Effect of cilostazol, a phosphodiesterase inhibitor, on carotid IMT in Japanese type 2 diabetic patients

Carotid Intima-Media Thickness Progression as Surrogate Marker for Cardiovascular Risk: Meta-Analysis of 119 Clinical Trials Involving 100 667 Patients

BACKGROUND

To quantify the association between effects of interventions on carotid intima-media thickness (cIMT) progression and their effects on cardiovascular disease (CVD) risk.

METHODS

We systematically collated data from randomized, controlled trials. cIMT was assessed as the mean value at the common-carotid-artery; if unavailable, the maximum value at the common-carotid-artery or other cIMT measures were used. The primary outcome was a combined CVD end point defined as myocardial infarction, stroke, revascularization procedures, or fatal CVD. We estimated intervention effects on cIMT progression and incident CVD for each trial, before relating the 2 using a Bayesian meta-regression approach.

RESULTS

We analyzed data of 119 randomized, controlled trials involving 100 667 patients (mean age 62 years, 42% female). Over an average follow-up of 3.7 years, 12 038 patients developed the combined CVD end point. Across all interventions, each 10 μm/y reduction of cIMT progression resulted in a relative risk for CVD of 0.91 (95% Credible Interval, 0.87-0.94), with an additional relative risk for CVD of 0.92 (0.87-0.97) being achieved independent of cIMT progression. Taken together, we estimated that interventions reducing cIMT progression by 10, 20, 30, or 40 μm/y would yield relative risks of 0.84 (0.75-0.93), 0.76 (0.67-0.85), 0.69 (0.59-0.79), or 0.63 (0.52-0.74), respectively. Results were similar when grouping trials by type of intervention, time of conduct, time to ultrasound follow-up, availability of individual-participant data, primary versus secondary prevention trials, type of cIMT measurement, and proportion of female patients.

CONCLUSIONS

The extent of intervention effects on cIMT progression predicted the degree of CVD risk reduction. This provides a missing link supporting the usefulness of cIMT progression as a surrogate marker for CVD risk in clinical trials.

Comparative effects of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on carotid artery intima-media thickness progression: a network meta-analysis

Background

Carotid artery intima-media thickness (cIMT) progression is a surrogate marker of atherosclerosis with a high predictive value for future CVD risk. This study evaluates the comparative efficacies of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on cIMT progression.

Methods

We conducted a network meta-analysis (NMA) to evaluate the relative efficacies of several drug classes in modifying cIMT progression. After a literature search in several electronic databases, studies were selected by following predetermined eligibility criteria. An inverse variance-heterogeneity model was used for NMA. Sensitivity analyses were performed to check the reliability of the overall NMA, and transitivity analyses were performed to examine the effects of modifiers on the NMA outcomes.

Results

Data were taken from 47 studies (15,721 patients; age: 60.2 years [95% confidence interval (CI) 58.8, 61.6]; BMI: 27.2 kg/m² [95% CI 26.4, 28.0]; and gender: 58.3% males [95% CI 48.3, 68.3]). Treatment duration was 25.8 months [95% CI 22.9, 28.7]. Of the 13 drug classes in the network, treatment with phosphodiesterase III inhibitors was the most effective in retarding annual mean cIMT against network placebo (weighted mean difference (WMD) − 0.059 mm [95% CI − 0.099, − 0.020) followed by the calcium channel blockers (WMD − 0.055 mm [95% CI − 0.099, 0.001]) and platelet adenosine diphosphate inhibitors (WMD − 0.033 mm [95% CI − 0.058, 0.008]). These 3 drug classes also attained the same positions when the NMA was conducted by using first-year changes in mean cIMT. In transitivity analyses, longer treatment duration, higher body mass index (BMI), and a higher baseline cIMT were found to be independently associated with a lesser reduction in annual mean cIMT. However, in a multivariate analysis with these 3 modifiers, none of these factors was significantly associated with annual change in mean cIMT. In the placebo group, age was inversely associated with annual change in mean cIMT independently.

Conclusion

Phosphodiesterase III inhibitors and calcium channel blockers are found more effective than other drug classes in retarding cIMT progression. Age, BMI, and baseline cIMT may have some impact on these outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0817-1) contains supplementary material, which is available to authorized users.

