Motherhood,Apple Pie,Hemoglobin A1c,and the DCCT

ObjectiveTo review recent literature on the limitations of hemoglobin A_1c (HbA_1c) as a marker of glycemic control.MethodsEnglish-language literature published between 1985 and 2011 was reviewed specific to analyses of major trials relating glycemic control to complications of diabetes mellitus, as expressed through HbA_1c as a marker of glycemic control.ResultsHbA_1c has been accepted as the most fundamental biomarker in diabetes, if not all of medicine, as it clearly predicts risk for diabetes-related complications. What is not generally appreciated is that HbA_1c is a crude marker of glycemia with many limitations. It is now accepted that HbA_1c does not reflect mean glucose for many people, and even for those it does, any level could represent a wide range of glycemia. While we have learned HbA_1c is not a perfect biomarker, we also know that in the Diabetes Control and Complications Trial, HbA_1c could only explain 11% of the variation in retinopathy risk between the conventional and intensive therapy groups. This important finding suggests that other glycemic and nonglycemic factors may be responsible for the pathogenesis of diabetes-related complications. One candidate is glycemic variability, which must be differentiated from postprandial hyperglycemia since hypoglycemia can also result in inflammatory activation. Importantly, although it is clear that in insulin-requiring patients glycemic variability is associated with hypoglycemia, we require a definitive prospective trial to confirm glycemic variability’s association with one or more vascular complications.ConclusionsWhat is abundantly clear is that the HbA_1c message, as we know it, is too simplistic. While certain wholesome concepts such as motherhood and apple pie are accepted by all, the HbA_1c message may be more complex than originally appreciated, and it may be time to reevaluate our most basic premise in diabetes. (Endocr Pract. 2012;18:78-84)     

Markedly Low Hemoglobin A1c in a Patient with an Unusual Presentation of ß-Thalassemia Minor

ObjectiveTo describe very low hemoglobin A_1c levels in a patient with type 2 diabetes mellitus and an unusual presentation of β-thalassemia minor.MethodsWe present the clinical and laboratory findings of the study patient.ResultsA 64-year-old African American man with type 2 diabetes mellitus was referred to the endocrinology clinic with a hemoglobin A_1c level of 1.6% despite elevated blood glucose concentrations. A red blood cell survival study with chromium-51 revealed that he had a reduced erythrocyte life span less than 25% of normal. He also had a markedly elevated reticulocyte count ranging from 236 to 534 x 10³/μL (reference range, 25-75 x 103/μL). The laboratory findings, which are not characteristic of ß-thalassemia minor, could be the cause of the markedly low hemoglobin A_1c in this patient.ConclusionsAlthough rare, when associated with marked erythrocyte turnover, β-thalassemia minor can lead to a severe reduction in HbA_1c levels. In this scenario, glycemic control is best assessed by measuring fructosamine. (Endocr Pract. 2010;16:89-92)     

Patients Achieving Good Glycemic Control (HBA1c <7%) Experience A Lower Rate of Hypoglycemia With Insulin Degludec Than with Insulin Glargine: A Meta-Analysis of Phase 3A Trials

Objective: Meta-analysis to compare hypoglycemia rates of basal insulin degludec (IDeg) with insulin glargine (IGlar) in patients with diabetes achieving good glycemic control (hemoglobin A_1c [HbA_1c] <7% at end of trial).Methods: In a preplanned meta-analysis, patient data from 7 randomized, treat-to-target, 26- or 52-week trials in patients with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) who administered IDeg (n = 2,899) or IGlar (n = 1,431) once daily were analyzed. Using a negative binomial regression model, this meta-analysis compared hypoglycemia rates in patients achieving HbA_1c <7% at end of trial with IDeg (n = 1,347) and IGlar (n = 697).Results: In all trials, IDeg was noninferior to IGlar in HbA_1c reduction from baseline. At end of trial, 2,044 patients (T2DM, n = 1,661; T1DM, n = 383) achieved HbA_1c <7%. The overall confirmed hypoglycemia rate, defined as plasma glucose <56 mg/dL or severe hypoglycemia if requiring assistance, was significantly lower with IDeg versus IGlar (estimated rate ratio [ERR] IDeg:IGlar, 0.86; 95% confidence interval [CI], 0.76 to 0.98). The nocturnal confirmed hypoglycemia rate, defined as occurring between midnight and 6:00 am, was significantly lower with IDeg (ERR, 0.63; 95% CI, 0.52 to 0.77). In the maintenance period (16 weeks onward when average insulin dose and glycemic levels stabilized), the overall confirmed hypoglycemia rate was significantly lower (ERR, 0.79; 95% CI, 0.68 to 0.92) and the nocturnal confirmed hypoglycemia rate was significantly lower (ERR, 0.57; 95% CI, 0.45 to 0.72) with IDeg versus IGlar.Conclusion: Patients with T1DM and T2DM achieved HbA_1c <7% with significantly lower rates of overall and nocturnal confirmed hypoglycemia with IDeg versus IGlar. The lower hypoglycemia rate with IDeg was more pronounced in the maintenance period.Abbreviations: ERR = estimated rate ratio; HbA_1c = hemoglobin A_1c; IDeg = insulin degludec; IGlar = insulin glargine; NPH = Neutral Protamine Hagedorn; PG = plasma glucose; T1DM = type 1 diabetes mellitus; T2DM = type 2 diabetes mellitus     

