Association between blood glucose level derived using the oral glucose tolerance test and glycated hemoglobin level

Liraglutide treatment for the prevention of glucose tolerance deterioration in women with prior gestational diabetes mellitus: A 52-week randomized controlled clinical trial

AIM

We investigated the effect of 52-week treatment with liraglutide, a glucagon-like peptide 1 receptor agonist, on glucose tolerance and incretin effect in women with previous gestational diabetes mellitus (pGDM).

MATERIALS AND METHODS

Women with overweight/obesity and pGDM were randomized to once daily subcutaneous liraglutide 1.8 mg or placebo for 52 weeks. Participants underwent oral glucose tolerance test (OGTT) and isoglycaemic intravenous glucose infusion at baseline and at 52 weeks, and an additional OGTT after the drug wash-out.

RESULTS

In total, 104 women [age: mean ± SD, 38 ± 5 years; fasting plasma glucose (FPG): 5.5 ± 0.4 mmol/L; glycated haemoglobin (HbA1c): 33 ± 4 mmol/mol, bodyweight: 88.2 ± 14.8 kg, body mass index: 31.1 ± 4.3 kg/m2 ] were assigned to liraglutide (n = 49) or placebo (n = 55). Estimated treatment difference (ETD) for area under curve during OGTT was -173 (95% confidence interval -250 to -97) mmol/L × min, p < .0001, but after wash-out the difference disappeared [ETD 58 (-30 to 146) mmol/L × min, p = .536]. Liraglutide reduced FPG [ETD -0.2 (-0.4 to -0.1) mmol/L, p = .018], HbA1c [-2.2 (-3.5 to -0.8) mmol/mol, p = .018] and bodyweight [-3.9 (-6.2 to -1.6) kg, p = .012]. No change in the incretin effect was observed. The number of women with prediabetes was reduced from 64% to 10% with liraglutide vs. 50% with placebo [adjusted odds ratio 0.10 (0.03-0.32), p = .002].

CONCLUSIONS

Treatment with liraglutide for 52 weeks improved glucose tolerance, FPG, HbA1c and bodyweight in women with overweight/obesity and pGDM. Progression to prediabetes while on drug was markedly reduced, but after a 1-week drug wash-out, the effect was lost.

Michaelis-Menten kinetic modeling of hemoglobin A1c status facilitates personalized glycemic control

INTRODUCTION

Discrepancy between measured HbA1c and HbA1c calculated from plasma glucose is associated with higher risk for diabetic complications. However, quantification of this difference is inaccurate due to the imperfect linear conversion models. We propose to introduce a mathematical formula that correlates with the observational data and supports individualized glycemic control.

METHODS

We analysed 175,437 simultaneous plasma glucose and HbA1c records stored in our laboratory database. Employing the Michaelis-Menten (MM) equation, we compared the calculated HbA1c levels to the measured HbA1c levels. Data from patients with multiple records were used to establish the patients' glycemic status and to assess the predictive power of our MM model.

RESULTS

HbA1c levels calculated with the MM equation closely matched the population's average HbA1c levels. The Michaelis constant (Km) had a negative correlation with HbA1c (r2 = 0.403). Using personalized Km values in the MM equation, 85.1% of HbA1c predictions were within 20% error (ADAG calculation: 78.4%). MM prediction also performed better in predicting pathologic HbA1c levels (0.904 AUC vs. 0.849 AUC for ADAG).

CONCLUSION

MM equation is an improvement over linear models and could be readily employed in routine diabetes management. Km is a reliable and quantifiable marker to characterize variations in glucose tolerance.

Adsorption Kinetics of Glycated Hemoglobin on Aptamer Microarrays with Antifouling Surface Modification

