Impaired NO-dependent vasodilation in patients with Type II (non-insulin-dependent) diabetes mellitus is restored by acute administration of folate

AIMS/HYPOTHESIS: Patients with diabetes are characterised by endothelial dysfunction and cardiovascular mortality. In particular endothelium-derived nitric oxide has emerged as a first line mechanism against atherosclerosis. Hyperglycaemia causes oxygen radical stress but has also been associated with endothelial nitric oxide synthase uncoupling, both lead to decreased nitric oxide-availability. We recently showed that folate reverses eNOS uncoupling in vitro. Therefore we hypothesise that folate improves endothelial function in Type II (non-insulin-dependent) diabetes mellitus in vivo. METHODS: Using forearm plethysmography, we evaluated the effect of local, intra-arterial administration of 5-methyltetrahydrofolate (5-MTHF, the active form of folic acid, 1 microg/100 ml FAV/min) on forearm blood flow in 23 patients with Type II diabetes and 21 control subjects, matched for age, sex, blood pressure, body mass index, weight and smoking habits. Serotonin as a stimulator of nitric oxide-dependent vasodilation and sodium nitroprusside as a stimulator of endothelium-independent vasodilation were infused. RESULTS: Serotonin-induced vasodilation was blunted (53+/-30 vs 102+/-66 M/C%, p<0.005) and nitroprusside-induced vasodilation was mildly reduced (275+/-146 vs 391+/-203 M/C%, p<0.05) in patients with Type II diabetes compared to control subjects. 5-MTHF improved nitric oxide-mediated vasodilation (from 53+/-30 to 88+/-59 M/C%, p<0.05) in patients with Type II diabetes mellitus. As expected, 5-MTHF had no effect on forearm blood flow in control subjects. CONCLUSION/INTERPRETATION: These data imply that folate can be used to improve nitric oxide status and to restore endothelial dysfunction in patients with Type II diabetes. Our results provide a strong rationale for the initiation of studies that investigate whether supplementation with folic acid prevents future cardiovascular events in this patient group.     

Atorvastatin improves diabetic dyslipidemia and increases lipoprotein lipase activity in vivo

A major factor contributing to cardiovascular mortality in type 2 diabetes is dyslipidemia, characterized by low HDL cholesterol and high triglycerides, rather than elevated LDL cholesterol. Lipoprotein lipase (LPL) is the rate-limiting enzyme of triglyceride removal from plasma and has been implicated in atherosclerosis. Since treatment with statins significantly reduces cardiovascular morbidity in diabetes, we analyzed the lipid profile and LPL activities in 61 patients with type 2 diabetes before and 8 weeks after initiation of atorvastatin (40 mg) or placebo treatment. Lipid parameters and LPL activity were unchanged under treatment with placebo. Atorvastatin treatment resulted in a 30% reduction of total and a 45% reduction of LDL cholesterol (6.06 +/- 1.39 mmol/L versus 4.14 +/- 1.27 mmol/L and 4.11 +/- 1.13 mmol/L versus 2.27 +/- 0.89 mmol/L, both P < 0.0001). Triglycerides and VLDL cholesterol were also significantly reduced by statin therapy (2.24 +/- 2.11 mmol/L versus 1.82 +/- 1.46 mmol/L and 1.08 +/- 1.56 mmol/L versus 0.67 +/- 0.66 mmol/L, both P < 0.05). HDL cholesterol was not different between the atorvastatin and the placebo group. Compared to baseline, LPL activity was increased by 25% after atorvastatin treatment (213.0 +/- 28.1 nmol/mL/min versus 171.9 +/- 17.7 nmol/mL/min, P < 0.01). Our data demonstrate that atorvastatin induces a significant improvement of diabetic dyslipidemia and a significant increase of LPL activity. Since low LPL activity indicates an increased cardiovascular risk, the statin-mediated increase in LPL activity may help to explain the reduction of CAD in diabetic patients treated with statins.     

