Determination of glycated hemoglobin in patients with advanced liver disease

Unraveling the mechanisms of hepatogenous diabetes and its therapeutic perspectives

The review focused mainly on the pathogenesis of hepatogenous diabetes (HD) in liver cirrhosis (LC). This review reveals parallels between the mechanisms of metabolic dysfunction observed in LC and type II diabetes (T2DM), suggesting a shared pathway leading to HD. It underscores the role of insulin in HD pathogenesis, highlighting key factors such as insulin signaling, glucose metabolism, insulin resistance (IR), and the influence of adipocytes. Furthermore, the impact of adipose tissue accumulation, fatty acid metabolism, and pro-inflammatory cytokines like Tumor necrosis factor-α (TNF-α) on IR are discussed in the context of HD. Altered signaling pathways, disruptions in the endocrine system, liver inflammation, changes in muscle mass and composition, and modifications to the gut microbiota collectively contribute to the complex interplay linking cirrhosis and HD. This study highlights how important it is to identify and treat this complex condition in cirrhotic patients by thoroughly analyzing the link between cirrhosis, IR, and HD. It also emphasizes the vitality of targeted interventions. Cellular and molecular investigations into IR have revealed potential therapeutic targets for managing and preventing HD.

Hepatogenous Diabetes as Compared to Type-2 Diabetes Mellitus and Non-diabetes in Patients With Liver Cirrhosis: Magnitude, Characteristics, and Implications

Aim

Hepatogenous diabetes (HD) is frequently underestimated among cirrhosis patients. The current study assessed the magnitude, clinical characteristics, and implications of HD in cirrhosis patients as compared to the patients with type-2 diabetes mellitus (T2DM) and non-diabetes (ND) cirrhosis.

Methods

In a prospective observational study, 338 consecutive eligible cirrhosis patients were screened for diabetes mellitus. A 2-hour oral glucose tolerance test (OGTT) was used to detect HD. The clinical characteristics, complications, and outcomes were ascertained and compared amongst HD, T2DM, and ND patients.

Results

In the final study cohort of 316 patients, the proportion of HD, T2DM, and ND was 22.5% (n = 71), 26.3% (n = 83), and 51.3% (n = 162), respectively. HD was the predominant form of diabetes (68.9%) in Child-Pugh class-C cirrhosis. The majority (73%) of HD patients had abnormal OGTT without fasting hyperglycaemia. A lower cut-off of 98.5 mg/dl for fasting blood glucose had a modest sensitivity (72%) and specificity (75%) for predicting HD. In comparison to T2DM patients, HD patients were younger, leaner, and had more advanced cirrhosis. In comparison to ND patients, HD patients were leaner but had higher glycemic indices, serum cholesterol, and arterial ammonia levels. During a median follow-up period of 12 (03-21) months, the frequency of hepatic encephalopathy and variceal haemorrhage were higher in HD and T2DM patients compared to that in the ND group.

Conclusions

HD is prevalent in about one fifth of cirrhosis patients. It differs from T2DM and ND in a number of ways, and has association with complications of cirrhosis.

A Prospective Study to Identify the Prevalence of Impaired Glucose Tolerance in Patients With Liver Cirrhosis Using Oral Glucose Tolerance Test

Introduction Diabetes mellitus (DM) is a global health problem that may affect the prognosis of liver cirrhosis by interfering with the various metabolic functions of the body. Hence it is important to know the glycemic status of the patients with liver cirrhosis to anticipate and treat the complications associated with it, which in turn will help in the prognosis. The conventional methods may underestimate impaired glucose tolerance (IGT). Hence, this study was undertaken to identify IGT prevalent among liver cirrhosis patients using an oral glucose tolerance test (OGTT). The aim of our study was to identify the prevalence of IGT in non-diabetic liver cirrhosis patients using OGTT. Materials and methods This was a prospective cross-sectional study done in the Department of General Medicine at Shri BM Patil Medical College and Hospital, Vijayapura. After obtaining institutional ethical committee approval, a sample size of 85 liver cirrhosis patients between the age of 20-80 years who were not known cases of diabetes mellitus were selected from patients attending inpatient and outpatient departments at our hospital. The period of study was from January 2021 to June 2022. Patients were tested with OGTT, and the results were recorded. Results Our study found that IGT was more common in the age group of 40-49 years. All the patients included were males. We found that alcohol-induced liver cirrhosis patients had the maximum of IGT and DM. Our study observed a prevalence of 36.47% of patients with IGT. Our study in addition to IGT, found that DM was more common in 30-39 years, and 24.71% of patients were diagnosed with diabetes mellitus in the 85 patients included in our study. Conclusion We conclude that performing OGTT to find the prevalence of IGT and DM in liver cirrhosis patients will help in diagnosing DM and IGT, aiding in the improvement of the prognosis of the cirrhosis. The glycemic status of the patient may help in deferring the complications associated with poor glucose control. The incidence of potential complications of DM can be reduced by prompt identification and treatment.

