Effectiveness of intensification therapies in Danes with Type 2 diabetes who use basal insulin: a population-based study

AIMS

To examine the usage and real-life effectiveness of intensification therapies in people with Type 2 diabetes treated with basal insulin.

METHODS

We used population-based healthcare databases in Denmark during 2000-2012 to identify all individuals with a first basal insulin prescription (with or without oral drugs), and evaluated subsequent intensification therapy with bolus insulin, premixed insulin or glucagon-like peptide-1 (GLP-1) receptor agonists. Poisson regression was used to compute the adjusted relative risks of reaching glycaemic control targets.

RESULTS

We included 7034 initiators of basal insulin (median age 64 years, diabetes duration 5.3 years, 84% with oral co-medication and median (interquartile range) pre-insulin HbA_1c level 77 (65-92) mmol/mol [9.2% (8.1-10.6%)]. Of these, 3076 (43.7%) received intensification therapy after a median of 11 months: 58.5% with premixed insulin, 29.0% with bolus insulin, 10.6% with GLP-1 receptor agonists, and 1.9% with more than one add-on. Overall, 22% had attained an HbA_1c level of < 53 mmol/mol (< 7%) by 3-6 months after intensification, while 38% attained an HbA_1c < 58 mmol/mol (< 7.5%). Compared with premixed insulin intensification, attainment of HbA_1c < 53 and < 58 mmol/mol was similar with bolus insulin add-on [adjusted relative risk 1.03 (95% CI 0.86-1.24) and 1.02 (95% CI 0.91-1.15), and higher for GLP-1 receptor agonist add-on [adjusted relative risk 1.56 (95% CI 1.27-1.92) and 1.27 (1.10-1.47)].

CONCLUSIONS

Among people with Type 2 diabetes, 22 and 38% reached a target HbA_1c < 53 mmol/mol (< 7%) or < 58 mmol/mol (< 7.5%), respectively, after intensification of their basal insulin therapy. Compared with premixed insulin, target attainment was similar with bolus insulin and higher with GLP-1 receptor agonists.

Patient-level predictors of achieving early glycaemic control in Type 2 diabetes mellitus: a population-based study

AIMS

To identify individual predictors of early glycaemic control in people with Type 2 diabetes mellitus after initiation of first glucose-lowering drug treatment in everyday clinical practice.

METHODS

Using medical registries, we identified a population-based cohort of people with a first-time glucose-lowering drug prescription in Northern Denmark in the period 2000-2012. We used Poisson regression analysis to examine patient-level predictors of success in reaching early glycaemic control [HbA_1c target of < 53 mmol/mol (7%)] < 6 months after treatment start.

RESULTS

Among the 38 418 people (median age 63 years), 27 545 (72%) achieved early glycaemic control. The strongest predictor of achieving early control was pre-treatment HbA_1c level; compared with a pre-treatment HbA_1c level of ≤ 58 mmol/mol (7.5%), the adjusted relative risks of attaining early control were 0.63 (95% CI 0.61-0.64) for baseline HbA_1c levels of > 58 and ≤ 75 mmol/mol (> 7.5 and ≤ 9%), and 0.58 (95% CI 0.57-0.59) for a baseline HbA_1c level of > 9% (> 75 mmol/mol). All other examined predictors were only weakly associated with the chance of achieving early control. After adjustment, the only characteristics that remained independently associated with early control (in addition to high baseline HbA_1c ) were being widowed (adjusted relative risk 0.95; 95% CI 0.93-0.97) and having a high Charlson comorbidity index score (score ≥ 3; adjusted relative risk 0.94; 95% CI 0.90-0.97).

CONCLUSIONS

In a real-world clinical setting, people with Type 2 diabetes mellitus initiating glucose-lowering medication had a similar likelihood of achieving glycaemic control, regardless of sex, age, comorbidities and other individual factors; the only strong and potentially modifiable predictor was HbA_1c before therapy start.

Early glycaemic control among patients with type 2 diabetes and initial glucose-lowering treatment: a 13-year population-based cohort study

AIM

To examine real-life time trends in early glycaemic control in patients with type 2 diabetes between 2000 and 2012.

METHODS

We used population-based medical databases to ascertain the association between achievement of glycaemic control with initial glucose-lowering treatment in patients with incident type 2 diabetes in Northern Denmark. Success in reaching glycated haemoglobin (HbA1c) goals within 3-6 months was examined using regression analysis.