Lipid and lipoprotein profiles in Ethiopian patients with diabetes mellitus

The association between dyslipidemia and diabetes mellitus is well established. Although various lipoprotein abnormalities have been described in patients with diabetes mellitus elsewhere, there is limited information from African patients. We undertook a cross-sectional study to assess the prevalence of dyslipidemia in Ethiopian patients with types 1 and 2 diabetes. A total of 193 subjects were included in the study (54 patients had type 1 diabetes mellitus, 92 patients had type 2 diabetes mellitus, and 47 were nondiabetic controls). Of these, 93 (48.6%) were men and 103 (51.4%) were women. The mean age+/-SEM for patients with type 1 diabetes mellitus, type 2 diabetes mellitus, and controls were 29.8+/-1.4, 51.2+/-1.1, and 29.0+/-1.7 years, respectively. Hypercholesterolemia and hypertriglyceridemia, defined as cholesterol level of greater than 5.2 mmol/L and triglyceride level of greater than 1.8 mmol/L, were found in 47.3% and 41.8% of patients with diabetes mellitus compared with 27% and 17% in controls (P<.05 for both). The mean total cholesterol level+/-SEM was significantly higher in patients with type 1 or 2 diabetes mellitus than controls (5.76+/-0.27 mmol/L in type 1 diabetes mellitus, 5.25+/-0.2 mmol/L in type 2 diabetes mellitus, and 4.67+/-0.28 mmol/L in healthy controls, P<.02). Triglycerides and low-density lipoprotein levels were also significantly higher in patients with diabetes than in controls, whereas high-density lipoprotein levels were significantly lower in patients with diabetes. In conclusion, our study demonstrates that in Ethiopians with diabetes mellitus, dyslipidemia occurs more frequently than in controls. Thus, we recommend periodic screening for dyslipidemia in all Ethiopian patients with diabetes. Other studies are needed to assess the potential negative effect of dyslipidemia and obesity on morbidity and mortality in Ethiopians with diabetes.     

Isradipine improves endothelium-dependent vasodilation in normotensive coronary artery disease patients with hypercholesterolemia

OBJECTIVE: The dihydropyridine calcium antagonist isradipine has anti-atherosclerotic effects in animals and improves endothelium-mediated nitric oxide (NO)-dependent vasodilation in vitro. As improved endothelial function may be beneficial we investigated its effects in patients with a high likelihood of endothelial dysfunction. DESIGN: Thirty patients (two female, age 55.4 +/- 10.5 years) with known coronary artery disease and elevated (> 6 mmol/l) total cholesterol (cholesterol: mean 6.7 +/- 0.78 mmol/l) or a cholesterol/high density lipoproteins (HDL) ratio of > 5 not on lipid lowering therapy, participated in the study. Endothelial vasodilator function was assessed before and after double-blind, randomized administration of isradipine 5 mg/day or placebo for 3 months. METHODS: Endothelial function was assessed as forearm blood flow (FBF, venous occlusion plethysmography) responses to graded brachial artery infusions of acetylcholine (Ach), to the NO-synthase blocker NG-monomethyl-L-arginine (L-NMMA) and to the endothelium-independent vasodilator sodium nitroprusside (SNP). Blood pressure was measured either directly from the brachial arterial or by sphygmomanometer during clinic visits. RESULTS: Blood pressure was unchanged in both groups after 3 months (isradipine: 88.8 versus 92.1 mmHg; placebo: 81.0 versus 82.5 mmHg; NS) but cholesterol levels decreased similarly in both groups (isradipine: 6.7 versus 6.1 mmol/l, NS; placebo: 6.6 versus 5.9 mmol/l, P< 0.05). The vasodilator response to SNP and the decrease in FBF in response to blockade of NO synthesis by L-NMMA were unchanged in both groups. However, isradipine, but not placebo, enhanced the NO-dependent vasodilator response to Ach (P < 0.05). CONCLUSION: Isradipine improves acetylcholine-mediated vasodilation in hypercholesterolemic patients independent of changes in lipids or blood pressure.     

Effect of atorvastatin on endothelium-dependent vasodilation in postmenopausal women with average serum cholesterol levels