Aptamers are oligonucleotides that bind with high affinity to target molecules of interest. One such target is glycated hemoglobin (gHb), a biomarker for assessing glycemic control and diabetes diagnosis. By the coupling of aptamers with surface plasmon resonance (SPR) sensing surfaces, a fast, reliable and inexpensive assay for gHb can be developed. In this study, we tested the affinity of SPR-sensing surfaces, composed of aptamers and antifouling self-assembled monolayers (SAMs), to hemoglobin (Hb) and gHb. First, we developed a gHb-targeted aptamer (GHA) through a modified Systematic Evolution of Ligands by EXponential (SELEX) enrichment process and tested its affinity to gHb using the Nano-Affi protocol. GHA was used to produce three distinct SAM-SPR-sensing surfaces: (Type-1) a SAM of GHA directly attached to a sensor surface; (Type-2) GHA attached to a SAM of 11-mercaptoundecanoic acid (11MUA) on a sensor surface; (Type-3) GHA attached to a binary SAM of 11MUA and 3,6-dioxa-8-mercaptooctan-1-ol (DMOL) on a sensor surface. Type-2 and Type-3 surfaces were characterized by cyclic voltammetry and electrochemical impedance spectroscopy to confirm that GHA bound to the underlying SAMs. The adsorption kinetics for Hb and gHb interacting with each SPR sensing surface were used to quantify their respective affinities. The Type-1 surface without antifouling modification had a dissociation constant ratio (K_D,Hb/K_D,gHb) of 9.7, as compared to 809.3 for the Type-3 surface, demonstrating a higher association of GHA to gHb for sensor surfaces with antifouling modifications than those without. The enhanced selectivity of GHA to gHb can likely be attributed to the inclusion of DMOL in the SAM-modified surface, which reduced interference from nonspecific adsorption of proteins. Results suggest that pairing aptamers with antifouling SAMs can significantly improve their target affinity, potentially allowing for the development of novel, low cost, and fast assays.

Optimal fasting plasma glucose and haemoglobin A1c levels for screening of prediabetes and diabetes according to 2-hour plasma glucose in a high-risk population: The Korean Diabetes Prevention Study

BACKGROUND

The primary aim of this study was to assess the utility of fasting plasma glucose (FPG) and HbA1c to identify diabetes by the 2-hour plasma glucose (PG) criterion in the Korean population at high risk for diabetes.

METHODS

A total of 1646 participants with a body mass index of ≥23 kg/m2 without having a history of diabetes were recruited in this study. The cut-off values of FPG and HbA1c for detecting diabetes were identified using the Youden index using receiver operating characteristic (ROC) analysis. The gold standard for diabetes prediction was defined by the 2-hour PG level of ≥200 mg/dL.

RESULTS

The participants comprised 54.0% women, and the mean age of all participants was 55.0 ± 8.1 years. At baseline, FPG was 104.1 ± 14.2 mg/dL, the 2-hour PG value was 162.9 ± 55.3 mg/dL, and HbA1c was 5.9% ± 0.5%. Four hundred and forty-six subjects (27.1%) were diagnosed with diabetes and 976 subjects (59.3%) were determined to be at prediabetes. The area under the ROC curve (AUC) of FPG and HbA1c for diabetes were 0.776 and 0.802, while the AUC of FPG and HbA1c for prediabetes were 0.515 and 0.477. The optimal cut-off value for diagnosing diabetes of FPG and HbA1c were 104.5 mg/dL (sensitivity 75.8%, specificity 67.5%) and 5.9% (sensitivity 80.6%, specificity 63.8%), respectively.

CONCLUSIONS

FPG of 104.5 mg/dL and HbA1c value of 5.9% (41 mmol/mol) can be used as an optimal screening value for diabetes by 2-hour PG criterion in the Korean population at high risk for diabetes.

A randomized trial of dapagliflozin and metformin, alone and combined, in overweight women after gestational diabetes mellitus

BACKGROUND

Women with a history of gestational diabetes mellitus are at a substantially increased risk of gestational diabetes mellitus recurrence and type 2 diabetes. Weight gain, particularly increased central adiposity after delivery, is strongly associated with deterioration of pancreatic beta cell compensation for insulin resistance. Weight management after gestational diabetes mellitus could have a significant benefit in these women who are at a high risk of developing type 2 diabetes.

OBJECTIVE

This study aimed to evaluate the treatment efficacy of dapagliflozin and metformin, alone and in combination, on body weight and anthropometric, cardiovascular, and metabolic parameters in overweight women with a recent history of gestational diabetes mellitus.

STUDY DESIGN

This was a prospective, single-blind, randomized, outpatient clinical trial with 3 parallel treatment groups. Overweight or obese (body mass index>25) females (n=66; ≥18-45 years) with gestational diabetes mellitus in pregnancy in the past 12 months were randomized in a single-blind manner to dapagliflozin, metformin, or dapagliflozin-metformin for 24 weeks. Body weight, height, body mass index, waist circumference, waist-to-height ratio, and blood pressure were determined at baseline and trial completion. Oral glucose tolerance tests were performed at baseline and 24 weeks to assess glycemia and mean blood glucose and calculate insulin sensitivity and secretion measures. Plasma lipid fractions, thyroid-stimulating hormone, and liver enzymes were also assessed in the fasting sample at the beginning and completion of the study trial.

