Hypoglycemia in childhood type 1 diabetes mellitus: Understanding and managing the dark side of intensive insulin therapy

Background: Despite the availability of advanced insulin delivery systems, blood glucose-monitoring equipment, and insulin analogue formulations, hypoglycemia remains a significant concern in the treatment of children and adolescents with type 1 diabetes mellitus (DM). Furthermore, patients who manage their blood glucose levels most effectively may also be the ones at greatest risk for hypoglycemia.Objective: The aim of this article was to review current issues surrounding the pathophysiology and frequency of hypoglycemia in children and adolescents with type 1 DM.Methods: Relevant articles for this review were identified through a search of MEDLINE (1992–2007; English-language articles only). The search terms used were children, adolescents, hypoglycemia, diabetes, insulin, and continuous subcutaneous insulin infusion.Results: The threat of severe hypoglycemia remains a major obstacle to the effective treatment of type 1 DM. Basalbolus therapy, using continuous subcutaneous insulin infusion or multiple daily injections, is the most effective and flexible method available for maintaining good glycemic control in children as well as in adults. Insulin analogues can be used effectively in these regimens and may be helpful toward addressing risks for hypoglycemia. Patient education should also be given a high priority in addressing the risk of hypoglycemia in children and adolescents with type 1 DM. The development of continuous glucose-monitoring systems offers the potential for an even brighter future for this group of patients.Conclusions: Recent advances in DM technology reduce but do not eliminate the risk of hypoglycemia in youth with type 1 DM. These observations underscore the need for a closed-loop insulin delivery system in which the rate of insulin infusion is regulated by real-time changes in glucose concentrations. (Insulin. 2007;2:157–165)Key words: type 1 diabetes mellitus; hypoglycemia; children; adolescents; insulin analogue; continuous subcutaneous insulin infusion; multiple daily injections; basal-bolus therapy.Accepted for publication 09052007     

Reducing oxidative stress in patients with type 2 diabetes mellitus: A primary care call to action

Background: Oxidative stress is believed to be the primary cause of the microvascular and macrovascular complications of type 2 diabetes mellitus (DM).Objective: This paper examines the evidence linking oxidative stress with long-term complications of type 2 DM and explores methods to minimize its effect.Methods: A literature search was performed to identify relevant studies for this review. Articles published in English from 2000 to 2008 were identified through searches of PubMed, Diabetes Care, and Google using the search terms oxidative stress, postprandial hyperglycemia, ACCORD Trial, and endothelial cell dysfunction.Results: The literature search identified 423 articles. Although chronic hyperglycemia can be effectively monitored and targeted using glycosylated hemoglobin concentrations, postprandial glucose levels are also important. Postprandial glucose excursions are exhibited by almost all patients with type 2 DM and are independent risk factors for cardiovascular morbidity and mortality. Furthermore, glucose fluctuations during the postprandial period elicit more oxidative stress than chronic, sustained hyperglycemia and can lead to endothelial dysfunction, vascular inflammation, and microvascular complications. In turn, endothelial dysfunction has been implicated in the development of vascular pathologies such as atherosclerosis. Pharmacologic interventions (eg, rapid-acting insulin analogues that target post-prandial glucose excursions) reduce oxidative stress and vascular inflammation and improve endothelial dysfunction.Conclusions: Given the important role of oxidative stress in the development of complications of type 2 DM, physi-cians should consider methods to reduce oxidative stress that may occur during both acute (postprandial) and chronic hyperglycemia. One critical aspect is to reduce postprandial glucose levels to <180 mg/dL while lowering fasting glucose levels to <110 mg/dL. By coaching patients to reach these goals, physicians and other health care professionals can minimize the risk of long-term complications of type 2 DM.     