After menopause, most healthy women show an impairment of peripheral vasodilation and an increase of plasma cholesterol levels. Statins have been shown to improve endothelial function in hypercholesterolemic men and women. The present study tests whether atorvastatin (10 mg) influences endothelium-dependent vasodilation in postmenopausal normocholesterolemic women. Twenty-eight healthy, postmenopausal women (mean age 51 +/- 2 years) with serum total cholesterol and low-density lipoprotein cholesterol within the desirable range entered a double-blind, single-crossover study. Postmenopausal women were randomized to receive either atorvastatin (10 mg/day) or placebo for 10 days and then crossed to the complementary treatment. Endothelium-dependent and -independent responses were assessed by means of strain-gauge plethysmography before and after intra-arterial infusion of acethylcholine (ACh) and sodium nitroprusside, in comparison to physiologic saline. The nitric oxide pathway was evaluated by repeating the infusion of ACh during admininstration of L-arginine and (G)-monomethyl-L-arginine (L-NMMA). Serum lipoproteins were not significantly modified by the active treatment. The vasodilation induced by ACh was significantly higher in the atorvastatin-treated women compared with the placebo-treated group (24 +/- 3 vs 13 +/- 2 ml/100 ml tissue/min, p <0.01). In contrast, responses to the endothelium-independent vasodilator sodium nitroprusside were not significantly modified by atorvastatin. The ACh-stimulated vasodilation induced by atorvastatin was additionally potentiated by L-arginine (800 +/- 105% vs 370 +/- 60%, p <0.05) and blunted by L-NMMA. No correlation was found between changes in plasma cholesterol and improvement in forearm blood flow. Our data show that the beneficial effect of atorvastatin on endothelium-dependent vasodilation is independent from changes in the lipid profile.     

Insulin resistance and endothelial dysfunction in type 2 diabetes patients with or without microalbuminuria

OBJECTIVE: To evaluate the relationship between insulin resistance and endothelial function in type 2 diabetes patients with or without microalbuminuria and to explore the pathophysiological mechanisms of the increased macrovascular risk in type 2 diabetes mellitus. METHODS: Twelve type 2 diabetes patients with microalbuminuria (urinary albumin 30-300 g/mg creatinine, DM-MA) and 12 type 2 diabetes patients without microalbuminuria (urinary albumin <30 g/mg creatinine, DM-NA) were recruited, matched for their sex, age, body mass index (BMI), diabetes duration, antidiabetic therapy. Their hemoglobin (HbA1C) was less than 7.5% and the blood pressure was lower than 140/90 mmHg. None had evidence of macrovascular disease and serum cholesterol levels were normal. Twelve healthy volunteers (C) were enrolled as controls. All subjects received a hyperinsulinemic euglycemic clamp study (insulin infusion rate, 120 mU/m2/min) to assess the peripheral glucose disposal rate (GDR) in the steady state and had a high-resolution ultrasonography to measure vasodilation in the brachial artery diameter in response to reactive hyperemia (endothelium-dependent) and administration of glyceryl trinitrate (endothelium-independent). Plasma free fatty acids (FFAs), plasminogen activator inhibitor type I (PAI-1), and von Willebrand factor (vWF) were also measured. RESULTS: The GDR was lower in type 2 diabetes patients with microalbuminuria (7.90 +/- 1.79 mg/kg/min) than in patients without microalbuminuria (9.46 +/- 1.59 mg/kg/min, P<0.05), and the GDR in both diabetes groups was decreased, compared with the findings from the healthy control group (13.06 +/- 1.98 mg/kg/min, P<0.01). Plasma FFAs concentration was different among the three groups (DM-MA-1008 +/- 229 mol/l, DM-NA-675 +/- 201 mol/l, P<0.01; C-364 +/- 169 mol/l, P<0.01). Endothelium-dependent vasodilation was impaired in the microalbuminuric patients (8.0 +/- 3.8%) compared with the normoalbuminuria patients (9.7 +/- 4.3%, P>0.05) and the healthy controls (14.2 +/- 5.0, P<0.05). Plasma PAI-1 and vWF levels increased in the microalbuminuric patients (61.9 +/- 18.2 ng/ml, 126.8 (76.5-212.7) %) compared with the levels in the normoalbuminuric patients (45.4 +/- 16.3 ng/ml, 87.9 (84.2-114) %) (PAI-1, P<0.05; vWF, P>0.05) and in the healthy controls (33.6 +/- 10.6 ng/ml, 67.2 (61.5-75.4) %, both P<0.01). In addition, the partial correlation analysis revealed a significant positive correlation between GDR and endothelium-dependent vasodilation (r=0.465, P<0.01, n=36), and a negative correlation between GDR and plasma FFA levels (P<0.05). CONCLUSIONS: Compared with type 2 diabetes patients with normoalbuminuria, patients with microalbuminuria had more severe insulin resistance, more prominent endothelial dysfunction, and higher plasma FFA, PAI-1, and vWF levels. Therefore we speculate that insulin resistance and endothelial dysfunction may act within the metabolic syndrome to increase the cardiovasular risk in this subset of patients, and improving insulin resistance and endothelial dysfunction may reduce the morbidity and mortality from macrovascular complications in type 2 diabetes patients.     