Effect of Glargine Insulin Delivery Method (Pen Device Versus Vial/Syringe) on Glycemic Control and Patient Preferences in Patients with Type 1 and Type 2 Diabetes

ObjectiveTo evaluate the effects of two different glargine insulin delivery methods (pen device vs. vial/ syringe) on glycemic control and patient preferences in a randomized, open-label, crossover, comparative effectiveness study.MethodsThirty-one patients discharged from the hospital were recruited for this study. In the hospital, all patients were treated with a basal-bolus insulin regimen. Upon discharge, 21 patients received glargine by pen device for 3 months and were then switched to vial/syringe for the next 3 months (group 1). Group 2 consisted of 10 patients discharged on vial/syringe and converted to pen device after 3 months. Hemoglobin A_1c (HbA_1c) was measured at enrollment and at 3 and 6 months. A questionnaire assessing patient preference was administered at 3 and 6 months.ResultsGroups 1 and 2 had similar baseline HbA_1c (10.7 ± 2.2% and 11.2 ± 2.5%, respectively) and similar reduction in HbA_1c at 3 months (7.8 ± 1.7% and 7.3 ± 1.4%, respectively; P < .001 vs. baseline). However, after crossover, the changes in HbA_1c from 3 to 6 months were significantly different between groups. HbA_1c increased to 8.5 ± 2.0% at 6 months in group 1 after switching to the vial/syringe but remained unchanged (7.1 ± 1.6%) in group 2 after switching to a pen device (P < .01, group 1 vs. group 2). Patient questionnaires after each phase of the trial revealed that patients found the pen device more convenient and were more likely to recommend this insulin delivery method to someone else.ConclusionPatients switching to a glargine pen device achieved lower HbA_1c at the 6-month follow-up. Patients in both groups overwhelmingly preferred glargine pens over vials/syringes. (Endocr Pract. 2014;20:536-539)     

Relationship between glycated hemoglobin and glucose concentrations in the adult Galician population: selection of optimal glycated hemoglobin cut-off points as a diagnostic tool of diabetes mellitus

Aims/hypothesisTo analyze the relationship between glucose and glycated hemoglobin (HbA_1c) in the adult Galician population, evaluate the use of HbA_1c for the screening and diagnosis of diabetes, and calculate the diagnostic threshold required for this purpose.MethodsWe analyzed data on 2848 subjects (aged 18–85 years) drawn from a study undertaken in 2004 to assess the prevalence of diabetes in Galicia. For study purposes, diabetes was defined using the criteria recommended in 2002. Participants were classified into four glucose-based groups. The relationship between glucose and HbA_1c was described using linear regression models, generalized additive models and Spearman's correlation. Diagnostic capacity was assessed, and optimal HbA_1c cut-off points were calculated as a diabetes marker using the receiver operating characteristic curve.ResultsPrevalence of pre-diabetes, unknown diabetes and known diabetes was 20.86, 3.37 and 4.39%, respectively. The correlations between HbA_1c and fasting glucose were higher than those obtained for HbA_1c and glycemia at 2 h of the oral glucose overload (0.344 and 0.270, respectively). Taking glucose levels as the gold standard, a greater discriminatory capacity was obtained for HbA_1c (area under de cruve: 0.839, 95% confidence intervals: 0.788–0.890). Based on the study criteria, the optimal minimum and maximum HbA_1c values were 5.9% and 6.7%, respectively.Conclusions/interpretationHbA_1c did not prove superior to glycemia for diagnosis of diabetes in the adult Galician population, and cannot therefore be used to replace the oral glucose tolerance test for screening and diagnosis purposes. Indeed, determination of glucose is essential to verify the diagnosis in the majority of cases.     

Mass spectrometry based characterization of Hb Beckman variant in a falsely elevated HbA1c sample

Glycated hemoglobin (HbA_1c) is a ‘gold standard’ biomarker for assessing the glycemic index of an individual. HbA_1c is formed due to nonenzymatic glycosylation at N-terminal valine residue of the β-globin chain. Cation exchange based high performance liquid chromatography (CE–HPLC) is mostly used to quantify HbA_1c in blood sample. A few genetic variants of hemoglobin and post-translationally modified variants of hemoglobin interfere with CE–HPLC-based quantification, resulting in its false positive estimation. Using mass spectrometry, we analyzed a blood sample with abnormally high HbA_1c (52.1%) in the CE–HPLC method. The observed HbA_1c did not corroborate the blood glucose level of the patient. A mass spectrometry based bottom up proteomics approach, intact globin chain mass analysis, and chemical modification of the proteolytic peptides identified the presence of Hb Beckman, a genetic variant of hemoglobin, in the experimental sample. A similar surface area to charge ratio between HbA_1c and Hb Beckman might have resulted in the coelution of the variant with HbA_1c in CE–HPLC. Therefore, in the screening of diabetes mellitus through the estimation of HbA_1c, it is important to look for genetic variants of hemoglobin in samples that show abnormally high glycemic index, and HbA_1c must be estimated using an alternative method.     