Design and Rationale of the Intima-Medial Thickness Sub-Study of the PreventIon of CArdiovascular Events in iSchemic Stroke Patients with High Risk of Cerebral hemOrrhage (PICASSO-IMT) Study

BACKGROUND

Atherosclerosis is one of the main mechanisms of stroke and cardiovascular diseases and is associated with increased risk of recurrent stroke and cardiovascular events. Intima-medial thickness (IMT) is a well-known surrogate marker of atherosclerosis and has been used to predict stroke and cardiovascular events. However, the clinical significance of IMT and IMT change in stroke has not been investigated in well-designed studies. The PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage-Intima-Media Thickness (PICASSO-IMT) sub-study is designed to investigate the effects of cilostazol, probucol, or both on IMT in patients with stroke.

METHODS

PICASSO-IMT is a prospective sub-study of the PICASSO study designed to measure IMT and plaque score at 1, 13, 25, 37, and 49 months after randomization.

RESULTS

The primary outcome is the change in mean carotid IMT, which is defined as the mean of the far-wall IMTs of the right and left common carotid arteries, between baseline and 13 months after randomization.

CONCLUSION

PICASSO-IMT will provide the largest IMT data set in a stroke population and will provide valuable information about the clinical significance of IMT in patients with ischemic stroke.

Efficacy of pioglitazone on glycemic control and carotid intima-media thickness in type 2 diabetes patients with inadequate insulin therapy

Aims/Introduction:  The present study was designed to determine the effects of pioglitazone on glycemic control and atherosclerosis in patients with poorly controlled type 2 diabetes on insulin therapy.

Materials and Methods:  The study was a prospective, randomized controlled trial involving 48 patients with inadequately controlled type 2 diabetes treated with insulin. We assigned patients to oral pioglitazone titrated from 15–30 mg (n = 22) or no pioglitazone (n = 26), to be taken in addition to their glucose‐lowering drugs and other medications. Daily insulin doses and numbers were recorded during the study period.

Results:  The adjusted mean glycosylated hemoglobin (HbA_1c) values decreased significantly by 1.13 ± 1.50% and 0.55 ± 0.76% in the pioglitazone and control groups, respectively. Significant decrease of HbA_1c level was observed in the pioglitazone group compared with the control group (P < 0.05). The insulin dose lowered by 0.04 ± 0.10 units/kg/day in the pioglitazone group and increased by 0.03 ± 0.10 units/kg/day in the control group (P < 0.05). The number of insulin injections decreased by 0.1 ± 0.6 times/day in the pioglitazone group and increased by 0.2 ± 0.4 times/day in the control group (P < 0.05). The carotid intima‐media thickness estimated by B‐mode echography was carried out in both groups and decreased significantly at the end‐point only in the pioglitazone group, relative to the baseline.

Conclusions:  These findings show that pioglitazone is useful in improving glycemic control and preventing the progression of atherosclerosis in poorly‐controlled type 2 diabetics on insulin therapy. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00064.x, 2010)

Clinical and molecular genetics of the phosphodiesterases (PDEs)

Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that have the unique function of terminating cyclic nucleotide signaling by catalyzing the hydrolysis of cAMP and GMP. They are critical regulators of the intracellular concentrations of cAMP and cGMP as well as of their signaling pathways and downstream biological effects. PDEs have been exploited pharmacologically for more than half a century, and some of the most successful drugs worldwide today affect PDE function. Recently, mutations in PDE genes have been identified as causative of certain human genetic diseases; even more recently, functional variants of PDE genes have been suggested to play a potential role in predisposition to tumors and/or cancer, especially in cAMP-sensitive tissues. Mouse models have been developed that point to wide developmental effects of PDEs from heart function to reproduction, to tumors, and beyond. This review brings together knowledge from a variety of disciplines (biochemistry and pharmacology, oncology, endocrinology, and reproductive sciences) with emphasis on recent research on PDEs, how PDEs affect cAMP and cGMP signaling in health and disease, and what pharmacological exploitations of PDEs may be useful in modulating cyclic nucleotide signaling in a way that prevents or treats certain human diseases.

