Diabetes treatments have differential effects on nontraditional cardiovascular risk factors

Elevated plasma levels of plasminogen activator inhibitor-1 are associated with risk of future incident venous thromboembolism

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1), the main inhibitor of fibrinolysis, is frequently elevated in obesity and could potentially mediate the risk of venous thromboembolism (VTE) in obese subjects. However, whether PAI-1 is associated with VTE remains uncertain.

OBJECTIVE

To investigate the association between plasma PAI-1 levels and risk of future incident VTE and whether PAI-1 could mediate the VTE risk in obesity.

METHODS

A population-based nested case-control study, comprising 383 VTE cases and 782 age- and sex-matched controls, was derived from the Tromsø Study cohort. PAI-1 antigen levels were measured in samples collected at cohort inclusion. Logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for VTE across PAI-1 tertiles.

RESULTS

The VTE risk increased dose-dependently across PAI-1 tertiles (P for trend <.001) in the age- and sex-adjusted model. The OR of VTE for the highest versus lowest tertile was 1.73 (95% CI 1.27-2.35), and risk estimates were only slightly attenuated with additional stepwise adjustment for body mass index (BMI; OR 1.59, 95% CI 1.16-2.17) and C-reactive protein (CRP; OR 1.54, 95% CI 1.13-2.11). Similar results were obtained for provoked/unprovoked events, deep vein thrombosis, and pulmonary embolism. In obese subjects (BMI of ≥30 kg/m2 vs. <25 kg/m2 ), PAI-1 mediated 14.9% (95% CI 4.1%-49.4%) of the VTE risk in analysis adjusted for age, sex, and CRP.

CONCLUSION

Our findings indicate that plasma PAI-1 is associated with increased risk of future incident VTE and has the potential to partially mediate the VTE risk in obesity.

Effect of the Interaction between Obstructive Sleep Apnea and Lipoprotein(a) on Insulin Resistance: A Large-Scale Cross-Sectional Study

Both obstructive sleep apnea (OSA) and decreased serum lipoprotein(a) (Lp(a)) concentrations are associated with insulin resistance. However, their interaction effect on insulin resistance has never been investigated. Therefore, we performed a cross-sectional study on OSA-suspected Chinese Han participants. Laboratory-based polysomnographic variables, biochemical indicators, anthropometric measurements, and medical history were collected. Linear regression and binary logistic regression analyses with interaction terms were used to investigate the potential effects of the interaction between the severity of OSA (assessed by the apnea-hypopnea index (AHI)) and Lp(a) concentrations on insulin resistance (assessed by the homeostasis model assessment of insulin resistance (HOMA-IR)), after adjusting for potential confounders including age, gender, body mass index, waist-to-hip circumference ratio, mean arterial pressure, smoking status, drinking status, and lipid profiles. A total of 4,152 participants were enrolled. In the OSA-suspected population, AHI positively correlated with insulin resistance and serum Lp(a) concentrations independently and inversely correlated with insulin resistance. In addition, the interaction analysis showed that the linear association between lgAHI and lgHOMA-IR was much steeper and more significant in subjects with relatively low Lp(a) concentrations, suggesting a significant positive interaction between lgLp(a) and lgAHI on lgHOMA-IR (P = 0.013). Furthermore, the interaction on a multiplicative scale also demonstrated a significant positive interaction (P = 0.044). A stronger association between AHI quartiles and the presence of insulin resistance (defined as HOMA-IR > 3) could be observed for participants within lower Lp(a) quartiles. In conclusion, a significant positive interaction was observed between OSA and decreased Lp(a) with respect to insulin resistance. This association might be relevant to the assessment of metabolic or cardiovascular disease risk in OSA patients.

Insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control

BACKGROUND

It is unclear whether people with type 2 diabetes mellitus on insulin monotherapy who do not achieve adequate glycaemic control should continue insulin as monotherapy or can benefit from adding oral glucose-lowering agents to the insulin therapy.

OBJECTIVES

To assess the effects of insulin monotherapy compared with the addition of oral glucose-lowering agents to insulin monotherapy for people with type 2 diabetes already on insulin therapy and inadequate glycaemic control.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and reference lists of articles. The date of the last search was November 2015 for all databases.