Atorvastatin lowers C-reactive protein and improves endothelium-dependent vasodilation in type 2 diabetes mellitus

Endothelial dysfunction is frequently found in diabetic subjects. This study was performed to investigate whether atorvastatin therapy was able to reverse endothelial dysfunction in type 2 diabetes and, if so, whether the effect was due to its antiinflammatory action. Eighty patients (baseline low density lipoprotein, 4.37 +/- 0.71 mmol/liter) were randomized to atorvastatin (10 mg daily for 3 months, followed by 20 mg daily for 3 months) or placebo in a double blind study. Endothelial function was assessed by high resolution vascular ultrasound, and high sensitivity C-reactive protein (CRP) was assessed by immunoturbidimetric assay. Diabetic patients had higher CRP (P < 0.01) than matched nondiabetic controls, and both endothelium-dependent and independent vasodilation were impaired (P < 0.01). Atorvastatin (10 and 20 mg) lowered plasma cholesterol by 32.9% and 38.0%, triglyceride by 15.4% and 23.1%, and low density lipoprotein by 43.4% and 50.1%, respectively. At 6 months, plasma CRP decreased in the atorvastatin group compared with baseline (P < 0.05). Endothelium-dependent vasodilation improved in the atorvastatin group compared with the placebo group (P < 0.05). The percent change in endothelium-dependent vasodilation at 6 months correlated with the percent change in CRP (r = -0.44; P < 0.05), but not with changes in plasma lipids. In conclusion, treatment with atorvastatin in type 2 diabetes led to a significant improvement in endothelium-dependent vasodilation, which might be partly related to its anti-inflammatory effect.     

Prevalence and phenotypic distribution of dyslipidemia in type 1 diabetes mellitus: effect of glycemic control

BACKGROUND: Data on the prevalence of dyslipidemia in type 1 diabetes mellitus are scarce and are based on total triglyceride and total cholesterol concentrations alone. OBJECTIVE: To assess the effect of glycemic optimization on the prevalence of dyslipidemia and low-density lipoprotein cholesterol (LDL-C) concentrations requiring intervention in patients with type 1 diabetes. PATIENTS: A total of 334 adults with type 1 diabetes and 803 nondiabetic control subjects. METHODS: Levels of glycosylated hemoglobin, total cholesterol, total triglyceride, high-density lipoprotein cholesterol (HDL-C), and LDL-C were assessed at baseline and after 3 to 6 months of intensive therapy with multiple insulin doses. RESULTS: Levels of LDL-C greater than 4.13 mmol/L (>160 mg/dL) and total triglyceride greater than 2.25 mmol/L (>200 mg/dL) and low HDL-C levels (<0.9 mmol/L [<35 mg/dL] in men or <1.1 mmol/L [<45 mg/dL] in women) were found in 16%, 5%, and 20% of patients and 13%, 6%, and 9% of controls, respectively (P<.001 for HDL-C). Diabetic women showed more hypercholesterolemia than nondiabetic women (15.6% vs 8.5%; P =.04). After glycemic optimization (mean +/- SD glycosylated hemoglobin decrease, 2.2 +/- 1.96 percentage points), the prevalence of LDL-C levels greater than 4.13 mmol/L (>160 mg/dL) became lower in diabetic men than in nondiabetic men (9.7% vs 17.5%; P =.04), but women showed frequencies of dyslipidemia similar to their nondiabetic counterparts. The proportion of patients with LDL-C concentrations requiring lifestyle (>2.6 mmol/L [>100 mg/dL]) or drug (>3.4 mmol/L [>130 mg/dL]) intervention decreased from 78% and 42% to 66% and 26%, respectively. CONCLUSIONS: Low HDL-C is the most frequent dyslipidemic disorder in patients with poorly controlled insulin-treated type 1 diabetes, and a high proportion show LDL-C levels requiring intervention. Less favorable lipid profiles could explain the absence of sex protection in diabetic women. The improvement caused by glycemic optimization puts forward intensive therapy as the initial treatment of choice for dyslipidemia in poorly controlled type 1 diabetes.     