Management of diabetes mellitus in patients with cirrhosis: An overview and joint statement

Type 2 diabetes mellitus (T2DM) is a frequent comorbidity in patients with cirrhosis that is projected to rise in prevalence due to the worldwide burden of obesity, insulin-resistance and non-alcoholic fatty liver disease. The management of T2DM in patients with cirrhosis is complex given the requirement for accurate adaptation according to the level of liver function impairment, with lack of summary of the little evidence available in the literature. Here, we summarise the data available with respect to the epidemiology and the impact of T2DM in patients with cirrhosis, as well as those on the management of T2DM in these patients. We provide guidance for the diagnosis of T2DM and the monitoring of glycaemic control in patients with cirrhosis, and for the management of nutrition and pharmacological treatments in relation to the level of liver dysfunction.

Management of the major complications of cirrhosis: Beyond guidelines

Along with a growing understanding of the pathophysiology of cirrhosis and its complications, new therapies and management strategies have emerged in recent years. Many of these advances have helped inform the current EASL clinical practice guidelines¹ on the management of some of the key complications of cirrhosis, such as ascites, variceal bleeding and infection. However, there are still some aspects of management where the evidence base is less clear, and/or where opinions amongst practitioners remain divided. Some of these more controversial areas are explored in this section, wherein we present evidence culminating in a suggested management approach based on expert opinion and extending beyond the current guidelines.

Prevalence and risk factors of undiagnosed diabetes mellitus among gastroenterological patients: a HbA1c-based single center experience

BACKGROUND

Diabetes mellitus is a major risk factor for microvascular disease, leading to chronic kidney injury or cardiovascular disease, but there is a tremendous proportion of patients worldwide who suffer from undiagnosed diabetes. Until now, little is known about the prevalence of undiagnosed diabetes in gastroenterology inpatients.

OBJECTIVE

To improve detection of undiagnosed diabetes, a routine screening procedure for gastroenterology inpatients, based on hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) measurement, was established.

METHODS

We conducted a retrospective analysis of the implemented diabetes screening. Diabetes mellitus was diagnosed according to the guideline of the German Diabetes Association in patients with an HbA1c of ≥6.5% anld/or fasting plasma glucose (FPG) ≥126 mg/dL. Univariate and multivariate analyses were performed to identify independent risk factors for undiagnosed diabetes.

RESULTS

Within a 3-month period, 606 patients were eligible for a diabetes screening. Pre-existing diabetes was documented in 120 patients (19.8 %), undiagnosed diabetes was found in 24 (3.9%), and 162 patients (26.7%) met the definition for prediabetes. Steroid medication use, age, and liver cirrhosis due to primary sclerosing cholangitis (PSC) were identified as risk factors for undiagnosed diabetes.

CONCLUSION

The prevalence of undiagnosed diabetes in gastroenterology inpatients is markedly elevated in comparison to the general population, and a substantial number of inpatients are in a prediabetic status, underlining the need for diabetes screening. In addition to previously described risk factors of patient age and steroid medication use, we identified PSC-related liver cirrhosis (but not liver cirrhosis due to another etiology) as an independent risk factor for undiagnosed diabetes.

Relationship Between Glycosylated Hemoglobin and Short-Term Mortality of Spontaneous Intracerebral Hemorrhage

Background: The relationship between glycosylated hemoglobin (HbA1c) and prognosis of spontaneous intracerebral hemorrhage (SICH) patients has not been fully elucidated. This study aimed to reveal the relationship between HbA1c levels and short-term mortality after patient admission with SICH. Methods: It was a large-scale, multicenter, cross-sectional study. From August 1, 2015, to July 31, 2019, a total of 41910 SICH patients were included in the study from the Chinese Stroke Center Alliance (CSCA) program. Finally, we comprehensively analyzed the data from 21,116 patients with SICH. HbA1c was categorized into four groups by quartile. Univariate and multivariate logistic regression analyses were used to assess the association between HbA1c levels and short-term mortality in SICH patients. Results: The average age of the 21,116 patients was 62.8 ± 13.2 years; 13,052 (61.8%) of them were male, and 507 (2.4%) of them died. Compared to the higher three quartiles of HbA1c, the lowest quartile (≤5.10%) had higher short-term mortality. In subgroup analysis with or without diabetes mellitus (DM) patients, the mortality of the Q3 group at 5.60-6.10% was significantly lower than that of the Q1 group at ≤5.10%. After adjustment for potential influencing factors, the ROC curve of HbA1c can better predict the short-term mortality of patients with SICH (AUC = 0.6286 P < 0.001). Conclusions: Therefore, we concluded that low or extremely low HbA1c levels (≤5.10%) after stroke were associated with higher short-term mortality in SICH patients, with or without DM.