RESULTS

Of 38 418 patients, 91% started with oral glucose-lowering drugs in monotherapy. Metformin initiation increased from 32% in 2000-2003 to 90% of all patients in 2010-2012. Pretreatment (interquartile range) HbA1c levels decreased from 8.9 (7.6-10.7)% in 2000-2003 to 7.0 (6.5-8.1)% in 2010-2012. More patients achieved an HbA1c target of <7% (<53 mmol/mol) in 2010-2012 than in 2000-2003 [80 vs 60%, adjusted relative risk (aRR) 1.10, 95% confidence interval (CI) 1.08-1.13], and more achieved an HbA1c target of <6.5% [(<48 mmol/mol) 53 vs 37%, aRR 1.07 95% CI 1.03-1.11)], with similar success rates observed among patients aged <65 years without comorbidities. Achieved HbA1c levels were similar for different initiation therapies, with reductions of 0.8% (from 7.3 to 6.5%) on metformin, 1.5% (from 8.1 to 6.6%) on sulphonylurea, 4.0% (from 10.4 to 6.4%) on non-insulin combination therapies, and 3.8% (from 10.3 to 6.5%) on insulin monotherapy.

CONCLUSIONS

Pretreatment HbA1c levels in patients with incident type 2 diabetes have decreased substantially, which is probably related to earlier detection and treatment in accordance with changing guidelines. Achievement of glycaemic control has improved, but 20% of patients still do not attain an HbA1c level of <7% within the first 6 months of initial treatment.

Comparison of two sulfonylureas with high and low myocardial K(ATP) channel affinity on myocardial infarct size and metabolism in a rat model of type 2 diabetes

AIMS/HYPOTHESIS

Sulfonylureas (SUs) may impair outcome in patients with acute coronary syndrome. Most experimental studies of the myocardial effects of SU treatment are performed in non-diabetic models. We compared the effect of two widely used SUs, glibenclamide (gb) and gliclazide (gc), with high and low myocardial K(ATP) channel affinity, respectively, at therapeutic concentrations on infarct size, left ventricular (LV) function and myocardial glycogen, lactate and alanine content before and after ischaemia/reperfusion (I/R).

METHODS

Non-diabetic Wistar and diabetic Goto-Kakizaki rat hearts were investigated in a Langendorff preparation. Gb (0.1 μmol/l) and gc (1.0 μmol/l) were administrated throughout the study. Infarct size was evaluated after 120 min of reperfusion. Myocardial metabolite content was measured before and after ischaemia.

RESULTS

Infarct size was smaller in diabetic hearts than in non-diabetic hearts (0.33 ± 0.03 vs 0.51 ± 0.05, p < 0.05). Gb increased infarct size (0.54 ± 0.04 vs 0.33 ± 0.03, p < 0.05) and reduced post-ischaemic LV developed pressure (60 ± 3 vs 76 ± 3 mmHg, p < 0.05) and coronary flow (4.9 ± 0.5 vs 7.1 ± 0.4 ml min(-1) g(-1), p < 0.05) in gb-treated diabetic rats compared with untreated diabetic rats. On comparing gb-treated diabetic rats with untreated diabetic rats, glycogen content was reduced before (9.1 ± 0.6 vs 13.6 ± 1.0 nmol/mg wet weight, p < 0.01) and after ischaemia (0.9 ± 0.2 vs 1.8 ± 0.2 nmol/mg wet weight, p < 0.05), and lactate (4.8 ± 0.4 vs 3.2 ± 0.3 nmol/mg wet weight, p < 0.01) and alanine (1.38 ± 0.12 vs 0.96 ± 0.09 nmol/mg wet weight, p < 0.05) contents were increased during reperfusion. Gc-treatment of diabetic and non-diabetic rats did not affect any of the measured variables.

CONCLUSIONS/INTERPRETATIONS

Gb, but not gc, exacerbates I/R injury and deteriorates LV function in diabetic hearts. These effects of gb on diabetic hearts may be due to detrimental effects on myocardial carbohydrate metabolism.

