Irene Hramiak

Effect of intensive treatment of hyperglycaemia on microvascular outcomes in type 2 diabetes: an analysis of the ACCORD randomised trial

BACKGROUND Hyperglycaemia is associated with increased risk of cardiovascular complications in people with type 2 diabetes. We investigated whether reduction of blood glucose concentration decreases the rate of microvascular complications in people with type 2 diabetes. METHODS ACCORD was a parallel-group, randomised trial done in 77 clinical sites in North America. People with diabetes, high HbA(1c) concentrations (>7.5%), and cardiovascular disease (or >or=2 cardiovascular risk factors) were randomly assigned by central randomisation to intensive (target haemoglobin A(1c) [HbA(1c)] of <6.0%) or standard (7.0-7.9%) glycaemic therapy. In this analysis, the prespecified composite outcomes were: dialysis or renal transplantation, high serum creatinine (>291.7 micromol/L), or retinal photocoagulation or vitrectomy (first composite outcome); or peripheral neuropathy plus the first composite outcome (second composite outcome). 13 prespecified secondary measures of kidney, eye, and peripheral nerve function were also assessed. Investigators and participants were aware of treatment group assignment. Analysis was done for all patients who were assessed for microvascular outcomes, on the basis of treatment assignment, irrespective of treatments received or compliance to therapies. ACCORD is registered with ClinicalTrials.gov, number NCT00000620. FINDINGS 10 251 patients were randomly assigned, 5128 to the intensive glycaemia control group and 5123 to standard group. Intensive therapy was stopped before study end because of higher mortality in that group, and patients were transitioned to standard therapy. At transition, the first composite outcome was recorded in 443 of 5107 patients in the intensive group versus 444 of 5108 in the standard group (HR 1.00, 95% CI 0.88-1.14; p=1.00), and the second composite outcome was noted in 1591 of 5107 versus 1659 of 5108 (0.96, 0.89-1.02; p=0.19). Results were similar at study end (first composite outcome 556 of 5119 vs 586 of 5115 [HR 0.95, 95% CI 0.85-1.07, p=0.42]; and second 1956 of 5119 vs 2046 of 5115, respectively [0.95, 0.89-1.01, p=0.12]). Intensive therapy did not reduce the risk of advanced measures of microvascular outcomes, but delayed the onset of albuminuria and some measures of eye complications and neuropathy. Seven secondary measures at study end favoured intensive therapy (p<0.05). INTERPRETATION Microvascular benefits of intensive therapy should be weighed against the increase in total and cardiovascular disease-related mortality, increased weight gain, and high risk for severe hypoglycaemia. FUNDING US National Institutes of Health; National Heart, Lung, and Blood Institute; National Institute of Diabetes and Digestive and Kidney Diseases; National Institute on Aging; National Eye Institute; Centers for Disease Control and Prevention; and General Clinical Research Centers.

Glucagon-Like Peptide I Reduces Postprandial Glycemic Excursions in IDDM

Effects of human glucagon-like peptide I (GLP-I)(7–36)amide were examined in volunteers having insulin-dependent diabetes mellitus (IDDM) with residual C-peptide (CP) secretion (n = 8, 7 men and 1 woman; age, 31 ± 1.4 years; body mass index, 24.7 ± 0.7 kg/m2; duration of diabetes, 3.2 ± 0.8 years; insulin dose, 0.41 ± 0.05 U · kg−1· day−1; meal-stimulated CP, 1.0 ± 0.2 nmol/l [means ± SE]). After a mixed meal (Sustacal, 30 kJ/kg body wt), intravenous injection of GLP-I, 1.2 pmol · kg−1 · min−1 through 120 min, virtually abolished increments of plasma glucose, CP, pancreatic polypeptide (PP), and glucagon concentrations, with no significant effect on plasma gastrin levels during the infusions. At reduced dosage (0.75 pmol · kg−1 · min−1), GLP-I had lesser effects on plasma glucose and CP levels. On cessation of intravenous GLP-I infusions after the meals, plasma glucose, CP, PP, and glucagon concentrations rebounded toward control levels by 180 min, and the response of plasma gastrin was prolonged. These rebound responses are consistent with intestinal delivery of food retained in the stomach on escape from inhibition of gastric emptying by GLP-I. Infusion of 1.2 pmol · kg−1 · min−1 GLP-I with 20 g glucose (10% dextrose in water) injected intravenously over 60 min enhanced plasma responses of immunoreactive CP; the mean incremental areas under concentration curves (0–60 min) increased sixfold, but the glycemic excursion was not affected. Thus, in CP-positive IDDM, pharmacological doses of GLP-I reduce glycemic excursions after meals by a mechanism(s) not dependent on stimulation of insulin secretion, presumably involving delayed gastric emptying. This effect of the peptide on blood glucose levels after meals may have therapeutic implications in both IDDM and non-insulin-dependent diabetes.