[Chronic kidney injury in patients with liver diseases - Reappraising pathophysiology and treatment options]

Acute and chronic kidney disease concurs commonly with liver disease and is associated with a wide array of complications including dialysis dependency and increased mortality. Patients with liver disease or liver cirrhosis show a higher prevalence of chronic kidney disease. This is attributed to concomitant comorbidities, such as metabolic syndrome, chronic inflammation, hypercoagulability, hyperfibrinolysis, diabetes mellitus and dyslipidaemias. But chronic progressive kidney disease is not always due to hepatorenal syndrome. Beyond that, other diseases or disease entities should be considered. Among them are diabetic nephropathy, secondary IgA nephropathy, hepatitis C -associated membranoproliferative Glomerulonephritis (MPGN) and hepatitis B-associated membranous nephropathy.Coexisting diseases, similar underlying pathophysiologic mechanisms, or simultaneously concurring pathophysiological processes and overlapping clinical manifestations, impede the etiologic diagnosis and corresponding treatment of chronic kidney disease in the setting of chronic liver disease. In this review, we focus on common and rare pathologies, which can lead to chronic kidney disease in this particular patient group and try to summarize the most recent therapeutic modalities.

Clinical implications, diagnosis, and management of diabetes in patients with chronic liver diseases

Diabetes mellitus (DM) negatively affects the development and progression of chronic liver diseases (CLD) of various etiologies. Concurrent DM and CLD are also associated with worse clinical outcomes with respect to mortality, the occurrence of hepatic decompensation, and the development of hepatocellular carcinoma (HCC). Unfortunately, early diagnosis and optimal treatment of DM can be challenging, due to the lack of established clinical guidelines as well as the medical complexity of this patient population. We conducted an exploratory review of relevant literature to provide an up-to-date review for internists and hepatologists caring for this patient population. We reviewed the epidemiological and pathophysiological associations between DM and CLD, the impact of insulin resistance on the progression and manifestations of CLD, the pathogenesis of hepatogenic diabetes, as well as the practical challenges in diagnosis and monitoring of DM in this patient population. We also reviewed the latest clinical evidence on various pharmacological antihyperglycemic therapies with an emphasis on liver disease-related clinical outcomes. Finally, we proposed an algorithm for managing DM in patients with CLD and discussed the clinical and research questions that remain to be addressed.

Influence of Type 2 Diabetes Mellitus and Preoperative Hemoglobin A1c Levels on Outcomes of Liver Transplantation

Liver transplant centers often establish hemoglobin A1c (HbA1C) criteria for candidates with type 2 diabetes mellitus (T2DM) based on data from other surgical specialties showing worse outcomes in patients with poor glycemic control. However, because of the reduced reliability of HbA1C in cirrhosis, it is unclear whether pretransplant HbA1C values are predictive of postoperative complications in liver recipients. We retrospectively examined the association between preoperative HbA1C and postoperative outcomes in 173 consecutive patients who underwent liver transplantation at the University of Cincinnati Medical Center between August 2012 and March 2015. Demographic correlates of pretransplant HbA1C included age, T2DM, native Model for End‐Stage Liver Disease, hemoglobin, serum albumin, and nonalcoholic steatohepatitis as the indication for transplantation. No association was identified between pretransplant HbA1C and most outcome measures, including survival, length of stay, reoperation or readmission rates, rejection, bacteremia, and viremia. Significant correlates of HbA1C in liver recipients with diabetes were posttransplant insulin requirement and anastomotic biliary stricture formation. On multivariate analysis, HbA1C was the sole determinant of biliary strictures, with patients in the highest quartile (HbA1C >7.3%) exhibiting a 4‐fold increased risk. Correlation of HbA1C with morning blood glucose levels was much tighter after versus before transplantation. Conclusion: Preoperative HbA1C is predictive of anastomotic biliary stricture formation and the need for insulin following liver transplantation.

Hemoglobin A1c Has Suboptimal Performance to Diagnose and Monitor Diabetes Mellitus in Patients with Cirrhosis

BACKGROUND

Glycated hemoglobin A1c (HbA1c) is routinely used to diagnose and monitor type 2 diabetes mellitus (T2DM) in cirrhotic patients. Remarkably, HbA1c may be falsely low in such patients.

AIMS

We assessed the diagnostic and monitoring yield of HbA1c in cirrhotic patients with T2DM (DM-Cirr) and without T2DM (NoDM-Cirr).

METHODS

We conducted a composite study allocating 21 NoDM-Cirr into a cross-sectional module and 16 DM-Cirr plus 13 controls with T2DM only (DM-NoCirr) into a prospective cohort. Oral glucose tolerance test (OGTT) was performed in NoDM-Cirr. DM-Cirr and DM-NoCirr were matched by sex, age, BMI, and T2DM treatment and studied with continuous glucose monitoring (CGM). Percent deviations from target, low/high blood glucose indexes (LBGI/HBGI) were calculated from CGM, as well as the average daily risk range (ADRR) as a marker of glucose variability.