Inpatient insulin therapy

Background: Many diabetic, as well as nondiabetic, hospitalized patients develop hyperglycemia. Numerous studies have demonstrated that critically ill, as well as noncritically ill, hospitalized patients who develop hyperglycemia are at increased risk for morbidity and mortality.Objective: The objective of this article was to review the risks associated with hyperglycemia in hospitalized patients, the biologic rationale for using insulin to prevent increases in glucose levels, and strategies for managing hyperglycemia in the hospital setting.Methods: We conducted a computerized search of biomedical journal literature from MEDLINE, PubMed, and Ovid published from 1994 to March 2008. We reviewed English-language original and review articles found under the subject headings “hospitalization and insulin therapy,” “inpatient diabetes and complications,” and “insulin and inflammation.”Results: More than 200 references were found during the literature search. According to the literature, the adverse outcomes that are associated with hyperglycemia may be attributed to the inflammatory and pro-oxidant effects of elevated glucose levels. The use of insulin, which has anti-inflammatory, vasodilatory, and antioxidant properties as well as the ability to inhibit lipolysis and platelet aggregation, can prevent many of these adverse outcomes.Conclusions: Hospitals should have protocols in place for using insulin to treat and prevent hyperglycemia. Subcutaneous insulin may be used for both purposes in most noncritically ill patients, whereas intravenous infusion of insulin is preferred in critically ill patients.     

Effects of botanical dietary supplements on cardiovascular,cognitive, and metabolic function in males and females

Background: The onset of menopause marks a pivotal time in which the incidence of hypertension and of cardiovascular disease (CVD) begins to increase dramatically in women. Before menopause, the incidences of these diseases are significantly lower in women than in age-matched men. After menopause, the rates of these diseases in women eventually approximate those in men. The loss of endogenous estrogen at menopause has been traditionally believed to be the primary factor involved in these changes.Objective: This review summarizes recent findings regarding the effectiveness of botanicals in the treatment of some menopausal symptoms and other symptoms of aging (eg, rise in arterial pressure, cognitive decline, insulin resistance, and hyperlipidemia).Methods: Articles were selected for inclusion in this review based on the significance of the research and contribution to the current understanding of how each botanical elicits cardioprotective effects. To this end, PubMed and MEDLINE databases were searched, using terms that included the name of the specific botanical along with the relevant aspects of its action(s), such as blood pressure, glycemic control, and lipids. Most of the articles used were published within the past 5 years, although some older articles that were seminal in advancing the current understanding of botanicals were also included.Results: Soy has been found to lower plasma lipid concentrations and arterial pressure in postmenopausal women and age-matched men, and to have protective effects in heart disease and atherosclerosis of the carotid and coronary circulation. Soy was also found to lower fasting insulin concentrations and glycosylated hemoglobin concentrations. Grape seed extract, another frequently used botanical, contains polyphenols that have been found to reduce arterial pressure and salt-sensitive hypertension in estrogendepleted animal models.Conclusion: Several botanical compounds have been found to have beneficial effects in the treatment of the symptoms of menopause and other symptoms of aging, including CVD, cognitive decline, and metabolic diseases.     

Evaluating the Accuracy of Modern Glucose Meters

Background: Self-mmonitoring of blood glucose (SSMBG) is important for all patients with diabetes, as it provides valuable feedback on the effects of diet, exercise, and medications. To maximize the potential benefits of SMBG, clinicians must have confidence in the accuracy of their patients' glucose meters.Objective: The aim of this article is to review several issues related to glucose meter accuracy and ways that accuracy can be enhanced.Methods: A MeDLINE search of English-language articles using the terms SMBG, glucose meter,and accuracy as an initial screen was performed. After articles describing the use of outdated technologies or vague methodologies were excluded, appropriate articles that analyzed various aspects regarding meter accuracy were selected.Results: Glucose meter accuracy studies are complicated by issues related to the reference method, the sample being assayed, nd he ay n which accuracy s reported. error rid analysis ives linicians a means to valuate the clinical importance of meter error. Modern glucose meters have many technological improvements and enhanced clinical accuracy; however, the accuracy of readings depends not only on the instrument but also on patient technique and other aspects of the overall testing process.Conclusions: SMBG has proven to be a valuable tool for the management of diabetes whether it is used to guide insulin dosing, provide feedback on the effect of meals, or detect hypoglycemia. Accuracy of SMBG can be optimized by patient education and continued improvements in meter technology.     