A Randomized Trial of a Home System to Reduce Nocturnal Hypoglycemia in Type 1 Diabetes

OBJECTIVE Overnight hypoglycemia occurs frequently in individuals with type 1 diabetes and can result in loss of consciousness, seizure, or even death. We conducted an in-home randomized trial to determine whether nocturnal hypoglycemia could be safely reduced by temporarily suspending pump insulin delivery when hypoglycemia was predicted by an algorithm based on continuous glucose monitoring (CGM) glucose levels. RESEARCH DESIGN AND METHODS Following an initial run-in phase, a 42-night trial was conducted in 45 individuals aged 15–45 years with type 1 diabetes in which each night was assigned randomly to either having the predictive low-glucose suspend system active (intervention night) or inactive (control night). The primary outcome was the proportion of nights in which ≥1 CGM glucose values ≤60 mg/dL occurred. RESULTS Overnight hypoglycemia with at least one CGM value ≤60 mg/dL occurred on 196 of 942 (21%) intervention nights versus 322 of 970 (33%) control nights (odds ratio 0.52 [95% CI 0.43–0.64]; P < 0.001). Median hypoglycemia area under the curve was reduced by 81%, and hypoglycemia lasting >2 h was reduced by 74%. Overnight sensor glucose was >180 mg/dL during 57% of control nights and 59% of intervention nights (P = 0.17), while morning blood glucose was >180 mg/dL following 21% and 27% of nights, respectively (P < 0.001), and >250 mg/dL following 6% and 6%, respectively. Morning ketosis was present <1% of the time in each arm. CONCLUSIONS Use of a nocturnal low-glucose suspend system can substantially reduce overnight hypoglycemia without an increase in morning ketosis.

Predictive Low-Glucose Insulin Suspension Reduces Duration of Nocturnal Hypoglycemia in Children Without Increasing Ketosis

OBJECTIVE Nocturnal hypoglycemia can cause seizures and is a major impediment to tight glycemic control, especially in young children with type 1 diabetes. We conducted an in-home randomized trial to assess the efficacy and safety of a continuous glucose monitor–based overnight predictive low-glucose suspend (PLGS) system. RESEARCH DESIGN AND METHODS In two age-groups of children with type 1 diabetes (11–14 and 4–10 years of age), a 42-night trial for each child was conducted wherein each night was assigned randomly to either having the PLGS system active (intervention night) or inactive (control night). The primary outcome was percent time <70 mg/dL overnight. RESULTS Median time at <70 mg/dL was reduced by 54% from 10.1% on control nights to 4.6% on intervention nights (P < 0.001) in 11–14-year-olds (n = 45) and by 50% from 6.2% to 3.1% (P < 0.001) in 4–10-year-olds (n = 36). Mean overnight glucose was lower on control versus intervention nights in both age-groups (144 ± 18 vs. 152 ± 19 mg/dL [P < 0.001] and 153 ± 14 vs. 160 ± 16 mg/dL [P = 0.004], respectively). Mean morning blood glucose was 159 ± 29 vs. 176 ± 28 mg/dL (P < 0.001) in the 11–14-year-olds and 154 ± 25 vs. 158 ± 22 mg/dL (P = 0.11) in the 4–10-year-olds, respectively. No differences were found between intervention and control in either age-group in morning blood ketosis. CONCLUSIONS In 4–14-year-olds, use of a nocturnal PLGS system can substantially reduce overnight hypoglycemia without an increase in morning ketosis, although overnight mean glucose is slightly higher.

Nine-year effects of 3.7 years of intensive glycemic control on cardiovascular outcomes

