A central role of eNOS in the protective effect of wine against metabolic syndrome

The effect of polyphenol-rich chardonnay seed supplements on peripheral endothelial function

OBJECTIVE

Peripheral endothelial dysfunction (PED) is associated with major adverse cardiovascular events. Similar to cardio-protective Mediterranean diet, Chardonnay seeds are rich in polyphenols, fibers, and grape seed oil. In this randomized double-blinded trial, we investigated safety and incremental benefit of Chardonnay seed polyphenols-rich (PR), compared to polyphenols-free (PF), supplements on PED.

METHODS

89 patients with PED [reactive hyperemia-peripheral arterial tonometry (RH-PAT) index ≤ 2) were randomized 1:1 to 4.8 g (6 capsules)/day PR or PF for 4 months. PR and PF capsules had equal amounts of seed oil (~ 7% capsule weight), fibers, and carbohydrates, but only PR capsules contained polyphenols (~ 11% capsule weight). Baseline and follow-up RH-PAT indices (primary endpoint) and endothelial progenitor cells (EPC) levels were measured. Patients were asked to maintain their regular diet and exercise habits during study period.

RESULTS

Baseline RH-PAT indices, demographics, lab values, and EPC levels were similar between groups. No significant adverse reactions to PR or PF were reported. Follow-up RH-PAT indices significantly increased (p < 0.05 vs. baseline) in both groups to similar extent (31 ± 39% PR vs. 49 ± 53% PF, p = 0.09). Circulating CD34 + EPCs equally increased (median + 55% vs. + 54%, p = 0.94) in PR and PF groups, respectively.

CONCLUSION

PR and PF Chardonnay seed supplements were safe and improved peripheral endothelial function to similar extent in PED patients. However, there were no incremental benefits of PR over PF on RH-PAT indices or CD34 + EPC levels. Chardonnay seed supplements role in primary prevention of atherosclerosis, as add-on to healthy lifestyle and guidelines directed medical therapy, should be further explored. CLINICALTRIALS.

GOV IDENTIFIER (NCT NUMBER)

NCT02093455.

Wine, food, and health

Wine has historically been associated with religious rights, used as a salubrious beverage, employed as a medication as well as a medicinal solvent, and consumed as a food accompaniment. It is the last use that is most intimately associated in the minds of most modern consumers. Despite this, there is little flavor commonality on which pairing could be based. The first section of the chapter examines this feature and wine's primary role as a palate cleanser and food condiment. The synergistic role of food and wine in suppressing each other's least pleasant attributes is also explained. The final section deals with the latest evidence relating to the many beneficial health effects of moderate wine consumption, shortfalls in the data, headache induction, dental erosion, and conditions under which wine intake is contraindicated.

Hypoglycemic and Hypolipemic Effects of a New Lecithin Formulation of Bergamot Polyphenolic Fraction: A Double Blind, Randomized, Placebo- Controlled Study

OBJECTIVE

Hyperlipemia represents an independent risk factor in the development of atherosclerosis in patients undergoing type 2 diabetes mellitus (DM). Moreover, the pharmacological treatment of dyslipemia in patients undergoing type 2 DM (e.g. by means of statins), is accompanied by relevant side effects and oral supplementation with natural antioxidants, such as Citrus polyphenols, has recently been suggested to improve cardioprotection in such patients. However, due to the poor gastrointestinal absorption of polyphenols, novel formulations have recently been developed for getting a better bioavailability of polyphenolic rich fractions of citrus species extract rich in polyphenols.

METHODS

Here, we investigated the effect of standard bergamot polyphenolic fraction (BPF®) as well as of its phytosomal formulation (BPF Phyto), in patients with type 2 DM and hyperlipemia. A randomized, double blind, placebo-controlled study was carried out in 60 patients suffering from type 2 DM and mixed hyperlipemia. Patients were divided into three groups: one receiving placebo, the second receiving standard BPF and the third BPF Phyto.