Weight Gain and Management Concerns in Patients on Insulin Therapy

Background: The benefits of tight glycemic control in preventing the onset and progression of microvascular complications in patients with type 2 diabetes mellitus (DM) are unarguable. The majority of patients with type 2 DM will eventually require insulin to achieve adequate glycemic control. Using insulin earlier rather than later in the course of type 2 DM may diminish the deleterious effects of hyperglycemia on β-cell function and therefore help prolong good glycemic control and prevent the occurrence of microvascular complications. However, weight gain is a potential adverse effect of insulin therapy.Objective: The goal of this article was to describe the benefit of insulin therapy early in the course of type 2 DM, review the association of weight gain with insulin therapy, and examine potential detrimental effects that insulin-associated weight gain could have in patients with type 2 DM.Methods: Materials used for this article were identified through a search of MEDLINE (1966–2006). English-language articles were chosen using the search terms diabetes mellitus type 2, insulin, and obesity.Results: Intensive insulin therapy is often associated with weight gain. Although there is concern that weight gain in patients with type 2 DM may have adverse effects on risk factors for cardiovascular disease, unfavorable changes in blood pressure and lipid levels have not been consistently observed in clinical trials. Furthermore, clinical evidence, including data from the United Kingdom Prospective Diabetes Study, supports the view that intensive insulin therapy does not increase the risk for cardiovascular disease.Conclusions: Early insulin therapy in patients with type 2 DM may be a strategy that will help patients achieve and maintain good glycemic control, thereby reducing the risk of developing microvascular complications. Although weight gain is commonly associated with insulin therapy, it does not appear to put these patients at greater risk for cardiovascular disease.     

Incorporating postprandial and fasting plasma glucose into clinical management strategies

Background: Targeting plasma glucose is a widely accepted practice in the treatment of both type 1 and type 2 diabetes mellitus (DM). Although clinicians have traditionally relied on fasting plasma glucose (FPG) levels for diagnosis and as a target for therapy, the focus has expanded to include the contribution of postprandial glucose (PPG) to glycosylated hemoglobin (A1C) levels.Objective: This article examines the contributions of FPG and PPG to A1C levels in patients with diabetes and discusses the impact of these findings on insulin treatment strategies for patients who fail to achieve recommended A1C goals.Methods: Relevant articles were identified through a PubMed search of the literature (1975–2007) using the following search terms: fasting plasma glucose, postprandial glucose, postprandial hyperglycemia, and glycemic control.Results: Changes in PPG levels are typically the first signs of abnormal glucose metabolism associated with type 2 DM, and they are a useful measure of glycemic control in patients with near-normal FPG and high A1C levels. A substantial proportion of patients considered to have good glycemic control (A1C <7.0%) may continue to experience elevated PPG levels, which have been linked to an increased risk of cardiovascular disease. FPG levels may predict the degree of postprandial hyperglycemia and the extent of PPG excursion. Conversely, correction of PPG levels may reduce FPG levels by suppressing hepatic glucose production. Evidence indicates that therapy targeting both FPG and PPG is associated with optimal reductions in A1C levels. At very high A1C levels (>9%-10%), FPG may play a greater role in overall glucose control than does PPG, but PPG becomes a more important contributor as A1C levels decrease. Increasing evidence supports the long-term benefits of early initiation of intensive insulin therapy. In particular, prandial insulin therapy may address the issue of postprandial hyperglycemia, which may be insufficiently controlled with oral agents and/or basal insulin alone.Conclusions: Both FPG and PPG affect A1C levels and are important contributors to determining overall glycemic control. Alternative insulin therapies (eg, inhaled insulin) that minimize barriers to insulin therapy and the appropriate targeting of FPG and PPG levels may improve long-term outcomes in patients with diabetes.     

