The SGLT2 Inhibitor Empagliflozin for the Treatment of Type 2 Diabetes Mellitus: a Bench to Bedside Review

INTRODUCTION

The treatment of type 2 diabetes mellitus (T2DM) continues to pose challenges for clinicians and patients. The dramatic rise in T2DM prevalence, which has paralleled the rise in obesity, has strained the healthcare system and prompted the search for therapies that not only effectively treat hyperglycemia, but are also weight neutral or promote weight loss. In most clinical situations after diagnosis, patients are advised to adopt lifestyle changes and metformin is initiated to help control blood glucose levels. However, metformin may not be tolerated, or may not be sufficient for those with higher glucose levels at diagnosis. Even among those who have initial success with metformin, the majority eventually require one or more additional agents to achieve their treatment goals. Because T2DM is a progressive disease, the requirement for combination treatment escalates over time, driving the need for therapies with complementary mechanisms of action.

METHODS AND RESULTS

Online public resources were searched using "empagliflozin", identifying 32 articles in PubMed, and 12 abstracts presented at the 2013 American Diabetes Association meeting. Peer-reviewed articles and abstracts describing preclinical studies and clinical trials were retrieved, and relevant publications included in this review. Trials registered on clinicaltrials.gov were searched for ongoing empagliflozin studies.

CONCLUSION

The sodium-glucose co-transporter 2 (SGLT2) inhibitors are of great interest since they provide a novel, insulin-independent mechanism of action. The SGLT2 inhibitor empagliflozin has demonstrated promising pharmacodynamic and pharmacokinetic properties. In clinical trials, empagliflozin has demonstrated a good efficacy and safety profile in a broad range of patients with T2DM, and appears to be an attractive adjunct therapeutic option for the treatment of T2DM. Ongoing trials, including patients with T2DM and comorbidities such as hypertension, are expected to provide important additional data, which will further define the role of empagliflozin in a growing movement toward individualized approaches to diabetes care.

Options for prandial glucose management in type 2 diabetes patients using basal insulin: addition of a short-acting GLP-1 analogue versus progression to basal-bolus therapy

Integrating patient-centered diabetes care and algorithmic medicine poses particular challenges when optimized basal insulin fails to maintain glycaemic control in patients with type 2 diabetes. Multiple entwined physiological, psychosocial and systems barriers to insulin adherence are not easily studied and are not adequately considered in most treatment algorithms. Moreover, the limited number of alternatives to add-on prandial insulin therapy has hindered shared decision-making, a central feature of patient-centered care. This article considers how the addition of a glucagon-like peptide 1 (GLP-1) analogue to basal insulin may provide new opportunities at this stage of treatment, especially for patients concerned about weight gain and risk of hypoglycaemia. A flexible framework for patient-clinician discussions is presented to encourage development of decision-support tools applicable to both specialty and primary care practice.

Retinopathy and clinical outcomes in patients with type 2 diabetes mellitus, chronic kidney disease, and anemia

OBJECTIVE

Retinopathy is an established microvascular complication of type 2 diabetes mellitus (T2DM), but its independent relationship with macrovascular and other microvascular complications is less well defined across the spectrum of kidney disease in T2DM. We examined the prognostic value of retinopathy in assessing the risk of developing end-stage renal disease (ESRD), cardiovascular morbidity or death among patients in the Trial to Reduce cardiovascular Events with Aranesp Therapy (TREAT).

DESIGN

TREAT enrolled 4038 patients with T2DM, chronic kidney disease (CKD) and moderate anemia. Patients were grouped by baseline history of retinopathy. Proportional hazards regression models were utilized to assess the association between retinopathy and subsequent ESRD, cardiovascular morbidity or death over an average of 2.4 years.

RESULTS

Although younger, the 1895 (47%) patients with retinopathy had longer duration of diabetes, lower estimated glomerular filtration rate, more proteinuria, and more microvascular complications. In univariate analysis, retinopathy was associated with a higher rate of ESRD, but not with cardiovascular events or mortality. After adjustment, retinopathy was no longer statistically significant for the prediction of ESRD or any clinical endpoint.

CONCLUSIONS

In a large cohort of patients with T2DM, CKD, and anemia, retinopathy was common but not independently associated with a higher risk of renal or cardiovascular morbidity or death.

TRIAL REGISTRATION NUMBER

NCT00093015.

