Nikolaos Kazakos

Determinants of vascular function in patients with type 2 diabetes

BackgroundType 2 diabetes mellitus (T2DM) is independently associated with an increased risk for cardiovascular diseases that is primarily due to the early development of advanced atherosclerotic vascular changes. The aim of our study was to investigate the predictors of vascular dysfunction in T2DM patients.MethodsWe studied 165 T2DM patients without known macrovascular or microvascular disease. Standard demographic (age, gender, cardiovascular risk factors, medications), clinical (body mass index, blood pressure) and laboratory (glucose, glycated hemoglobin, lipids, renal function) parameters were included in analyses. Brachial artery flow-mediated dilation (FMD), nitrate mediated dilation (NMD) and Carotid-Femoral Pulse Wave Velocity (PWV) were measured.ResultsMedian age was 66 years and duration since T2DM diagnosis was 10 years, 70% were females and 79% hypertensives, while only 10% had a glycated hemoglobin <7%. FMD was positively associated with NMD (r 0.391, P < 0.001), while PWV was inversely associated with FMD (r -0.218, P = 0.014) and NMD (r -0.309, P < 0.001). Time since diagnosis of diabetes was the single independent predictor of FMD (β -0.40, P = 0.003). Increased age and fasting glucose and the presence of hypertension were independent predictors of decreased NMD (P < 0.001). Increased age and systolic blood pressure were independently associated with increased PWV (P < 0.001).ConclusionsIn T2DM patients, impairment of endothelium-dependent vasodilation was independently associated only with longer diabetes duration while no association with other established risk factors was found. Vascular smooth muscle dysfunction and increased arterial stiffness were more prominent in older T2DM patients with hypertension. Worse glycemic control was associated with impaired vascular smooth muscle function.

Pioglitazone vs glimepiride: Differential effects on vascular endothelial function in patients with type 2 diabetes

OBJECTIVE The aim of this study was to compare the effect of glimepiride and pioglitazone on endothelial function in patients with type 2 diabetes already on metformin. METHODS Twenty-eight patients with type 2 diabetes already on metformin, without known cardiovascular disease, were randomized in 2 groups; glimepiride (4 mg od) was added in group A (n=14) and pioglitazone (30 mg od) in group B (n=14) for 6 months. Flow-mediated dilation (FMD) in the brachial artery was assessed in all patients, at baseline and at follow-up. RESULTS The 2 groups did not differ in age (mean+/-S.D., 63.6+/-7.3 years vs 62.8+/-7.2 years respectively), or any measured variable at baseline. Fasting glucose and glycated haemoglobin improved similarly in both groups. There were significant differences between the 2 groups in the absolute changes observed at follow-up in waist circumference, +1.86+/-3.11 cm vs -1.86+/-1.88 cm in groups A and B respectively; fasting insulin levels, +14.79+/-12.56 pmol/L vs -25.84+/-28.09 pmol/L; homeostasis model assessment (HOMA), +0.66+/-1.01 vs -1.83+/-1.38; HDL cholesterol levels, -0.07+/-0.22 mmol/L vs +0.14+/-0.20 mmol/L and FMD, +0.14+/-1.09% vs +2.02+/-2.05% (p<0.05 for all). The only independent predictor factor of the FMD improvement was treatment-induced changes in HOMA (R(2): 0.488, slope: -0.782, [95% CI: -1.128, -0.436], p=0.0001). CONCLUSIONS In patients with type 2 diabetes already on metformin, addition of pioglitazone as compared to glimepiride, improved endothelial function despite similar glycemic control. The improvement in endothelial function was mainly due to a reduction in insulin resistance.