Optimized Human Regular U-500 Insulin Treatment Improves β-Cell Function in Severely Insulin-Resistant Patients with Long-Standing Type 2 Diabetes and High Insulin Requirements

Objective: To assess β-cell function and insulin sensitivity following improvement in glycemic control in severely insulin-resistant patients with poorly controlled type 2 diabetes (T2D).Methods: A subset of patients in a 24-week, open-label, randomized trial comparing thrice-daily (n = 14/162) versus twice-daily (n = 11/163) human regular U-500 insulin (U-500R) underwent mixed meal tolerance testing at baseline and endpoint. Baseline characteristics were similar between treatment groups (combined means: age, 54.0 years; diabetes duration, 13.6 years; body mass index, 38.8 kg/m²; glycated hemoglobin &lsqb;HbA_1c], 8.3%; U-100 insulin dose, 287.6 units/day, 2.6 units/kg/day). Primary outcome measure was ratio of area under the curve (AUC) for C-peptide to glucose (AUC_C-peptide/AUC_glucose) at 24-week endpoint.Results: Change from baseline HbA_1c, daily U-500R dose, and weight were -1.17% (P = .0002), +80.8 units (P = .0003), and +5.9 kg (P = .33), respectively. β-Cell function significantly improved after 24 weeks of U-500R therapy in combined treatment groups. The AUC_C-peptide/AUC_glucose increased 34.0% (ratio of least-squares geometric mean, 1.34; 95% confidence interval, 1.18 to 1.52; P = .0001). Integral of total insulin secretion rate increased from 27.0 to 33.7 nmol/m², and glucose sensitivity improved from 18.3 to 24.0 pmol/min/m²/mM (both, P = .02). Matsuda index improved from 0.8 to 1.3 (P = .008).Conclusion: Despite long-standing diabetes and poor glycemic control at baseline, functional recovery of β-cells was observed with improved glycemic control in these severely insulin-resistant patients with T2D, possibly due to alleviation of glucotoxicity.Abbreviations:AUC = area under the curveBID = twice dailyHbA_1c = glycated hemoglobinISR = insulin secretion rateLSM = least-squares meanMMTT = mixed meal tolerance testPG = plasma glucoseT2D = type 2 diabetesTDD = total daily doseTID = thrice dailyU-500R = human regular U-500 insulin     

Assessment of AACE/ACE Recommendations for Initial Dual Antihyperglycemic Therapy Using the Fixed-Dose Combination of Sitagliptin and Metformin Versus Metformin

ObjectiveThe American Association of Clinical Endocrinologists and American College of Endocrinology (AACE/ACE) diabetes algorithm recommends a stratified approach to initial therapy to achieve a glycated hemoglobin (HbA_1c) goal of <6.5% in patients with type 2 diabetes mellitus (T2DM) who have inadequate glycemic control. Data from a double-blind study in drug-naïve T2DM patients comparing initial monotherapy with metformin (MET) with initial dual therapy with a fixed-dose combination of sitagliptin and MET (SITA/MET FDC) was used to determine AACE/ACE HbA_1c goal attainment in these treatment groups.MethodsA total of 1,250 patients (mean baseline HbA_1c = 9.9%) were randomized 1:1 to SITA/MET FDC 50/500 mg twice daily (b.i.d.) or MET 500 mg b.i.d. for 18 weeks. SITA/MET FDC and MET were uptitrated over 4 weeks to 50/1,000 mg b.i.d. and 1,000 mg b.i.d., respectively.ResultsAt week 18, a higher percentage of patients receiving SITA/MET FDC had HbA_1c levels <6.5% and <7% than those receiving MET alone within each of the 3 AACE/ACE HbA_1c categories (6.5-7.5%, >7.5-9.0%, and >9.0%). Of patients with a baseline HbA_1c >7.5-9.0% who initiated SITA/MET FDC, 48.6% achieved an HbA_1c <6.5% at week 18 compared with 23.1% of patients who initiated MET monotherapy (P<.001). In patients with a baseline HbA >9.0%, 24.0% on SITA/MET FDC achieved an HbA_1c <6.5% compared with 12.8% on MET alone (P<.001).ConclusionIn T2DM patients with a baseline HbA_1c >7.5-9.0%, substantially more achieved the HbA_1c goal of <6.5% with initial dual therapy (SITA/MET FDC) than with initial monotherapy (MET), which is in agreement with the AACE/ACE diabetes algorithm.(Endocr Pract. 2013;19:751-757)     