Linagliptin added to sulphonylurea in uncontrolled type 2 diabetes patients with moderate-to-severe renal impairment

Glucose-lowering treatment options are limited for uncontrolled type 2 diabetes mellitus (T2DM) patients with advanced stages of renal impairment (RI). This retrospective analysis evaluated glycaemic efficacy and tolerability of the dipeptidyl peptidase-4 inhibitor linagliptin added to sulphonylurea. Three randomized phase 3 studies (n = 619) including T2DM subjects with moderate or severe RI [estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²] were analysed; only sulphonylurea-treated subjects who received additional linagliptin (n = 58) or placebo (n = 33) were evaluated. Linagliptin provided meaningful placebo-adjusted HbA1c reductions of -0.68% (95% confidence interval: -1.19, -0.17), -1.08% (-2.02, -0.14) and -0.62% (-1.25, 0.01) after 24, 18 and 12 weeks, respectively. There was a similar incidence of overall adverse events (linagliptin: 79.3%, placebo: 75.8%) and hypoglycaemia (linagliptin: 37.9%, placebo: 39.4%). Severe hypoglycaemia was more common with placebo (linagliptin: 1.7%, placebo: 6.1%). These data suggest that linagliptin is a safe and effective glucose-lowering treatment in T2DM patients with moderate-to-severe RI for whom sulphonylurea treatment is no longer sufficient.

Effect of gender on treatment outcomes in type 2 diabetes mellitus

AIM

To evaluate the effect of gender on clinical outcomes in people with type 2 diabetes mellitus (T2DM) receiving antidiabetes therapy.

METHODS

This is a pooled analysis from nine similarly designed phase 3 and 4 randomized, controlled studies evaluating insulin glargine and an active comparator (NPH insulin, insulin lispro, premixed insulin, oral antidiabetes drugs, dietary intervention) in adults with T2DM. Impact of gender on outcomes including HbA1c, fasting plasma glucose (FPG), weight-adjusted insulin dose, and hypoglycemia incidence was evaluated after 24 weeks of treatment.

RESULTS

Overall, 1651 male and 1287 female individuals were included; 49.8% and 50.2% were treated with insulin glargine or comparators, respectively. Females receiving insulin glargine were less likely than males to achieve a glycemic target of HbA1c≤7.0% (53mmol/mol) (54.3% vs 60.8%, respectively, p=0.0162); there was no difference between females and males receiving comparators (52.7% vs 51.3%, respectively, p=0.4625). Females had significantly greater reductions in FPG (3.1mg/dL, p=0.0458), required significantly higher insulin doses (0.03IU/kg, p=0.0071), and had significantly higher annual rates of symptomatic (p<0.0001), glucose-confirmed (<50 and <70mg/dL) symptomatic (p=0.0005 and p<0.0001), and severe hypoglycemia (p=0.0020) than males.

CONCLUSIONS

Females in this analysis had smaller reductions in HbA1c and were less likely to reach glycemic goals despite higher insulin doses and more hypoglycemic events than males. Differences in gender responses to therapy should be considered when individualizing treatment for people with T2DM.

Differences in the management of type 1 diabetes among adults under excellent control compared with those under poor control in the T1D Exchange Clinic Registry

OBJECTIVE

Optimizing glycemic control in type 1 diabetes is important to minimize the risk of complications. We used the large T1D Exchange clinic registry database to identify characteristics and diabetes management techniques in adults with type 1 diabetes, differentiating those under excellent glycemic control from those with poorer control.

RESEARCH DESIGN AND METHODS

The cross-sectional analysis included 627 participants with HbA1c <6.5% (excellent control) and 1,267 with HbA1c ≥8.5% (fair/poor control) at enrollment who were ≥26 years of age (mean ± SD 45.9 ± 13.2 years), were not using continuous glucose monitoring, and had type 1 diabetes for ≥2 years (22.8 ± 13.0 years).

RESULTS

Compared with the fair/poor control group, participants in the excellent control group had higher socioeconomic status, were more likely to be older and married, were less likely to be overweight, were more likely to exercise frequently, and had lower total daily insulin dose per kilogram (P < 0.0001 for each). Excellent control was associated with more frequent self-monitoring of blood glucose (SMBG), giving mealtime boluses before a meal rather than at the time of or after a meal, performing SMBG before giving a bolus, and missing an insulin dose less frequently (P < 0.0001 for each). Frequency of severe hypoglycemia was similar between groups, whereas diabetic ketoacidosis was more common in the fair/poor control group.