Effect of cilostazol on arterial stiffness and vascular adhesion molecules in type 2 diabetic patients with metabolic syndrome: a randomised, double-blind, placebo-controlled, crossover trial

BACKGROUND

The phosphodiesterase inhibitor cilostazol has beneficial effects on atherosclerosis by virtue of vasodilatory and antiplatelet effects. However, less is known about the effect of cilostazol on arterial stiffness and biochemical markers related to vascular inflammation and endothelial dysfunction in type 2 diabetic patients with metabolic syndrome.

METHODS

In this randomized, double-blind, crossover trial, 45 diabetic patients with metabolic syndrome were randomly assigned to either the cilostazol group (50 mg for 2 weeks, 100 mg for 6 weeks) or placebo group for an 8-week treatment phase, and then crossed over. Brachial-ankle pulse wave velocity (baPWV) and serum levels of inflammatory cytokines and vascular cellular adhesion molecules were measured before and after each treatment phase.

RESULTS

Compared with the placebo group, the mean baPWV did not improve in the cilostazol group (mean difference 31.42 cm/sec, 95% CI -55.67 to 118.5). Cilostazol treatment significantly reduced soluble vascular cellular adhesion molecule-1 (sVCAM-1) level (from 1288.7 ± 285.6 to 1168.2 ± 252.3 ng/dL, P = 0.0003), and there was also significant mean difference between groups (mean difference 105.18 ng/dL, 95% CI 10.65 to 199.71). However, other biochemical markers including lipid profiles, high sensitivity C-reactive protein, adiponectin, interleukin-6, tumor necrosis factor-alpha, monocyte chemotactic protein-1, and soluble intercellular adhesion molecule-1 did not improve with cilostazol treatment.

CONCLUSION

Cilostazol treatment significantly reduced serum sVCAM-1 level, but this short term treatment was not associated with beneficial effect on arterial stiffness and other inflammatory markers.

TRIAL REGISTRATION

(Clinical trial reg. no. NCT00573950, clinicaltrials.gov.).

Effects of cilostazol against the progression of carotid IMT in symptomatic ischemic stroke patients

Carotid intima-media thickness (IMT) is a surrogate marker for evaluating atherosclerotic vascular diseases. The phosphodiesterase inhibitor cilostazol attenuates the increase in carotid IMT in diabetes patients. We studied whether cilostazol can reduce the progression of carotid IMT in symptomatic ischemic stroke patients. From our prospective registry of acute ischemic stroke patients who were admitted during a 4.5-year period, follow-up carotid ultrasound was performed in a random sample of survivors. Patients were divided into two groups: the cilostazol group, who continued cilostazol treatment during the follow-up period; and the control group, who were prescribed antiplatelets other than cilostazol. Analysis of covariance and propensity score-matched analysis were used to evaluate the difference between groups. Among a total of 1,049 cases in our registry, 208 patients were utilized to construct two comparable sets by propensity score analysis, including 101 who received cilostazol and 107 who took antiplatelet medication without cilostazol. Both maximum and mean carotid IMT values were significantly reduced in the cilostazol group but increased in the control group (maximum left –0.048 ± 0.186 vs. 0.022 ± 0.163 mm, p = 0.001; maximum right –0.037 ± 0.173 vs. 0.050 ± 0.200 mm, p = 0.001; mean left –0.052 ± 0.102 vs. 0.023 ± 0.112 mm, p < 0.001; and mean right –0.038 ± 0.106 vs. 0.042 ± 0.139 mm, p < 0.001). After matching by propensity score, the improvements in both maximum and mean carotid IMT values in the cilostazol group remained significant. This study shows that cilostazol causes a significant regression in carotid IMT in symptomatic stroke patients.

Cilostazol in Diabetic Neuropathy

Peripheral neuropathy remains a major chronic complication of diabetes mellitus. Its pathogenesis mainly involves chronic glucose toxicity and nerve ischemia. Preclinical studies have shown that cilostazol, a reversible selective inhibitor of phosphodiesterase-3A with antiplatelet, antithrombotic, and vasodilatory properties, exerts beneficial effects on nerve function in experimental diabetes. Clinical data, however, is sparse. Two recent randomized placebo-controlled clinical trials showed that cilostazol did not improve diabetic neuropathy in humans. Hence, more data is needed to confirm or refute the poor clinical efficacy of cilostazol. Importantly, future studies should include larger patient series, provide longer follow-up data, and employ more accurate diagnostic tools.