OBJECTIVE In the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, ∼4 years of intensive versus standard glycemic control in participants with type 2 diabetes and other cardiovascular risk factors had a neutral effect on the composite cardiovascular outcome, increased cardiovascular and total mortality, and reduced nonfatal myocardial infarction. Effects of the intervention during prolonged follow-up were analyzed. RESEARCH DESIGN AND METHODS All surviving ACCORD participants were invited to participate in the ACCORD Follow-on (ACCORDION) study, during which participants were treated according to their health care provider’s judgment. Cardiovascular and other health-related outcomes were prospectively collected and analyzed using an intention-to-treat approach according to the group to which participants were originally allocated. RESULTS A total of 8,601 people, representing 98% of those who did not suffer a primary outcome or death during the ACCORD trial, were monitored for a median of 8.8 years and a mean of 7.7 years from randomization. Intensive glucose lowering for a mean of 3.7 years had a neutral long-term effect on the primary composite outcome (nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death), death from any cause, and an expanded composite outcome that included all-cause death. Moreover, the risk of cardiovascular mortality noted during the active phase (hazard ratio 1.49; 95% CI 1.19, 1.87; P < 0.0001) decreased (HR 1.20; 95% CI 1.03, 1.39; P = 0.02). CONCLUSIONS In high-risk people with type 2 diabetes monitored for 9 years, a mean of 3.7 years of intensive glycemic control had a neutral effect on death and nonfatal cardiovascular events but increased cardiovascular-related death.

Combined intensive blood pressure and glycemic control does not produce an additive benefit on microvascular outcomes in type 2 diabetic patients

A reduction of either blood pressure or glycemia decreases some microvascular complications of type 2 diabetes, and we studied here their combined effects. In total, 4733 older adults with established type 2 diabetes and hypertension were randomly assigned to intensive (systolic blood pressure less than 120 mm Hg) or standard (systolic blood pressure less than 140 mm Hg) blood pressure control, and separately to intensive (HbA1c less than 0.060) or standard (HbA1c 0.070-0.079) glycemic control. Prespecified microvascular outcomes were a composite of renal failure and retinopathy and nine single outcomes. Proportional hazard regression models were used without correction for type I error due to multiple tests. During a mean follow-up of 4.7 years, the primary outcome occurred in 11.4% of intensive and 10.9% of standard blood pressure patients (hazard ratio 1.08), and in 11.1% of intensive and 11.2% of standard glycemia control patients. Intensive blood pressure control only reduced the incidence of microalbuminuria (hazard ratio 0.84), and intensive glycemic control reduced the incidence of macroalbuminuria and a few other microvascular outcomes. There was no interaction between blood pressure and glycemic control, and neither treatment prevented renal failure. Thus, in older patients with established type 2 diabetes and hypertension, intensive blood pressure control improved only 1 of 10 prespecified microvascular outcomes. None of the outcomes were significantly reduced by simultaneous intensive treatment of glycemia and blood pressure, signifying the lack of an additional beneficial effect from combined treatment.

Determinants of Clinical Remission in Recent-Onset IDDM

Objective— To assess the relationship of SI and insulin secretion (C-peptide levels) to remission status in recent-onset IDDM. Research Design and Methods— We followed 22 newly diagnosed patients, of whom 16 received immunomodulatory treatment with low-dose (5 mg·kg−1·day−1) CsA and/or short-term (72 h) methylprednisolone and 6 received standard insulin treatment, at 3-mo intervals for 12 mo. Insulin secretion was assessed by C-peptide levels and AIRglu, which was determined as the area under the insulin response curve, above the fasting level, from 0–10 min after a 0.3 g·kg−1·i.v. glucose xbolus. SI was assessed by the minimal model technique applied to a frequently sampled IVGTT. Clinical remission was defined in those patients who maintained normal range GHb and capillary blood glucose levels <7.8 mM premeal without insulin therapy for a minimum of 14 days. Results— The rate of clinical remission was not different with immunomodulatory treatment; nor were the metabolic parameters of plasma C-peptide levels, AIRglu, and S1 different in the treatment groups. The mean plasma C-peptide level improved significantly at 3 mo and was maintained to 12 mo. AIRglu was grossly subnormal throughout, but a significant improvement was seen at 3 and 6 mo. Mean SI was normalized at 3 and 6 mo but not maintained beyond 9 mo. The maximum rate of clinical remission was seen at 6 mo. Conclusions— Clinical remission in recent-onset IDDM patients is associated with improvement in both insulin secretion and SI. Although the improvement in basal C-peptide persisted, AIRglu increased only transiently and declined as loss of remission occurred in most patients. Loss of remission to an insulin-requiring state is associated with a decrease in SI.