A novel insulin sensitizer (S15511) enhances insulin-stimulated glucose uptake in rat skeletal muscles

Type 2 diabetes is preceded by the presence of skeletal muscle insulin resistance, and drugs that increase insulin sensitivity in skeletal muscle prevent the disease. S15511 is an original compound with demonstrated effects on insulin sensitivity in animal models of insulin resistance. However, the mechanisms behind the insulin-sensitizing effect of S15511 are unknown. The aim of our study was to explore whether S15511 improves insulin sensitivity in skeletal muscles. Insulin sensitivity was assessed in skeletal muscles from S15511-treated rats by measuring intracellular insulin-signaling activity and insulin-stimulated glucose transport in isolated muscles. In addition, GLUT4 expression and glycogen levels were assessed after treatment. S15511 treatment was associated with an increase in insulin-stimulated glucose transport in type IIb fibers, while type I fibers were unaffected. The enhanced glucose transport was mirrored by a fiber type-specific increase in GLUT4 expression, while no improvement in insulin-signaling activity was observed. S15511 is a novel insulin sensitizer that is capable of improving glucose homeostasis in nondiabetic rats. The compound enhances skeletal muscle insulin sensitivity and specifically targets type IIb muscle fibers by increasing GLUT4 expression. Together these data show S15511 to be a potentially promising new drug in the treatment and prevention of type 2 diabetes.

Insulin and contraction directly stimulate UCP2 and UCP3 mRNA expression in rat skeletal muscle in vitro

To study the regulation of the mitochondrial uncoupling protein 2 and 3 (UCP2 and UCP3), we studied the effect of insulin and muscle contraction on UCP mRNA expression in rat skeletal muscle in vitro. Insulin dose-dependently increased skeletal muscle UCP2 and UCP3 mRNA expression in m. extensor digitorum longus (EDL) with maximal stimulation obtained at around 0.6-6 nM. The concentration of insulin giving half-maximal stimulation was 60 pM for the UCP2 and 48 pM for the UCP3 mRNA expression. The effect of insulin was maximal after 2 h and the effect was sustained during the whole study period (6 h). The insulin-induced increase in UCP mRNA was independent of the glucose uptake (as UCP mRNA was stimulated even in incubations without glucose). In addition, electrically induced contractions (in vitro) increased UCP2 and UCP3 mRNA expression 60-120 min after a single bout of contraction (for 10 min). Both the increment of UCP2 and UCP3 mRNA were sustained throughout the study period (4 h) (153 +/- 62 and 216 +/- 71% above basal, P < 0.05 respectively). Finally, 5-aminoimidazole-4-carboxamid-ribosid (AICAR), an activator of the AMP-activated protein kinase (AMPK), that is activated during exercise, was able to mimic the increase in UCP2 and UCP3 mRNA expression. In conclusion, UCP2 and UCP3 mRNA expression in skeletal muscle are stimulated rapidly by insulin and contraction in vitro, thus the stimulation is direct and not caused by changes in other hormones or metabolites. Even a brief bout of contraction induces an increase in UCP2 and UCP3 expression, an effect that could be mimicked by activation of the AMP-activated protein kinase by AICAR.

Chronic treatment with 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside increases insulin-stimulated glucose uptake and GLUT4 translocation in rat skeletal muscles in a fiber type-specific manner

Recent studies have demonstrated that chronic administration of AICAR (5-aminoimidazole-4-carboxamide- 1-beta-D-ribofuranoside), an activator of the AMP-activated protein kinase, increases hexokinase activity and the contents of total GLUT4 and glycogen in rat skeletal muscles. To explore whether AICAR also affects insulin-stimulated glucose transport and GLUT4 cell surface content, Wistar rats were subcutaneously injected with AICAR for 5 days in succession (1 mg/g body wt). Maximally insulin-stimulated (60 nmol/l) glucose uptake was markedly increased in epitrochlearis (EPI) muscle (average 63%, P < 0.001, n = 18-19) and in extensor digitorum longus muscle (average 26%, P < 0.001, n = 26-30). In contrast, administration of AICAR did not maximally influence insulin-stimulated glucose transport in soleus muscle. Studies of EPI muscle with the 4,4'-O-[2-[2-[2-[2-[2-[6-(biotinylamino)hexanoyl]amino]ethoxy]ethoxy] ethoxy]-4-(1-azi-2,2,2,-trifluoroethyl)benzoyl]amino-1,3-propanediyl]bis-D-mannose photolabeling technique showed a concomitant increase (average 68%, P < 0.02) in cell surface GLUT4 content after insulin exposure in AICAR-injected rats when compared with controls. In conclusion, 5 days of AICAR administration induces a pronounced fiber type-specific increase in insulin-stimulated glucose uptake and GLUT4 cell surface content in rat skeletal muscle with the greatest effect observed on white fast-twitch glycolytic muscles (EPI). These results are comparable with the effects of chronic exercise training, and it brings the AMP-activated protein kinase into focus as a new interesting target for future pharmacological intervention in insulin-resistant conditions.