CONCLUSIONS

Diabetes self-management related to insulin delivery, glucose monitoring, and lifestyle tends to differ among adults with type 1 diabetes under excellent control compared with those under poorer control. Future studies should focus on modifying diabetes management skills in adult type 1 diabetes patients with suboptimal glycemic control.

Change in albuminuria and eGFR following insulin sensitization therapy versus insulin provision therapy in the BARI 2D study

BACKGROUND AND OBJECTIVES

In the Bypass Angioplasty Revascularization Investigation 2 Diabetes randomized trial, glycemic control with insulin-sensitization therapy was compared with insulin-provision therapy in patients with type 2 diabetes and coronary artery disease. This study examined differences in albumin excretion and renal function in the insulin-sensitization group versus the insulin-provision group over 5 years.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

In total, 1799 patients with measurements of creatinine and urine albumin/creatinine ratio at baseline and at least two follow-up visits were included. Management of BP, lipids, and lifestyle counseling was uniform. Progression of albuminuria was defined as doubling of baseline albumin/creatinine ratio to at least 100 mg/g or worsening of albumin/creatinine ratio status on two or more visits. Worsening renal function was defined as >25% decline in estimated GFR and annualized decline of >3 ml/min per 1.73 m(2) per year.

RESULTS

By 6 months and thereafter, the mean glycated hemoglobin levels were lower in the insulin-sensitization group compared with the insulin-provision group (P<0.002 for each time point; absolute difference=0.4%). Albumin/creatinine ratio increased over time in the insulin-sensitization group (P value for trend<0.001) and was stable in the insulin-provision group. Risk for progression of albumin/creatinine ratio was higher in the insulin-sensitization group compared with the insulin-provision group (odds ratio, 1.59; 95% confidence interval, 1.25 to 2.02; P=0.02). Over 5 years, albumin/creatinine ratio increased from 11.5 (interquartile range=5.0-46.7) to 15.7 mg/g (interquartile range=6.2-55.4) in the insulin-sensitization group (P<0.001) and from 12.1 (interquartile range=5.3-41.3) to 12.4 mg/g (interquartile range=5.8-50.6) in the insulin-provision group (P=0.21). Estimated GFR declined from 75.0±20.6 to 66.3±22.6 ml/min per 1.73 m(2) in the insulin-sensitization group (P<0.001) and from 76.1±29.5 to 66.8±22.1 ml/min per 1.73 m(2) in the insulin-provision group (P<0.001).

CONCLUSION

Over 5 years, despite lower glycated hemoglobin levels, the insulin-sensitization treatment group had greater progression of albumin/creatinine ratio compared with the insulin-provision treatment group. Decline in estimated GFR was similar.

Impact of sex on the heart's metabolic and functional responses to diabetic therapies

Increased myocardial lipid delivery is a determinant of myocardial substrate metabolism and function in animal models of type 2 diabetes (T2DM). Sex also has major effects on myocardial metabolism in the human heart. Our aims were to determine whether 1) sex affects the myocardial metabolic response to lipid lowering in T2DM, 2) altering lipid [fatty acid (FA) or triglyceride] delivery to the heart would lower the elevated myocardial lipid metabolism associated with T2DM, and 3) decreasing lipid delivery improves diastolic dysfunction in T2DM. To this end, we studied 78 T2DM patients (43 women) with positron emission tomography, echocardiography, and whole body tracer studies before and 3 mo after randomization to metformin (MET), metformin + rosiglitazone (ROSI), or metformin + Lovaza (LOV). No treatment main effects were found for myocardial substrate metabolism, partly because men and women often had different responses to a given treatment. In men, MET decreased FA clearance, which was linked to increased plasma FA levels, myocardial FA utilization and oxidation, and lower myocardial glucose utilization. In women, ROSI increased FA clearance, thereby decreasing plasma FA levels and myocardial FA utilization. Although LOV did not change triglyceride levels, it improved diastolic function, particularly in men. Group and sex also interacted in determining myocardial glucose uptake. Thus, in T2DM, different therapeutic regimens impact myocardial metabolism and diastolic function in a sex-specific manner. This suggests that sex should be taken into account when designing a patient's diabetes treatment.

Evidence of a strong association between frequency of self-monitoring of blood glucose and hemoglobin A1c levels in T1D exchange clinic registry participants

OBJECTIVE

Despite substantial evidence of the benefit of frequent self-monitoring of blood glucose (SMBG) in type 1 diabetes, certain insurers limit the number of test strips that they will provide. The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA1c levels across a wide age range of children and adults.

