Delayed vasodilation is associated with cardiovascular risk

BACKGROUND

Flow-mediated dilation (FMD) of the brachial artery is widely used to assess cardiovascular risk. In recent years, much attention has been paid to the kinetics of vasodilation in an attempt to better characterize the endothelial function. Here, we investigated whether FMD magnitude and/or latency are most related to individual cardiovascular risk.

MATERIALS AND METHODS

Four hundred subjects were recruited. Individual risk prediction was estimated by Framingham cardiovascular risk score and CUORE project calculator. Subjects were divided into Early dilators (peak FMD at 50 s), Late dilators (peak FMD over 50 s) and No dilators.

RESULTS

Cardiovascular risk was highest in No dilators and significantly higher in Late than Early dilators despite comparable peak FMD. When divided according to peak FMD quintiles, Early and Late dilators showed decreased cardiovascular risk with increasing magnitude of vasodilation. However, subjects in the first three quintiles of Late dilators had a markedly higher risk score despite a peak vasodilation similar to that of Early dilators.

CONCLUSION

These results suggest that the magnitude of the FMD and its latency are both important for identifying patients at risk of cardiovascular disease. Subjects with a delayed though significant vasodilation associated with a blunted early response exhibit the highest cardiovascular risk.

Biphasic hemodynamic effects of LDL-apheresis in common carotid artery

OBJECTIVE

Heparin-induced Extracorporeal Low Density Lipoprotein Precipitation (HELP) Apheresis gives beneficial reductions in Low Density Lipoprotein (LDL) cholesterol levels; otherwise, extracorporeal circulation settings might elicit inflammation and platelet aggregation. The net effect of these variations on carotid hemodynamic has not been established. Aim of the present study was to investigate periprocedural variations of common carotid artery wall shear stress, circumferential wall tension, and Peterson's elastic modulus.

METHODS

Measurements were sequentially performed on 22 procedures: immediately before apheresis (T1), within one hour after (T2), after 24 (T3) and 48 hours (T4). In order to confirm acute effects, in additional 30 procedures measurements were performed at T1 and T2.

RESULTS

Mean shear stress was decreased at T2, with an improvement at T4. Mean circumferential wall tension showed an improvement at T4; arterial stiffness showed the same trend, but only close to statistical significance. The following 30 procedures, where measurements were performed at T1 and T2 only, confirmed previous results, showing a deep wall shear stress decrease at T2 (-21%).

CONCLUSION

LDL apheresis seems to have a biphasic effect on common carotid hemodynamics: the acute worsening of shear stress, probably mediated by extracorporeal circulation, was followed by its improvement, possibly driven by LDL cholesterol reduction.

Blood viscosity in subjects with normoglycemia and prediabetes

OBJECTIVE

Blood viscosity (BV) is higher in diabetic patients and might represent a risk factor for the development of insulin resistance and type 2 diabetes. However, data in subjects with normal glucose or prediabetes are missing. In the current study, we evaluated the relationship between BV and blood glucose in subjects with normal glucose or prediabetes.

RESEARCH DESIGN AND METHODS

Enrolled subjects were divided into three groups according to blood glucose: group A (n = 74), blood glucose <90 mg/dL; group B (n = 96), blood glucose ranging from 90 to 99 mg/dL; and group C (n = 94), blood glucose ranging from 100 to 125 mg/dL. BV was measured at 37°C with a cone-plate viscometer at shear rates ranging from 225 to 22.5 s(-1).

RESULTS

Blood pressure, blood lipids, fibrinogen, and plasma viscosity were similar in the three groups. BMI and waist circumference were significantly increased in group C. Hematocrit (P < 0.05) and BV (P between 0.01 and 0.001) were significantly higher in groups B and C compared with group A. Blood glucose was significantly and inversely correlated with HDL cholesterol and directly with BMI, waist, hematocrit (r = 0.134), and BV (from 225 s(-1) to 22.5 s(-1); r ranging from 0.162 to 0.131). BV at shear rate 225 s(-1) was independently associated with blood glucose.

