95% CI 1.29, 2.84), elevated HbA1c (aRR 1.31; 95% CI 1.14, 1.51) and inflammation (aRR 3.47; 95% CI 2.61, 4.61). Inflammation increased the risk of hypertension (aRR 1.42; 95% CI 1.14, 1.78). Aging increased the risk of hypertension, obesity and inflammation. Further, inadequate sanitation increased the risk for diabetes (aRR 1.65; 95% CI 1.17, 2.34) and iron deficiency increased the risk of elevated HbA1c (aRR 1.21; 95% CI 1.09, 1.33). The high prevalence of cardiometabolic risk factors and their co-existence in Gambian women is concerning. Although controlling obesity seems to be key, multifaceted strategies to tackle the risk factors separately are warranted to reduce the prevalence or minimize the risk of CVD.

Gestational iron deficiency anemia is associated with preterm birth, fetal growth restriction, and postpartum infections

OBJECTIVES

Gestational IDA has been linked to adverse maternal and neonatal outcomes, but the impact of iron supplementation on outcome measures remains unclear. Our objective was to assess the effects of gestational IDA on pregnancy outcomes and compare outcomes in pregnancies treated with either oral or intravenous iron supplementation.

METHODS

We evaluated maternal and neonatal outcomes in 215 pregnancies complicated with gestational IDA (Hb<100 g/L) and delivered in our tertiary unit between January 2016 and October 2018. All pregnancies from the same period served as a reference group (n=11,545). 163 anemic mothers received oral iron supplementation, and 52 mothers received intravenous iron supplementation.

RESULTS

Gestational IDA was associated with an increased risk of preterm birth (10.2% vs. 6.1%, p=0.009) and fetal growth restriction (FGR) (1.9% vs. 0.3%, p=0.006). The gestational IDA group that received intravenous iron supplementation had a greater increase in Hb levels compared to those who received oral medication (18.0 g/L vs. 10.0 g/L, p<0.001), but no statistically significant differences in maternal and neonatal outcomes were detected.

CONCLUSIONS

Compared to the reference group, prematurity, FGR, postpartum infections, and extended hospital stays were more common among mothers with gestational IDA, causing an additional burden on the families and the healthcare system.

Influence of Serum Albumin on HbA1c and HbA1c-Defined Glycemic Status: A Retrospective Study

Background: Glycated hemoglobin (HbA1c) is commonly used in the diagnosis and evaluation of glycemic control in diabetes, and it may be influenced by several non-glycemic and glycemic factors, including albumin. This retrospective study investigated the influence of albumin on HbA1c and HbA1c-defined glycemic status. Methods: The demographic, hematological, and biochemical data were collected for 11,922 patients undergoing routine physical examination. Univariate and multivariate linear regression analyses, stratified analyses and interaction analyses, and multiple logistic regression were conducted to identify the association between albumin and HbA1c in people with different glycemic status. Results: HbA1c levels were inversely associated with serum albumin level (P < 0.0001) in all participants. Risk factors leading to the association included age > 45 years, high fasting plasma glucose (≥7.0 mmol/L), and anemia. The negative association between HbA1c and albumin was curved (P < 0.0001) and had a threshold effect in the HbA1c-defined diabetic population; the association was significantly stronger when the albumin level fell below 41.4 g/L (β: -0.31, 95% CI: -0.45 to -0.17, P < 0.0001). A 2 g/L increase in albumin reduced the odds of HbA1c-defined dysglycemia, diabetes, and poor glycemia control by 12% to 36%, after adjustment for all possible confounders. Conclusions: HbA1c was inversely associated with albumin level in all participants, and the association was significantly stronger in people with diabetes (defined by HbA1c criteria). For diabetic patients with lower albumin level, there was an increased risk of an erroneous HbA1c-based identification and management of glycemic status.