Effect of cilostazol on the progression of carotid intima-media thickness: a meta-analysis of randomized controlled trials

BACKGROUND

It has been well established that cilostazol has anti-proliferative effect against in-stent restenosis. However, it remains unclear whether cilostazol can prevent the progression of carotid atherosclerosis.

METHODS AND RESULTS

We performed a meta-analysis of all relevant randomized controlled trials (RCTs) to evaluate the effect of cilostazol on the progression of carotid intima-media thickness (IMT). Five RCTs with 698 patients [597 subjects with type 2 diabetes mellitus (T2DM)] were included in this study. Cilostazol was associated with a significant reduction in the progression of carotid IMT (WMD, -0.08mm, 95% CI -0.13, -0.04; P=0.00003). Subgroup analysis shows that cilostazol monotherapy or addition to dual antiplatelet therapy (aspirin and clopidogrel) was superior to placebo (WMD, -0.04mm, 95% CI -0.05, -0.03; P<0.00001), no antiplatelet medication (WMD, -0.12mm, 95% CI -0.21, -0.03; P=0.008), aspirin monotherapy (WMD, -0.06mm, 95% CI -0.12, 0.00; P=0.04) or dual antiplatelet therapy (WMD, -0.16mm, 95% CI -0.30, -0.02; P=0.03) in preventing the progression of carotid IMT. Cilostazol resulted in a significant decrease in total cholesterol (WMD -8.47mg/dl, 95% CI -14.18, -2.75; P=0.004) and LDL-C (WMD -8.25mg/dl, 95% CI -14.15, -2.36; P=0.006) and favorable trends in reducing triglyceride (WMD -15.83mg/dl, 95% CI -32.14, 0.48; P=0.06).

CONCLUSION

It suggests that cilostazol may have beneficial effects in preventing the progression of carotid atherosclerosis and improving pro-atherogenic lipid profile, especially in patients with T2DM. Whether the anti-atherosclerotic effect of cilostazol is independent of improving pro-atherogenic dyslipidemia is worth further investigation.

Mammalian Cyclic Nucleotide Phosphodiesterases: Molecular Mechanisms and Physiological Functions

The superfamily of cyclic nucleotide (cN) phosphodiesterases (PDEs) is comprised of 11 families of enzymes. PDEs break down cAMP and/or cGMP and are major determinants of cellular cN levels and, consequently, the actions of cN-signaling pathways. PDEs exhibit a range of catalytic efficiencies for breakdown of cAMP and/or cGMP and are regulated by myriad processes including phosphorylation, cN binding to allosteric GAF domains, changes in expression levels, interaction with regulatory or anchoring proteins, and reversible translocation among subcellular compartments. Selective PDE inhibitors are currently in clinical use for treatment of erectile dysfunction, pulmonary hypertension, intermittent claudication, and chronic pulmonary obstructive disease; many new inhibitors are being developed for treatment of these and other maladies. Recently reported x-ray crystallographic structures have defined features that provide for specificity for cAMP or cGMP in PDE catalytic sites or their GAF domains, as well as mechanisms involved in catalysis, oligomerization, autoinhibition, and interactions with inhibitors. In addition, major advances have been made in understanding the physiological impact and the biochemical basis for selective localization and/or recruitment of specific PDE isoenzymes to particular subcellular compartments. The many recent advances in understanding PDE structures, functions, and physiological actions are discussed in this review.

Cilostazol versus aspirin for secondary prevention of vascular events after stroke of arterial origin

BACKGROUND

Aspirin is widely used for secondary prevention after stroke. Cilostazol has shown promise as an alternative to aspirin in Asian people with stroke.

OBJECTIVES

To determine the relative effectiveness and safety of cilostazol compared directly with aspirin in the prevention of stroke and other serious vascular events in patients at high vascular risk for subsequent stroke, those with previous transient ischaemic attack (TIA) or ischaemic stroke of arterial origin.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched September 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 4), MEDLINE (1950 to May 2010) and EMBASE (1980 to May 2010). In an effort to identify further published, ongoing and unpublished studies we searched journals, conference proceedings and ongoing trial registers, scanned reference lists from relevant studies and contacted trialists and Otsuka Pharmaceutical Co Ltd.