CONCLUSIONS

The current study shows a direct relationship between BV and blood glucose in nondiabetic subjects. It also suggests that, even within glucose values considered completely normal, individuals with higher blood glucose levels have increased BV comparable with that observed in subjects with prediabetes.

Genistein and endothelial function in postmenopausal women with metabolic syndrome

BACKGROUND

Previous data have suggested that genistein could exert beneficial effects on endothelial function and on predictors of cardiovascular risk in healthy postmenopausal women. In a randomized clinical trial, we studied the effects of genistein on endothelial function in postmenopausal women with metabolic syndrome (MS).

METHODS

Twenty postmenopausal women with MS, according to modified NCEP-ATP III criteria were randomly assigned to receive placebo or genistein (54 mg/day) for 6 months, along with a Mediterranean-style diet. Postmenopausal women without MS (n = 15), served as controls. The primary goal was the assessment of endothelial function by flow-mediated vasodilation (FMD) of brachial artery; moreover, time-to-peak dilation in the FMD response has been evaluated. Secondary outcomes were fasting glucose, fasting insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, visfatin, adiponectin and homocysteine blood levels. Data on adverse events were also recorded.

RESULTS

After 6 months of treatment, FMD at 50s and peak FMD significantly increased in genistein recipients compared with placebo. Moreover, genistein significantly decreased the blood levels of total cholesterol, triglycerides, homocysteine and visfatin compared with placebo, while blood adiponectin levels were increased. Genistein recipients neither experienced more side-adverse effects than placebo nor discontinued the study.

CONCLUSIONS

Six months of treatment with genistein effectively improves brachial artery flow-mediated vasodilation in postmenopausal women with metabolic syndrome.

Markers of insulin resistance and carotid atherosclerosis. A comparison of the homeostasis model assessment and triglyceride glucose index

AIMS

The present investigation was designed to test the association between carotid atherosclerosis and two simple markers of insulin resistance, i.e. HOMA-Index and TyG-Index.

MATERIALS AND METHODS

The study was performed in two different cohorts. In the first cohort, 330 individuals were enrolled. Blood pressure, lipids, glucose, waist and cigarette smoking were evaluated. HOMA-IR and TyG-Index were calculated as markers of prevalent hepatic and muscular insulin resistance respectively. Carotid atherosclerosis was assessed by Doppler ultrasonography. The association between cardiovascular risk factors, markers of insulin resistance and carotid atherosclerosis was assessed by multiple logistic regression analyses. In the second cohort, limited to the evaluation of TyG-Index, 1432 subjects were studied.

RESULTS

In the first cohort, TyG-Index was significantly associated with carotid atherosclerosis in a model including age, sex, diabetes, cigarette smoking and LDL cholesterol, while HOMA-IR was not. When components of metabolic syndrome were added to the model as dichotomous variables (absent/present), TyG-Index retained its predictive power. The same result was obtained when the metabolic syndrome was added to the model (absence/presence). The association between TyG-Index and carotid atherosclerosis was confirmed in the second cohort.

CONCLUSIONS

The present findings suggest that TyG-Index is better associated with carotid atherosclerosis than HOMA-IR.

Common carotid and brachial artery hemodynamic alterations in periodontal disease

AIM

In patients affected by periodontal disease, hypertension and systemic inflammation might cause an arterial hemodynamic derangement; this, in turn, can act as a mediator of the atherogenic process often seen in these patients. This study aimed at a comprehensive hemodynamic evaluation in periodontal patients.

METHODS

Fourty-eight subjects participating to a cardiovascular prevention programme were enrolled. Periodontitis, classical risk factors for atherosclerosis, and shear and tensile forces in both carotid and brachial arteries were evaluated. Calculated periodontal indexes were plaque, gingival and pocket deep (PD) indexes. Simple and multiple regression analyses were performed. Afterwards, 30 of them with normal PD index were compared with 30 carefully - matched patients with periodontitis.