Two Treatment Approaches for Human Regular U-500 Insulin in Patients With Type 2 Diabetes not Achieving Adequate Glycemic Control on High-Dose U-100 Insulin Therapy With or Without Oral Agents: A Randomized,Titration-To-Target Clinical Trial

Objective: To compare the efficacy and safety of 2 dosing regimens for human regular U-500 insulin (U-500R, 500 units/mL) replacing high-dose U-100 insulins with or without oral antihyperglycemic drugs in patients with inadequately controlled type 2 diabetes (T2D).Methods: We conducted a 24-week, open-label, parallel trial in 325 patients (demographics [means]: age, 55.4 years; diabetes duration, 15.2 years; body mass index, 41.9 kg/m²; glycated hemoglobin [HbA_1c], 8.7%; U-100 insulin dose, 287.5 units administered in 5 injections/day [median; range, 2 to 10]). Patients were randomized to thrice-daily (TID, n = 162) or twice-daily (BID, n = 163) U-500R after a 4-week lead-in period. The primary outcome was HbA_1c change from baseline.Results: After 24 weeks, both treatments demonstrated significant HbA_1c reductions (TID, -1.12%; BID, -1.22%; both, P<.001) and clinical equivalence (difference, -0.10%; 95% confidence interval, -0.33 to 0.12%; noninferiority margin, 0.4%). Comparable increases in total daily U-500R dose (TID, 242.7 to 343.1 units; BID, 249.0 to 335.0 units) were observed. Incidence and rate of documented symptomatic hypoglycemia (≤70 mg/dL) were lower for TID versus BID (P = .003 and P = .02, respectively); severe hypoglycemia was similar between treatments. Weight gain was similar in both groups (TID, 5.4 kg; BID, 4.9 kg).Conclusion: Initiation and titration of U-500R using either algorithm (TID or BID) improves glycemic control effectively and safely with fewer injections in patients with T2D treated with high-dose/high-volume U-100 insulin. These results provide clinicians with a practical framework for using U-500R in severely insulin-resistant patients with suboptimally controlled T2D.Abbreviations: BID = twice daily FAS = full analysis set HbA_1c = glycated hemoglobin PG = plasma glucose SMPG = self-monitored plasma glucose T2D = type 2 diabetes TDD = total daily dose TID = thrice daily U-500R = human regular U-500 insulin     

Value of Hemoglobin A1C In Diagnosing Diabetes Mellitus within a Chronic Disease Management System Illustrated by the Receiver Operating Characteristic Curve

ObjectiveTo develop a receiver operating characteristic (ROC) curve of glycosylated hemoglobin (HbA_1c) for diagnosing diabetes mellitus within a chronic disease management system.MethodsA case-control study including medical records from January 1, 1997, to December 31, 2005, was conducted at the Sioux Falls Veterans Affairs Medical Center. Medical records for the case group (patients with diabetes) were selected based on 1 of 3 criteria: International Classification of Diseases, Ninth Revision, Clinical Modification or Current Procedural Terminology codes specific for type 1 and type 2 diabetes; patients’ use of medications (oral hypoglycemic agents, antidiabetes agents, or insulin); or results from random blood or plasma glucose tests (at least 2 measurements of blood glucose ≥ 200 mg/dL). Records for the control group were selected based on patients having HbA_1c measured, but not meeting the above diagnostic criteria for diabetes during the study period. Records for cases and controls were randomly frequency-matched, one-to-one. The control group was randomly divided into 5 sets of an equal number of records. Five sets of an equal number of cases were then randomly selected from the total number of cases. Each test data set included 1 case group and 1 control group, resulting in 5 independent data sets.ResultsIn total, 5040 patient records met the case definition in the diabetes registry. Records of 15 patients who were prescribed metformin only, but did not meet any other case criteria, were reviewed and excluded after determining the patients were not diabetic. The control group consisted of 5 sets of 616 records each (totaling 3080 records), and the case group consisted of 5 sets of 616 records each (totaling 3080 records). Thus, each of the 5 independent data sets of 1 case group and 1 control group contained 1232 records. The case group was predominantly composed of white men (mean age, 69 years; mean body mass index, 31 kg/m²). Demographic data were similar for control patients. The ROC curve revealed that a HbA_1c ≥ 6.3% (mean + 1 SD) offered the most accurate cutoff value for diagnosing type 2 diabetes mellitus, with the following statistical values: C statistic, 0.78; sensitivity, 70%; specificity, 85%; and positive likelihood ratio, 4.6 (95% confidence interval, 4.2-5.0).ConclusionA HbA_1c value ≥ 6.3% may be a useful benchmark for diagnosing diabetes mellitus within a chronic disease management system and may be a useful tool for monitoring high-risk populations. (Endocr Pract. 2010;16:14-20)     

Impact of Race/Ethnicity on the Efficacy and Safety of Commonly used Insulin Regimens: A Post HOC Analysis of Clinical Trials in Type 2 Diabetes Mellitus