SELECTION CRITERIA

Randomised controlled clinical trials of at least two months' duration comparing insulin monotherapy with combinations of insulin with one or more oral glucose-lowering agent in people with type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, extracted data and evaluated overall quality of the evidence using GRADE. We summarised data statistically if they were available, sufficiently similar and of sufficient quality. We performed statistical analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 37 trials with 40 treatment comparisons involving 3227 participants. The duration of the interventions ranged from 2 to 12 months for parallel trials and two to four months for cross-over trials.The majority of trials had an unclear risk of bias in several risk of bias domains. Fourteen trials showed a high risk of bias, mainly for performance and detection bias. Insulin monotherapy, including once-daily long-acting, once-daily intermediate-acting, twice-daily premixed insulin, and basal-bolus regimens (multiple injections), was compared to insulin in combination with sulphonylureas (17 comparisons: glibenclamide = 11, glipizide = 2, tolazamide = 2, gliclazide = 1, glimepiride = 1), metformin (11 comparisons), pioglitazone (four comparisons), alpha-glucosidase inhibitors (four comparisons: acarbose = 3, miglitol = 1), dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) (three comparisons: vildagliptin = 1, sitagliptin = 1, saxagliptin = 1) and the combination of metformin and glimepiride (one comparison). No trials assessed all-cause mortality, diabetes-related morbidity or health-related quality of life. Only one trial assessed patients' treatment satisfaction and showed no substantial differences between the addition of either glimepiride or metformin and glimepiride to insulin compared with insulin monotherapy.Insulin-sulphonylurea combination therapy (CT) compared with insulin monotherapy (IM) showed a MD in glycosylated haemoglobin A1c (HbA1c) of -1% (95% confidence interval (CI) -1.6 to -0.5); P < 0.01; 316 participants; 9 trials; low-quality evidence. Insulin-metformin CT compared with IM showed a MD in HbA1c of -0.9% (95% CI -1.2 to -0.5); P < 0.01; 698 participants; 9 trials; low-quality evidence. We could not pool the results of adding pioglitazone to insulin. Insulin combined with alpha-glucosidase inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.2); P < 0.01; 448 participants; 3 trials; low-quality evidence). Insulin combined with DPP-4 inhibitors compared with IM showed a MD in HbA1c of -0.4% (95% CI -0.5 to -0.4); P < 0.01; 265 participants; 2 trials; low quality evidence. In most trials the participants with CT needed less insulin, whereas insulin requirements increased or remained stable in participants with IM.We did not perform a meta-analysis for hypoglycaemic events because the included studies used different definitions.. In most trials the insulin-sulphonylurea combination resulted in a higher number of mild episodes of hypoglycaemia, compared to the IM group (range: 2.2 to 6.1 episodes per participant in CT versus 2.0 to 2.6 episodes per participant in IM; low-quality evidence). Pioglitazone CT also resulted in more mild to moderate hypoglycaemic episodes compared with IM (range 15 to 90 episodes versus 9 to 75 episodes, respectively; low-quality evidence. The trials that reported hypoglycaemic episodes in the other combinations found comparable numbers of mild to moderate hypoglycaemic events (low-quality evidence).The addition of sulphonylureas resulted in an additional weight gain of 0.4 kg to 1.9 kg versus -0.8 kg to 2.1 kg in the IM group (220 participants; 7 trials; low-quality evidence). Pioglitazone CT caused more weight gain compared to IM: MD 3.8 kg (95% CI 3.0 to 4.6); P < 0.01; 288 participants; 2 trials; low-quality evidence. Metformin CT was associated with weight loss: MD -2.1 kg (95% CI -3.2 to -1.1), P < 0.01; 615 participants; 7 trials; low-quality evidence). DPP-4 inhibitors CT showed weight gain of -0.7 to 1.3 kg versus 0.6 to 1.1 kg in the IM group (362 participants; 2 trials; low-quality evidence). Alpha-glucosidase CT compared to IM showed a MD of -0.5 kg (95% CI -1.2 to 0.3); P = 0.26; 241 participants; 2 trials; low-quality evidence.Users of metformin CT (range 7% to 67% versus 5% to 16%), and alpha-glucosidase inhibitors CT (14% to 75% versus 4% to 35%) experienced more gastro-intestinal adverse effects compared to participants on IM. Two trials reported a higher frequency of oedema with the use of pioglitazone CT (range: 16% to 18% versus 4% to 7% IM).