Effect of the insulin sensitizers metformin and pioglitazone on endothelial function in young women with polycystic ovary syndrome: a prospective randomized study

OBJECTIVE To compare the effect of two different insulin sensitizers, metformin and pioglitazone, on endothelial function in women with polycystic ovary syndrome (PCOS). DESIGN Prospective randomized study. SETTING University Hospital endocrinology outpatient clinic. PATIENT(S) Young women with PCOS (aged 23.3±4.9 years). INTERVENTION(S) Patients were assigned randomly to no treatment (n=14), metformin 850 mg two times per day (n=15), and pioglitazone 30 mg daily (n=14) for 6 months. Healthy age- and body mass index-matched women served as controls (n=14). MAIN OUTCOME MEASURE(S) Brachial artery flow-mediated dilation was studied at baseline and 6 months. RESULT(S) Women with PCOS had higher insulin resistance and hyperandrogenism indices and lower flow-mediated dilation compared with controls. The three groups of women with PCOS did not differ at baseline. No differences were observed at follow-up in women who received no treatment. Metformin and pioglitazone improved flow-mediated dilation to a similar extent, restoring it to normal values at 6 months. Both insulin sensitizers induced favorable changes in insulin resistance and hyperandrogenism indices in women with PCOS. Independent predictors of flow-mediated dilation improvement at 6 months were treatment with insulin sensitizers and reduction in insulin resistance. CONCLUSION(S) In young women with PCOS, treatment with metformin or pioglitazone for 6 months induces a similar beneficial effect on endothelial function; this may be partially attributed to an improvement in insulin resistance. Further research is needed to investigate whether treatment with insulin sensitizers in women with PCOS also reduces cardiovascular risk.

Sudden Death Due to an Unrecognized Cardiac Hydatid Cyst

Echinococcosis is an endemic disease, most common in sheep-raising communities, usually caused by the larval or cyst stage of the tapeworm Echinococcus granulosus. Isolated cardiac hydatid cyst is uncommon at any age, occurs through the coronary circulation, and accounts for less than 3% of all hydatid disease. We describe a case of an 1%-year-old female, who died suddenly. The post-mortem examination revealed an isolated cyst in the left ventricle of the heart with intact wall. The cytologic examination of the cyst fluid demonstrated the presence of the characteristic scolices and hooklets and established the diagnosis of cardiac hydatid cyst. The present case is of special interest because of the rare primary localization and the onset of sudden death in a young person as the initial manifestation of the disease.

Rosiglitazone improves endothelial function in patients with type 2 diabetes treated with insulin

An increased incidence of myocardial infarction with rosiglitazone in patients with type 2 diabetes mellitus (T2DM) has been reported. This study aimed to assess the effect of rosiglitazone on endothelial function, assessed by flow-mediated dilation (FMD), in 34 patients with advanced T2DM treated with insulin without known cardiovascular disease. Patients were randomised into two groups: no additional treatment was given in 17 patients, while 17 patients were given rosiglitazone for 6 months. Addition of rosiglitazone significantly reduced glycosylated haemoglobin (HbA1c) (p < 0.0005) and fasting glucose (p < 0.05) and improved FMD (p < 0.005). No significant changes were observed in the insulin-only group. The single independent predictor of FMD improvement was rosiglitazone treatment (p = 0.048). These results show that, in patients with advanced T2DM treated with insulin, addition of rosiglitazone may have a beneficial effect on endothelial function. Further research is needed to investigate why this beneficial effect does not translate into improved cardiovascular prognosis in these patients.

Effects of pioglitazone and metformin on vascular endothelial function in patients with type 2 diabetes treated with sulfonylureas

Pioglitazone and metformin are insulin sensitisers used for the treatment of T2DM. The effects of pioglitazone and metformin on endothelial function, assessed by FMD, in T2DM patients treated with sulfonylureas were compared. Patients were randomised to receive pioglitazone (n = 15) 30 mg once daily or metformin (n = 16) 850 mg twice daily for six months. Pioglitazone significantly decreased fasting insulin, HbA1C and HOMA-IR (p < 0.05 for all) and increased FMD (p = 0.002). Metformin induced a significant decrease in HbA1C (p = 0.02) and only a trend for increase in FMD (p = 0.08). The greater improvement in FMD with pioglitazone, compared with metformin, did not reach significance (p = 0.11). Treatment-induced changes in FMD were not associated with the effects of the two insulin sensitisers on glycaemic control or insulin resistance. The beneficial effects of pioglitazone and metformin on endothelial function in T2DM patients did not differ greatly. Larger studies are needed to explore whether a potentially greater benefit with pioglitazone may exist.