RESULTS

Overall, HbA1c and OGTT diagnostic yield agreed in 12 patients (57%, ρ = 0.45, p < 0.03). CGM captured 3463 glucose determinations in DM-Cirr and 4273 in DM-NoCirr (p = 0.42). Regression analysis showed an inferior association between HbA1c and CGM in DM-Cirr (R² = 0.52), when compared to DM-NoCirr (R² = 0.94), and fructosamine did not improve association for DM-Cirr (R² = 0.31). Interestingly, cirrhosis and Child-Turcotte-Pugh class accounted for HbA1c variance (p < 0.05). Patients in DM-Cirr were less frequently within target glucose (70-180 mg/dL), but at higher risk for hyperglycemia (HBGI > 9) when compared to DM-NoCirr, and they also showed higher glucose variability (ADRR 13.9 ± 2.5 vs. 8.9 ± 1.8, respectively, p = 0.03).

CONCLUSION

HbA1c inaccurately represents chronic glycemia in patients with cirrhosis, likely in relation to increased glucose variability.

HbA1c: a review of non-glycaemic variables

Identification of the correlation between HbA1c and diabetic complications has yielded one of the most clinically useful biomarkers. HbA1c has revolutionised the diagnosis and monitoring of diabetes mellitus. However, with widespread adoption of HbA1c has come increasing recognition that non-glycaemic variables can also affect HbA1c, with varying clinical significance. Furthermore, the identification of a discrepancy between predicted and measured HbA1c in some individuals, the so-called 'glycation gap', may be clinically significant. We aimed to review the current body of evidence relating to non-glycaemic variables to quantify any significance and provide subsequent suggestions. A PubMed-based literature search was performed, using a variety of search terms, to retrieve articles detailing the non-glycaemic variables suggested to affect HbA1c. Articles were reviewed to assess the relevance of any findings in clinical practice and where possible guidance is given. A range of non-glycaemic variables have statistically significant effects on HbA1c. While the clinical implications are generally irrelevant, a small number of non-glycaemic variables do have clinically significant effects and alternative biomarkers should be considered instead of, or in addition to, HbA1c. There are a small number of non-glycaemic variables which have a clinically significant effect on HbA1c, However, the vast majority of non-glycaemic variables have no clinical relevance. While clinicians should have an awareness of those non-glycaemic variables with clinical significance, in the vast majority of clinical scenarios HbA1c should continue to be used with confidence.

Association Between Type 2 Diabetes Mellitus, HbA1c and the Risk for Spontaneous Bacterial Peritonitis in Patients with Decompensated Liver Cirrhosis and Ascites

Introduction

Type 2 diabetes mellitus (DM) is a frequent comorbidity among patients with liver cirrhosis. However, data regarding the impact of DM on spontaneous bacterial peritonitis (SBP) are quite limited. Our aim was to analyze the impact of DM and HbA1c values on the incidence of SBP and mortality in patients with liver cirrhosis and ascites.

Methods

A number of 475 consecutive patients with liver cirrhosis and ascites were analyzed. Presence of DM as well as HbA1c was assessed at the time of the first paracentesis. Patients were followed up for a mean of 266 days. Primary endpoints were SBP development and mortality.

Results

Overall, 118 (25%) patients were diagnosed with DM. DM patients had an increased risk for developing a SBP during follow-up (HR: 1.51; p = 0.03). SBP incidence was particularly high in DM patients with HbA1c values ≥6.4%, significantly higher than in DM patients with HbA1c values <6.4% (HR: 4.21; p = 0.0002). Of note, DM patients with HbA1c <6.4% at baseline had a similar risk for SBP as those without DM (HR: 0.93; p = 0.78, respectively). After excluding all patients who were eligible for secondary antibiotic prophylaxis, HbA1c ≥6.4% but neither bilirubin nor ascites protein level were associated with primary SBP development in the multivariate analysis (p = 0.003).

Conclusions

Individuals with liver cirrhosis and concomitant DM have a higher risk for developing a SBP. HbA1c values may be useful to further stratify the risk for SBP among DM patients, which may help to identify those who benefit from antibiotic prophylaxis.

Hepatogenous Diabetes: An Underestimated Problem of Liver Cirrhosis

The prevalence of diabetes mellitus in cirrhotic patients is much higher than that in the general population. Two types of diabetes are usually seen in patients with cirrhosis: type 2 diabetes mellitus and hepatogenous diabetes (HD). The HD is an acquired condition which is believed to be caused by impaired insulin clearance and pancreatic β-cell dysfunction in cirrhotic patients. Increased levels of advanced glycation end products and hypoxia-inducible factors have been implicated in the pathogenesis of HD. Patients with HD typically present with normal fasting glucose, but abnormal response to an oral glucose tolerance test, which is required for the diagnosis. Because the level of glycated hemoglobin is often falsely low in patients with cirrhosis, it does not help in the early diagnosis of HD. HD is associated with an increased rate of complications of cirrhosis, decreased 5-year survival rate, and increased risk of hepatocellular carcinoma. The major complications of cirrhosis associated with HD include hepatic encephalopathy (HE), spontaneous bacterial peritonitis, sepsis, variceal hemorrhage, and renal dysfunction. Treatment of HD may be difficult as many antihyperglycemic therapies are associated with increased risk of complications in cirrhosis, particularly hypoglycemia. Biguanides, alpha-glucosidase inhibitors, and new medications such as dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter 2 inhibitors appear to be safe in patients with cirrhosis. Though insulin therapy is currently advocated, requirement of insulin is variable and is difficult to predict. The liver transplantation usually results in reversal of HD. This review article provides an overview of magnitude, patients' characteristics, clinical implications, pathophysiological mechanisms, diagnosis, and management of HD.