Effects of atorvastatin and vitamin C on endothelial function of hypercholesterolemic patients

We tested the effects of vitamin C and atorvastatin treatment on endothelium-dependent and endothelium-independent vasodilation in 18 hypercholesterolemic patients (ten men and eight women, aged 20-46 years) in comparison with 12 normal volunteers (seven men and five women, aged 20-45 years). The responses of the forearm blood flow (FBF) to acetylcholine (ACh) (7.5, 15 and 30 microg/min), sodium nitroprusside (SNP) (0.8, 1.6, 3.2 microg/min) and L-NMMA (2, 4, 8 micromol/min) were evaluated at baseline and after 1 month of atorvastatin (10 mg/day) treatment. Drugs were infused into the brachial artery and FBF was measured by strain-gauge plethysmography. At baseline, the response to ACh was significantly attenuated in hypercholesterolemics versus controls: at the highest dose (30 microg/min), FBF was 27.0+/-3.4 versus 11.5+/-1.9 ml.100 ml tissue(-1).min(-1) respectively (P<0.0001). No significant differences were found between groups during SNP infusion. The atorvastatin treatment significantly improved ACh-stimulated FBF: at highest dose the FBF increased to 14.9+/-1.5 ml.100 ml tissue(-1). min(-1) (P<0.0001). Similarly, the L-NMMA endothelial effects were significantly enhanced by lipid-lowering treatment, supporting the improvement of basal nitric oxide. Vitamin C increased ACh-vasodilation in the same way before and after atorvastatin treatment. In conclusion, the endothelial dysfunction in hypercholesterolemics is due to an oxidative stress and atorvastatin rapidly improves both basal and stimulated endothelium-dependent vasodilation.     

Effect of improving glycemic control on low-density lipoprotein particle size in type 2 diabetes

The current study sought to assess the effect of improving glycemic control in type 2 diabetes on the components of diabetic dyslipidemia, especially low-density lipoprotein (LDL) size. A total of 33 type 2 diabetic patients (48.5% women, age 59.6 +/- 11.1 years, body mass index [BMI] 28.9 +/- 4.9, diabetes duration 6 [0 to 40] years, 40.7% on insulin) were seen at the hospital because of poor glycemic control (hemoglobin A(1c) [HbA(1c)] 10.33% +/- 1.89%). Triglyceride, LDL-cholesterol (LDLc, Friedewald/ ultracentrifugation), high-density lipoprotein HDL-cholesterol (HDLc, direct method), apolipoproteins AI (apoAI) and B (apoB) (immunoturbidimetry), and LDL size (gradient gel electrophoresis) were measured at baseline and after improvement in glycemic control (decrease >/= 1 percentage point in HbA(1c) and final HbA(1c) 相似文献   

2型糖尿病患者血管舒张功能和一氧化氮释放变化及与动脉硬化的关系

目的　探讨 2型糖尿病患者血管舒张功能和一氧化氮释放与糖尿病血管病变的关系。方法　选择 2 0名正常人 (对照组 )和 62例 2型糖尿病患者 (糖尿病组 ) ,并根据患者是否合并冠心病进行分组分析。采用高频超声方法测定反应性充血试验和口服硝酸甘油前后的肱动脉内径变化 ,以反映血管内皮依赖性和非内皮依赖性舒张功能 ,以及静脉闭塞试验测定一氧化氮储备释放 ,同时利用超声方法检测颈总动脉内膜厚度。结果　与对照组比较 ,糖尿病组的非内皮依赖性血管舒张功能无显著变化 (P >0 .0 5 ) ,而内皮依赖性血管舒张功能和内皮一氧化氮释放明显低下 (P<0 .0 5～ 0 .0 1) ,颈总动脉内膜厚度明显增厚 (P <0 .0 1)。糖尿病合并冠心病患者血管内皮依赖性和非内皮依赖性舒张功能均较非合并冠心病患者明显低下。结论　高频超声检测方法能够较好地判断糖尿病患者血管舒张功能。糖尿病患者存在明显的动脉硬化和因一氧化氮释放减少而出现的内皮依赖性舒张功能障碍 ,此与糖尿病性血管病变密切相关     

Impaired endothelium-dependent vasodilation in type 2 diabetes mellitus and the lack of effect of simvastatin.