AUTHORS' CONCLUSIONS

The addition of all oral glucose-lowering agents in people with type 2 diabetes and inadequate glycaemic control who are on insulin therapy has positive effects on glycaemic control and insulin requirements. The addition of sulphonylureas results in more hypoglycaemic events. Additional weight gain can only be avoided by adding metformin to insulin. Other well-known adverse effects of oral glucose-lowering agents have to be taken into account when prescribing oral glucose-lowering agents in addition to insulin therapy.

Therapeutic angiogenesis improves fibrinolytic imbalance in patients with critical limb ischemia

The mechanisms of fibrinolysis have been suggested to be linked to the pathogenesis of peripheral artery disease. The impact of therapeutic angiogenesis on the parameters of fibrinolysis was studied in critical limb ischemia (CLI). CLI patients (N = 29) and blood donors as controls (N = 29) were enrolled. Bone marrow (600 ± 50 ml) was centrifuged (3200g, 20 min, 22°C), bone marrow-derived mononuclear cells (100-120 ml) were separated by Optipress I and implanted into the ischemic limb using intramuscular injections. ELISA was employed for the assessment of plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) levels. Patients were followed-up prior to the procedure and after 1, 3 and 6 months. All stage-IV patients (N = 22) had ischemic lesions. The lesions resolved in 10 patients. Five patients underwent major amputation; they all were stage-IV. Ischemic lesions persisted in seven patients beyond 6 months. The t-PA levels were higher in patients compared with the healthy controls both at baseline (P < 0.01) and after 6 months (P < 0.05). No significant changes were observed in the t-PA levels during the follow-up. PAI-1 was higher in patients than in the healthy individuals at baseline (P < 0.001) and at month 1 (P < 0.05). However, no difference in PAI-1 levels between the patients and the healthy individuals was found after 3 and 6 months. The PAI-1 levels were significantly downregulated during the follow-up compared with the baseline (P < 0.0001). Therapeutic angiogenesis for the CLI downregulates PAI-1 levels, thus having a systemic effect on fibrinolysis.

Relationships of plasma lipoprotein(a) levels with insulin resistance in hypertensive patients

BACKGROUND

Lipoprotein(a) [Lp(a)] is an emergent cardiovascular risk factor that is related to the presence and severity of cardiovascular damage in hypertensive patients. In these patients, insulin resistance is frequently detected but its relationship with plasma Lp(a) is not clear. The aim of this study was to examine the relationships between Lp(a) and variables of glucose metabolism in hypertension.

METHODS

In 527 consecutive, non-diabetic, middle-aged hypertensive patients we measured anthropometric indexes, 24-hour creatinine clearance, lipid profile including Lp(a) levels, fasting glucose, insulin and C-peptide, and calculated the Homeostatic Model Assessment (HOMA) index.

RESULTS

Lp(a) levels were significantly and progressively lower with increasing HOMA-index values. Lp(a) was inversely related to fasting glucose, insulin, and C-peptide, HOMA-index, and creatinine clearance and directly related to LDL-cholesterol. Multiple regression analysis adjusted for age, sex, body mass index, blood pressure, smoking habit, alcohol intake, renal function, lipid profile, history of cardiovascular events, and drug use showed that HOMA-index and creatinine clearance were inversely and independently associated to Lp(a) levels.

CONCLUSIONS

Insulin resistance and higher fasting insulin levels are associated with lower plasma Lp(a) in hypertensive patients. This association might be relevant in the assessment of cardiovascular risk in these patients.

Double-blind, randomized, multicentre, and active comparator controlled investigation of the effect of pioglitazone, metformin, and the combination of both on cardiovascular risk in patients with type 2 diabetes receiving stable basal insulin therapy: the PIOCOMB study

BACKGROUND

We analyzed specific effects of an add-on therapy with pioglitazone compared to metformin and their combination in patients with basal insulin treatment on biomarkers of CV risk.

METHODS

In this double-blind, randomized, multicentre, active comparator controlled trial, 121 patients with type 2 diabetes were enrolled. Inclusions: treatment with basal insulin, HbA(1C) 6.5%-8.5%, age 30-75 years. After glargine therapy over 2 weeks for titration towards FBG ≤ 7.8 mmol/L, patients received either (A) bid 850 mg metformin (n = 42), (B) bid 15 mg pioglitazone (n = 40), or (C) 30 mg pioglitazone plus 1.7 g metformin (n = 39) over 6 months. Matrix Metal Proteinase 9 (MMP-9) was primary objective, together with biomarkers of CV risk.