RESEARCH DESIGN AND METHODS

The analysis included 20,555 participants in the T1D Exchange clinic registry with type 1 diabetes ≥1 year and not using a continuous glucose monitor (11,641 younger than age 18 years and 8,914 18 years old or older). General linear models were used to assess the association between the number of SMBG measurements and HbA1c levels after adjusting for potential confounding variables.

RESULTS

A higher number of SMBG measurements per day were associated with non-Hispanic white race, insurance coverage, higher household income, and use of an insulin pump for insulin delivery (P < 0.001 for each factor). After adjusting for these factors, a higher number of SMBG measurements per day was strongly associated with a lower HbA1c level (adjusted P < 0.001), with the association being present in all age-groups and in both insulin pump and injection users.

CONCLUSIONS

There is a strong association between higher SMBG frequency and lower HbA1c levels. It is important for insurers to consider that reducing restrictions on the number of test strips provided per month may lead to improved glycemic control for some patients with type 1 diabetes.

Long-term efficacy and safety of linagliptin in patients with type 2 diabetes and severe renal impairment: a 1-year, randomized, double-blind, placebo-controlled study

OBJECTIVE

This placebo-controlled study assessed long-term efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with type 2 diabetes and severe renal impairment (RI).

RESEARCH DESIGN AND METHODS

In this 1-year, double-blind study, 133 patients with type 2 diabetes (HbA(1c) 7.0-10.0%) and severe RI (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m(2)) at screening were randomized to linagliptin 5 mg (n = 68) or placebo (n = 65) once daily, added to existing background therapy. The primary efficacy end point was HbA(1c) change from baseline to week 12. Efficacy and safety end points were assessed after 1 year.

RESULTS

At week 12, adjusted mean HbA(1c) decreased by -0.76% with linagliptin and -0.15% with placebo (treatment difference, -0.60%; 95% CI -0.89 to -0.31; P < 0.0001). HbA(1c) improvements were sustained with linagliptin (-0.71%) over placebo (0.01%) at 1 year (treatment difference -0.72%, -1.03 to -0.41; P < 0.0001). Mean insulin doses decreased by -6.2 units with linagliptin and -0.3 units with placebo. Overall adverse event incidence was similar over 1 year (94.1 vs. 92.3%). Incidence of severe hypoglycemia with linagliptin and placebo was comparably low (three patients per group). Linagliptin and placebo had little effect on renal function (median change in eGFR, -0.8 vs. -2.2 mL/min/1.73 m(2)), and no drug-related renal failure occurred.

CONCLUSIONS

In patients with type 2 diabetes and severe RI, linagliptin provided clinically meaningful improvements in glycemic control with very low risk of severe hypoglycemia, stable body weight, and no cases of drug-related renal failure. The potential for linagliptin to spare insulin and provide long-term renal safety warrants further investigations.

Weight-bearing versus nonweight-bearing exercise for persons with diabetes and peripheral neuropathy: a randomized controlled trial

OBJECTIVE

To determine the effects of weight-bearing (WB) versus nonweight-bearing (NWB) exercise for persons with diabetes mellitus (DM) and peripheral neuropathy (PN).

DESIGN

Randomized controlled trial with evaluations at baseline and after intervention.

SETTING

University-based physical therapy research clinic.

PARTICIPANTS

Participants with DM and PN (N=29) (mean age ± SD, 64.5±12.5y; mean body mass index [kg/m(2)] ± SD, 35.5±7.3) were randomly assigned to WB (n=15) and NWB (n=14) exercise groups. All participants (100%) completed the intervention and follow-up evaluations.

INTERVENTIONS

Group-specific progressive balance, flexibility, strengthening, and aerobic exercise conducted sitting or lying (NWB) or standing and walking (WB) occurred 3 times a week for 12 weeks.

MAIN OUTCOME MEASURES

Measures included the 6-minute walk distance (6MWD) and daily step counts. Secondary outcome measures represented domains across the International Classification of Functioning, Disability and Health.

RESULTS

The WB group showed greater gains than the NWB group over time on the 6MWD and average daily step count (P<.05). The mean and 95% confidence intervals (CIs) between-group difference over time was 29m (95% CI, 6-51) for the 6MWD and 1178 (95% CI, 150-2205) steps for the average daily step count. The NWB group showed greater improvements than the WB group over time in hemoglobin A1c values (P<.05).