OBJECTIVE: Although type 2 diabetes is recognized as an independent risk factor for cardiovascular disease and cardiovascular disease is associated with endothelial dysfunction, the influence of type 2 diabetes per se on the endothelial function is controversial. HMG-CoA-reductase inhibitors have been shown to have short-term beneficial effects on endothelial dysfunction among patients with dyslipidemia or cardiovascular disease. The effect of HMG-CoA reductase inhibitors on the endothelial function in diabetes is largely unknown. METHODS: Seventeen patients with type 2 diabetes, free of cardiovascular disease and no other cardiovascular risk factors, except for dyslipidemia, were studied together with ten healthy volunteers. The effect of 5-hydroxytryptamine, as an endothelium-dependent vasodilator, and sodium nitroprusside, as an endothelium-independent vasodilator, on the forearm blood flow was measured using venous occlusion plethysmography. RESULTS: 5-Hydroxytryptamine and sodium nitroprusside, infused in the brachial artery, caused a dose-dependent vasodilation. The vasodilator response to 5-hydroxytryptamine was significantly lower among the diabetic patients, 42 and 56%, than among the controls, 73 and 103%, at a dose of 0.3 and 0.9 ng/kg/min, respectively (P<0.05 and P<0.001). Vasodilator responses to sodium nitroprusside were comparable among the diabetic patients and controls. A 6-week treatment with simvastatin 40 mg once daily did not change the vasodilator responses to 5-hydroxytryptamine or sodium nitroprusside among the patients with diabetes. CONCLUSIONS: The results of this study indicate that the endothelial function is impaired in type 2 diabetes and is not restored after a 6-week treatment period with simvastatin 40 mg.     

Effect of a short-term primary prevention program on endothelium-dependent vasodilation in adults at risk for atherosclerosis

BACKGROUND: Endothelium-dependent vasodilation is impaired in asymptomatic subjects with risk factors for atherosclerosis. PURPOSE: To determine whether a three-month integrative primary prevention program can improve endothelial function in asymptomatic subjects with risk factors for atherosclerosis. PATIENTS AND METHODS: Twenty-two asymptomatic middle-aged men and women (13 men and nine women) aged 55 +/- 7 years with sedentary lifestyle and dyslipidemia (low density lipoprotein [LDL] level greater than 3.4 mmol/L) underwent an exercise test, determination of fasting blood lipid levels and noninvasive measurement of brachial artery reactivity before and three months after the beginning of a prevention program. The program consisted of exercise training (three times per week) and National Cholesterol Education Program step 1 diet in all subjects. A smoking cessation program was offered when applicable (six patients). Brachial artery diameter was measured by using high resolution ultrasound at rest, during reactive hyperemia (flow-mediated dilation [FMD], which is endothelium-dependent) and after sublingual nitroglycerin (NTG) (endothelium-independent vasodilation). RESULTS: After three months, peak oxygen uptake increased significantly from 25.4 +/- 4.9 to 27.5 +/- 4.8 mL/kg/min (P < 0.005), and LDL level decreased significantly from 4.48 +/- 0.92 to 4.00 +/- 0.83 mmol/L (P < 0.005). FMD and NTG responses assessed as percentage of diameter change from baseline, however, did not change (FMD 5.4 +/- 4.3% before and 5.1 +/- 3.9% at three months, not significant; NTG 8.4 +/- 3.8% before and 7.4 +/- 4.5% at three months, not significant). CONCLUSIONS: Short-term application of the currently recommended lifestyle intervention in adults with coronary risk factors did not improve vascular endothelial function. Longer and more aggressive programs may be needed to improve vascular function in subjects with risk factors for atherosclerosis.     

2型糖尿病高危人群的血管内皮功能与血浆游离脂肪酸水平

目的研究2型糖尿病（T2DM）患者、糖耐量正常的2型糖尿病一级亲属（FDRs）、糖耐量减低（IGT）人群的血管内皮功能、血浆游离脂肪酸（FFA）水平并与健康对照组进行比较。方法测定36例健康人（男16例,女20例）、57例FDRs（男27例,女30例）、59例IGT（男25例,女34例）,35例T2DM（男15例,女20例）的FFA水平、内皮依赖性血管舒张功能（EDV）以及空腹胰岛素、TC、TG、BMI、腰臀围比、空腹血糖及糖化血红蛋白,同时计算胰岛素敏感性指数（IAI）。结果FDRs、IGT及T2DM组的EDV显著低于健康对照组[FDRs组（5．03±0．34）％,IGT组（3．09±0．28）％,T2DM组（2．62±0．29）％,对照组（12．45±3．37）％];FFA水平高于对照组[FDRs组（0．52±0．08）mmol／L,IGT组（0．52±0．12）mmol／L,T2DM组（0．59±0．23）mmol／L,对照组（0．46±0．18）mmol／L];IAI低于对照组（FDRs组-4．20±0．38,IGT组-4．41±0．72,T2DM组-4．65±0．64,对照组-3．79±0．57）,差异均有统计学意义（P值均〈0．05）。结论T2DM、糖耐量正常的FDRs及IGT人群存在IAI降低、血管内皮功能受损、FFA升高。     