Management of Type 2 Diabetes Mellitus with Basal-Prandial Insulin Therapy: A Case-Based Review

Background: Diabetes mellitus (DM) is a growing epidemic in the United States—20.8 million people are affected and 90% to 95% of all diagnosed cases are type 2 DM. Nevertheless, implementation of insulin therapy is often delayed in patients with type 2 DM. This delay can increase the risk of DM-related complications, including microvascular neuropathy, nephropathy, retinopathy, and cardiovascular disease.Objective: This article provides a case-based review outlining a novel strategy for advancing therapy with a modified basal and prandial insulin regimen to achieve recommended glycemic targets in type 2 DM as quickly as possible. Evidence-based treatment strategies are also discussed.Methods: Materials used for this article were identified through an English-language literature search of MEDLINE (1967-2007) using the following terms: insulin, postprandial glucose control, and type 2 diabetes.Results: As shown with this male 46-year-old case study patient, type 2 DM is treated initially with diet and exercise, followed by oral antidiabetic drugs (OADs). However, oral therapy typically reduces glycosylated hemoglobin values only by -1.5% to 2.0%. Intensive therapy with once-daily basal insulin in combination with a previously prescribed OAD regimen can achieve normoglycemia and reduce the long-term complications of DM. In patients with postprandial glucose excursions, prandial insulin can be added using a rapid-acting insulin analogue (aspart, lispro, or glulisine).Conclusions: A key factor in this case patient's ability to reach glycemic targets within I year of diagnosis of type 2 DM was the accelerated implementation of insulin therapy. Such a therapeutic approach obviates the risk for uncontrolled hyperglycemia, which is associated with the standard practice of beginning treatment with diet and exercise alone and slowly advancing by i OAD at a time, ending with insulin therapy as a last resort. (Insulin. 2007;2:118-126)     

Role of Insulin Sensitizers on Cardiovascular Risk Factors in Polycystic Ovarian Syndrome: A Meta-Analysis

Objective: Polycystic ovarian syndrome (PCOS) is associated with an increase in cardiovascular (CV) risk factors such as insulin resistance, with accompanying hyperinsulinemia and hyperlipidemia, which are predisposing factors for type 2 diabetes mellitus and CV disease. The aim of this meta-analysis is to examine the effect of insulin sensitizers on clinical and biochemical features of PCOS and risk factors for CV disease.Methods: A systematic literature review was conducted, and randomized controlled clinical trials were identified by a search of bibliographic databases: Medline database (from 1966 forward), EMBASE (January 1985 forward), and Cochrane Central Register of Controlled Trials. Reviews of reference lists further identified candidate trials. Data was independently abstracted in duplicate by 2 investigators using a standardized data-collection form. Articles without a comparison group and randomization allocation were excluded. Reviewers worked independently and in duplicate to determine the methodological quality of trials, then collected data on patient characteristics, interventions, and outcomes.Results: Of 455 studies, 44 trials were eligible. A random effects model was used. Significant unadjusted results favoring treatment with insulin sensitizers were obtained for body mass index (BMI) (effect size [ES] of 0.58), waist to hip ratio (WHR) (ES of 0.02), low-density-lipoprotein cholesterol (LDL-C) (ES of 0.11), fasting insulin (ES of 2.82), fasting glucose (ES of 0.10), free testosterone (ES of 1.88), and androstenedione level (ES of 0.76).Conclusion: Treatment with insulin sensitizers in women with PCOS results in improvement in CV factors such as BMI, WHR, LDL-C, fasting insulin, glucose, free testosterone, and androstenedione.Abbreviations: BMI = body mass index CI = confidence interval CVD = cardiovascular disease DM = diabetes mellitus EE = ethinyl estradiol ES = effect size FSH = follicle-stimulating hormone GnRH = gonadotropin-releasing hormone HDL = high-density lipoprotein HDL-C = high-density-lipoprotein cholesterol HR = hazard ratio IR = insulin resistance LDL = low-density-lipoprotein LDL-C = low-density-lipoprotein cholesterol LH = luteinizing hormone PCOS = polycystic ovarian syndrome TGs = triglycerides TZD = thiazolidinedione WHR = waist to hip ratio     