SELECTION CRITERIA

We selected all randomised controlled trials (RCTs) comparing cilostazol with aspirin where participants were treated for at least one month and followed systematically for development of vascular events.

DATA COLLECTION AND ANALYSIS

Data extracted from eligible studies included: (1) a composite outcome of vascular events (stroke, myocardial infarction or vascular death) during follow up (primary outcome); (2) separate outcomes of stroke (ischaemic or haemorrhagic, fatal or non-fatal), myocardial infarction (MI) (fatal or non-fatal), vascular death and death from all causes; and (3) main outcomes of safety including any intracranial, extracranial or gastrointestinal (GI) haemorrhage and other outcomes during treatment follow up (secondary outcomes). We computed an estimate of treatment effect and performed a test for heterogeneity between trials. We analysed data on an intention-to-treat basis and assessed bias for all included studies.

MAIN RESULTS

We included two RCTs with 3477 Asian participants. Compared with aspirin, cilostazol was associated with a significantly lower risk of composite outcome of vascular events (6.77% versus 9.39%, risk ratio (RR) 0.72, 95% confidence interval (CI) 0.57 to 0.91), and lower risk of haemorrhagic stroke (0.53% versus 2.01%, RR 0.26, 95% CI 0.13 to 0.55). In terms of outcome of safety compared with aspirin, cilostazol was significantly associated with minor adverse effects (8.22% versus 4.95%, RR 1.66, 95% CI 1.51 to 1.83).

AUTHORS' CONCLUSIONS

Cilostazol is more effective than aspirin in the prevention of vascular events secondary to stroke. Cilostazol has more minor adverse effects, although there is evidence of fewer bleeds.

Cilostazol enhances macrophage reverse cholesterol transport in vitro and in vivo

OBJECTIVE

Recent failure of an HDL-cholesterol raising strategy using a cholesteryl ester transfer protein inhibitor highlights the importance of the anti-atherogenic function rather than plasma concentration of HDL. Cilostazol, a selective inhibitor of phosphodiesterase 3, has been widely used in patients with atherosclerotic diseases and is known to increase HDL-cholesterol. However, it remains unclear whether cilostazol enhances anti-atherogenic properties by promoting reverse cholesterol transport (RCT), a major anti-atherogenic function of HDL.

METHODS AND RESULTS

We observed that treatment of THP-1 macrophages, human monocyte-derived macrophages, and RAW264.7 cells with cilostazol increased ABCA1 and ABCG1 expression in a concentration-dependent manner, translating into enhanced apoA-I- and HDL-mediated cholesterol efflux from the macrophages. However, other cyclic AMP (cAMP)-elevating agents did not increase ABCA1 gene expression in THP-1 macrophages. Cilostazol did not change intracellular cAMP levels in THP-1 macrophages and RAW264.7 cells, and a protein kinase A (PKA) inhibitor did not affect cilostazol-induced ABCA1 and ABCG1 expression. To further investigate RCT in vivo, (3)H-cholesterol-labeled and acetyl LDL-loaded RAW264.7 cells were intraperitoneally injected into mice and the appearance of the (3)H-tracer was monitored in plasma, liver, and feces. Supporting the in vitro data, cilostazol was found to significantly increase (3)H-tracer levels in both plasma and feces.

CONCLUSIONS

These findings indicate that cilostazol might provide anti-atherosclerotic effects by promoting RCT through increased ABCA1/G1 expression in macrophages.

WITHDRAWN: Effect of cilostazol in alleviating cardiovascular complications through regulation of type 1 plasminogen activator inhibitor and transforming growth factor-β1 overexpression in experimental rats

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Tissue-specific expression of PPAR mRNAs in diabetic rats and divergent effects of cilostazol