RESULTS

Brachial and carotid parietal tension were significantly associated with periodontal indexes, especially PD-Sum, in both simple (r = 0.42, p < 0.001 for carotid artery and r = 0.36, p < 0.02 for brachial artery) and multiple regression analyses. Shear stress gave similar results. In case-control analysis, shear stress was lower by 15% and 30%, respectively, in carotid and brachial artery in patients with high PD; common carotid parietal tension was higher. Arterial stiffness resulted not associated with periodontitis.

CONCLUSIONS

Periodontal disease is associated to a complex atherosclerotic prone hemodynamic derangement, particularly in large elastic arteries.

Exenatide improves endothelial function assessed by flow mediated dilation technique in subjects with type 2 diabetes: results from an observational research

The GLP-1 receptor agonist exenatide has been approved for adjunctive treatment of type 2 diabetes. Continuous GLP-1 infusion improves endothelial function in vivo; no evidence about a beneficial effect of exenatide on vascular function has been published. The aim of our observational study was to evaluate whether exenatide would improve brachial artery function evaluated by the flow mediated dilation (FMD) technique, compared with glimepiride, in subjects with type 2 diabetes. FMD time course was assessed by ultrasound, after 5 min forearm ischaemia, at baseline and after 16-week treatment. At the end of the study FMD was significantly higher in subjects who assumed exenatide compared with glimepiride (9.1 ± 3.6 vs. 5.6 ± 1.0, p = 0.01). Even if limited by the small number of studied subjects, who were not matched in the two treatment groups, this research study represents the first FMD evidence suggesting that chronic administration of exenatide improves arterial dilation.

Delayed flow-mediated vasodilation and carotid atherosclerosis

BACKGROUND

In a previous study, we identified temporally distinct postischaemic flow-mediated dilation (FMD) patterns comparing the standard clinical measurement time of 50s postcuff release with measurement at 2 min. The comparison revealed a cohort with the highest FMD at 50s (Early FMD), another cohort with the highest FMD at 2 min (Late FMD) and a third cohort with no FMD (Absent FMD). The aim of this study was to examine whether these temporally distinct FMD patterns associated with different degrees of carotid atherosclerosis.

MATERIALS AND METHODS

One hundred and twenty-four free-living white subjects, participating in a cardio-vascular disease prevention campaign, were enrolled. FMD was measured at 50s, 2 min and 3 min after forearm ischaemia. The intima-media thickness (IMT) of the common carotid artery was measured, and the artery was evaluated for the presence and number of carotid plaques.

RESULTS

Fifty-seven subjects had Early FMD, 34 had Late FMD and 33 had Absent FMD. The three groups were comparable for age, sex and cardiovascular risk factors. The number of plaques in the carotid arteries, and IMT, increased progressively from Early, to Late, and to Absent FMD (P < 0·03), indicating that the FMD pattern is an independent predictive variable for IMT and carotid atherosclerosis.

CONCLUSIONS

The present study demonstrates that temporal patterns associated with the degree of atherosclerosis of the carotid arteries. Patients with delayed vasodilation (Late FMD) had a higher degree of atherosclerosis than those with early vasodilation (Early FMD), and subjects with no postischaemic vasodilation (Absent FMD) had the most atherosclerosis.

Human common carotid wall shear stress as a function of age and gender: a 12-year follow-up study

Hemodynamic forces play a role in the development of atherosclerosis. Their variations with age have been assessed in cross-sectional, but not longitudinal, studies. The aim of the present study was to investigate in both sexes the age-dependent change in wall shear stress and arterial stiffness in subjects studied twice 12 years apart. Forty-eight subjects (15 women and 33 men) were studied twice 12 years apart. Subjects underwent blood viscosity measurement and echo-Doppler of carotid arteries, from which the intima-media thickness (IMT) was measured and the wall shear stress and Peterson's elastic modulus were calculated. Blood viscosity increased in both sexes, more markedly in women (+13.2%) than men (+7.2%). Common carotid diameter increased in both sexes, but in men (+7.4%) more than in women (+5.5%). Peak and mean velocity decreased at follow-up by 10.7% and 18.9% in women and by 14.2% and 18.1% in men. Peak and mean shear stress significantly decreased in men by 13.0% and 17.5%, respectively, while in women only the mean shear stress was reduced (-11.8%). The IMT of the common carotid artery increased by 29% in women and 20% in men. Arterial stiffness significantly increased (+74.5% in women and +28.0% in men). The percent change in mean shear stress was significantly and inversely associated with the percent change in IMT. The data of this study show that, in a middle-aged population observed for almost 12 years, the mean shear stress decreases significantly in both sexes, while peak shear stress decreases significantly only in men. The change in mean shear stress is inversely associated with changes in IMT. Arterial stiffness, on the other hand, increases with aging.