CONCLUSIONS

The results of this study indicate the ability of this population with chronic disease to increase 6MWD and daily step count with a WB exercise program compared with an NWB exercise program.

Addition of exenatide twice daily to basal insulin for the treatment of type 2 diabetes: clinical studies and practical approaches to therapy

BACKGROUND

Type 2 diabetes is a progressive disease that requires stepwise additions of non-insulin and insulin therapies to meet recommended glycaemic goals. The final stage of intensification may require prandial insulin, adding complexity and increased risks of hypoglycaemia and weight gain.

AIMS

This review assesses the benefits and risks of adding exenatide twice daily, a glucagon-like peptide 1 receptor agonist, in patients with type 2 diabetes who are currently treated with basal insulin, but have failed to reach their glycaemic goals.

METHODS AND RESULTS

Based on data from published studies, exenatide has a number of actions that complement basal insulin therapy. Exenatide has been shown to increase glucose-dependent insulin production, suppress abnormal plasma glucagon production, slow gastric emptying, enhance liver uptake of glucose and promote satiety. A recently published randomised clinical trial reported that the addition of exenatide twice daily to titrated basal insulin provided greater glycaemic control than titrated basal insulin alone, and did so without an increase in hypoglycaemic events and with modest weight loss. Exenatide use was associated with gastrointestinal side effects. The recent randomised trial confirmed and extended data from a number of prior observational studies that demonstrated the efficacy and safety of insulin/exenatide combination therapy. Practical considerations for adding exenatide twice daily to ongoing basal insulin are discussed.

Hyperandrogenism and intersex controversies in women's olympics

International sports governing bodies such as the International Association for Athletics Federation and the International Olympic Committee have recently revised their policies for inclusion of athletes competing in women's international sports competitions. Previously, the focus was on verification of gender or femininity. The mishandling of Caster Semanya's case brought the complex issues of fairness with regard to athletes with disorders of sexual development or hyperandrogenism into both public and private debates. The new International Association for Athletics Federation and International Olympic Committee policies for inclusion in women's sporting events rest largely on the serum testosterone level, mandating that it be less than the lower limit of normal for men as the defining criteria. This report provides an overview of past problems and an update of the newly adopted policies for eligibility for competition in women's events. Endocrinologists will play a key role in the evaluation and treatment of women athletes who have elevated androgen levels, regardless of the underlying cause.

Linagliptin for type 2 diabetes mellitus: a review of the pivotal clinical trials

Patients with type 2 diabetes mellitus (T2DM) frequently require multiple therapies to effectively control hyperglycemia, and many new agents for glucose control have been developed over the past few decades. Linagliptin is a recently approved oral antidiabetic drug that acts by inhibiting the enzyme dipeptidyl peptidase-4 (DPP-4). Unlike other DPP-4 inhibitors, linagliptin is excreted chiefly via the enterohepatic system, and can be used without dose adjustment in patients with renal or hepatic impairment. Linagliptin was approved by the US Food and Drug Administration based on a large development program, including four pivotal trials in patients with T2DM, assessing the efficacy and safety of linagliptin when used as monotherapy or in combination with other oral antidiabetes drugs. Linagliptin was associated with significant improvements in glycosylated hemoglobin, fasting plasma glucose and postprandial glucose, and more patients receiving linagliptin showed meaningful improvements and achieved targets for glycosylated hemoglobin. Linagliptin was well tolerated, with an adverse event profile similar to that of placebo, and low rates of hypoglycemic events. Taken together, the pivotal trials confirm linagliptin is effective and safe in patients with T2DM: the convenience of oral dosing with no requirement for dose adjustment in patients with renal or hepatic impairment make linagliptin a valuable option when considering therapies for patients with T2DM.