RESULTS

The study was completed by 49 participants (74%). Significant reduction of weight, waist circumference, and waist-to-height ratio and improved glycemia and insulin sensitivity index derived from oral glucose tolerance test were found with dapagliflozin-metformin vs metformin monotherapy. Both dapagliflozin and dapagliflozin-metformin therapy were superior to metformin in increasing high-density lipoprotein levels, reducing triglyceride concentrations, lowering the triglyceride-to-high-density lipoprotein cholesterol ratio, and improving glucose excursion after an oral glucose tolerance test. The early insulin response to a glucose challenge significantly improved with only dapagliflozin-metformin compared with single-drug treatments.

CONCLUSION

This is the first report comparing the efficacy of a sodium-glucose cotransporter 2 inhibitor alone and in combination with metformin in this patient population. We found that combination dapagliflozin-metformin treatment over a 24-week period had a greater positive effect on body weight, waist circumference, and glycemic, cardiovascular, and metabolic parameters than metformin monotherapy in overweight or obese at-risk women with a recent history of gestational diabetes mellitus.

Cohort Profile: The Cardiovascular and Metabolic Diseases Etiology Research Center Cohort in Korea

Mortalities from cardiovascular disease in Korea have decreased markedly over the past three decades. The major cardiovascular and metabolic risk factors, however, remain prevalent, and their burden on health is large. The Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) planned a cohort study in order to identify novel risk factors and to develop evidence-based prevention strategies of cardiovascular and metabolic diseases. The CMERC deliberately designed two prospective cohorts, a community-based general population cohort (the CMERC cohort) and its sister cohort (a hospital-based high-risk patient cohort), covering a broad spectrum of cardiovascular and metabolic diseases. This paper describes the CMERC cohort study of community-dwelling adults aged 30 to 64 years. A total of 8097 adults completed baseline measurement between 2013 and 2018. Baseline measurements assessed socio-demographic factors, medical history, health-related behaviors, psychological health, social network and support, anthropometry, body composition, and resting blood pressure and comprised electrocardiography, carotid artery ultrasonography, fasting blood analysis, and urinalysis. Both active follow-up through an annual telephone survey and a 5-year on-site health examination survey and passive follow-up through secondary data linkage with national databases, such as national death records, have been applied. Researchers interested in collaborative research may contact the corresponding author.

Glycated albumin in chronic kidney disease: Pathophysiologic connections

Nephropathy in diabetes patients is the most common etiology of end-stage kidney disease (ESKD). Strict glycemic control reduces the development and progression of diabetes-related complications, and there is evidence that improved metabolic control improves outcomes in subjects having diabetes mellitus with advanced chronic kidney disease (CKD). Glycemic control in people with kidney disease is complex. Changes in glucose and insulin homoeostasis may occur as a consequence of loss of kidney function and dialysis. The reliability of measures of long-term glycemic control is affected by CKD and the accuracy of glycated haemoglobin (HbA1c) in the setting of CKD and ESKD is questioned. Despite the altered character of diabetes in CKD, current guidelines for diabetes management are not specifically adjusted for this patient group. The validity of indicators of long-term glycemic control has been the focus of increased recent research. This review discusses the current understanding of commonly used indicators of metabolic control (HbA1c, fructosamine, glycated albumin) in the setting of advanced CKD.

Association between Blood Mercury Level and Visceral Adiposity in Adults

BACKGROUND

Few studies have examined the association between mercury exposure and obesity. The aim of this study is to investigate the association between blood mercury concentrations and indices of obesity in adults.

METHODS

A total of 200 healthy subjects, aged 30 to 64 years, who had no history of cardiovascular or malignant disease, were examined. Anthropometric and various biochemical profiles were measured. Visceral adipose tissue (VAT) was measured using dual-energy X-ray absorptiometry (DXA).

RESULTS

All subjects were divided into three groups according to blood mercury concentrations. Compared with the subjects in the lowest tertile of mercury, those in the highest tertile were more likely to be male; were current alcohol drinkers and smokers; had a higher body mass index (BMI), waist circumference (WC), and VAT; had higher levels of blood pressure, fasting glucose, and insulin resistance; and consumed more fish. The blood mercury concentration was significantly associated with anthropometric parameters, showing relationships with BMI, WC, and VAT. After adjusting for multiple risk factors, the odds ratios (ORs) for high mercury concentration was significantly higher in the highest VAT tertile than in the lowest VAT tertile (OR, 2.66; 95% confidence interval, 1.05 to 6.62; P<0.05).