RESULTS

In the groups receiving BPF and BPF Phyto, a significant reduction of fasting plasma glucose, serum LDL cholesterol and triglycerides accompanied by increased HDL cholesterol was observed. This effect was associated with significant reduction of small dense atherogenic LDL particles, as detected by means of proton NMR Spectroscopy, thus confirming the hypolipemic and hypoglycemic effect of bergamot extract both when using standard formulation as well as BPF Phyto. No differences were seen in the therapeutic response among groups receiving BPF and BPF Phyto, thus suggesting a substantial bioequivalence in their hypoglycemic and hypolipemic profile. However, when comparing the pharmacokinetic profile of naringin (the major component of BPF) and its metabolites, in patients treated with BPF Phyto, an at least 2,5 fold increase in its absorption was found, confirming in human studies the better profile of BPF Phyto compared to standard BPF.

CONCLUSION

These data suggest that better absorption and tissue distribution of BPF Phyto formulation represents an innovative approach in supplementation treatments of cardiometabolic disorders.

Wine: An Aspiring Agent in Promoting Longevity and Preventing Chronic Diseases

INTRODUCTION

Moderate wine consumption is a characteristic of the Mediterranean diet. Studies around the world have shown a beneficial effect of moderate alcohol intake, especially wine, on health. This review aims to critically summarise the most recent studies that investigate the beneficial effects of moderate wine intake on human health.

METHODS

The PubMed database was comprehensively searched to identify trials published from 2013 to 2018 that investigated the association between moderate wine consumption and health.

RESULTS

The most recent studies confirm the valuable role of moderate wine consumption, especially red wine, in the prevention and treatment of chronic diseases such as cardiovascular disease, metabolic syndrome, cognitive decline, depression, and cancer. In the meantime, recent studies also highlight the beneficial role of red wine against oxidative stress and in favour of desirable gut bacteria. The beneficial role of red wine has been attributed to its phytochemical compounds, as highlighted by clinical trials, where the effect of red wine has been compared to white wine, non-alcoholic wine, other alcoholic drinks, and water.

CONCLUSIONS

Moderate wine intake, at 1⁻2 glasses per day as part of the Mediterranean diet, has been positively associated with human health promotion, disease prevention, and disease prognosis.

Wine grape pomace flour improves blood pressure, fasting glucose and protein damage in humans: a randomized controlled trial

BACKGROUND

The Mediterranean diet is a healthy diet with positive scientific evidence of preventing chronic diseases. Bioactive components support the healthy properties of the Mediterranean diet. Antioxidants and fiber, two components of the Mediterranean diet, are key functional nutrients for healthy eating and nutrition. Wine grape pomace is a rich source of these dietary constituents and may be beneficial for human health. Our hypothesis was that the intake of red wine grape pomace flour (WGPF) prepared from red wine grapes (Cabernet Sauvignon variety) reduced the metabolic syndrome in humans. To evaluate the effect of WGPF on components of metabolic syndrome we design a 16-week longitudinal intervention study. Thirty-eight males, 30-65 years of age, with at least one component of metabolic syndrome, were randomly assigned to either the intervention group (n = 25) or the control group (n = 13). At lunch, the intervention group was given 20 g of WGPF per day, which contained 10 g of dietary fiber, 822 mg of polyphenols and an antioxidant capacity of 7258 ORAC units. Both groups were asked to maintain their regular eating habits and lifestyles. Clinical evaluation, anthropometric measurements and biochemical blood analyses were done at the beginning and the end of the study.

RESULTS

WGPF intake significantly decreased systolic and diastolic blood pressure as well as fasting glucose levels. Plasma γ-tocopherol and δ-tocopherol increased and carbonyl group in plasma protein decreased in WGPT group, significantly. No significant effect was observed for waist circumference, HDL cholesterol, triglycerides, total antioxidant capacity and vitamin C in and between groups. The group-dependent magnitude of the differences between the baseline and final postprandial insulin values and γ-tocopherol concentrations was statistically significant.

CONCLUSIONS

The consumption of WGPF-rich in fiber and polyphenol antioxidants, as a food supplement in a regular diet improves blood pressure, glycaemia and postprandial insulin. In addition, increased antioxidant defenses and decreased oxidative protein damage indicating attenuation of oxidative stress. WGPF might be a useful food ingredient for health promotion and chronic disease prevention.