Efficacy and safety of atorvastatin in hyperlipidemic, type 2 diabetic patients. A 34-week, multicenter, open-label study

Hyperlipidemia is common in type 2 diabetic patients and is an independent risk factor for cardiovascular disease. The aim of this trial was to evaluate the efficacy and safety of once-daily atorvastatin 10-80 mg for the treatment of hyperlipidemia in type 2 diabetics with plasma low-density lipoprotein cholesterol (LDL-C) levels exceeding 3.4 mmol/l (130 mg/dl). One hundred and two patients met the study criteria and received 10 mg/day atorvastatin. Patients who reached the target LDL-C level of 相似文献   

Upregulation of inducible nitric oxide synthase contributes to attenuated cutaneous vasodilation in essential hypertensive humans

Essential hypertension is a proinflammatory, proconstrictor disease coinciding with endothelial dysfunction and inward vessel remodeling. Using the skin circulation, our aim was to determine whether inducible NO synthase (iNOS) upregulation attenuates NO-dependent cutaneous vasodilation in hypertensive humans. We hypothesized that, with hypertension, localized iNOS inhibition would restore vasodilation in response to NO-dependent stimuli, and iNOS expression would be increased and phosphorylated vasodilator-stimulated phosphoprotein would be decreased. For, in vivo protocols, 4 intradermal microdialysis fibers were placed in 9 hypertensive and 10 normotensive men and women (systolic blood pressure: 146±4 versus 113±2 mm Hg; P<0.001). Microdialysis fibers served as control, iNOS inhibited (1400 W), neuronal NO synthase inhibited (N(ω)-propyl-l-arginine), and nonselective NOS inhibited (N(G)-nitro-l-arginine methyl ester). Cutaneous vascular conductance was calculated (percentage of sodium nitroprusside) during standardized local heating (42°C) and acetylcholine dose-response protocols (0.01, 0.10, 1.00, 5.00, 10.00, 50.00, 100.00 mmol/L). The NO-dependent local heating response was attenuated at control (95±2% versus 76±2% cutaneous vascular conductance; P<0.05) and neuronal NO synthase-inhibited sites (94±4% versus 77±3% cutaneous vascular conductance; P<0.01) in hypertensives. iNOS inhibition augmented the NO-dependent local heating response (93±2% versus 89±10% cutaneous vascular conductance). Acetylcholine-induced vasodilation was attenuated in control sites at doses ≥0.1 mmol/L of acetylcholine in hypertensives and was restored with iNOS inhibition (0.1 mmol/L, P<0.05; 1, 5, and 10 mmol/L, P<0.001; 50 and 100 mmol/L, P<0.01). In vitro iNOS expression was increased (P=0.006) and phosphorylated vasodilator-stimulated phosphoprotein was decreased in skin from hypertensive humans (P=0.04). These data suggest that iNOS is upregulated in essential hypertensive humans and contributes to reduced NO-dependent cutaneous vasodilation.     

Effect of oral vitamin E (alpha-tocopherol) supplementation on vascular endothelial function in Type 2 diabetes mellitus.

AIMS: Vascular endothelial dysfunction, an early marker of atherosclerosis, has been demonstrated in Type 2 diabetes mellitus (DM). Vitamin E preserves endothelial function in animal models of diabetes and reduces cardiovascular risk. We examined endothelial function and the effect of vitamin E supplements in uncomplicated Type 2 DM. METHODS: Forty-eight subjects with Type 2 DM and 21 controls had endothelial function assessed using forearm venous occlusion plethysmography with endothelium-independent (sodium nitroprusside) and dependent (acetylcholine, bradykinin) vasodilators. Those with diabetes received 1600 i.u. daily oral alpha-tocopherol or placebo, double-blind for 8 weeks, and had endothelial function reassessed. RESULTS: The diabetic group had higher HbA1c (6.9+/-1.4 vs 4.8+/-0.6%; P<0.01) and systolic (145+/-15 vs. 130+/-16 mm Hg; P<0.01) but not diastolic blood pressure (79+/-8 vs. 76+/-9 mm Hg; P = 0.15). There was blunted vasodilation to acetylcholine (15 microg/min; P<0.01) in subjects with diabetes. Vasodilation to sodium nitroprusside and bradykinin was similar (all P>0.1). Alpha-tocopherol did not affect vasodilation to nitroprusside (P>0.1), acetylcholine (P>0.1) or bradykinin (P>0.1). CONCLUSIONS: There may be receptor-specific endothelial dysfunction in subjects with uncomplicated Type 2 DM. This is not improved by treatment with alpha-tocopherol.     