Challenges in diagnosing and monitoring diabetes in patients with chronic liver diseases

The prevalence and mortality of diabetes mellitus and liver disease have risen in recent years. The liver plays an important role in glucose homeostasis, and various chronic liver diseases have a negative effect on glucose metabolism with the consequent emergence of diabetes. Some aspects related to chronic liver disease can affect diagnostic tools and the monitoring of diabetes and other glucose metabolism disorders, and clinicians must be aware of these limitations in their daily practice. In cirrhotic patients, fasting glucose may be normal in up until 23% of diabetes cases, and glycated hemoglobin provides falsely low results, especially in advanced cirrhosis. Similarly, the performance of alternative glucose monitoring tests, such as fructosamine, glycated albumin and 1,5-anhydroglucitol, also appears to be suboptimal in chronic liver disease. This review will examine the association between changes in glucose metabolism and various liver diseases as well as the particularities associated with the diagnosis and monitoring of diabetes in liver disease patients. Alternatives to routinely recommended tests will be discussed.

Utility and Limitations of Glycated Hemoglobin (HbA1c) in Patients with Liver Cirrhosis as Compared with Oral Glucose Tolerance Test for Diagnosis of Diabetes

INTRODUCTION

To study the utility of glycated hemoglobin (HbA1c) in the diagnosis of diabetes in patients with cirrhosis as compared to the gold standard oral glucose tolerance test (OGTT) and to see the effect of anemia and severity of cirrhosis on its performance.

METHODS

Individuals (n = 100) with an established diagnosis of liver cirrhosis were recruited. The OGTT was performed as described by the World Health Organization (WHO). The severity of cirrhosis was calculated using the Child-Turcotte-Pugh (CTP) score. The severity of anemia was defined according to WHO criteria. The utility of HbA1c was compared against the OGTT results. Test sensitivity and specificity were used to describe the diagnostic accuracy of HbA1c.

RESULTS

A total of 100 subjects aged 46.9 ± 9.1 years (mean ± standard deviation) participated in the study, of whom 65% were recruited from out patient department of our hospital. The overall sensitivity and specificity of a HbA1c level of ≥ 6.5% for the diagnosis of diabetes in patients with cirrhosis was 77.1% (95% CI 59.9, 89.6) and 90.8% (95% CI 81.0, 96.5), respectively. The positive and negative predictive values were 81.8% (95% CI 67.3, 90.8) and 88.1% (95% CI 80.0, 93.2), respectively. The area under the curve was 0.85 (95% CI 0.75-0.94). The sensitivity of HbA1c for diagnosing diabetes in outpatients was 87.0% (95% CI 66.4, 97.2) and was better than that for diagnosing diabetes in hospitalized patients (58.3%; 95% CI 27.7, 84.8). The sensitivity of HbA1c for diagnosing diabetes was poor in patients with moderate to severe anemia. The difference in sensitivity and specificity was not statistically different for CTP classes A, B and C. The prevalence of diabetes as defined by American Diabetes Association OGTT criteria was 35% (95% CI 25.7-45.2%).

CONCLUSIONS

Taking OGTT as the gold standard, the sensitivity of HbA1c for diagnosing diabetes is good when used in outpatients with cirrhosis. However, the sensitivity of HbA1c decreases when it is used for hospitalized patients, suggesting that it is not a good test for diagnosis of diabetes in such cases. It also performs poorly if the patient has moderate to severe anemia.

Effect of age on the diagnostic efficiency of HbA1c for diabetes in a Chinese middle-aged and elderly population: The Shanghai Changfeng Study

Background and aims

Glycated hemoglobin A1c (HbA1c) ≥6.5% (or 48mmol/mol) has been recommended as a new diagnostic criterion for diabetes; however, limited literature is available regarding the effect of age on the HbA1c for diagnosing diabetes and the causes for this age effect remain unknown. In this study, we investigated whether and why age affects the diagnostic efficiency of HbA1c for diabetes in a community-based Chinese population.