RESULTS

Pioglitazone (B) reduced MMP-9 versus baseline by 54.1 ± 187.1 ng/mL, with metformin (A) it was increased by 49.6 ± 336.2 ng/mL (p = 0.0345; B vs. A), and with the combination of both (C) it was decreased by 67.8 ± 231.4 ng/mL (A vs. C: p = 0.0416; B vs. C: p = 0.8695). After logarithmic transformation due to high variances the exploratory results showed significance for A vs. B (p = 0.0043) and for A vs. C (p = 0.0289).Insulin dosage was reduced by 7.3 units in group B (p < 0.0001), by 6.0 units in C (p = 0.0004), but was increased by 2.5 units (p = 0.1539) in A at follow up. Reduction in hs-CRP was significant within treatment groups for B (p = 0.0098) and C (p < 0.0001), and between the groups for A vs. C (p = 0.0124). All three single regimens reduced PAI-1. Adiponectin was significantly elevated in B and C (p < 0.0001) and between-groups. HbA(1C) was only significantly decreased in the combination group. No significant effects were observed for NFkB and PGFα. peripheral edema were seen in 11.9% vs. 40.0% vs. 20.5%, and weight change was -0.7 kg vs. +4.3 kg vs. +2.7 kg (A vs. B vs. C).

CONCLUSIONS

Addition of pioglitazone but not of metformin reduces MMP-9, hs-CRP and increased insulin sensitivity and adiponectin in this study. The combination of both had no additional effect on inflammation. Pioglitazone is suggested to be a rational add-on therapy to basal insulin in patients with high CV risk.

Chronic insulin therapy reduces adipose tissue macrophage content in LDL-receptor-deficient mice

AIMS/HYPOTHESIS

Insulin has anti-inflammatory effects in short-term experiments. However, the effects of chronic insulin administration on inflammation are unknown. We hypothesised that chronic insulin administration would beneficially alter adipose tissue inflammation and several circulating inflammatory markers.

METHODS

We administered two forms of long-acting insulin, insulin glargine (A21Gly,B31Arg,B32Arg human insulin) and insulin detemir (B29Lys[ε-tetradecanoyl],desB30 human insulin), to LDL-receptor-deficient mice. After 8 weeks on a diet that causes obesity, hyperglycaemia, adipose tissue macrophage accumulation and atherosclerosis, the mice received subcutaneous glargine, detemir or NaCl (control) for 12 weeks. Serum amyloid A (SAA) and serum amyloid P (SAP), metabolic variables, adipose tissue macrophages and aortic atherosclerosis were evaluated.

RESULTS

Weight gain was equivalent in all groups. The glycated haemoglobin level fell equivalently in both insulin-treated groups. Plasma cholesterol and triacylglycerol levels, and hepatic triacylglycerol level significantly improved in the glargine compared with the detemir or control groups. Levels of mRNA expression for monocyte chemotactic protein-1 and F4/80, a macrophage marker, in adipose tissue were decreased only in the glargine group (p < 0.05). Visceral adipose tissue macrophage content decreased in both insulin groups (p < 0.05), whereas atherosclerosis decreased only in the glargine group. Circulating SAA and SAP did not decrease in either insulin-treated group, but IL-6 levels fell in the glargine-treated mice.

CONCLUSIONS/INTERPRETATION

While chronic insulin administration did not decrease SAA and SAP, administration of glargine but not detemir insulin improved dyslipidaemia, IL-6 levels and atherosclerosis, and both insulins reduced macrophage accumulation in visceral adipose tissue. Thus, chronic insulin therapy has beneficial tissue effects independent of circulating inflammatory markers in this murine model of diet-induced obesity and diabetes.

Therapeutic approaches to target inflammation in type 2 diabetes

BACKGROUND

Chronic inflammation may participate in the pathogenesis of insulin resistance, type 2 diabetes, and cardiovascular disease and may be a common denominator that links obesity to these disease states.

CONTENT

Epidemiologic studies have linked inflammatory biomarkers to incident diabetes and cardiovascular disease risk. Cellular and animal studies have provided support to the idea that inflammation mediates these disease processes, providing impetus to pharmacologically target these pathways for disease treatment and prevention. We review clinical strategies to target inflammation, with a focus on the antiinflammatory and antihyperglycemic effects of salicylates.