Cilostazol and ligands of peroxisome proliferator-activated receptors (PPARs) have been effectively used to alleviate diabetic complications, but the common and tissue-specific expression patterns of PPARs in different tissues in diabetic patients and those treated with cilostazol have not been reported. Here, we aimed to assess the effects of diabetes and cilostazol on mRNA expression of PPARalpha and PPARgamma in the aorta, renal cortex, and retina of diabetic rats treated with cilostazol for 8 weeks. PPARalpha mRNA expression showed uniform downregulation in all these tissues in diabetic rats, and this effect was reversed by cilostazol treatment. Surprisingly, PPARgamma mRNA expression was reduced in the renal cortex and retina, yet increased in the aorta of diabetic rats, although cilostazol still reversed these changes. Interestingly, cilostazol, a well-known phosphodiesterase 3 inhibitor and cAMP elevator, augmented cAMP content only in the aorta, but showed no significant effects in the renal cortex of diabetic rats. In conclusion, mRNA expression of PPARs is tissue-specific in diabetes and may be differently affected by cilostazol, possibly because of its tissue-specific effects on cAMP content.

Potencial terapêutico para a prevenção e tratamento da nefropatia e neuropatia diabéticas: evidências do uso do cilostazol

O cilostazol é um inibidor seletivo da fosfodiesterase tipo III com ação vasodilatadora, antiagregante plaquetária e antitrombótica. É considerada a droga de primeira escolha na claudicação intermitente devido à doença arterial obstrutiva periférica. Vários estudos demonstraram melhora significativa na distância percorrida na caminhada sem dor e na qualidade de vida, sem aumentar o risco de sangramento. Essas ações também foram verificadas em pacientes diabéticos, pois o cilostazol não afeta o metabolismo da glicose. Estudos, principalmente experimentais, têm mostrado resultados satisfatórios na melhora do fluxo sangüíneo neural, na atividade da bomba de sódio e potássio, na resistência à insulina e na microalbuminúria. Neste artigo, apresentamos uma revisão do uso do cilostazol na prevenção e no tratamento das complicações do diabetes mellitus, como nefropatia e neuropatia. Ressalta-se a necessidade do controle adequado dos níveis glicêmicos, da hipertensão arterial sistêmica e do tabagismo. Um maior número de estudos clínicos é necessário para melhor compreensão desses efeitos benéficos.

Nateglinide reduces carotid intima-media thickening in type 2 diabetic patients under good glycemic control

OBJECTIVE

Postprandial hyperglycemia observed in type 2 diabetes mellitus is a risk factor for atherosclerosis. The aim of this study was to investigate the effect of strict glycemic control by nateglinide on common carotid far wall intima-media thickness in type 2 diabetic patients who were already under good glycemic control.

METHODS AND RESULTS

We performed an open labeled randomized prospective trial on 78 drug-naive type 2 diabetic patients whose HbA1c was less than 6.5%. Thirty-eight patients were randomly assigned to receive nateglinide (270 mg/dL) and 40 to control group (no treatment). After 12 months, a significant reduction in HbA1c was observed in the nateglinide group, whereas a significant increase of HbA1c was observed in the untreated group. The carotid intima-media thickness at the end of 1-year follow-up was significantly reduced in the nateglinide group compared with the untreated group (-0.017+/-0.054 mm/year versus 0.024+/-0.066 mm/year, P=0.0064). Whereas nateglinide treatment also reduced triglyceride, highly-sensitive C-reactive protein, and E-selectin, multiple regression analysis identified HbA1c as the only significant independent determinant of the change in carotid intima-media thickness.

CONCLUSION

In type 2 diabetic patients with good glycemic control, further strict glycemic control by nateglinide results in regression of carotid intima-media thickness.

Eicosapentaenoic acid reduces the progression of carotid intima-media thickness in patients with type 2 diabetes

To investigate the effect of highly purified eicosapentaenoic acid (EPA) on the progression of diabetic macroangiopathy, we performed an open-label randomized prospective trial. A total of 81 Japanese type 2 diabetes were randomly assigned to the EPA (1800 mg/day) treated group or the control group. Carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV) were evaluated before and after treatment in both groups. Sixty patients (EPA group, n=30; control group, n=30) completed this study. During the study period of 2.1+/-0.2 years, the mean IMT and max IMT of the EPA treated group showed a significant annual decrease compared with that of the control group (mean IMT, -0.029+/-0.112 mm versus 0.016+/-0.109 mm, respectively, P=0.029; max IMT, -0.084+/-0.113 mm versus -0.005+/-0.108 mm, respectively, P=0.0008). The baPWV was also improved significantly in the EPA treated group compared with the control group (-22.1+/-127.9 cm/s versus 62.3+/-223 cm/s, respectively, P=0.021). Multiple regression analysis showed that the administration of EPA was a significant and independent factor associated with an annual improvement of mean IMT (R2=0.067). In summary, this is the first demonstration that administration of purified EPA improves the carotid IMT and the baPWV in patients with type 2 diabetes.