ObjectiveTo explore the impact of race/ethnicity on the efficacy and safety of commonly used insulin regimens in patients with type 2 diabetes mellitus.MethodsIn this post hoc analysis, pooled data from 11 multinational clinical trials involving 1455 patients with type 2 diabetes were used to compare specific insulin treatments in Latino/Hispanic, Asian, African-descent, and Caucasian patients. Insulin treatments included once daily insulin glargine or neutral protamine Hagedorn (BASAL), insulin lispro mix 75/25 twice daily (LMBID), or insulin lispro mix 50/50 three times daily (LMTID).ResultsRace/ethnicity was associated with significant outcome differences for each of the insulin regimens. BASAL therapy was associated with greater improvement in several measures of glycemic control among Latino/Hispanic patients compared with Caucasian patients (lower end point hemoglobin A1c, greater reduction in hemoglobin A1c from baseline, and a larger proportion of patients achieving hemoglobin A1c level < 7%). In contrast, LMBID therapy was associated with higher end point hemoglobin A_1c and a smaller decrease in hemoglobin A_1c from baseline in Latino/Hispanic and Asian patients than in Caucasian patients. Furthermore, fewer Asian patients attained a hemoglobin A_1c level < 7% than did Caucasians patients. For LMTID therapy, hemoglobin A_1c outcomes were comparable across patient groups. Fasting blood glucose and glycemic excursions varied among racial/ethnic groups for the 3 insulin regimens. Weight change was comparable among racial/ethnic groups in each insulin regimen. During treatment with LMTID, Asian patients experienced higher incidence and rate of severe hypoglycemia than Caucasian patients.ConclusionsLatino/Hispanic, Asian, and African-descent patients with type 2 diabetes show different metabolic responses to insulin therapy, dependent in part on insulin type and regimen intensity. (Endocr Pract. 2010: 818-828:pp)     

Effects of Colesevelam,Rosiglitazone, or Sitagliptin on Glycemic Control and Lipid Profile in Patients with Type 2 Diabetes Mellitus Inadequately Controlled by Metformin Monotherapy

ObjectiveTo evaluate the glycemic effect of colesevelam, rosiglitazone, or sitagliptin when added to metformin monotherapy in patients with type 2 diabetes mellitus (DM) and to examine the effects of these antidiabetes agents on lipid and lipoprotein levels.MethodsThis 16-week, open-label pilot study conducted between May 2007 and April 2008 at 20 sites in the United States, 7 sites in Mexico, and 6 sites in Colombia, enrolled adults with inadequately controlled type 2 DM (glycated hemoglobin [HbA_1c], 7.0%-10.0%) on a stable metformin regimen (1500-2550 mg daily for ≥ 3 months). At Week 0, participants were randomly assigned 1:1:1 to open-label colesevelam hydrochloride, 3.75 g daily; openlabel rosiglitazone maleate, 4 mg daily; or open-label sitagliptin phosphate, 100 mg daily, in addition to existing metformin therapy. The primary efficacy variable was the change in HbA_1c from baseline to Week 16 with last (postbaseline) observation carried forward.ResultsIn total, 169 participants were randomly assigned to treatment groups (colesevelam, n = 57; rosiglitazone, n = 56; and sitagliptin, n = 56), and 141 participants (83.4%) completed the study. Least-squares mean reductions in HbA_1c from baseline were observed in all groups at Week 16 last observation carried forward (colesevelam, -0.3% [P <.031]; rosiglitazone: -0.6% [P <.001]; sitagliptin: -0.4% [P <.009]) At study end, 10 of 56 participants (17.9%) in the colesevelam group, 19 of 54 (35.2%) in the rosiglitazone group, and 15 of 55 (27.3%) in the sitagliptin group achieved HbA_1c < 7.0%. Colesevelam significantly reduced mean low-density lipoprotein (LDL)-cholesterol levels relative to baseline (11.6%), whereas levels were significantly increased with rosiglitazone and sitagliptin at Week 16 last observation carried forward (7.8% and 7.7%, respectively). Twenty-two of 52 participants (42.3%) in the colesevelam group, 12 of 51 (23.5%) in the rosiglitazone group, and 13 of 53 (24.5%) in the sitagliptin group achieved LDL cholesterol < 100 mg/dL at Week 16 last observation carried forward.ConclusionAll 3 antidiabetes agents significantly improved glycemic control, but only colesevelam also significantly reduced LDL-cholesterol levels in patients with type 2 DM. (Endocr Pract. 2010;16:53-63)     

Association of HbA1c values with mortality and cardiovascular events in diabetic dialysis patients. The INVOR study and review of the literature

Background

Improved glycemic control reduces complications in patients with diabetes mellitus (DM). However, it is discussed controversially whether patients with diabetes mellitus and end-stage renal disease benefit from strict glycemic control.

Methods

We followed 78 patients with DM initiating dialysis treatment of the region of Vorarlberg in a prospective cohort study applying a time-dependent Cox regression analysis using all measured laboratory values for up to more than seven years. This resulted in 880 HbA_1c measurements (with one measurement every 3.16 patient months on average) during the entire observation period. Non-linear P-splines were used to allow flexible modeling of the association with mortality and cardiovascular disease (CVD) events.