Modulating the vascular behavior of metastatic breast cancer cells by curcumin treatment

The spreading of tumor cells to secondary sites (tumor metastasis) is a complex process that involves multiple, sequential steps. Vascular adhesion and extravasation of circulating tumor cells (CTCs) is one, critical step. Curcumin, a natural compound extracted from Curcuma longa, is known to have anti-tumoral, anti-proliferative, anti-inflammatory properties and affect the expression of cell adhesion molecules, mostly by targeting the NF-κB transcription factor. Here, upon treatment with curcumin, the vascular behavior of three different estrogen receptor negative (ER^–) breast adenocarcinoma cell lines (SK-BR-3, MDA-MB-231, MDA-MB-468) is analyzed using a microfluidic system. First, the dose response to curcumin is characterized at 24, 48, and 72 h using a XTT assay. For all three cell lines, an IC₅₀ larger than 20 µM is observed at 72 h; whereas no significant reduction in cell viability is detected for curcumin concentrations up to 10 µM. Upon 24 h treatment at 10 µM of curcumin, SK-BR3 and MDA-MB-231 cells show a decrease in adhesion propensity of 40% (p = 0.02) and 47% (p = 0.001), respectively. No significant change is documented for the less metastatic MDA-MB-468 cells. All three treated cell lines show a 20% increase in rolling velocity from 48.3 to 58.7 µm/s in SK-BR-3, from 64.1 to 73.77 µm/s in MDA-MB-231, and from 57.5 to 74.4 µm/s in MDA-MB-468. Collectively, these results suggest that mild curcumin treatments could limit the metastatic potential of these adenocarcinoma cell lines, possibly by altering the expression of adhesion molecules, and the organization and stiffness of the cell cytoskeleton. Future studies will elucidate the biophysical mechanisms regulating this curcumin-induced behavior and further explore the clinical relevance of these findings.

Transaminase levels in the upper normal range are associated with oral hypoglycemic drug therapy failure in patients with type 2 diabetes

Incident diabetes and the worsening of diabetes have recently been linked to hepatic steatosis. Aim of our study was to determine whether oral hypoglycemic agent failure is associated with higher transaminase levels (valid measure of liver steatosis). We selected 200 patients, attenders (3 consecutive annual evaluations) in our clinic, with type 2 diabetes among which 100 with oral hypoglycemic agents failure and 100 who were still responsive to oral therapy. Failure to therapy was defined as glycated hemoglobin >7.5% despite maximal-dose oral therapy. We analyzed patient histories and laboratory data. Compared with oral-therapy-responsive patients, those with failure had a significantly higher level mostly of alanine aminotransferase at the time of therapy failure and 2 years before. They were more likely to have had symptoms of hyperglycemia at the time of diabetes diagnosis. Regression analysis indicated that each 5-unit increase in transaminase levels independently increased the risk for oral hypoglycemic agents failure by 1.70. Higher liver transaminase levels, especially in patients who had symptomatic hyperglycemia at diabetes diagnosis, associate with oral hypoglycemic agent failure. The possible pathogenetic link between transaminase and declining islet function might consist of insulin resistance and increased circulating fatty acid levels, in turn causing liver steatosis and beta-cell dysfunction.