Gender differences in the association of hazardous alcohol use with hypertension in an urban cohort of people living with HIV in South Florida

Objective

Industrialized countries are currently experiencing an epidemic of high blood pressure (HBP) extending to people living with HIV (PLWH). Given the prevalence of hazardous alcohol use (HAU), this study examines the relationship between alcohol consumption and hypertension in PLWH. Including a gender analysis is critical, given the high rates of HAU and HIV among females.

Method

We followed PLWH including both HAU and non-HAU (200 each). Participants were assessed twice for body weight, blood pressure, alcohol consumption, and other BP-associated lifestyle factors. High blood pressure (defined as systolic/diastolic blood pressure above 140/90 mmHg and/or treatment of HBP) was the primary outcome.

Results

Overall prevalence of hypertension was 38% and higher among HAU compared to non-HAU (42% vs. 34%, p = 0.02). Less than half with HBP (42%) were receiving treatment for hypertension. Overall, males had a 50% higher risk of HBP than women (odds ratio: 1.5, 95% CI: 1–2.6, p = 0.05). However among HAU, females were twice as likely to suffer HBP as their male counterparts (95% CI: 1–3.9, p = 0.02). Those HAU who preferred liquor, versus wine, had higher adjusted mean BP (132.6±18 vs. 122.3±14 mm Hg, p = 0.05). Additional analyses indicated that consumption of >1 standard drink of liquor or beer/day was associated with HBP. Risk of hypertension was noted in those with daily consumption of >3 glasses of wine. For those reporting <1 drink per day, the odds ratio of having HBP was 0.97 (CI: 0.6–0.99, p = 0.05). Factors associated with hypertension in the multivariate model included increased age, gender, BMI, HAU particularly of liquor, and smoking.

Conclusions

Excessive hypertension burden in this population and its association with HAU and sub-optimal care indicate the need for preventive and educational intervention in PLWH. Analyses highlight the necessity of gender and type-of-beverage specific approaches.

Endothelium and its alterations in cardiovascular diseases: life style intervention

The endothelium, which forms the inner cellular lining of blood vessels and lymphatics, is a highly metabolically active organ that is involved in many physiopathological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion, and trafficking and inflammation. In this review, we summarized and described the following: (i) endothelial cell function in physiological conditions and (ii) endothelial cell activation and dysfunction in the main cardiovascular diseases (such as atherosclerosis, and hypertension) and to diabetes, cigarette smoking, and aging physiological process. Finally, we presented the currently available evidence that supports the beneficial effects of physical activity and various dietary compounds on endothelial functions.

Wine, Food and Health

Wine has historically been associated with religious rights, used as a salubrious beverage, employed as a medication as well as a medicinal solvent, and consumed as a food accompaniment. It is the latter that is most intimately associated in the minds of most modern consumers. Despite this, there is little flavor commonality on which pairing could be based. The first section of the chapter examines this feature, and wine’s primary role as a palate cleanser and food condiment. The synergistic role of food and wine in suppressing each other’s least pleasant attributes is also explained. The final section deals with the latest evidence relating to the many beneficial health effects of moderate wine consumption, shortfalls in the data, headache induction, dental erosion, and conditions under which wine intake is contraindicated.

Mitochondrial dysfunction in metabolic syndrome and asthma

Though severe or refractory asthma merely affects less than 10% of asthma population, it consumes significant health resources and contributes significant morbidity and mortality. Severe asthma does not fell in the routine definition of asthma and requires alternative treatment strategies. It has been observed that asthma severity increases with higher body mass index. The obese-asthmatics, in general, have the features of metabolic syndrome and are progressively causing a significant burden for both developed and developing countries thanks to the westernization of the world. As most of the features of metabolic syndrome seem to be originated from central obesity, the underlying mechanisms for metabolic syndrome could help us to understand the pathobiology of obese-asthma condition. While mitochondrial dysfunction is the common factor for most of the risk factors of metabolic syndrome, such as central obesity, dyslipidemia, hypertension, insulin resistance, and type 2 diabetes, the involvement of mitochondria in obese-asthma pathogenesis seems to be important as mitochondrial dysfunction has recently been shown to be involved in airway epithelial injury and asthma pathogenesis. This review discusses current understanding of the overlapping features between metabolic syndrome and asthma in relation to mitochondrial structural and functional alterations with an aim to uncover mechanisms for obese-asthma.