Results

We observed a decreased mortality risk with increasing HbA_1c values (HR = 0.72 per 1% increase, p = 0.024). Adjustment for age and sex and additional adjustment for other CVD risk factors only slightly attenuated the association (HR = 0.71, p = 0.044). A non-linear P-spline showed that the association did not follow a fully linear pattern with a highly significant non-linear component (p = 0.001) with an increased risk of all-cause mortality for HbA_1c values up to 6–7%. Causes of death were associated with HbA_1c values. The risk for CVD events, however, increased with increasing HbA_1c values (HR = 1.24 per 1% increase, p = 0.048) but vanished after extended adjustments.

Conclusions

This study considered the entire information collected on HbA_1c over a period of more than seven years. Besides the methodological advantages our data indicate a significant inverse association between HbA_1c levels and all-cause mortality. However, for CVD events no significant association could be found.     

A 24-Week,Prospective, Randomized,Open-Label,Treat-To-Target Pilot Study of Obese Type 2 Diabetes Patients with Severe Insulin Resistance to Assess the Addition of Exenatide on the Efficacy of U-500 Regular Insulin Plus Metformin

ObjectiveTo compare the efficacy of 500 U/mL (U-500) regular insulin + metformin with U-500 regular insulin + metformin + exenatide in improving glycemic control in patients with severely insulin-resistant type 2 diabetes mellitus (T2DM).MethodsThirty patients with T2DM and severe insulin resistance were screened, and 28 were randomized to regular insulin U-500 + metformin or the GLP-1 analog exenatide, U-500, and metformin. Glycated hemoglobin (HbA_1c) levels, body weight, and insulin doses were documented at baseline and at 3 and 6 months. The number and severity hypoglycemic episodes were noted.ResultsThere were 7 males and 7 females in each group (U-500 + metformin and U-500 + metformin + exenatide). Overall, U-500 insulin + metformin, either alone or with the addition of exenatide, resulted in a significant improvement in HbA_1c in both groups, with no significant difference between the 2 groups. There was no meaningful weight change in those utilizing exenatide. Those on U-500 insulin and metformin alone had a tendency toward some weight gain. No severe hypoglycemia occurred during the study period. Symptomatic hypoglycemia was more common in the group on exenatide, but this occurred in only 5 patients, and the clinical significance of this is uncertain. Insulin dosage changes on U-500 regular insulin were variable but tended to be lower in those subjects on exenatide.ConclusionsU-500 regular insulin + metformin is effective for the treatment of T2DM patients with severe insulin resistance. The addition of exenatide may ameliorate potential weight gain but provides no additional improvement in glycemia. (Endocr Pract. 2014;20:1143-1150)     

Patient-Led Versus Physician-Led Titration of Insulin Glargine in Patients with Uncontrolled Type 2 Diabetes: A Randomized Multinational Atlas Study

ObjectiveSelf-adjustment of insulin dose is commonly practiced in Western patients with type 2 diabetes but is usually not performed in Asian patients. This multinational, 24-week, randomized study compared patient-led with physician-led titration of once-daily insulin glargine in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering agents.MethodsPatient-led (n = 275) or physician-led (n = 277) subjects followed the same dose-titration algorithm guided by self-monitored fasting blood glucose (FBG; target, 110 mg/dL [6.1 mmol/L]). The primary endpoint was change in mean glycated hemoglobin (HbA_1c) at week 24 in the patient-led versus physician-led titration groups.ResultsPatient-led titration resulted in a significantly higher drop in HbA_1c value at 24 weeks when compared with physician-led titration (− 1.40% vs. − 1.25%; mean difference, − 0.15; 95% confidence interval, − 0.29 to 0.00; P = .043). Mean decrease in FBG was greatest in the patient-led group (− 2.85 mmol/L vs. − 2.48 mmol/L; P = .001). The improvements in HbA_1c and FBG were consistent across countries, with similar improvements in treatment satisfaction in both groups. Mean daily insulin dose was higher in the patient-led group (28.9 units vs. 22.2 units; P < .001). Target HbA_1c of < 7.0% without severe hypoglycemia was achieved in 40.0% and 32.9% in the patient-led and physician-led groups, respectively (P = .086). Severe hypoglycemia was not different in the 2 groups (0.7%), with an increase in nocturnal and symptomatic hypoglycemia in the patient-led arm.ConclusionPatient-led insulin glargine titration achieved near-target blood glucose levels in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering drugs, demonstrating that Asian patients can self-uptitrate insulin dose effectively when guided. (Endocr Pract. 2015;21:143-157)     

Fructosamine Is a Useful Indicator of Hyperglycaemia and Glucose Control in Clinical and Epidemiological Studies – Cross-Sectional and Longitudinal Experience from the AMORIS Cohort

Context

Fructosamine is a glycemic biomarker which may be useful for indication and control of diabetes respectively.