Lack of association between systolic blood pressure and blood viscosity in normotensive healthy subjects

OBJECTIVE

A direct relationship between blood pressure and viscosity has frequently been reported, although clear data are not available. To better understand the relationship between these two variables, we evaluated blood viscosity and blood pressure in a group of healthy subjects without cardiovascular risk factors.

METHODS

Healthy subjects were selected from participants in a campaign of prevention of cardiovascular disease (n = 103). They underwent blood sampling for measurement of plasma and blood viscosity, haematocrit, blood lipids and glucose. The quantity and distribution of body fat was assessed by body mass index and waist/hip ratio, respectively.

RESULTS

Systolic blood pressure (SBP) correlated significantly with age (r = 0.222) and waist/hip ratio (r = 0.374). Diastolic blood pressure (DBP) correlated significantly with waist/hip ratio (r = 0.216), haematocrit (r = 0.333) and blood viscosity (r = 0.258). Multiple linear regression analyses demonstrated that the only variable significantly associated with SBP was age, while haematocrit was the only variable significantly associated with DBP. Blood viscosity was closely related to waist/hip ratio.

CONCLUSION

These findings show that SBP, in healthy subjects, is not influenced by haematocrit and blood viscosity. In contrast, DBP is related to the values of haematocrit. Among classical cardiovascular risk factors, waist/hip ratio is closely related to blood viscosity.

Exenatide improves glycemic variability assessed by continuous glucose monitoring in subjects with type 2 diabetes

BACKGROUND

Daily glycemic fluctuation leads to development of long-term complications. The aim of our pilot study was to determine if exenatide reduces glycemic variability, assessed with a continuous glucose monitoring (CGM) system, compared with glimepiride.

METHODS

We enrolled six consecutive subjects with type 2 diabetes, for whom exenatide was suggested as second-line treatment, and six control subjects, for whom glimepiride was suggested as second-line treatment. CGM was performed at baseline and after 16 weeks of treatment. As measures of glycemic variability we calculated the total daily mean glucose (MG), SD, and mean amplitude of glycemic excursions (MAGE).

RESULTS

Exenatide significantly reduced MG, SD, and MAGE, whereas glimepiride did not. Fasting glucose and glycated hemoglobin were lowered in both groups, even if the reduction was not significant.

CONCLUSION

Exenatide can reduce glycemic variability compared with glimepiride, providing additional beneficial effects in controlling glucose homeostasis.

Metabolic syndrome in subjects at high risk for type 2 diabetes: the genetic, physiopathology and evolution of type 2 diabetes (GENFIEV) study

BACKGROUND AND AIM

We evaluated the relationship between insulin resistance (IR) and insulin secretion with the metabolic syndrome (MS) in 885 subjects (377 men/508 women, age 49±11 years, BMI 29±5.2kgm(-2)) at risk of diabetes enrolled in the genetics, pathophysiology and evolution of type 2 diabetes (GENFIEV) study.

METHODS AND RESULTS

All subjects underwent a 75-g oral glucose tolerance test (OGTT) for the estimation of plasma levels of glucose and C-peptide, as well as fasting insulin and lipid profile. IR was arbitrarily defined as HOMA-IR value above the 75th centile of normal glucose tolerance (NGT) subjects. Overall MS prevalence (National Cholesterol Treatment Panel-Adult Treatment Panel (NCEP-ATPIII) criteria) was 33%, 19% in subjects with NGT, 42% in impaired fasting glucose (IFG), 34% in impaired glucose tolerance (IGT), 74% in IFG+IGT subjects, and 56% in newly diagnosed diabetic patients. Prevalence was slightly higher with IDF criteria. MS prevalence was >50% in subjects with 2h glucose >7.8mmoll(-1), independently of fasting plasma glucose. IR prevalence was higher in subjects with MS than in those without (63% vs. 23%; p<0.0001) and increased from 54% to 73% and 88% in the presence of three, four or five traits, respectively. IR occurred in 42% of subjects with non-diabetic alterations of glucose homeostasis, being the highest in those with IFG+IGT (IFG+IGT 53%, IFG 45%, IGT 38%; p<0.0001). Individuals with MS were more IR irrespective of glucose tolerance (p<0.0001) with no difference in insulinogenic index. Hypertriglyceridaemia (OR: 3.38; Confidence Interval, CI: 2.294.99), abdominal obesity (3.26; CI: 2.18-4.89), hyperglycaemia (3.02; CI: 1.80-5.07) and hypertension (1.69; CI: 1.12-2.55) were all associated with IR.