Association of C-reactive protein with early-stage carotid atherosclerosis in Japanese patients with early-state type 2 diabetes mellitus

The aim of this study was to assess the association between high sensitivity-C-reactive protein (hs-CRP), a sensitive marker of inflammation, and early-stage carotid atherosclerosis, in patients with early-state type 2 diabetes mellitus. The study subjects were 75 patients with type 2 diabetes mellitus without obvious diabetic vascular complications, who were not on any medication, and whose HbA(1c) level was less than 6.5%. We evaluated the mean intima-media thickness (IMT) of the common carotid artery (CCA) by ultrasound B-mode imaging. Then, we investigated various factors associated with CCA-IMT including hs-CRP. Serum hs-CRP levels correlated well with factors strongly associated with insulin resistance such as homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin level, and body mass index. Serum hs-CRP also correlated with mean CCA-IMT and serum levels of soluble intercellular adhesion molecule-1. Multivariate regression analysis using mean CCA-IMT as the dependent variable identified only age, hs-CRP, and diastolic blood pressure as independent determinants of mean CCA-IMT. While hs-CRP associates with insulin resistance and subclinical atherosclerosis in ealy-state type 2 diabetes, our data suggest that hs-CRP is a useful marker of subclinical atherosclerosis in early-state type 2 diabetes mellitus independent of factors that directly reflect insulin resistance.

Cilostazol protects diabetic rats from vascular inflammation via nuclear factor-kappa B-dependent down-regulation of vascular cell adhesion molecule-1 expression

Vascular cell adhesion molecule (VCAM)-1 plays a critical role in the initiation and development of vascular inflammation and selective inhibition of adhesion molecules expressed by endothelial cells may present a new therapeutic strategy for the treatment of vascular complications associated with diabetes mellitus. Increasing evidence indicates that cilostazol, a cAMP phosphodiesterase inhibitor, reduces VCAM-1 expression on endothelial cells. In this study, we have tested the effect of cilostazol on the development of vascular inflammation in rats with streptozotocin-induced diabetes and determined the mechanism by which cilostazol prevents diabetes-induced vascular inflammation in the aorta. Diabetic rats were treated with different dose of cilostazol (27 or 9 mg/kg/day) for 8 weeks, and aortae were removed for the evaluation of vascular inflammation. The VCAM-1 protein expression and VCAM-1 mRNA transcripts were analyzed by immunohistochemical staining and in situ hybridization assay, respectively. Our results demonstrated that cilostazol treatment prevents the overexpression of VCAM-1 and protects diabetic rats from vascular inflammation. More importantly, our mechanistic studies suggested that cilostazol controls the VCAM-1 overexpression via inhibiting the activation of nuclear factor-kappaB.

Strict glycemic control ameliorates the increase of carotid IMT in patients with type 2 diabetes

The aim of this study was to investigate the effect of strict glycemic control on the carotid artery intima-media thickness (IMT) in type 2 diabetic patients who initially had good glycemic control (HbA1c between 5.8 and 6.4 %). The subjects were 67 patients showing deterioration of the mean HbA1c over 3 years by more than 0.2% from baseline (D group) and 33 subjects showing improvement of the mean HbA1c by more than 0.2% from baseline (A group). The clinical characteristics and annual change of IMT during the observation period were compared between the two groups in a 3-year retrospective longitudinal study. The baseline characteristics and the mean values of BMI, blood pressure, and serum lipids during the study period did not differ significantly between the two groups. However, the mean HbA1c of A group was significantly lower than that of D group (5.67 +/- 0.10 vs. 6.28 +/- 0.08, mean +/- SE, p<0.001). The adjusted annual increase rate of IMT was significantly less in A group than in D group (-0.035 +/- 0.019 vs. 0.036 +/- 0.015 mm, M +/- SEM, p<0.001). These results indicate that further improvement of glycemic control from a good HbA1c value can prevent an increase of IMT in type 2 diabetic patients.