Objective

The objective of the study was to evaluate fructosamine as an indicator of hyperglycaemia and glucose control in subjects with diabetes.

Design, Setting & Patients

From the AMORIS cohort, subjects with serum glucose, fructosamine and HbA_1c from the same examination were studied cross-sectionally and longitudinally (n = 10,987; 5,590 overnight-fasting). The guidelines of the American Diabetes Association were followed for classification of prediabetes and diabetes. Separate analyses were performed in patients with a newly detected or a known diagnosis of type 1 or type 2 diabetes respectively.

Results

All three biomarkers were strongly correlated. With regard to the association between fructosamine and HbA_1c Pearson linear correlation coefficients in the range of 0.67–0.75 were observed in fasting and non-fasting subjects with type 1 or type 2 diabetes. Analyses of glucose control in fasting patients with type 2 diabetes having all three biomarkers measured at three separate occasions within on average 290 days of the index examination showed similar trends over time for glucose, fructosamine and HbA_1c. Discrimination of subjects with and without diabetes across the range of fructosamine levels was good (area under curve (AUC) 0.91–0.95) and a fructosamine level of 2.5 mmol/L classified subjects to diabetes with a sensitivity of 61% and a specificity of 97%.

Conclusions

Fructosamine is closely associated with HbA_1c and glucose respectively and may be a useful biomarker of hyperglycaemia and glucose control in clinical and epidemiological studies.     

Efficacy and Safety of Linagliptin in Black/African American Patients with Type 2 Diabetes: A 6-Month,Randomized, Double-Blind,Placebo-Controlled Study

ObjectiveAlthough black/African American individuals are disproportionately affected by type 2 diabetes, there is scant clinical trial information available on antidiabetes therapies in this group. We compared linagliptin with placebo in black/African American adults who were treatment-naïve or receiving one oral antidiabetes drug.MethodsOf 226 patients randomized to 24 weeks’ linagliptin 5 mg/day or placebo, 208 had baseline and at least one on-treatment glycated hemoglobin (HbA_1c) measurement. Mean baseline HbA_1c was 8.6% in the linagliptin group (n = 98) and 8.68% in the placebo group (n = 110). The primary outcome was change in HbA_1c from baseline to week 24.ResultsBy week 24, mean HbA_1c changes were − 0.84% with linagliptin and − 0.25% with placebo (treatment difference, − 0.58%; P < .001), and more patients in the linagliptin group achieved HbA_1c < 7.0% (26.8% vs. 8.3%; P = .001) or an HbA_1c reduction ≥ 0.5% (54.1% vs. 30.0%; P < .001). Mean weight loss was − 1.1 kg in both groups. During the treatment period, 8 of 98 linagliptingroup patients and 17 of 110 placebo-group patients required rescue therapy (odds ratio, 0.5; P = .14). For postprandial glucose, values were available for few patients (11 placebo, 10 linagliptin), and thus the between-group difference was associated with wide confidence intervals (CIs) (difference, − 1.97 mg/dL; 95% CI, − 53.80 to 49.86; P = .94). In the overall study population, a similar proportion of patients in both groups had adverse events (58.5% vs. 61.7%); most events were mild or moderate and considered unrelated to study drug. Investigator-defined hypoglycemia was rare (3 linagliptin-group patients and 1 placebogroup patient), with no severe events (requiring external assistance).ConclusionThis study confirms that linagliptin is efficacious and well tolerated in black/African American patients with type 2 diabetes. (Endocr Pract. 2014;20: 412-420)     

Greater Combined Reductions in Hba1C ≥1.0% and Weight ≥5.0% with Semaglutide Versus Comparators in type 2 Diabetes

Objective: Semaglutide is a glucagon-like peptide 1 (GLP-1) analog for the once-weekly treatment of type 2 diabetes (T2D). In the global SUSTAIN clinical trial program, semaglutide demonstrated superior glycated hemoglobin (HbA_1c) and body weight reductions versus comparators. This post hoc analysis compared the proportion of patients achieving combined reductions in glycemia and body weight versus comparators.Methods: A total of 5,119 subjects with T2D in the phase 3 SUSTAIN 1 through 5 and 7 trials, from 33 countries, were included in this post hoc analysis. Subjects received subcutaneous semaglutide 0.5 or 1.0 mg, placebo or active comparator (sitagliptin 100 mg, exenatide extended release 2.0 mg, insulin glargine, dulaglutide 0.75 or 1.5 mg). The main endpoint was a composite of ≥1.0% HbA_1c reduction and ≥5.0% weight loss at end of treatment.Results: Significantly greater proportions of subjects achieved the composite endpoint with semaglutide 0.5 (25 to 38%) and 1.0 mg (38 to 59%) versus comparators (2 to 23%). More subjects treated with semaglutide versus comparators achieved ≥1.0% HbA_1c reductions (58 to 77% and 75 to 83% for semaglutide 0.5 and 1.0 mg versus 12 to 68%) and ≥5.0% weight loss (37 to 46%, 45 to 66% versus 4 to 30%). Proportions of subjects achieving targets were significantly higher with semaglutide 1.0 versus 0.5 mg in four of five trials. Semaglutide was well tolerated, with a safety profile similar to other GLP-1 receptor agonists.Conclusion: Significantly more subjects achieved both ≥1.0% HbA_1c reduction and ≥5.0% weight loss with once-weekly subcutaneous semaglutide treatment versus comparators in the SUSTAIN trials. A dose-dependent effect was observed with semaglutide.Abbreviations: AE = adverse event; CV = cardiovascular; ER = extended release; GLP-1 = glucagon-like peptide 1; GLP-1 RA = glucagon-like peptide 1 receptor agonist; HbA_1c = glycated hemoglobin; OAD = oral antidiabetic drug; sc = subcutaneous; T2D = type 2 diabetes     