Prevalence and determinants of metabolic syndrome among women in Chinese rural areas

Background and Aims

Metabolic syndrome (MS) is prevalent in recent years but few data is reported in the rural areas in China. The aim of this study was to examine MS prevalence and its risk factors among women in rural China.

Methods and Results

The Nantong Metabolic Syndrome Study (NMSS), a population based cross-sectional study, was conducted during 2007–2008 in Nantong, China. In person interviews, blood glucose and lipid measurements were completed for 13,505 female participants aged 18–74 years. The International Diabetes Federation (IDF), the US Third Report of the National Cholesterol Education Program, the Adult Treatment Panel (ATPIII) and modified ATPIII for Asian population has determined three criteria of MS. These criteria for MS were used and compared in this study. The prevalence of MS was 22.0%, 16.9% and 23.3% according to IDF, ATPIII and ATPIII-modified criteria, respectively. Levels of agreement of these criteria for MS were above 0.75. We found that vigorous-intensity of occupational physical activity was associated with a low prevalence of MS with OR of 0.76 (95% confidence interval (CI): 0.63–0.91). Rice wine drinkers (alcohol >12.8 g/day) had about 34% low risks of developing MS with OR of 0.66 (95% CI: 0.48–0.91), compared with non-drinkers. Odds ratio of MS was 1.81 (95% CI: 1.15–2.84) in women who smoked more than 20 pack-years, compared to non-smokers. Odds ratio of MS was 1.56 (95% CI: 1.25–1.95) in women who had familial history of diseases, including hypertension, diabetes and stroke, compared to women without familial history of those diseases.

Conclusion

MS is highly prevalent among women in rural China. Both physical activity and rice wine consumption play a protective role, while family history and smoking are risk factors in MS development. Educational programs should be established for promoting healthy lifestyles and appropriate interventions in rural China.

Methoxy VO-salen stimulates pancreatic β cell survival by upregulation of eNOS and downregulation of apoptosis in STZ-induced diabetic rats

The present study was designed to investigate the effect of MetVO-salen in ameliorating diabetes and oxidative stress in the pancreas of diabetic rats. Streptozotocin (STZ)-induced diabetic rats were treated with MetVO-salen complex intraperitonially (0.3 and 0.6 mg/kg) thrice a week and continued for 8 weeks. Total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides in serum, and blood glucose were estimated. Furthermore, oxidative stress in rats was also investigated in terms of superoxide dismutase (SOD), catalase, lipid peroxidation, and glutathione (GSH). In addition, the anti-diabetic activity of MetVO-salen was also investigated by assessing histopathological, immunohistochemical in terms of endothelial nitric oxide synthase expression, and apoptotic events in pancreas. Treatment with MetVO-salen complex reduced the blood glucose level and significantly altered the serum biochemical parameters of diabetic rats. Treatment with above complex decreased the lipid peroxidation and the antioxidant enzymes such as SOD, CAT, and GSH to near-control levels. Histopathological, immunohistochemical, and apoptotic studies also revealed that MetVO-salen-induced amelioration of the diabetic state appears to be significant to the preservation of a functional portion of the pancreatic β cells which initially prevent STZ toxicity. This study provides new direction for the management of diabetes but needs further clinical evaluation.

The 27-bp VNTR polymorphism in intron 4 of the human eNOS gene in healthy Singaporean Chinese, Indians, and Malays

Human endothelial nitric oxide synthase (eNOS) is one isoform of the nitric oxide synthases that are responsible for nitric oxide synthesis from L-arginine. The gene encoding eNOS contains a 27-bp VNTR polymorphism in intron 4. We report here for the first time the presence of a novel allele 3, which was absent in all other populations studied to date, in 1.7% each of Singaporean Indians and Malays. We also detected the presence of a novel genotype 3/5 in 3.4% each of Singaporean Indians and Malays. Allele 6, which was absent in Han Chinese from northern China and Taiwan and was also absent in Indians from the Indian subcontinent, was found in 2.1% of Singaporean Chinese and in 0.3% of Singaporean Indians.