Pharmacotherapy in type 2 diabetes: a functional schema for drug classification

With growing awareness that long-term hyperglycemia is directly implicated in the tissue damage characteristic of diabetes, there has been a corresponding increase in clinicians' willingness to employ intensive treatment to achieve euglycemia, which may require diabetes drugs in combination. The expanding array of drugs with different mechanisms of action calls for a clear method of classification to guide rational combination therapy. Contemporary and historical literature was surveyed to document changes in awareness of toxicity from hyperglycemia and consequent changes in treatment strategy. References were selected for clinical applicability and explanation of drug mechanisms of action, with the goal of proposing a useful schema for classification. Diabetes drugs may be classified in the following categories: insulin providers, which increase the supply of insulin through administration of exogenous human insulin or analogues or drugs that stimulate endogenous insulin secretion (sulfonylureas and meglitinides are direct insulin secretagogues, whereas glucagon- like peptide-1 analogues and dipeptidyl peptidase-4 inhibitors act to increase the supply of insulin); insulin sensitizers (metformin, thiazolidinediones), which offset the effects of insulin resistance; and insulin-independent drugs, which work in the gut to impede intestinal absorption of glucose into the circulation (α-glucosidase inhibitors) or in the kidney to prevent renal reabsorption of glucose back into the circulation (sodium-glucose cotransporter 2 inhibitors, currently investigational). Awareness of these categories facilitates rational combinations of drugs with differing mechanisms of action to address hyperglycemia from separate directions, in accordance with current treatment guidelines.

Sex and type 2 diabetes: obesity-independent effects on left ventricular substrate metabolism and relaxation in humans

Patients with type 2 diabetes (T2DM), particularly women, are at risk for heart failure. Myocardial substrate metabolism derangements contribute to cardiac dysfunction in diabetic animal models. The purpose of this study was to determine the effects of diabetes and sex on myocardial metabolism and diastolic function in humans, separate from those of obesity. Thirty-six diabetic subjects (22 women) and 36 nondiabetic, BMI-matched subjects (21 women) underwent positron emission tomography (myocardial metabolism) and echocardiography (structure, function). Myocardial blood flow and oxygen consumption (MVO(2)) were higher in women than men (P = 0.003 and <0.0001, respectively). Plasma fatty acid (FA) levels were higher in diabetics (vs. obese, P < 0.003) and sex and diabetes status interacted in its prediction (P = 0.03). Myocardial FA utilization, oxidation, and esterification were higher and percent FA oxidation lower in diabetics (vs. obese, P = 0.0004, P = 0.007, P = 0.002, P = 0.02). FA utilization and esterification were higher and percent FA oxidation lower in women (vs. men, P = 0.03, P = 0.01, P = 0.03). Diabetes and sex did not affect myocardial glucose utilization, but myocardial glucose uptake/plasma insulin was lower in the diabetics (P = 0.04). Left ventricular relaxation was lower in diabetics (P < 0.0001) and in men (P = 0.001), and diabetes and sex interacted in its prediction (P = 0.03). Sex, T2DM, or their interaction affect myocardial blood flow, MVO(2), FA metabolism, and relaxation separate from obesity's effects. Sexually dimorphic myocardial metabolic and relaxation responses to diabetes may play a role in the known cardiovascular differences between men and women with diabetes.

Comparing the effects of insulin glargine and thiazolidinediones on plasma lipids in type 2 diabetes: a patient-level pooled analysis

BACKGROUND

The prevalence of dyslipidaemia and the risk of cardiovascular disease are elevated in patients with type 2 diabetes. This analysis compared the effects of insulin glargine versus thiazolidinediones (TZDs) on lipid profiles.

METHODS

Patient-level data were pooled from two randomized clinical studies. The population included 552 men and women aged >18 years, diagnosed with type 2 diabetes for at least 6 months, on metformin and/or sulphonylurea, and with A(1C) ≥7.5% and <12.0% at screening. Lipid outcome measures included change from baseline in lipid levels [low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol, triglycerides, and free fatty acids] and attainment of lipid goals for LDL-C, non-HDL-C, and triglycerides.

RESULTS

Both insulin glargine and TZDs improved lipid profiles from baseline values. Compared with TZDs, treatment with insulin glargine led to 7.9% greater reduction in LDL-C (p < 0.0003), 7.5% greater reduction in non-HDL-C (p < 0.0001), and 7.8% greater reduction in total cholesterol (p < 0.0001), whereas the HDL-C increase with TZD was 7.6% greater than that with insulin glargine (p < 0.0001). The percentage of patients attaining the lipid goals was comparable between insulin glargine and pioglitazone, but lower for rosiglitazone. Insulin glargine improved glycaemic control more than TZDs; however, insulin glargine caused more hypoglycaemia. Treatment with TZDs caused more weight gain and peripheral oedema.

CONCLUSION

These findings suggest that the favourable effects of insulin glargine on plasma lipid profiles should be considered among the advantages of treatment with insulin glargine as they are for TZDs.