CONCLUSION

The blood mercury concentration was significantly associated with VAT in healthy adults. Further studies are warranted to confirm our findings.

Current status of managing diabetes mellitus in Korea

Diabetes mellitus is an increasing global health problem. Guidelines for diabetic care recommend management of lifestyle and risk factors (glucose, blood pressure, and cholesterol), as well as regular screening for complications associated with treatment of the conditions related to diabetes. The prevalence of diabetes increased from 8.6% to 11.0% from 2001 to 2013. According to the diabetes fact sheet 2015, the proportion of patients with diabetes treated with antihypertensive medications increased from 56.0% to 62.5% from 2006 to 2013, and 49.5% of those with diabetes were being treated with lipid-lowering medications in 2013, a 1.8-fold increase since 2006. According to the 2014 Korea National Health and Nutrition Examination Survey data, 45.6% of patients with diabetes achieved a hemoglobin A1c level of < 7.0%, 72.8% achieved a blood pressure of < 140/85 mmHg, and 58.0% achieved a low density lipoprotein cholesterol level of < 100 mg/dL. Only 19.7% of patients with diabetes had good control of all three of these parameters. Despite improvements in health promotion efforts, the rates of adherence to medication and risk-factor control are low. Therefore, a systematic approach to managing diabetes, including self-management education, is needed to prevent or delay complications. The government needs to establish a long-term policy to address the growing burden of diabetes.

Visceral Fat Mass Has Stronger Associations with Diabetes and Prediabetes than Other Anthropometric Obesity Indicators among Korean Adults

PURPOSE

This study determined which obesity measurement correlates the best with diabetes and prediabetes.

MATERIALS AND METHODS

This cross-sectional study enrolled 1603 subjects (611 men, 992 women; age 30-64 years) at the Cardiovascular and Metabolic Diseases Etiology Research Center. Body mass index, waist circumference, waist-height ratio, waist-hip ratio, waist-thigh ratio, and visceral fat were used as measures of obesity. Visceral fat was acquired using dual-energy X-ray absorptiometry (DXA). The prevalences of diabetes and prediabetes were defined using the criteria in the American Diabetes Association 2015 guidelines.

RESULTS

After adjusting for age and other potential confounding factors, participants with a visceral fat mass in the upper 10th percentile had a higher odds ratio (OR) for diabetes and prediabetes than the upper 10th percentile of other adiposity indices [men, OR=15.9, 95% confidence interval (CI)=6.4-39.2; women, OR=6.9, 95% CI=3.5-13.7]. Visceral fat mass also had the highest area under the curve with diabetes and prediabetes in both men (0.69, 95% CI=0.64-0.73) and women (0.70, 95% CI=0.67-0.74) compared to other anthropometric measurements of obesity.

CONCLUSION

Visceral fat mass measured using DXA is an indicator of diabetes or prediabetes, due to its ability to differentiate between abdominal visceral and subcutaneous fat.

Impact of Cadmium Exposure on the Association between Lipopolysaccharide and Metabolic Syndrome

Cadmium (Cd) is an environmental contaminant that has a direct impact on the gut microbiome. Perturbations in the gut microbiome have been linked to metabolic disorders associated with inflammation generated by lipopolysaccharide (LPS). We investigated the impact of Cd on the association between LPS and metabolic syndrome. The study population consisted of 200 apparently healthy subjects (30–64 years of age; 96 men, 104 women). Serum LPS and blood Cd concentrations were measured by ELISA and graphite furnace-atomic absorption spectrophotometry (GF-AAS), respectively. The highest LPS quartile was associated with a greater prevalence of metabolic syndrome in men. There was a significant association between LPS activity and metabolic syndrome in men with blood Cd concentrations higher than the 50th percentile (OR = 3.05, 95% CI = 1.39–6.70); however, this relationship was not significant in men with blood Cd concentrations lower than the 50th percentile. The results of this study provide evidence for a strong association between high LPS activity and the prevalence of metabolic syndrome in men with relatively high blood Cd concentrations. Therefore, exposure to Cd may potentiate the association between LPS and metabolic syndrome in men.