High prevalence of metabolic syndrome in an elderly Croatian population - a multicentre study

OBJECTIVE

To investigate the prevalence and characteristics of metabolic syndrome (MetS) in a healthy elderly Croatian population.

DESIGN

Cross-sectional study consisting of a health check including anthropometric measures and food questionnaires as well as analysis of biochemical parameters related to MetS. The diagnostic criteria of the International Diabetes Federation (IDF) were used for diagnosis of MetS.

SETTING

Four centres in continental (Virovitica and Zagreb) and Adriatic coast (Split and Omiš) regions of Croatia.

SUBJECTS

Free-living elderly persons aged 70-90 years (n 320).

RESULTS

Significantly lower MetS prevalence was found among participants from small urban centres compared with those from large urban centres (59·1 % v. 69·6 %; P = 0·051). Participants without MetS consumed wine more frequently (P = 0·05) than those with MetS. Compared with their peers with HDL cholesterol (HDL-C) <1·03 mmol/l, more male participants with HDL-C ≥1·03 mmol/l consumed wine (P = 0·04) or pelagic fish (P = 0·03). The prevalence of participants with TAG ≥1·7 mmol/l was higher in wine non-consumers (P = 0·05) than in wine consumers. Multivariate analysis with age and gender as covariates showed a significant inverse association of wine consumption with total cholesterol (P < 0·001), a positive association with HDL-C (P < 0·001) and a marginally inverse association with TAG (P = 0·06). In the male population, alkaline phosphatase and γ-glutamyl transferase activities were higher in participants with MetS (P < 0·05).

CONCLUSIONS

High MetS prevalence was observed in an elderly Croatian population. Data showed that moderate consumption of wine and/or pelagic fish has a protective role against MetS in the population studied.

A novel component of the metabolic syndrome: the oxidative stress

The metabolic syndrome (MS) represents a cluster of cardiovascular (CV) risk factors associated to CV disease and type 2 diabetes. It is still under debate whether MS is a mere aggregation of risk factors or it represents a clinical entity with visceral obesity as underlying pathophysiological trigger. The publication of several diagnostic criteria of MS by scientific associations or experts panels reflects this uncertainty in understanding the real nature of MS. Besides the metabolic disturbances of MS, as visceral obesity, hypertriglyceridemia, low HDL cholesterol, hypertension and hyperglycemia, novel mechanisms of arterial damage have been identified. This paper reviews the evidence showing that MS and MS factors are characterized by increased oxidative stress, a relevant factor contributing to the development of metabolic and cardiovascular complications. In the next future, the measure of plasma oxidative stress may contribute to identify a subset of MS patients at increased CV risk, candidates to more intensive therapies.

Regular moderate intake of red wine is linked to a better women's sexual health

INTRODUCTION

While some evidence does exist for a positive correlation between moderate wine intake and men's sexual health, there is no study addressing the potential correlation between red wine intake and women's sexual function.

AIM

The aim of our study was to assess whether there is a tie between daily red wine intake and sexual function in a sample of healthy Italian women, living in the Chianti area (Tuscany) not complaining of any sexual disorders.

METHODS

We recruited 798 women (age 18-50), living in the Chianti area (Tuscany), not complaining of any sexual disorders. We divided the participants into three groups: daily moderate (one to two glasses) red wine intake (group 1); teetotallers (group 2); and daily intake of more than two glasses of red wine and/or other types of alcoholic drinks (including white wine), as well as of those reporting occasional drinking (group 3).

MAIN OUTCOME MEASURES

All participants completed anonymously the Female Sexual Function Index (FSFI) questionnaire and were asked to report on their amount and type of alcohol consumption.