The Use of Premixed Insulin Analogues in the Treatment of Patients with Type 2 Diabetes Mellitus: Advantages and Limitations

Background:Intensive, target-oriented therapy is the standard of care in the management of patients with type 2 diabetesmellitus (DM). Early and aggressive use of insulin that is as close as possible to the physiologic pattern of insulin secretion from healthy pancreatic β-cells is advocated to achieve glycemic goals and reduce complications of DM.Objective:The objective of this article was to review the characteristics, advantages, and drawbacks of premixedinsulin analogues and to evaluate their role in the treatment of patients with type 2 DM.Methods:A PubMed search of articles from 1990 to 2006 was undertaken using the search terms type 2 diabetes, basalbolus therapy, premixed insulins, biphasic insulins, and insulin analogues. Pertinent content from relevant articles was extracted and combined with the authors' knowledge, experience, and clinical expertise.Results:The advent of insulin analogues has streamlined the treatment of patients with DM. When to initiate insulin during the course of treatment is the subject of much debate. Insulin therapy targeting both fasting and postprandial hyperglycemia is important in achieving optimal blood glucose (BG) control in patients with type 2 DM. A practical and feasible option is the use of >1 injection of premixed insulin analogues. Premixed insulin preparations provide both basal and prandial coverage because of their biphasic pharmacokinetic properties. Clinical trials have shown that these agents improve glycemic control, are associated with an acceptably low rate of severe hypoglycemia, and have a high degree of patient acceptance. Limitations include the inability to adjust the long- and short-acting components separately, to use a flexible regimen of self-titration and premeal bolus-insulin calculations, and to adequately treat postlunch and earlymorning BG elevations.Conclusion:Clinicians should be aware of premixed insulin analogues' advantages and limitations so that these agentscan be used appropriately in the treatment of patients with type 2 DM.     

Metabolic surgery for type 2 diabetes mellitus

Background: Metabolic surgery for morbid obesity induces significant weight loss and resolution of many obesity-related comorbidities, the most notable of which is remission of type 2 diabetes mellitus (DM). Such changes seem to precede significant weight loss in this population shortly after undergoing diversionary procedures.Objective: This article explores the evidence for salutary metabolic benefits of bariatric surgery, with special emphasis on glycemic control and remission of type 2 DM.Methods: We conducted a query of the PubMed database for articles published in English within the past 15 years using the search terms bariatric surgery, obesity, type 2 diabetes, gastric bypass, gastric banding, incretins, enteroinsular axis, GLP-1 (glucagon-like peptide-1), and GIP (glucose-dependent insulinotropic polypeptide). We targeted review articles as well as those discussing the effects of bariatric surgery on the enteroinsular axis and the respective effects on glyce-mic control.Results: Most of the clinical reports indicated a high remission rate (≥85%) for type 2 DM, and relatively higher rates in patients who underwent diversionary procedures. Studies with small cohorts and laboratory data suggested a role for gastrointestinal hormones in the regulation of glucose homeostasis after bariatric surgery.Conclusions: Gastrointestinal surgery for severe obesity, through restrictive and/or neurohormonal effects, is an effective treatment for type 2 DM. Surgically induced weight loss was found to be sustainable, durable, and associated with remission of type 2 DM, a reduction in mortality, and improvement in quality of life.     