Effect of ethinylestradiol/cyproterone acetate on endothelial function in young non-obese women with polycystic ovary syndrome: a pilot study

Background. Combined oral contraceptives are used in polycystic ovary syndrome (PCOS) women for the treatment of hyperandrogenism and menstrual cycle disturbances. Aim. To assess the effect of ethinylestradiol and cyproterone acetate (EE/CA) on endothelial function in young, non-obese PCOS women in a pilot study. Methods. Thirteen young, non-obese PCOS women (20.9 ± 3.7 years, 23.0 ± 4.0 kg/m2) received 35 mcg EE & 2 mg CA for 6 months. Fourteen age- and body mass index (BMI)-matched healthy women served as controls. Endothelial function assessed by brachial artery flow-mediated dilation (FMD), indices of hyperandrogenism, and insulin resistance were studied at baseline and 6-month follow-up. Results. FMD was impaired in PCOS compared to control women (4.67 ± 2.38% vs. 10.12 ± 3.19%, p < 0.001), but increased significantly following EE/CA (9.99 ± 2.11%, p < 0.001 vs. baseline), reaching normal values (p = NS vs. controls). EE/CA also significantly decreased hyperandrogenism indices and increased total and HDL cholesterol and triglycerides (p < 0.05 vs. baseline). The only independent predictor of treatment-induced FMD improvement in PCOS women was the decrease in free androgen index. Conclusions. Treatment with combination of estrogens and antiandrogens reverses endothelial dysfunction in young, non-obese PCOS women mainly via improving hyperandrogenism. Further research is needed to investigate whether this treatment may also reduce cardiovascular risk in these women.

Association of vascular indices with novel circulating biomarkers as prognostic factors for cardiovascular complications in patients with type 2 diabetes mellitus

BACKGROUND The pathophysiology of atherosclerosis in type 2 diabetes mellitus (T2DM) is multifactorial. The association of vascular indices with circulating biomarkers of inflammation and insulin resistance and their role in the long-term cardiovascular prognosis in T2DM patients were currently investigated. PATIENTS AND METHODS Patients with T2DM and poor glycemic control without known cardiovascular diseases (n=119) at baseline were enrolled and followed for about 9years. The end-point was the occurrence of any cardiovascular event (coronary heart disease, stroke, peripheral artery disease or cardiovascular death). Aortic pulse wave velocity (PWV), augmentation index (AIx), brachial flow-mediated dilation (FMD), hsCRP, Chitinase-3-like protein 1 (YKL-40), Neutrophil Gelatinase-Associated Lipocalin (NGAL), Fatty Acid Binding Protein (FABP-4) were assessed. RESULTS Higher YKL-40 and NGAL were associated with higher PWV, while higher YKL-40 and FABP-4 were related to higher AIx (p<0.05 for all). In univariate Cox regression analysis, PWV>10m/s, YKL-40>78ng/ml and NGAL>42ng/ml were associated with cardiovascular events (p<0.05 for all). In multivariate analysis, after adjusting for classical risk factors and glycemic control, increased NGAL, YKL-40 and PWV and decreased FMD (i.e. ≤2.2%) (p<0.05 for all) were independently associated with cardiovascular events. CONCLUSION In T2DM patients without established cardiovascular disease, novel indices of vascular inflammation (NGAL and YKL-40) were associated with subclinical atherosclerosis (arterial stiffness) but also with adverse clinical prognosis. Arterial stiffness and endothelial dysfunction were also independently related to adverse prognosis.