Diabetes and Frailty: An Expert Consensus Statement on the Management of Older Adults with Type 2 Diabetes

Prognosis and appropriate treatment goals for older adults with diabetes vary greatly according to frailty. It is now recognised that changes may be needed to diabetes management in some older people. Whilst there is clear guidance on the evaluation of frailty and subsequent target setting for people living with frailty, there remains a lack of formal guidance for healthcare professionals in how to achieve these targets. The management of older adults with type 2 diabetes is complicated by comorbidities, shortened life expectancy and exaggerated consequences of adverse effects from treatment. In particular, older adults are more prone to hypoglycaemia and are more vulnerable to its consequences, including falls, fractures, hospitalisation, cardiovascular events and all-cause mortality. Thus, assessment of frailty should be a routine component of a diabetes review for all older adults, and glycaemic targets and therapeutic choices should be modified accordingly. Evidence suggests that over-treatment of older adults with type 2 diabetes is common, with many having had their regimens intensified over preceding years when they were in better health, or during more recent acute hospital admissions when their blood glucose levels might have been atypically high, and nutritional intake may vary. In addition, assistance in taking medications, as often occurs in later life following implementation of community care strategies or admittance to a care home, may dramatically improve treatment adherence, leading to a fall in glycated haemoglobin (HbA1c) levels. As a person with diabetes gets older, simplification, switching or de-escalation of the therapeutic regimen may be necessary, depending on their level of frailty and HbA1c levels. Consideration should be given, in particular, to de-escalation of therapies that may induce hypoglycaemia, such as sulphonylureas and shorter-acting insulins. We discuss the use of available glucose-lowering therapies in older adults and recommend simple glycaemic management algorithms according to their level of frailty.

Tuberculosis, Human Immunodeficiency Virus, and the Association With Transient Hyperglycemia in Periurban South Africa

Background

Diabetes mellitus (DM) increases tuberculosis (TB) risk. We assessed the prevalence of hyperglycemia (DM and impaired glucose regulation [IGR]) in persons with TB and the association between hyperglycemia and TB at enrollment and 3 months after TB treatment in the context of human immunodeficiency virus (HIV) infection.

Methods

Adults presenting at a Cape Town TB clinic were enrolled. TB cases were defined by South African guidelines, while non-TB participants were those who presented with respiratory symptoms, negative TB tests, and resolution of symptoms 3 months later without TB treatment. HIV status was ascertained through medical records or HIV testing. All participants were screened for DM using glycated hemoglobin and fasting plasma glucose at TB treatment and after 3 months. The association between TB and DM was assessed.

Results

Overall DM prevalence was 11.9% (95% confidence interval [CI], 9.1%–15.4%) at enrollment and 9.3% (95% CI, 6.4%–13%) at follow-up; IGR prevalence was 46.9% (95% CI, 42.2%–51.8%) and 21.5% (95% CI, 16.9%–26.3%) at enrollment and follow-up. TB/DM association was significant at enrollment (odds ratio [OR], 2.41 [95% CI, 1.3–4.3]) and follow-up (OR, 3.3 [95% CI, 1.5–7.3]), whereas TB/IGR association was only positive at enrollment (OR, 2.3 [95% CI, 1.6–3.3]). The TB/DM association was significant at enrollment in both new and preexisting DM, but only persisted at follow-up in preexisting DM in patients with HIV-1 infection.

Conclusions

Our study demonstrated high prevalence of transient hyperglycemia and a significant TB/DM and TB/IGR association at enrollment in newly diagnosed DM, but persistent hyperglycemia and TB/DM association in patients with HIV-1 infection and preexisting DM, despite TB therapy.

Effect of anaemia and erythrocyte indices on canine glycated haemoglobin

BACKGROUND

The major fraction of glycated haemoglobin (HbA1c) depends on blood glucose concentration and erythrocyte lifespan, and consequently erythrocyte indices may affect HbA1c; our objective was to study this effect in dogs.

METHODS

Blood samples from two (healthy and anaemic) age- and sex-matched, normoglycaemic populations were prospectively included. Advia 120 and Capillarys 2 flex-piercing were used for the haematological and HbA1c analyses, respectively.

RESULTS

Lower mean HbA1c was found in dogs with regenerative (n = 8, 0.88 ± 0.58%) and non-regenerative anaemia (n = 12, 1.36 ± 0.56%) compared to healthy ones (n = 40, 1.68 ± 0.48%); the difference was significant (p < 0.001) between the healthy dogs and those with regenerative anaemia. HbA1c was significantly correlated (p < 0.05) with red blood cell count (r = 0.506), haemoglobin (r = 0.474), haematocrit (r = 0.467), mean corpuscular volume (r = -0.289), mean corpuscular haemoglobin concentration (r = 0.284), red cell distribution width (r = -0.286) and reticulocytes (r_s = -0.542).

CONCLUSION

Anaemia, particularly if regenerative, can lower HbA1c. The significant correlation between HbA1c and erythrocyte indices likely reflects the effect of erythrocyte turnover on HbA1c.