The effect of atorvastatin on serum lipids,lipoproteins and NMR spectroscopy defined lipoprotein subclasses in type 2 diabetic patients with ischaemic heart disease

The effect of statin therapy on subclasses of LDL, VLDL and HDL lipoproteins is unclear. We compared changes in serum lipids, apolipoproteins and nuclear magnetic resonance (NMR) spectroscopy measured lipoprotein subclass concentration and average particle size over a minimum 6 months treatment period of atorvastatin 10 mg vs. placebo in 122 men and women. All subjects had type 2 diabetes and a modest dyslipidaemia (mean LDL-cholesterol 3.2 mmol/l and median triglycerides 1.8 mmol/l) and had a previous myocardial infarction. Compared with placebo, atorvastatin therapy was associated with a greater decrease in medium VLDL (median within person change -13.4 vs. -5.9 nmol/l, P<0.001 adjusted for baseline level), small VLDL (median change -17.8 vs. -8.1 nmol/l, P=0.002), large LDL (mean within person change -167.9 vs. -48.6 nmol/l, P<0.001) and medium LDL (median within person change -101.8 vs. -22.3 nmol/l, P=0.017). Atorvastatin therapy was also associated with a greater increase in large HDL than placebo (median change 1.40 vs. 0.80 micromol/l, P=0.02) and there was little change in small HDL so that average HDL particle size increased significantly with atorvastatin (P=0.04). In addition to reducing levels of (enzymatically measured) triglyceride, LDL-cholesterol and apolipoprotein B in diabetic patients, atorvastatin significantly reduces NMR measured medium and small VLDL and large and medium LDL, and increases large HDL.     

Current status of diabetes management in elderly Koreans with diabetes

Knowledge about the current status of diabetes management is indispensable for the improvement of diabetes management. We performed a survey to investigate the current trend of diabetes management in elderly Koreans, at eight hospitals located throughout the country. A total of 539 patients with type 2 diabetes older than 65 years (men=224, women=315) were recruited. Their mean age was 71.5+/-4.9 years and BMI 24.3+/-3.4 (men=23.6+/-2.8, women=24.9+/-3.7)kg/m(2), and 38.2% of the patients were obese (BMI> or =25 kg/m(2), men=29.5%, women=44.4%). The mean duration of the diabetes was 13.1+/-9.2 years. Although 37.3% of the patients had A1C below 7.0%, 33.8% of the patients had A1C more than 8.0%. Three hundred and sixty three patients (67.4%) were treated with oral hypoglycemic agents and 175 patients (32.5%) were treated with insulin or combination with oral agents. The glycemic control was better in patients treated with oral agents (oral agent group=7.7+/-4.6%, insulin group=8.5+/-1.9%). Although mean SBP and DBP were 131.4+/-16.7 and 75.9+/-10.4 mmHg, respectively, 67.4% of the patients had hypertension and 38.2% of the patients with hypertension did not reach the goal (<130/80 mmHg). Of 539 elderly patients, 253 patients (47.4%) had dyslipidemia (LDL-C> or =4.1 mmol/l and/or triglyceride> or =2.5 mmol/l and/or HDL-C<1.1 mmol/l) and 72.7% of the patients with dyslipidemia took the lipid lowering agents. However, 47.4% of them did not achieve the goal (LDL-C<2.6 mmol/l and/or triglyceride<1.7 mmol/l and/or HDL-C>1.1 mmol/l). Twenty-eight patients (5.5%) had been admitted to the hospital because of severe hypoglycemia. Half of the patients (57%) had microvascular complications (retinopathy, neuropathy or overt proteinuria), and 28% of the patients had macro-vascular complications (CVD, stroke or peripheral vascular disease). As elderly diabetic patients are usually polymorbid, diabetes mellitus in old age is needed a more comprehensive approach to not only the treatment of hyperglycemia but also of hypertension, dyslipidemia and other associated diseases.