SUMMARY

The evolving concept of diet-induced obesity driving insulin resistance, type 2 diabetes, and cardiovascular disease through immunologic processes provides new opportunities for the use of antiinflammatory strategies to correct the metabolic consequences of excess adiposity.

Diabetes and obesity: therapeutic targeting and risk reduction - a complex interplay

Obesity is a major risk factor for the development of diabetes and predisposes individuals to hypertension and dyslipidaemia. Together these pathologies increase the risk for cardiovascular disease (CVD), the major cause of morbidity and mortality in type 2 diabetes mellitus (T2DM). Worsening trends in obesity and T2DM raise a serious conundrum, namely, how to control blood glucose, blood pressure, and lipids when many antidiabetic agents cause weight gain and thereby exacerbate other cardiovascular risk factors associated with T2DM. Further, evidence suggests that some established antihypertensive agents may worsen glucose intolerance. Many patients who are obese, hypertensive, and/or hyperlipidaemic fail to achieve blood pressure, lipid and glycaemic goals, and this failure may in part be explained by physician reluctance to utilize complex combination regimens for fear of off-target effects. Thus, a clear need exists for clinicians to understand the risks and benefits of different pharmacologic, and indeed non-pharmacologic, options in order to maximize treatment outcomes. While intensive lifestyle modification remains an elusive gold standard, newer diabetes targets, including the incretin axis, may offer greater cardiovascular risk reduction than other antidiabetes therapies, although definitive clinical trial data are needed. The glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide and the dipeptidyl peptidase-4 (DPP-4) inhibitors sitagliptin and vildagliptin effectively lower HbA1c; exenatide and liraglutide reduce weight and blood pressure and improve lipid profiles. Sitagliptin and vildagliptin are weight neutral but also appear to improve lipid profiles. Integration of incretin therapies into the therapeutic armamentarium is a promising approach to improving outcomes in T2DM, and perhaps even in reducing complications of T2DM, such as co-morbid hypertension and dyslipidaemia. Additional long-term studies, including CVD end-point studies, will be necessary to determine the appropriate places for incretin-based therapies in treatment algorithms.

Cytokine and cytokine-like inflammation markers, endothelial dysfunction, and imbalanced coagulation in development of diabetes and its complications

CONTEXT

Recent developments indicate that pathophysiological mechanisms leading to beta-cell damage, insulin resistance, and the vascular complications of diabetes include an activation of the inflammation cascade, endothelial dysfunction, and procoagulant imbalance. Their circulating biomarkers may therefore provide opportunities for early diagnosis and targets for novel treatments.

EVIDENCE

Circulating biomarkers of these pathways such as TNFalpha, IL-6, C-reactive protein (CRP) (inflammation), vascular cellular adhesion molecule-1, interstitial cellular adhesion molecule-1, E-selectin, von Willebrand factor (endothelial dysfunction), plasminogen activator inhibitor-1, fibrinogen, P-selectin (procoagulant state), and adiponectin (antiinflammation) may be associated with development of both type 1 and type 2 diabetes and some studies, particularly in type 2 diabetes, have demonstrated that certain biomarkers may have independent predictive value. Similarly studies have shown that these biomarkers may be associated with development of diabetic nephropathy and retinopathy, and again, particularly in type 2 diabetes, with cardiovascular events as well. Finally, the comorbidities of diabetes, namely obesity, insulin resistance, hyperglycemia, hypertension and dyslipidemia collectively aggravate these processes while antihyperglycemic interventions tend to ameliorate them.

CONCLUSIONS

Increased CRP, IL-6, and TNFalpha, and especially interstitial cellular adhesion molecule-1, vascular cellular adhesion molecule-1, and E-selectin are associated with nephropathy, retinopathy, and cardiovascular disease in both type 1 and type 2 diabetes. Whereas further work is needed, it seems clear that these biomarkers are predictors of increasing morbidity in prediabetic and diabetic subjects and should be the focus of work testing their clinical utility to identify high-risk individuals as well as perhaps to target interventions.

Pleiotropic effects of thiazolidinediones on traditional and non-traditional atherosclerotic risk factors

BACKGROUND

The thiazolidinediones pioglitazone and rosiglitazone have established efficacy in improving insulin sensitivity, glycaemic control, dyslipidaemia, hypertension and microalbuminuria in patients with type 2 diabetes. As specific agonists of peroxisome proliferator-activated receptor-gamma, thiazolidinediones have also demonstrated protective effects on a variety of atherosclerosis biomarkers and surrogate measures of cardiovascular disease.