Methods

In total, 4325 participants without previously known diabetes were enrolled in this study. Participants were stratified by age. Receiver operating characteristic curve (ROC) was plotted for each age group and the area under the curve (AUC) represented the diagnostic efficiency of HbA1c for diabetes defined by the plasma glucose criteria. The area under the ROC curve in each one-year age group was defined as AUCage. Multiple regression analyses were performed to identify factors inducing the association between age and AUCage based on the changes in the β and P values of age.

Results

The current threshold of HbA1c (≥6.5% or 48mmol/mol) showed low sensitivity (35.6%) and high specificity (98.9%) in diagnosing diabetes. ROC curve analyses showed that the diagnostic efficiency of HbA1c in the ≥75 years age group was significantly lower than that in the 45–54 years age group (AUC: 0.755 vs. 0.878; P<0.001). Pearson correlation analysis showed that the AUCage of HbA1c was negatively correlated with age (r = -0.557, P = 0.001). When adjusting the red blood cell (RBC) count in the multiple regression model, the negative association between age and AUCage disappeared, with the regression coefficient of age reversed to 0.001 and the P value increased to 0.856.

Conclusions

The diagnostic efficiency of HbA1c for diabetes decreased with aging, and this age effect was induced by the decreasing RBC count with age. HbA1c is unsuitable for diagnosing diabetes in elderly individuals because of their physiologically decreased RBC count.

What Clinical Laboratorians Should Do in Response to Extremely Low Hemoglobin A1c Results

Extremely low hemoglobin A1c (HbA1c) results below reference range are rare, and the causes and clinical implications associated with low HbA1c results are not well understood among clinical laboratorians. A case of extremely low HbA1c results was reported, in which liver cirrhosis, subacute hemorrhage and recent transfusion all contributed to the low result. This case illustrates when HbA1c should not be used as a clinically relevant diabetes marker. However, low or extremely low HbA1c (<5.0% or <4.0%) may occur in apparently healthy individuals. When this occurs, it is an independent risk factor associated with liver diseases, hospitalization, and all-cause mortality. From the clinical laboratory perspective, the clinical cause of extremely low HbA1c should be determined, and suggestions of different test utilization or increased health surveillance should be given to care providers.

Diabetes mellitus in patients with cirrhosis: clinical implications and management

Disorders of glucose metabolism, namely glucose intolerance and diabetes, are frequent in patients with chronic liver diseases. In patients with cirrhosis, diabetes can be either a classical type 2 diabetes mellitus or the so-called hepatogenous diabetes, i.e. a consequence of liver insufficiency and portal hypertension. This review article provides an overview of the possible pathophysiological mechanisms explaining diabetes in patients with cirrhosis. Cirrhosis is associated with portosystemic shunts as well as reduced hepatic mass, which can both impair insulin clearance by the liver, contributing to peripheral insulin resistance through insulin receptors down-regulation. Moreover, cirrhosis is associated with increased levels of advanced-glycation-end products and hypoxia-inducible-factors, which may play a role in the development of diabetes. This review also focuses on the clinical implications of diabetes in patients with cirrhosis. First, diabetes is an independent factor for poor prognosis in patients with cirrhosis. Specifically, diabetes is associated with the occurrence of major complications of cirrhosis, including ascites and renal dysfunction, hepatic encephalopathy and bacterial infections. Diabetes is also associated with an increased risk of hepatocellular carcinoma in patients with chronic liver diseases. Last, the management of patients with concurrent diabetes and liver disease is also addressed. Recent findings suggest a beneficial impact of metformin in patients with chronic liver diseases. Insulin is often required in patients with advanced cirrhosis. However, the favourable impact of controlling diabetes in patients with cirrhosis has not been demonstrated yet.

Glycated Hemoglobin Levels in Patients with Decompensated Cirrhosis

Introduction. Aim of this study is to determine if HbA1c levels are a reliable predictor of glycemic control in patients with decompensated cirrhosis. Methods. 200 unique patients referred for liver transplantation at University of Tennessee/Methodist University Transplant Institute with a HbA1c result were included. Three glucose levels prior to the "measured" A1c (MA1c) were input into an HbA1c calculator from the American Diabetes Association website to determine the "calculated" A1c (CA1c). The differences between MA1c and CA1c levels were computed. Patients were divided into three groups: group A, difference of <0.5; group B, 0.51-1.5; and group C, >1.5. Results. 97 (49%) patients had hemoglobin A1c of less than 5%. Discordance between calculated and measured HbA1c of >0.5% was seen in 47% (n = 94). Higher level of discordance of greater than >1.5 was in 12% of patients (n = 24). Hemoglobin was an independent predictor for higher discordance (odds ratio 0.77 95%, CI 0.60-0.99, and p value 0.04). HbA1c was an independent predictor of occurrence of HCC (OR 2.69 955, CI 1.38-5.43, and p value 0.008). Conclusion. HbA1c is not a reliable predictor of glycemic control in patients with decompensated cirrhosis, especially in those with severe anemia.

Alterations in carbohydrate metabolism in cirrhotic patients before and after liver transplant

AIM

The main objective of this study is to demonstrate whether carbohydrate metabolism alterations identified in patients with advanced cirrhosis show any improvement after liver transplant.