CONCLUSIONS

These results show that in subjects with altered glucose tolerance (in particular IFG+IGT) MS prevalence is high and is generally associated to IR. Some combinations of traits of MS may significantly contribute to identify subjects with IR.

Primary hyperlipidemias in children: effect of plant sterol supplementation on plasma lipids and markers of cholesterol synthesis and absorption

Plant sterols lower serum cholesterol concentration. Available data have confirmed the lipid-lowering efficacy in adults, while there is a relative dearth of data in children and almost exclusively restricted to subjects with familial hypercholesterolemia (FH). Aim of the present study was to evaluate the efficacy, tolerability and safety of plant sterol supplementation in children with different forms of primary hyperlipidemias. The effect of plant sterol consumption on plasma lipids was evaluated in 32 children with heterozygous FH, 13 children with Familial Combined Hyperlipidemia (FCH) and 13 children with Undefined Hypercholesterolemia (UH) in a 12-week open-label intervention study using plant sterol-enriched yoghurt. Plasma lipids and apolipoproteins were measured by routine methods. Markers of cholesterol synthesis (lathosterol) and absorption (campesterol and sitosterol) were measured by GC-MS. Tolerability and adherence to recommended regimen was very high. A significant reduction was observed in LDL-cholesterol in the three groups (10.7, 14.2 and 16.0% in FH, FCH and UH, respectively). Lathosterol concentrations were unchanged, reflecting a lack of increased synthesis of cholesterol. Of the two absorption markers, only sitosterol showed a slight but significant increase. Daily consumption of plant sterol dairy products favorably changes lipid profile by reducing LDL-cholesterol. To our knowledge, this is the first report of the use of plant sterols-enriched foods in treating children with primary hyperlipidemia such as FCH and UH, likely to be the most frequent form also in the young age in the western populations.

Periodontal disease and carotid atherosclerosis: are hemodynamic forces a link?

OBJECTIVE

The link between periodontal disease and atherosclerosis has not yet been clarified, though systemic inflammation seems to be the common soil for both conditions. Inflammation influences also hemodynamic forces, that act as local risk factors for carotid plaques. It is not known if the link between periodontitis and carotid atherosclerosis is mediated, at least in part, by physical forces. Therefore, aim of the present study was to evaluate the association between carotid shear stress force and periodontal disease.

METHODS

Thirty-three subjects underwent complete cardiovascular screening, carotid hemodynamic evaluation and dental inspection. Presence of classical risk factors for atherosclerosis, common carotid peak and mean wall shear stress values and periodontal indices of disease (plaque index, gingival index and pocket deep) have been evaluated.

RESULTS

Worse periodontal health was associated to the presence of carotid atherosclerosis. Patients with carotid plaques (n=19) had higher periodontal indices compared with subjects without plaques (n=14) (gingival index: 1.40 ± 0.71 vs. 0.69 ± 0.64, p=0.006). These relations were independent of the presence of cardiovascular risk factors in multiple logistic regression analysis. In the 66 examined common carotids, wall shear stress was inversely related to all periodontal indices (r=0.54, p<0.00001 for peak wall shear stress and gingival index). These relations remained significant also in multiple regression analysis, after correction for cardiovascular risk factors, gender and age.

CONCLUSIONS

The present study identifies for the first time a link between periodontal indices and wall shear stress, suggesting that an alteration of hemodynamic profile might contribute to atherosclerosis in subjects with periodontal disease.