AIM

This paper reviews the evidence for pleiotropic effects on a variety of non-traditional atherosclerotic risk factors.

DISCUSSION

Thiazolidinediones attenuate circulating levels of pro-inflammatory mediators in patients with type 2 diabetes, including C-reactive protein, interleukin-6, CD40L, monocyte chemoattractant protein-1 and metalloproteinase-9. These agents also increase levels of the vascular protective adipokine, adiponectin. The clinical significance of these findings is supported by evidence of improved endothelial dysfunction, reduced carotid intima media thickness and improvements in stenosis following coronary artery stent implantation in patients treated with thiazolidinediones. Limited data suggest that thiazolidinediones might also improve the circulating levels and functional activity of angiogenic endothelial progenitor cells, which independently predict the incidence of cardiovascular events and death. It should be noted that the US Food and Drug Administration and the European Medicines Agency have requested changes to the prescribing information for rosiglitazone to highlight the possibility of an increased risk with this agent in patients with ischaemic heart disease; on review, no such amendment was required for the pioglitazone prescribing information. Both agencies continue to suggest that the benefits of both thiazolidinediones outweight any possible detrimental effects. Further research remains to be conducted to elucidate the potentially differential vascular protective effects of thiazolidinediones. In the US, there are black box heart failure warnings for both agents.

CONCLUSION

In light of the established importance of reducing cardiovascular risk in patients with type 2 diabetes, current evidence continues to support the use of pioglitazone within multifactorial risk management strategies.

Pioglitazone and cardiovascular risk. A comprehensive meta-analysis of randomized clinical trials

AIM

The aim of this meta-analysis of randomized clinical trials (RCT) was to assess whether pioglitazone is also associated with increased cardiovascular risk, as recently reported for rosiglitazone.

METHODS

RCT of pioglitazone were retrieved from Medline (any date up to 31 August 2007; English language only). Unpublished RCT were identified through http://www.clinicaltrials.gov or http://www.fda.gov websites, and results on cardiovascular outcomes were retrieved from investigators and/or sponsors, whenever possible. RCT were included in meta-analysis if pioglitazone was compared with other treatments (placebo, active comparators or no treatment) for at least 4 weeks. Ninety-four trials, 10 of which were unpublished, were retrieved; those included in the analysis, which excluded PROspective PioglitAzone Clinical Trial In MacroVascular Events (PROACTIVE), enrolled 11 268 and 9912 patients in the pioglitazone and comparator groups respectively. Data for analysis, extracted independently by two observers, included all-cause and cardiovascular mortality and incidence of non-fatal coronary events and heart failure. Proportions of outcome measures across treatment groups were compared by odds ratios (ORs) and 95% confidence interval.

RESULTS

Pioglitazone was associated with reduced all-cause mortality [OR 0.30 (0.14-0.63); p < 0.05], with no relevant effect on non-fatal coronary events. The observed increase in incidence of non-fatal heart failure was not statistically significant [OR 1.38 (0.90-2.12)].

CONCLUSION

The use of pioglitazone does not appear to be harmful in terms of cardiovascular events and all-cause deaths.

The effect of metformin treatment on VEGF and PAI-1 levels in obese type 2 diabetic patients

The aim of the study was to evaluate the effect of metformin on markers of endothelial function, vascular inflammation and factors of thrombosis in obese type 2 diabetic patients. Twenty-four type 2 diabetic patients (15 female, 9 male) previously under medical nutrition treatment (MNT)+regular exercise programme (REP) without chronic micro or macrovascular complications with the mean age of 50.5+/-1.5 years, diabetes duration of 17.9+/-6.3 months and body mass index (BMI) of 31.7+/-0.8 kg/m(2) were enrolled in the study. In the first 4 weeks, all the patients continued MNT+REP. In the following 12 weeks, metformin (mean daily dosage of 1381+/-85 mg) was added. After the first period with MNT+REP, BMI, waist circumference, fat percentage, blood pressure and HDL cholesterol decreased significantly. After metformin addition, there was a significant decrement in BMI, waist circumference, fat percentage, fasting and postprandial plasma glucose, hemoglobin A1C, plasminogen activator inhibitor-1 (PAI-1), vascular endothelial growth factor (VEGF) and increment in beta cell reserve values of the patients. Our results indicated that, metformin addition had beneficial effect on VEGF and PAI-1 levels in obese type 2 diabetic patients under MNT+REP, independent from its' favourable effects on BMI and glycemic control.