Integrated Insulin Pump and Continuous Glucose Monitoring Technology in Diabetes Care Today: A Perspective of Real-Life Experience With the Minimed™ 670G Hybrid Closed-Loop System

Objective: Intensive glucose management with insulin pump and continuous glucose monitoring therapy in insulin-treated patients with diabetes poses many challenges in all aspects of daily life. Automated insulin delivery (AID) is the ultimate goal of insulin replacement therapy to reduce the burden of managing this condition. Many systems are being tested in the clinical research setting, and one hybrid closed-loop (HCL) system has received Food and Drug Administration (FDA) approval for use in type 1 diabetes patients above the age of 14 years.Methods: Literature review and clinical practice experience from the Diabetes and Technology Program at an academic medical center.Results: This review outlines recent advances in AID systems, focusing on the FDA-approved MiniMed™ 670G HCL system and the real-life experience 1-year post-release in an academic medical center with over 60 patients on this system. The unique challenges of adapting to this new system outside the clinical trial setting are highlighted, and a training protocol designed specifically for the onboarding of first-time users is described.Conclusion: HCL insulin therapy offers several advantages, at the same time posing unique challenges to the user. Systematic training of patients with diabetes transitioning to this system is essential for retention and success of use.Abbreviations: AID = automated insulin delivery; CGM = continuous glucose monitoring; FDA = Food and Drug Administration; HbA1c = glycated hemoglobin; HCL = hybrid closed-loop; ICR = insulin to carbohydrate ratio; SAP = sensor augmented pump; T1DM = type 1 diabetes     

Management of Diabetes During Air Travel: A Systematic Literature Review of Current Recommendations and their Supporting Evidence

Objective: Individuals with diabetes are increasingly seeking pretravel advice, but updated professional recommendations remain scant. We performed a systematic review on diabetes management during air travel to summarize current recommendations, assess supporting evidence, and identify areas of future research.Methods: A systematic review of the English literature on diabetes management during air travel was undertaken utilizing PubMed and MEDLINE. Publications regarding general travel advice; adjustment of insulin and noninsulin therapies; and the use of insulin pumps, glucometers and subcutaneous glucose sensors at altitude were included. Gathered information was used to create an updated summary of glucose-lowering medication adjustment during air travel.Results: Sixty-one publications were identified, most providing expert opinion and few offering primary data (47 expert opinion, 2 observational studies, 2 case reports, 10 device studies). General travel advice was uniform, with increasing attention to preflight security. Indications for oral antihyperglycemic therapy adjustments varied. There were few recommendations on contemporary agents and on nonhypoglycemic adverse events. There was little consensus on insulin adjustment protocols, many antedating current insulin formulations. Most publications advocated adjusting insulin pump time settings after arrival; however, there was disagreement on timing and rate adjustments. Glucometers and subcutaneous glucose sensors were reported to be less accurate at altitude, but not to an extent that would preclude their clinical use.Conclusion: Recommendations for diabetes management during air travel vary significantly and are mostly based on expert opinion. Data from systematic investigation on glucose-lowering medication adjustment protocols may support the development of a future consensus statement.Abbreviations:CSII = continuous subcutaneous insulin infusion (device)DPP-4 = dipeptidyl peptidase 4EGA = error grid analysisGDH = glucose dehydrogenaseGOX = glucose oxidaseGLP1 = glucagon-like peptide-1NPH = neutral protamine HagedornSGLT2 = sodium-glucose cotransporter-2     