METHODS

The study included 86 patients who underwent liver transplant between March 2010 and February 2011. An oral glucose tolerance test was performed before the liver transplant, and 6 and 12 months after. Beta cell function and insulin resistance were also calculated, applying formulae that use basal plasma glycaemia and insulin, and plasma glycaemia and insulin during an oral glucose tolerance test. Risk factors for pre- and post-transplant diabetes were also studied. The diagnosis of diabetes was based on an OGTT.

RESULTS

The proportion of patients with diabetes before transplant, and at month 6 and 12 after transplant were 70.9%, 48.8% and 39.2%, respectively. Compared to baseline, at month 6 the odds ratio of having diabetes was 0.39 (IC 95% [0.21, 0.73]) and at month 12 it was 0.26 (IC 95% [0.14, 0.50]). The composite insulin sensitivity index values at 6 and 12 months were 1.72 units higher (IC 95% [0.84, 2.58]) and 1.58 units higher (IC 95% [0.68, 2.44)] than baseline. A statistically significant association was found between high MELD values and high body mass index, and risk of pre-transplant diabetes (p=0.001 and p=0.033, respectively). Cirrhosis aetiology did not influence the risk of diabetes.

CONCLUSIONS

In this study, we were able to ascertain that alterations in carbohydrate metabolism typical of advanced cirrhosis improve after liver transplant. This improvement is mainly due to an improvement in insulin resistance.

Diabetes mellitus defined by hemoglobin A1c value: Risk characterization for incidence among Japanese subjects in the JPHC Diabetes Study

Aims/Introduction:  Although several risk factors for type 2 diabetes have been identified, most of them have been identified in studies on Western populations, and they should be evaluated in a Japanese population. In 2010, new diagnostic criteria for diabetes mellitus using hemoglobin A1c (HbA1c) were released and its use in epidemiological studies has many advantages. The aim of the present study was to evaluate risk factors for type 2 diabetes defined based on HbA1c values in a Japanese population.

MATERIALS AND METHODS

  A total of 9223 subjects (3076 men and 6147 women) were followed up for 5 years. Diabetes was defined based on self-report or HbA1c value. Risk factors for diabetes were evaluated as odds ratios adjusted for potential confounding factors by logistic regression.

RESULTS

  During the 5-year follow-up period, we documented 518 incident cases of diabetes (232 men and 286 women). Of the 518 incident cases, 310 cases were diagnosed by HbA1c alone. Among the men, age, smoking (both past smoking and current smoking) and family history of diabetes significantly increased the risk of diabetes. Among the women, body mass index, family history of diabetes and hypertension significantly increased the risk of diabetes. These results did not change markedly after adjustment for the baseline HbA1c values, and the baseline HbA1c value itself was a significant risk factor for diabetes mellitus.

CONCLUSIONS

  Known risk factors for diabetes established in Western populations also increased the risk of diabetes in a Japanese population defined on the basis of HbA1c values. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00119.x, 2011).

The Janus face of PAMAM dendrimers used to potentially cure nonenzymatic modifications of biomacromolecules in metabolic disorders-a critical review of the pros and cons

Diabetes mellitus, which is characterised by high blood glucose levels and the burden of various macrovascular and microvascular complications, is a cause of much human suffering across the globe. While the use of exogenous insulin and other medications can control and sometimes prevent various diabetes-associated sequelae, numerous diabetic complications are still commonly encountered in diabetic patients. Therefore, there is a strong need for safe and effective antihyperglycaemic agents that provide an alternative or compounding option for the treatment of diabetes. In recent years, amino-terminated poly(amido)amine (PAMAM) dendrimers (G2, G3 and G4) have attracted attention due to their protective value as anti-glycation and anti-carbonylation agents that can be used to limit the nonenzymatic modifications of biomacromolecules. The focus of this review is to present a detailed survey of our own data, as well as of the available literature regarding the toxicity, pharmacological properties and overall usefulness of PAMAM dendrimers. This presentation pays particular and primary attention to their therapeutic use in poorly controlled diabetes and its complications, but also in other conditions, such as Alzheimer’s disease, in which such nonenzymatic modifications may underlie the pathophysiological mechanisms. The impact of dendrimer administration on the overall survival of diabetic animals and on glycosylation, glycoxidation, the brain-blood barrier and cellular bioenergetics are demonstrated. Finally, we critically discuss the potential advantages and disadvantages accompanying the use of PAMAM dendrimers in the treatment of metabolic impairments that occur under conditions of chronic hyperglycaemia.

Haemoglobin A1c cut-off point to identify a high risk group of future diabetes: results from the Omiya MA Cohort Study

AIMS

Using the HbA(1c) level to define diabetes has several advantages and these advantages also apply to define a high-risk group. However, the risk of diabetes increases as HbA(1c) increases and a certain degree of arbitrariness in the cut-off for the high risk group is unavoidable. The aim of this study was to determine the HbA(1c) cut-off for defining a high-risk group that corresponds to the fasting plasma glucose cut-off by comparing the risk of diabetes against the fasting plasma glucose and HbA(1c) levels in the Japanese population.