Hepatic steatosis, carotid atherosclerosis and metabolic syndrome: the STEATO Study

PURPOSE

Hepatic steatosis is frequently observed in subjects with metabolic syndrome (MS). In type 2 diabetics, it is independently associated with cardiovascular diseases. In order to confirm and extend this finding, a large group of patients with risk factors for atherosclerosis was studied.

METHODS

Carotid atherosclerosis was investigated by echo-Doppler, and hepatic steatosis by ultrasound and transaminase values. Strict exclusion criteria were chosen in order to avoid secondary forms of fatty liver and interference on transaminase values.

RESULTS

Among 970 enrolled patients, about 20% were diabetics, half had MS and 76% presented echographic hepatic steatosis. In multivariate analyses, fatty liver and MS were associated with carotid atherosclerosis [odds ratio (95% confidence intervals) 2.15 (1.27-3.63) and 1.72(1.12-2.64), respectively], whereas HOMA index was not. Aspartate aminotransferase and alanine aminotransferase were not independently associated with carotid atherosclerosis, whereas gamma-glutamyl transferase showed a link with atherosclerosis beyond MS and steatosis presence. The analyses of the 780 non diabetics recruited showed similar results.

CONCLUSIONS

The results of the present study demonstrate that hepatic steatosis measured by echography is associated with carotid atherosclerosis in a large population mostly carrying cardiovascular or metabolic risk factors, independently of MS, cardiovascular diseases, diabetes mellitus and/or insulin resistance.

Plasma and blood viscosity in metabolic syndrome

BACKGROUND AND AIM

The relationship between metabolic syndrome (MS) and blood and plasma viscosity has been scarcely investigated. In the present study we have evaluated the difference in blood and plasma viscosity between subjects with and without MS, in order to verify whether viscosity measurement can add more information on the overall cardiovascular risk connected with the presence of the MS.

METHODS AND RESULTS

Two hundred and sixty nine women and 520 men have been enrolled. Blood and plasma viscosity have been measured with a cone-plate viscometer equipped with a cp-40 spindle. MS has been defined according to the third report of the National Cholesterol Education Program, Adult Treatment Panel III. Eighty four women and 154 men fulfilled the criteria for MS. Hematocrit adjusted blood viscosity was higher in subjects with MS compared to those without the syndrome, both in males (shear rate 225 s(-1): 4.60+/-0.38 vs. 4.52+/-0.33 cP, p<0.01) and females (4.57+/-0.28 vs. 4.46+/-0.31 P, p<0.01). Blood viscosity was correlated with all components of MS but glucose, and after adjustment for them the difference between subjects with or without MS was completely abolished. Plasma viscosity was significantly higher only in females with MS.

CONCLUSIONS

These data demonstrate that blood viscosity is increased in subjects with MS, but the increase seems to depend on the metabolic alterations of the syndrome. The independent contribution of the rise in blood viscosity to the cardiovascular risk connected with the presence of MS seems therefore negligible. The increased plasma viscosity in females with MS needs further clarification.

Poor glycemic control is an independent risk factor for low HDL cholesterol in patients with type 2 diabetes

OBJECTIVE To determine whether the association observed between poor glycemic control and low HDL cholesterol in type 2 diabetes is dependent on obesity and/or hypertriglyceridemia. RESEARCH DESIGN AND METHODS We performed a cross-sectional study of 1,819 patients with type 2 diabetes and triglycerides <400 mg/dl enrolled at three diabetes centers in Italy. The risk for low HDL cholesterol was analyzed as a function of A1C levels. Odds ratios (ORs) were calculated after adjustment for confounding factors. RESULTS A 1% increase in A1C significantly increased the risk for low HDL cholesterol (OR 1.17 [95% CI 1.1-1.2], P = 0.00072); no changes were observed when age, sex, smoking, and lipid-lowering therapy were included in the model (1.17 [1.1-1.2], P = 0.00044). The association remained strong after adjustments for obesity and hypertriglyceridemia in multivariate analysis (1.12 [1.05-1.18], P = 0.00017). CONCLUSIONS Poor glycemic control appears to be an independent risk factor for low HDL cholesterol in type 2 diabetes.