The effects of insulin on the endothelium

Recent data suggest that diabetes in general, and particularly diabetes in association with insulin resistance, obesity, and hyperglycemia, results in inflammatory changes including the production of cytokines, adhesion molecules, and reactive oxygen species that are toxic to the endothelium and could lead to vascular damage. Insulin suppresses these effects, either indirectly by decreasing glucose levels or directly by stimulating nitric oxide production and inhibiting important pathways in the inflammatory cascade. In addition, insulin directly reduces plasma concentrations of adhesion molecule production in endothelial cells and thus may decrease vascular inflammation. Some of these effects of insulin may be attenuated in patients with insulin resistance, and this finding may provide a mechanistic link for the increase in vascular disease seen in patients with insulin resistance. Doses of insulin adequate to restore normoglycemia may help overcome these abnormalities, although some patients may require insulin sensitization with lifestyle changes or pharmacologic therapy.

Long-term effects of pioglitazone versus gliclazide on hepatic and humoral coagulation factors in patients with type 2 diabetes

This study compared the long-term effects of pioglitazone and gliclazide on the production of coagulation factors in patients with type 2 diabetes. Patients (n=283) with glycosylated haemoglobin > 7.5% were randomised to receive either pioglitazone (30-45 mg/day) or gliclazide (80-320 mg/day) for one year. Coagulation factors were measured at baseline and at six and 12 months. While both pioglitazone and gliclazide induced a comparable improvement in glycaemic control, only pioglitazone improved insulin sensitivity. Pioglitazone significantly (p < or = 0.001) decreased circulating levels of von Willebrand factor (-9.7%, -9.4%) and plasminogen activator inhibitor-1 (-16.8 ng/ml, -12.3 ng/ml), and increased levels of antithrombin-III (+1.3 mg/dL, +1.5 mg/dL) after six and 12 months, respectively. The beneficial effects of pioglitazone on glycaemic control, lipid homeostasis, and coagulation and thrombosis, may improve vascular outcomes in patients with type 2 diabetes.

Effects of periodontal therapy on serum C-reactive protein, sE-selectin, and tumor necrosis factor-? secretion by peripheral blood-derived macrophages in diabetes. A pilot study

BACKGROUND AND OBJECTIVE

Diabetes is associated with an increased risk for vascular disease and periodontitis. The aim of this study was to assess the effects of periodontal treatment in diabetes with respect to alterations in the pro-inflammatory potential of peripheral blood mononuclear cells.

MATERIAL AND METHODS

Ten patients with diabetes and moderate to severe periodontitis received full-mouth subgingival debridement. Blood samples for serum/plasma and mononuclear cell isolation were collected prior to and 4 wk after therapy. Mononuclear cells were analyzed by flow cytometry and stimulated with lipopolysaccharide or ionomycin/phorbol ester to determine the pro-inflammatory capacity of macrophages and lymphocytes, respectively.

RESULTS

Following periodontal treatment, all patients demonstrated a significant improvement in clinical periodontal status (p < 0.05), despite only modest reduction in subgingival bacterial load or homologous serum immunoglobulin G titers. CD14(+) blood monocytes decreased by 47% (p < 0.05), and the percentage of macrophages spontaneously releasing tumor necrosis factor-alpha decreased by 78% (p < 0.05). There were no significant changes in the capacity of lymphocytes to secrete interferon-gamma. Among a number of serum inflammatory markers tested, high-sensitivity-C-reactive protein significantly decreased by 37% (p < 0.01) and soluble E-selectin decreased by 16.6% (p < 0.05).

CONCLUSION

These data suggest a reduced tendency for monocyte/macrophage-driven inflammation with periodontal therapy and a potential impact on atherosclerosis-related complications in diabetic individuals.

Pioglitazone has anti-inflammatory effects in patients with Type 2 diabetes

BACKGROUND

Type 2 diabetes is characterized by increased acute phase serum proteins. They are also risk factors for cardiovascular disease. We wanted to study how improvement of glycemic control with pioglitazone or glibenclamide affects their serum concentrations.