RESULTS

Group 1 had significantly higher total (P = 0.001), as well as desire and lubrication domain (P = 0.001 and P = 0.001, respectively) FSFI scores than participants in groups 2 and 3. No significant differences between the groups were observed concerning sexual arousal, satisfaction, pain, and orgasm. Univariate analysis showed a significant correlation between age, alcohol consumption (P = 0.009), and a better score at questionnaire examination. During multivariate analysis, alcohol consumption was identified as an independent prognostic parameter (P = 0.002) in predicting the better score at questionnaire examination.

CONCLUSIONS

The finding that regular moderate intake of red wine is associated with higher FSFI scores for both sexual desire, lubrication, and overall sexual function as compared to the teetotaller status is intriguing. While this finding needs to be interpreted with some caution, because of the small sample size, self-reported data, and the lack of support from laboratory exams, it nevertheless suggests a potential relationship between red wine consumption and better sexuality.

Erythritol is a sweet antioxidant

OBJECTIVE

Hyperglycemia, oxidative stress, and the onset and progression of diabetic complications are strongly linked. Reduction of oxidative stress could be of utmost importance in the long-term treatment of diabetic patients. The chronic nature of the disease calls for a mode of antioxidant intake that can be sustained easily, e.g., by the diet. Erythritol, a simple polyol, could be such a compound. It is orally available, well tolerated, and its chemical structure resembles that of mannitol, a well-known hydroxyl radical (HO*) scavenger.

METHODS

We studied the antioxidant properties of erythritol in vitro and subsequently determined its antioxidant activity and its vasoprotective effect in the streptozotocin diabetic rat.

RESULTS

Erythritol was shown to be an excellent HO* radical scavenger and an inhibitor of 2,2'-azobis-2-amidinopropane dihydrochloride-induced hemolysis but inert toward superoxide radicals. High-performance liquid chromatographic and electron spin resonance spectroscopy studies showed that the reaction of erythritol with hydroxyl radicals resulted in the formation of erythrose and erythrulose by abstraction of a carbon-bound hydrogen atom. In the streptozotocin diabetic rat, erythritol displayed an endothelium-protective effect and, in accordance with the in vitro experiments, erythrose was found in the urine of erythritol-consuming rats.

CONCLUSION

Erythritol acts as an antioxidant in vivo and may help protect against hyperglycemia-induced vascular damage.

The Asp298 allele of endothelial nitric oxide synthase is a risk factor for myocardial infarction among patients with type 2 diabetes mellitus

BACKGROUND

Endothelial dysfunction plays a central role in atherosclerotic progression and cardiovascular complications of type 2 diabetes mellitus (T2DM). Given the role of nitric oxide in the vascular system, we aimed to test hypotheses of synergy between the common endothelial nitric oxide synthase (eNOS) Asp298 allele and T2DM in predisposing to acute myocardial infarction (AMI).

METHODS

In a population-based patient survey with 403 persons with T2DM and 799 healthy subjects from the population without diabetes or hypertension, we analysed the relation between T2DM, sex and the eNOS Asp298 allele versus the risk for AMI.

RESULTS

In an overall analysis, T2DM was a significant independent risk factor for AMI. In patients with T2DM, homozygosity for the eNOS Asp298 allele was a significant risk factor (HR 3.12 [1.49-6.56], p = 0.003), but not in subjects without diabetes or hypertension. Compared to wild-type non-diabetic subjects, all patients with T2DM had a significantly increased risk of AMI regardless of genotype. This risk was however markedly higher in patients with T2DM homozygous for the Asp298 allele (HR 7.20 [3.01-17.20], p < 0.001), independent of sex, BMI, systolic blood pressure, serum triglycerides, HDL -cholesterol, current smoking, and leisure time physical activity. The pattern seemed stronger in women than in men.

CONCLUSION

We show here a strong independent association between eNOS genotype and AMI in patients with T2DM. This suggests a synergistic effect of the eNOS Asp298 allele and diabetes, and confirms the role of eNOS as an important pathological bottleneck for cardiovascular disease in patients with T2DM.