Sputum Glucose and Glycemic Control in Cystic Fibrosis-Related Diabetes: A Cross-Sectional Study

Cystic fibrosis-related diabetes affects up to half of cystic fibrosis patients and is associated with increased mortality and more frequent pulmonary exacerbations. However, it is unclear to what degree good glycemic control might mitigate these risks and clinical outcomes have not previously been studied in relation to glucose from the lower airways, the site of infection and CF disease progression. We initially hypothesized that diabetic cystic fibrosis patients with glycosylated hemoglobin (HbA_1c) > 6.5% have worse pulmonary function, longer and more frequent exacerbations and also higher sputum glucose levels than patients with HbA_1c ≤ 6.5% or cystic fibrosis patients without diabetes. To test this, we analyzed spontaneously expectorated sputum samples from 88 cystic fibrosis patients. The median sputum glucose concentration was 0.70 mM (mean, 4.75 mM; range, 0-64.6 mM). Sputum glucose was not correlated with age, sex, body mass index, diabetes diagnosis, glycemic control, exacerbation frequency or length, or pulmonary function. Surprisingly, sputum glucose was highest in subjects with normal glucose tolerance, suggesting the dynamics of glycemic control, sputum glucose and pulmonary infections are more complex than previously thought. Two-year mean HbA_1c was positively correlated with the length of exacerbation admission (p < 0.01), and negatively correlated with measures of pulmonary function (p < 0.01). While total number of hospitalizations for exacerbations were not significantly different, subjects with an HbA_1c > 6.5% were hospitalized on average 6 days longer than those with HbA_1c ≤ 6.5% (p < 0.01). Current clinical care guidelines for cystic fibrosis-related diabetes target HbA_1c ≤ 7% to limit long-term microvascular damage, but more stringent glycemic control (HbA_1c ≤ 6.5%) may further reduce the short-term pulmonary complications.     

Diabetes Status and Race are Associated With Cardiovascular Risk Markers in Obese Adolescents

ObjectiveThe objective of this study was to evaluate differences in cardiovascular disease (CVD) risk markers in obese adolescents based on diabetes status and race in order to improve risk-reduction intervention strategies.MethodsThis was a retrospective, cross-sectional study of obese adolescents, age 10 to 21 years, who were evaluated at Children’s of Alabama between 2000 and 2012. Subjects were classified by glycated hemoglobin (HbA_1c) as having normoglycemia, prediabetes, or type 2 diabetes mellitus (T2DM).ResultsThere were a total of 491 African American (AA) or Caucasian American (CA) subjects. Body mass index was not different between HbA_1c and racial groups. Compared to subjects with normoglycemia or prediabetes, subjects with T2DM had higher levels of total cholesterol (TC) (178.6 ± 43.8 mg/dL vs. 161.5 ± 32.5 mg/dL vs. 162.4 ± 30.6 mg/dL; P < .0001) and low-density-lipoprotein cholesterol (107.4 ± 39.2 mg/dL vs. 97.0 ± 31.0 mg/dL vs. 97.5 ± 26.9 mg/dL; P = .0073). Compared with AA subjects, CA subjects had lower high-density-lipoprotein cholesterol (HDL-C) levels (40.4 ± 10.4 mg/dL vs. 44.3 ± 11.9 mg/dL; P = .0005) and higher non-HDL-C levels (129.6 ± 36.2 mg/dL vs. 122.5 ± 37.5 mg/dL; P = .0490). Of the characteristics studied, HbA_1c had the most significant positive association with dyslipidemia and was strongly correlated with both TC (β, 4.21; P < .0001) and non-HDL-C (β, 4.3; P < .0001).ConclusionObese adolescents with T2DM have more abnormal lipoprotein profiles than those with normoglycemia or prediabetes. Obese CA adolescents have more abnormal lipids than obese AA adolescents. HbA_1c was the characteristic most highly associated with abnormal lipoprotein profiles in our subjects. Our results show that CVD risk markers in obese adolescents vary by race and HbA_1c concentration. (Endocr Pract. 2015;21:165-173)