METHODS

A retrospective cohort study was conducted using data from annual health examinations performed in Omiya city. A total of 11,271 subjects between the ages of 40 and 79 years without diabetes at baseline were followed for up to 7 years. According to the new diagnostic criteria, diabetes was defined as an fasting plasma glucose level ≥ 7 mmol/l or an HbA(1c) level ≥ 48 mmol/mol (≥ 6.5%) or a self-report. The HbA(1c) cut-off corresponding to the fasting plasma glucose cut-off was determined using the incidence, hazard ratio, and a receiver operating characteristic analysis.

RESULTS

Eight hundred and sixty subjects developed diabetes. The incidence, hazard ratio, and receiver operating characteristic analysis all indicated that an HbA(1c) cut-off of 39 mmol/mol (5.7%) corresponded to an fasting plasma glucose level of 5.6 mmol/l.

CONCLUSIONS

Our results suggested that the HbA(1c) cut-off for high-risk of diabetes should be 39 mmol/mol (5.7%), consistent with the American Diabetes Association recommendation. Further research is needed to determine whether our results are applicable to other populations.

The relationship between HbA1c and fasting plasma glucose in patients with increased plasma liver enzyme measurements

BACKGROUND

HbA(1c) is currently being introduced for diagnostic purpose in diabetes. Previous studies have, however, indicated that patients with liver disease have false low HbA(1c) levels. We therefore investigated the correlation between HbA(1c) and plasma glucose in patients with different levels of increased liver enzyme concentrations.

METHODS

Data from 10,065 patients with simultaneous measurement of HbA(1c), venous fasting plasma glucose, alanine aminotransferase and γ-glutamyl transferase were extracted from our laboratory database. Correlations were investigated in four patient groups divided according to their liver enzyme concentrations.

RESULTS

The correlation between HbA(1c) and plasma glucose was high in all groups, with r = 0.77 for men and r = 0.78 for women (P < 0.001), a correlation confirmed with multiple regression analysis (P < 0.001). However, interaction analysis revealed that linear regression lines were significantly different for men and women, with increase of both liver enzyme measurements and also, for women, with increased alanine aminotransferase. When compared with biological variation for HbA(1c), only men with increased measurements of both liver enzymes had a clinically important decrease in HbA(1c).

CONCLUSIONS

Increased liver enzyme concentrations do not bias the correlation between HbA(1c) and fasting plasma glucose. However, men with low plasma glucose and increased concentrations of both liver enzymes do have a slightly decreased HbA(1c) and, if the clinical suspicion is strong enough, one should consider supplement testing.

Current controversies in the use of haemoglobin A1c

Haemoglobin A(1c) (HbA(1c)) has recently been adopted by the World Health Organization into its recommended criteria for diabetes diagnosis. Much debate continues regarding the relative benefits and potential disadvantages surrounding the use of HbA(1c) for this purpose. There is a lack of consensus as to whether this alteration to the definition of diabetes is a step forward or whether it could add further confusion and ambiguity to the debate on the method and criteria for the diagnosis of this globally important disease. This review provides a comprehensive overview of the current issues surrounding how HbA(1c) is measured and reported; and of the evidence for and against its use in diagnosis.

Evaluation of serum biomarkers in nutritional disorders: glycated apolipoprotein B, fasting serum glucose, fructosamine, stable and labile glycated hemoglobin in diabetic and non-diabetic subjects

Glycated apolipoprotein B (ApoB-G), a non enzymatically glycated protein, has recently been associated with myocardial infarction. Our aim is to evaluate, in diabetic and non diabetic subjects, the relationship of ApoB-G with serum fasting glucose, fructosamine, stable and labile fractions of glycated hemoglobin ((S)HbA(1c), (L)HbA(1c), respectively) and insulin. The subjects were recruited from a previous study on ApoB-G and myocardial infarction: 141 of them were studied, 43 with and 98 without diabetes. ApoB-G was measured using a monoclonal antibody, and linear regression and correlation were used for statistical analysis of the data. ApoB-G was higher in diabetic than in non diabetic subjects. There was a statistically significant correlation of ApoB-G with triglycerides (r = 0.38, p = 0.01) in diabetic subjects, and with total proteins (r = 0.37, p = 0.0002), triglycerides (r = 0.34, p = 0.0007), and cholesterol (r = 0.23, p = 0.02) in non diabetic subjects. In the most parsimonious multiple linear regression model of ApoB-G on all the other serum variables, there was a statistically significant association of ApoB-G with triglycerides, in both diabetic and non diabetic subjects. The main results of this study suggest that serum ApoB-G is associated with serum triglycerides in both diabetic and non diabetic subjects.