Subcutaneous Glucagon-Like Peptide I Combined With Insulin Normalizes Postcibal Glycemic Excursions in IDDM

OBJECTIVE To determine whether a subcutaneous injection of truncated glucagon-like peptide 1 (tGLP-I)(7–36) amide that delays gastric emptying transiently can prevent postcibal hyperglycemia in IDDM without causing hypoglycemia when administered with insulin. RESEARCH DESIGN AND METHODS The postcibal increase in plasma human pancreatic polypeptide (HPP) was used as a presumptive indicator of arrival of nutrient in the small intestine. Studies in seven normal human volunteers established the dose of tGLP-I that delayed the postcibal rise in HPP by 30 min. This dose was tested in six patients with IDDM with a range of residual endogenous insulin secretion. The patients received a standard liquid test meal with or without subcutaneous tGLP-I and their usual dose of regular insulin before the meal. Blood samples collected at timed intervals were assayed for plasma concentrations of glucose, C-peptide (CP), immunoreactive insulin (IR1), HPP, and glucagon (GLN). RESULTS In normal subjects after administration of tGLP-I, postcibal plasma glucose concentration at 20 min fell below fasting levels in a dose-dependent manner. At 10 and 20 min, transient increments in plasma CP and IRI, and decrements in GLN, occurred. Subsequently, through 60 min, the excursions of plasma HPP, CP, and IRI were negatively correlated to the dose of tGLP-I. In subjects with IDDM, the selected dose of tGLP-I given with insulin before the meal delayed the plasma HPP response for 30 min and confined excursions of plasma glucose within the range observed in normal subjects receiving saline injections, whereas administration of insulin with saline injections in IDDM was followed by supranormal increases of plasma glucose. In IDDM, this dose of subcutaneous tGLP-I had no effect on plasma CP, IRI, or GLN. CONCLUSIONS In normal subjects, transient hypoglycemia after injections of tGLP-I with a meal was associated with transient stimulation of insulin secretion and inhibition of glucagon secretion. These actions together with delayed gastric emptying may account for the hypoglycemia, but other unidentified mechanisms cannot be excluded. In the subjects with IDDM, the selected relatively low dose of tGLP-I delayed excursions of plasma HPP as in normal subjects, but did not reduce the plasma glucose below the fasting level and had no effect on plasma CP, IRI, or GLN. However, injection of tGLP-I reduced the postcibal glycemic excursion and confined it within the normal range. Thus, in IDDM, a pharmacological dose of subcutaneous tGLP-I that presumably delays gastric emptying by ∼30 min can normalize glycemic excursions after a meal when given in combination with insulin. Because this cannot be achieved with regular insulin alone without risk of hypoglycemia, this combination of glucoregulatory peptides has therapeutic potential in insulin-requiring diabetes.

Insulin Resistance in Latent Autoimmune Diabetes of Adulthood

Abstract: Insulin resistance in patients with latent autoimmune diabetes of adulthood (LADA) was determined by homeostasis model assessment (HOMA). LADA was identified by a clinical phenotype of type 2 diabetes with antibodies to GAD65 and/or IA‐2/ICA512. All patients were managed with insulin therapy. Insulin resistance in LADA was lower than in antibody‐negative type 2 diabetes, higher than in normal humans and in recent‐onset type 1 diabetes, and similar to that in long‐term type 1 diabetes. Mean values for HOMA varied linearly with mean values for BMI, which accounted for much of the insulin resistance in these forms of diabetes. LADA resembles long‐term type 1 diabetes with respect to insulin resistance and BMI, but occurs at an older age.

Trends in Antihyperglycemic Medication Prescriptions and Hypoglycemia in Older Adults: 2002-2013

Background Over the last decade, several new antihyperglycemic medications have been introduced including those associated with a lower hypoglycemia risk. We aimed to investigate how these medications are being prescribed to older adults in our region. Methods We conducted population-based cross-sectional analyses of older adults (mean age 75 years) with treated diabetes in Ontario, Canada from 2002 until 2013, to examine the percentage prescribed insulin, sulphonylureas, alpha-glucosidase inhibitors, metformin, thiazolidinediones, meglitinides, and dipeptidyl peptidase-4 inhibitors. Over the study period, we also examined their hospital encounters for hypoglycemia (emergency room or inpatient encounter). Results The mean age of treated patients increased slightly over the study quarters and the proportion that were women declined. With the exception of chronic kidney disease, cancer, dementia, and neuropathy, the percentage with a comorbidity appeared to decline. The percentage of treated patients prescribed metformin, gliclazide and dipeptidyl peptidase-4 inhibitors increased as did combination therapy. Glyburide and thiazolidinedione prescriptions declined, and insulin use remained stable. In those with newly treated diabetes, the majority were prescribed metformin, with smaller percentages prescribed insulin and other oral agents. Although the absolute number of treated patients with a hypoglycemia encounter increased until mid-2006 and then decreased, the overall percentage with an encounter declined over the study period (0.8% with an event in the first quarter, 0.4% with an event in the last quarter). Conclusions Antihyperglycemic medications with safer profiles are being increasingly prescribed to older adults. In this setting there has been a decrease in the percentage of treated patients with a hospital encounter for hypoglycemia.