Prediction and prevention of treatment-related inpatient hypoglycemia

BACKGROUND

Prolonged severe hypoglycemia (SH) in hospitalized patients is associated with increased morbidity and mortality. This study was undertaken to identify risk factors for SH, to apply that knowledge to the development of a prediction algorithm, and to institute a prevention program at a tertiary medical center.

METHODS

We analyzed SH events for 172 patients and developed computer algorithms to predict SH that were tested on a population of 3028 inpatients who were found to have blood glucose (BG) <90 mg/dl during their hospital stay. Variables with significant bivariate associations were entered into partition analyses to identify interactions. Logistic regression was performed by calculating parameters related to the odds of hypoglycemia below each cut point. Sensitivity and specificity were determined at various cut points. The cut points resulting in 50% sensitivity for each hypoglycemia level were determined. These algorithms were tested against the initial 172 adjudicated patients.

RESULTS

Variables related to the BG <40 mg/dl cut off point were basal and adjustment scale insulin doses, weight, and creatinine clearance, while variables related to the 60 mg/dl and 70 mg/dl cut points were basal, prandial, and adjustment scale insulin doses, weight, creatinine clearance, and sulfonylurea use. The 50% sensitivity cut point developed using the <70 mg/dl algorithm correctly identified 71% of the adjudicated cases, while the <60 mg/dl and <40 mg/dl algorithms identified 70% and 55% respectively.

CONCLUSIONS

A validated prediction algorithm for SH can aid in the identification of patients at risk for SH and may be useful in the development of prevention strategies.

Stroke in patients with type 2 diabetes mellitus, chronic kidney disease, and anemia treated with Darbepoetin Alfa: the trial to reduce cardiovascular events with Aranesp therapy (TREAT) experience

BACKGROUND

More strokes were observed in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT) among patients assigned to darbepoetin alfa. We sought to identify baseline characteristics and postrandomization factors that might explain this association.

METHODS AND RESULTS

A multivariate logistic regression model was used to identify baseline predictors of stroke in 4038 patients with diabetes mellitus, chronic kidney disease, and anemia randomized to receive darbepoetin alfa or placebo. To determine whether postrandomization blood pressure, hemoglobin level, platelet count, or treatment dose were responsible for the increased risk related to darbepoetin alfa, we performed a nested case-control analysis (1:10 matching) identifying nonstroke controls with propensity matching. The risk of stroke was doubled with darbepoetin alfa. Overall, 154 patients had a stroke, 101/2012 (5.0%) in the darbepoetin alfa arm and 53/2026 (2.6%) in the placebo arm (hazard ratio 1.9; 95% confidence interval, 1.4-2.7). Independent predictors of stroke included assignment to darbepoetin alfa (odds ratio 2.1; 95% confidence interval, 1.5-2.9), history of stroke (odds ratio 2.0; 95% confidence interval, 1.4-2.9), more proteinuria, and known cardiovascular disease. In patients assigned to darbepoetin alfa, postrandomization systolic and diastolic blood pressure, hemoglobin level, platelet count, and darbepoetin alfa dose did not differ between those with and without stroke. Additional sensitivity analyses using maximal values, latest values, or changes over varying periods of exposure yielded similar results.

CONCLUSIONS

The 2-fold increase in stroke with darbepoetin alfa in TREAT could not be attributed to any baseline characteristic or to postrandomization blood pressure, hemoglobin, platelet count, or dose of treatment. These readily identifiable factors could not be used to mitigate the risk of darbepoetin alfa-related stroke.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT00093015.

Peroxisome proliferator-activated receptor pathway gene polymorphism associated with extent of coronary artery disease in patients with type 2 diabetes in the bypass angioplasty revascularization investigation 2 diabetes trial

BACKGROUND

Coronary artery disease (CAD) is the major cause of death in patients with type 2 diabetes mellitus. Although demographic and clinical factors associated with extent of CAD in patients with diabetes mellitus have been described, genetic factors have not. We hypothesized that genetic variation in peroxisome proliferator-activated receptor (PPAR) pathway genes, important in diabetes mellitus and atherosclerosis, would be associated with extent of CAD in patients with diabetes mellitus.