Hyperglycemia Management In Patients With Posttransplantation Diabetes

Objective: Posttransplantation diabetes (PTDM) is a common occurrence after solid-organ transplantation and is associated with increased morbidity, mortality, and health care costs. There is a limited number of studies addressing strategies for hyperglycemia management in this population, with a few articles emerging recently.Methods: We performed a PubMed search of studies published in English addressing hyperglycemia management of PTDM/new-onset diabetes after transplant (NODAT). Relevant cited articles were also retrieved.Results: Most of the 25 publications eligible for review were retrospective studies. Insulin therapy during the early posttransplantation period showed promise in preventing PTDM development. Thiazolidinediones have been mostly shown to exert glycemic control in retrospective studies, at the expense of weight gain and fluid retention. Evidence with metformin, sulfonylureas, and meglitinides is very limited. Incretins have shown promising results in small prospective studies using sitagliptin, linaglitpin, and vildagliptin and a case series using liraglutide.Conclusion: Prospective randomized studies assessing the management of hyperglycemia in PTDM are urgently needed. In the meantime, clinicians need to be aware of the high risk of PTDM and associated complications and current concepts in management.Abbreviations:A1c = glycated hemoglobin A1cCHF = congestive heart failureCNI = calcineurin inhibitorsCS = corticosteroidsDM = diabetes mellitusDPP-4 = dipeptidyl peptidase-4GLP-1 = glucagon-like peptide-1ICU = intensive care unitIGT = impaired glucose toleranceNODAT = new-onset diabetes after transplantationOGTT = oral glucose tolerance testPTDM = posttransplantation diabetesSU = sulfonylureaT2DM = type 2 diabetes mellitusTZD = thiazolidinedione     

Insulin-Like Growth Factor Binding Protein 1 Predicts Insulin Sensitivity And Insulin Area-Under-The-Curve In Obese,Nondiabetic Adolescents

Objective: To compare fasting insulin-like growth factor binding protein 1 (IGFBP-1) to other fasting indices as a surrogate marker of insulin sensitivity and resistance calculated from a 3-hour oral glucose tolerance test (oGTT).Methods: Fasting IGFBP-1 and oGTT were performed at 0 (n = 77), 52 (n = 54), and 100 (n = 38) weeks in a study investigating metformin treatment of obesity in adolescents. Insulin area-under-the-curve (IAUC) and the composite insulin sensitivity index (CISI) calculated from the oGTT were compared to fasting IGFBP-1, homeostasis model assessment–insulin resistance, and corrected insulin release at the glucose peak (CIR_gp).Results: IGFBP-1 and the ratio of IGFBP-1 to fasting insulin were significantly correlated with indices based on timed sampling, including IAUC, CISI, and CIR_gp. In addition, a significant effect of IGFBP-1, but not IGFBP-1 to insulin at time zero, was observed for IAUC and CISI.Conclusion: Our results indicate that fasting IGFBP-1 may be a useful marker of insulin sensitivity and secretion.Abbreviations:CIR_gp = corrected insulin release at the glucose peakCISI = composite insulin sensitivity indexFSIVGTT = frequently sampled intravenous glucose tolerance testingHOMA-IR = homeostasis model assessmentinsulin resistanceIAUC = insulin area-under-the-curveIGFBP-1 = insulin-like growth factor binding protein 1INS₀ = insulin level at time zerooGTT = oral glucose tolerance testSi = insulin sensitivity indexWBISI = whole-body insulin sensitivity index     

Evaluation of Total Daily Dose and Glycemic Control for Patients Taking U-500 Regular Insulin Admitted to the Hospital

