Insulin analogs as an add-on to metformin after failure to oral treatment in type 2 diabetic patients increase diastole duration. The INSUlin Regimens and VASCular Functions (INSUVASC) study.

BACKGROUND: Fast acting insulin analogues are known to improve arterial stiffness. The combination of metformin with insulin represents a widely used therapeutic strategy in diabetes. We hypothesized that insulin treatment in patients with type 2 diabetes (T2D) with long-acting, fast-acting or basal bolus insulin as an add-on to metformin would provide additional improvement of arterial stiffness. METHODS: The INSUlin Regimens and VASCular Functions (INSUVASC) study is a pilot, randomized, open label three-arms study that included 42 patients with type 2 diabetes (T2D) in primary prevention, after a failure to oral antidiabetic agents. Arterial stiffness measurements were performed at fasting and after a standardized breakfast. During the first visit (V1) pre-randomization, participants took only metformin to perform the tests. The same tests were repeated after 4 weeks of insulin treatment during the second visit (V2). RESULTS: Data were available for final analysis in 40 patients, with a mean age of 53.6±9.7 years and a mean duration of diabetes of 10.6±5.6 years. Twenty-one were females (52.5%), hypertension and dyslipidemia were present in 18 (45%) and 17 patients (42.5%), respectively. After insulin treatment, the metabolic control was associated to a decrease in oxidative stress and improvement of endothelial functions, with a post prandial diastole duration increased and a decrease of the peripheral arterial stiffness, with a better post prandial pulse pressure ratio and ejection duration after insulin. In hypertensive patients, insulin treatment provided positive effects by decreasing the pulse wave velocity and improving reflection time. CONCLUSIONS: A short time treatment by insulin in addition to metformin improved myocardial perfusion. Moreover, insulin treatment in hypertensive patients provides a better hemodynamic profile in large arteries.

Effects of insulin analogs as an add-on to metformin on cutaneous microcirculation in type 2 diabetic patients.

BACKGROUND: A single insulin injection was shown to improve microcirculatory blood flow. Our aim was to examine the effects of 4weeks of insulin therapy by three randomly assigned insulin analog regimens (Detemir, Aspart, and their combination) on cutaneous blood flow (CBF) and microcirculatory endothelial function as an add-on to metformin in type 2 diabetic patients poorly controlled on oral antidiabetic treatment. METHODS: Fourty-two type 2 diabetic patients with no history of cardiovascular disease in secondary failure to oral antidiabetic agents had CBF measurements before and after acetylcholine (Ach) iontophoretic administration. CBF measurements were performed at fasting and after a standardized breakfast during the post-prandial period. Before randomization (Visit 1, V1) during the tests, participants took only metformin. The same tests were repeated after 4weeks of insulin treatment (Visit 2, V2). RESULTS: Thirty-four patients had good quality recordings for both visits. During V1, CBF and CBF response to Ach increased in the post-prandial period. After 4weeks of insulin treatment, metabolic parameters improved. Compared to V1, CBF at fasting did not increase at V2 but there was an improvement in endothelial function at fasting after Ach iontophoresis, without difference across insulin regimens. Oxidative stress markers were not modified, and E-selectin and vascular cell adhesion molecule 1 levels decreased after insulin treatment, without differences between insulin groups. CONCLUSIONS: A strategy of improving glycemic control for 4weeks with insulin analogs improves microcirculatory endothelial reactivity and reduces endothelial biomarkers at fasting, whatever the insulin regimen used. Insulin therapy associated to metformin is able to improve fasting microvascular endothelial function even before complete metabolic control.

Cardiovascular risk prediction is improved by adding asymptomatic coronary status to routine risk assessment in type 2 diabetic patients.

OBJECTIVE: To evaluate if silent myocardial ischemia (SMI) and silent coronary artery disease (CAD) provide significant additional value to routine cardiovascular risk assessment in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: We followed up to a first cardiovascular event 688 subjects (322 men, aged 59 ± 8 years) out of 731 consecutive asymptomatic type 2 diabetic patients with ≥1 additional risk factor who had been prospectively screened between 1992 and 2006 for SMI by stress myocardial scintigraphy and for silent CAD by coronary angiography. RESULTS: SMI was found in 207 (30.1%) patients and CAD in 76 of those with SMI. Of the patients, 98 had a first cardiovascular event during a 5.4 ± 3.5 (range: 0.1-19.2) year follow-up period. Cox regression analysis considering parameters predicting events but not SMI and CAD ("routine assessment") showed in univariate analyses that macroproteinuria (hazard ratio [HR] 3.33 [95% CI 1.74-6.35]; P < 0.001), current multifactorial care (0.27 [0.15-0.47]; P < 0.001), and peripheral/carotid occlusive arterial disease (PCOAD; 4.33 [2.15-8.71]; P < 0.001) independently predicted cardiovascular events. When added into the model, SMI (HR 1.76 [1.00-3.12]; P = 0.05) and CAD (2.28 [1.24-4.57]; P < 0.01) were also independently associated with events. SMI added to the prediction of an event in the following 5 years above and beyond routine assessment risk prediction (c statistic with or without SMI 0.788 [0.720-0.855] and 0.705 [0.616-0.794], respectively). CONCLUSIONS: Although screening for SMI and silent CAD should not be systematic, these complications are predictive of cardiovascular events in type 2 diabetic patients in addition to routine risk predictors, especially represented by PCOAD, macroproteinuria, and nonintensive management.