MATERIALS AND METHODS

A total of 59 patients with Type 2 diabetes (age 57.3+/-1.2 yr, glycosylated hemoglobin (HbA1c) 8.3+/-0.7%, body mass index (BMI) 31.4+/-0.8 kg/m2) participated in the study. They were previously treated either with diet alone or in combination with one oral antihyperglycemic medicine. After a 1-week lead-in period on diet only, the patients were randomized to pioglitazone or glibenclamide. Blood samples for alpha-1-acid glycoprotein (A1GP), Creactive protein (CR P) and serum amyloid A (SAA) were taken before the treatments and during the therapy after 20 and 52 weeks.

RESULTS

Baseline A1GP correlated with CR P (r=0.70, p<0.001) and fasting glucose (r=0.32, p<0.02). Baseline CR P correlated with HbA1c (r=0.26, p<0.05) and insulin (r=0.37, p<0.01). The anti-hyperglycemic effect was comparable with HbA1c levels decreasing both in the pioglitazone (from 8.18+/-0.09% to 7.63+/-0.17%, p<0.01) and glibenclamide (from 8.35+/-0.12% to 7.77+/-0.16%, p<0.01) groups. Pioglitazone treatment was associated with a reduction in A1GP at 20 weeks (p<0.001) and at 52 weeks (p<0.05) as compared to baseline. The significance remained also after comparison to glibenclamide therapy (p<0.001 and p<0.05, 20 and 52 weeks respectively). CR P was also more reduced in the pioglitazone group at 20 weeks of treatment (p<0.05).

CONCLUSIONS

Inflammatory factors and markers of hyperglycemia are associated in patients with Type 2 diabetes. Pioglitazone treatment results in reduced A1GP concentration suggesting an anti-inflammatory effect.

Value of serum glycated albumin and high-sensitivity C-reactive protein levels in the prediction of presence of coronary artery disease in patients with type 2 diabetes

Background

Coronary artery disease (CAD) is a major vascular complication of diabetes mellitus and reveals high mortality. Up to 30% of diabetic patients with myocardial ischemia remain asymptomatic and are associated with worse prognosis compared to non-diabetic counterpart, which warrants routine screening for CAD in diabetic population. The purpose of this study was to evaluate the clinical value of serum glycated albumin and high-sensitivity C-reactive protein (hs-CRP) levels in predicting the presence of CAD in patients with type 2 diabetes.

Methods

Three hundred and twenty-four patients with type 2 diabetes were divided into two groups based on presence (CAD group, n = 241) or absence (control group, n = 83) of angiographically-documented CAD (lumen diameter narrowing ≥70%). Serum levels of glycated albumin and hs-CRP as well as serum concentrations of glucose, lipids, creatinine, blood urea nitrogen and uric acid were measured in both groups. Predictors of CAD were determined using multivariate logistic regression model and receiver-operating characteristic (ROC) curves.

Results

Serum glycated albumin and hs-CRP levels were significantly increased in diabetic patients with CAD. Multivariate regression analysis revealed that male gender, age, serum levels of glycated albumin, hs-CRP, creatinine and lipoprotein (a) were independent predictors for CAD. Areas under the curve of glycated albumin and hs-CRP and for regression model were 0.654 (95%CI 0.579–0.730, P < 0.001), 0.721 (95%CI 0.658–0.785, P < 0.001) and 0.824 (95% CI 0.768–0.879, P < 0.001), respectively. The optimal values of cut-off point were 18.7% (sensitivity 67.9%, specificity 60.0%) for glycated albumin and 5.2 mg/l (sensitivity 72.2%, specificity 60.0%) for hs-CRP to predict CAD. Logistic regression model was defined as: P/(1-P) = EXP(-1.5 + 1.265 gender + 0.812 age + 1.24 glycated albumin + 0.953 hs-CRP + 0.902 lipoprotein(a) + 1.918 creatinine). The optimal probability value for predicting CAD in type 2 diabetic patients was 0.648 (sensitivity 82.3%, specificity 68.6%).

Conclusion

Serum glycated albumin and hs-CRP levels were significantly elevated in patients with type 2 diabetes and CAD. The logistic regression model incorporating with glycated albumin, hs-CRP and other major risk factors of atherosclerosis may be useful for screening CAD in patients with type 2 diabetes.