Objective: Patients using U-500 regular insulin are severely insulin resistant, requiring high doses of insulin. It has been observed that a patient's insulin requirements may dramatically decrease during hospitalization. This study sought to systematically investigate this phenomenon.Methods: We performed a retrospective chart review of patients with U-500 insulin outpatient regimens who were admitted to the San Antonio Military Medical Center over a 5-year period. Each patient's outpatient total daily dose (TDD) of insulin was compared to the average inpatient TDD. The outpatient estimated average glucose (eAG) was calculated from the glycated hemoglobin (HbA1c) and compared to the average inpatient glucose.Results: There were 27 patients with a total of 62 separate admissions. The average age was 64.4 years, with a mean body mass index of 38.9 kg/m² and eAG of 203 mg/dL (HbA1c, 8.7%, 71.6 mmol/mol). All patients were converted from U-500 to U-100 upon admission. The average inpatient TDD of insulin was 91 units, versus 337 units as outpatients (P<.001). Overall, 89% of patients received ≤50% of their outpatient TDD. The average inpatient glucose was slightly higher than the outpatient eAG, 234 mg/dL versus 203 mg/dL (P = .003).Conclusion: U-500 insulin is prone to errors in the hospital setting, so conversion to U-100 insulin is a preferred option. Despite a significant reduction in insulin TDD, these patients had clinically similar glucose levels. Therefore, patients taking U-500 insulin as an outpatient can be converted to a U-100 basal-bolus regimen with at least a 50% reduction of their outpatient TDD.Abbreviations:BG = blood glucoseeAG = estimated average glucoseHbA1c = glycated hemoglobinNPO = nil per osSPSS = Statistical Package for the Social SciencesTDD = total daily dose     

Excess Thyroid Hormone and Carbohydrate Metabolism

ObjectiveTo review the pertinent basic and clinical research describing the complex effects of excess thyroid hormone on carbohydrate metabolism.MethodsWe performed a MEDLINE search of the English-language literature using a combination of words (ie, “thyrotoxicosis and diabetes,” “diabetic ketoacidosis and thyroid storm,” “carbohydrate metabolism and hyperthyroid,” “glucose homeostasis and thyrotoxicosis”) to identify key articles addressing various aspects of the thyroid’s influence on carbohydrate metabolism.ResultsThyroid hormone affects glucose homeostasis via its actions on a variety of organs including increased hepatic glucose output, increased futile cycling of glucose degradation products between the skeletal muscle and the liver, decreased glycogen stores in the liver and skeletal muscle, altered oxidative and nonoxidative glucose metabolism, decreased active insulin output from the pancreas, and increased renal insulin clearance. Thyroid hormone also affects adipokines and adipose tissue, further predisposing the patient to ketosis.ConclusionsThyrotoxicosis can alter carbohydrate metabolism in a type 2 diabetic patient to such an extent that diabetic ketoacidosis develops if untreated. Based on the current understanding of this relationship, all diabetic patients should be screened for thyroid dysfunction because correcting hyperthyroidism can profoundly affect glucose homeostasis. Similarly, patients presenting in diabetic ketoacidosis should undergo a thyroid function assessment. (Endocr Pract. 2009;15:254-262)     

Temporal Occurrences and Recurrence Patterns of Hypoglycemia During Hospitalization

Objective: To describe the temporal distribution of hypoglycemia and its rate of recurrence during hospitalization to aid in the development of strategies to prevent hypoglycemia in hospitalized patients.Methods: Retrospective review of hypoglycemia (blood glucose <50 mg/dL) audit data in adult hospitalized patients at 2 academic hospitals. Demographics, timing, and blood glucose values were recorded. Antihyperglycemic medications, number of recurrent events, and change in basal insulin dose following the hypoglycemic event were also extracted.Results: A total of 274 index occurrences of hypoglycemia were analyzed. The mean age of the patients was 53.8 years, with roughly equal gender distributions. Twenty-eight percent of the events occurred in the absence of antihyperglycemic therapy. The incidence of hypoglycemia peaked between midnight and 6 AM. There were 36 instances of recurrent hypoglycemia associated with antihyperglycemic therapy, with 78% (n = 28) cases involving basal insulin. Patients on basal insulin who developed hypoglycemia did not have their dose changed prior to the time of the next administration in 75% of the cases.Conclusion: Hypoglycemia in hospitalized patients may occur with greater frequency overnight. Although cumbersome, routine nocturnal glycemic testing should be considered. Education regarding insulin management in the hospital and improved communication between night and day staff may aid in decreasing subsequent hypoglycemic events.Abbreviations: BG = blood glucose EHR = electronic health record ICU = intensive care unit IV = intravenous