Role of nitric oxide in alcohol-induced changes in lipid profile of moderate and heavy alcoholics

Biochemical changes in plasma and red cell membrane in moderate and heavy alcoholics were investigated to compare them with teetotalers in the present study. Significant changes in lipid, lipoprotein profile, and lipid peroxidation were evident from the study suggesting the cardioprotective effect in moderate alcoholics, and adverse changes leading to cardiovascular risk in heavy alcoholics. Both nitrite and nitrate levels in plasma of moderate alcoholics increased significantly when compared with teetotalers and the increase is more pronounced in heavy alcoholics. The results of the present study showed no significant difference in osmotic hemolysis in red cells from moderate and heavy alcoholics incubated with NaCl at concentrations ranging from 0.1% to 0.9%. Further, the study showed a possible relationship of nitric oxide (NO) with changes in plasma lipid profile. To sum up, these changes in both moderate and heavy alcoholics clearly indicated the involvement of NO in rendering tolerance to alcohol-induced effects and also in modulation of alcohol effects.

Protective effect of endothelial nitric oxide synthase against induction of chemically-induced diabetes in mice

Since activation of endothelial nitric oxide synthase has been shown to exert protective effects against the metabolic syndrome, while endothelial nitric oxide synthase knockout mice develop hyperinsulinemia and glucose intolerance, we hypothesised that endothelial nitric oxide might play a protective role against induction of diabetes. The role of endothelial nitric oxide in the development of chemically-induced diabetes has been determined using mice in which the bioavailability of endothelial nitric oxide was either increased, through upregulation of endothelial nitric oxide synthase, or absent, through deletion of endothelial nitric oxide synthase gene. Diabetes was induced intraperitoneally with either a single dose of alloxan, streptozotocin, or multiple low doses of streptozotocin and blood glucose monitored twice a week. The role of cyclic guanosine monophosphate was investigated in wildtype mice by treatment with the phosphodiesterase inhibitor, tadalafil, during diabetes induction. Results showed that the incidence of diabetes was markedly decreased in mice overexpressing endothelial nitric oxide synthase, compared to wildtype or endothelial nitric oxide synthase knockout mice, regardless of the method of diabetes induction. Under normal physiological conditions, or during diabetes induction with alloxan or multiple low doses of streptozotocin, blood glucose was significantly lower in mice overexpressing endothelial nitric oxide synthase compared to wildtype or knockout mice. Treatment with tadalafil had no effect on the incidence or severity of diabetes in wildtype mice. We conclude that upregulation of endothelial nitric oxide synthase exerts a protective action against diabetes induction through a direct effect of nitric oxide, independently of cyclic guanosine monophosphate.

Environmental vascular risk factors: new perspectives for stroke prevention

Despite intensive evaluation of acute stroke patients, perhaps only half of the attributable stroke risk is usually identified. In addition to traditional and non-traditional vascular risk factors-including most recently homocysteine, inflammation, and alterations of coagulation-a number of environmental risk factors for stroke have been identified in the last decade. In this update we review the following: lower education and poor socioeconomic status (probable surrogates for exposure to traditional high-risk behaviors such as smoking, poor nutrition, lack of prenatal control, absence of preventive medical and dental care, and non-compliance of treatment of conditions such as hypertension); depression, stress and affective disorders; obstructive sleep apnea; passive smoking and environmental pollution; infections, in particular periodontal diseases that increase C-reactive protein (CRP); raised body mass index (obesity); exercise, and diet. The possible role of high-fructose corn syrup in the epidemic of obesity in the USA is reviewed. Protective diets include higher consumption of fish, olive oil, grains, fruits and vegetables (Mediterranean diet), as well as probiotic bacteria in yogurt and dairy products. Careful attention should be given to the patient's environment looking for modifiable factors. The effects of clean environmental air and water, adequate diet and appropriate nutrition, healthy teeth, exercise, and refreshing sleep in the prevention of stroke and cardiovascular disease appear to be quite compelling. Although some of these modifiable risk factors lack evidence-based information, judicious clinical sense should be used to counteract the potentially damaging effects of adverse environmental vascular risk factors.