METHODS AND RESULTS

We genotyped 1043 patients (702 white, 175 blacks) from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) genetic cohort for 3351 variants in 223 PPAR pathway genes using a custom targeted-genotyping array. Angiographic end points were determined by a core laboratory. In whites, a single variant (rs1503298) in TLL1 was significantly (P=5.5 × 10(-6)) associated with extent of CAD, defined as number of lesions with percent diameter stenosis ≥20%, after stringent Bonferroni correction for all 3351 single nucleotide polymorphisms. This association was validated in the diabetic subgroups of 2 independent cohorts, the Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status (TRIUMPH) post-myocardial infarction registry and the prospective Family Heart Study (FHS) of individuals at risk for CAD. TLL1rs1503298 was also significantly associated with extent of severe CAD (≥70% diameter stenosis; P=3.7 × 10(-2)) and myocardial jeopardy index (P=8.7 × 10(-4)). In general linear regression modeling, TLL1rs1503298 explained more variance of extent of CAD than the previously determined clinical factors.

CONCLUSIONS

We identified a variant in a single PPAR pathway gene, TLL1, that is associated with the extent of CAD independently of clinical predictors, specifically in patients with type 2 diabetes mellitus and CAD. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00006305.

Reduction in insulin sensitivity following administration of the clinically used low-dose pressor, norepinephrine

BACKGROUND

Hyperglycaemia in acutely ill patients is well described and correcting this hyperglycaemia improves outcomes. It has been generally attributed to endogenous factors, specifically decreased secretion of insulin or increased secretion of anti-insulin hormones, and cytokines, or both. Norepinephrine is the most commonly used vasopressor in critically ill patients. When titrated, it has anecdotally been found to cause wide swings in blood glucose levels. We tested the hypothesis that norepinephrine, a plausible exogenous, iatrogenic cause of hyperglycaemia, causes resistance to insulin action with the hyperinsulinaemic-euglycaemic clamp method.

METHODS

Hyperinsulinaemic-euglycaemic (about 100 mg dL(-1) ) clamps were performed before and during infusion of norepinephrine, in doses of 110 ng kg(-1) min(-1) , which raised mean arterial pressure from 82 ± 7 to 94 ± 8 mmHg (p < 0.01) in 11 healthy adults.

RESULTS

The glucose infusion rate required to maintain euglycaemia during the clamps, a marker of whole-body insulin sensitivity, decreased from 11.2 ± 3.7 mg kg(-1) min(-1) at baseline to 9.0 ± 2.6 mg kg(-1) min(-1) (p = 0.015) during the norepinephrine infusion. Steady-state insulin and C-peptide levels did not significantly change. Cortisol levels showed diurnal variation in the beginning and were also different at steady state.

CONCLUSIONS

Infusion of pressor doses of norepinephrine causes resistance to insulin action in humans.

Potentiation of abnormalities in myocardial metabolism with the development of diabetes in women with obesity and insulin resistance

BACKGROUND

Because studies in animal models of type-2 diabetes mellitus (DM) show that excessive myocardial fatty acid (FA) metabolism (at the expense of glucose metabolism) cause cardiac dysfunction, we hypothesized that women with DM would have more FA and less glucose myocardial metabolism than normal or even obese (OB) women.

RESEARCH DESIGN AND METHODS

Women who were lean volunteers (NV) (N = 14; age 35 ± 17 years, body mass index 23 ± 1 kg/m(2)), OB (N = 28;31 ± 6 years, BMI 39 ± 7 kg/m2), and DM (n = 22; 54 ± 11 years, BMI 38 ± 5 kg/m2) were studied. Cardiac positron emission tomography was performed for the determination of myocardial blood flow, oxygen consumption, FA and glucose metabolism. Cardiac work was measured by echocardiography and efficiency by the ratio of work to myocardial oxygen consumption.

RESULTS

Fractional glucose uptake was comparable between NV and OB but lower in DM (P < .05 versus NV). Myocardial FA utilization and oxidation were both higher in DM compared with NV and OB (P < .0001). Myocardial FA utilization and oxidation had positive correlations with HOMA (R = 0.35, P = .005 and R = 0.40, P = .001, respectively) whereas fractional glucose uptake exhibited an inverse correlation (R = -.31, P = .01). Cardiac work and efficiency were similar among the three groups.

CONCLUSIONS

In women, the presence of OB and DM compared with OB alone is associated with a greater reliance on myocardial FA metabolism at the expense of glucose metabolism. These perturbations in myocardial metabolism are not associated in a decline left ventricular efficiency or function suggesting that the metabolic perturbations may precede an eventual decline left ventricular function as is seen in animal models of DM.