Endothelial nitric oxide synthase (eNOS) variants were previously demonstrated in cardiovascular disease. To evaluate whether eNOS gene variants are associated with insulin resistance and type 2 diabetes, we evaluated polymorphisms in Exon7 (E298D), intron 18 (IVS18 ؉ 27A3 C), and intron 23 (IVS23 ؉ 10G3 T) in 159 type 2 diabetic patients without macrovascular complications and in 207 healthy control subjects. Samples for all hormonal and metabolic variables were obtained after an overnight fast. The D298 and IVS18 ؉ 27C alleles, but not the IVS23 ؉ 10G3 T variant, were significantly more frequent in type 2 diabetic patients than in control subjects. The two-and three-loci haplotype analysis showed that there is a statistically significant association between the eNOS variants and type 2 diabetes. No significant differences were observed in the clinical characteristics of type 2 diabetic patients according to genotypes (except for visceral obesity [waist-to-hip ratio], which was significantly more present in D298 homozygotes). Healthy control subjects homozygous for both D298 and IVS18 ؉ 27C presented higher insulin, C-peptide, and nitric oxide levels, as well as higher HOMA (homeostasis model assessment) values than the double wild-type homozygotes, with values superimposable on those found in type 2 diabetic patients. In conclusion, we described a significant association between eNOS gene polymorphisms and type 2 diabetes, suggesting a new genetic susceptibility factor for hyperinsulinemia, insulin resistance, and type 2 diabetes. Diabetes 52:1270 -1275, 2003 T ype 2 diabetes is associated with a marked increase in coronary heart disease (CHD) (1), and increased risk factors for CHD before the onset of type 2 diabetes have been shown in several populations (2,3). In addition, type 2 diabetic patients with clinical cardiovascular disease sustain a worse prognosis for survival than cardiovascular disease patients without diabetes (4). This seems correlated to the high atherogenic state already present in a prediabetic state, which might be partly related to insulin resistance (5).Recently, endothelial dysfunction, such as nitric oxide (NO) impairment, is regarded as an early step in the development of insulin resistance, atherosclerosis, and type 2 diabetes (6 -8). Studies evaluating the relation between CHD and endothelial dysfunction have clearly demonstrated that reduced NO-dependent endothelial vasodilation is an early functional disturbance in the development of atherosclerotic lesions (6 -8). In addition, among the many activities of NO, it has demonstrated its ability to modulate peripheral and hepatic glucose metabolism and insulin secretion, according to Pieper (9), who suggested that NO alterations play an important role in the evolution of insulin resistance and type 2 diabetes. Moreover, our group has found high NO levels and endothelial dysfunction in type 2 diabetic patients and first-degree relatives of subjects with type 2 diabetes (10), as well as in subjects with the insulin resistance syndrome...
OBJECTIVE -The aim of this study was to evaluate whether long-term administration of L-arginine acting through a normalization of NO/cyclic-guanosine-3Ј,5Ј-cyclic monophosphate (cGMP) pathway was able to ameliorate peripheral and hepatic insulin sensitivity in 12 lean type 2 diabetic patients. RESEARCH DESIGN AND METHODS-A double-blind study was performed for 3 months. In the first month, patients were treated with their usual diet. Then they were randomly allocated into two groups. In group 1, patients were treated with diet plus placebo (orally three times per day) for 2 months. In group 2 patients were treated for 1 month with diet plus placebo (orally, three times per day) and then for 1 month with diet plus L-arginine (3 g three times per day). At the end of the first and the second month of therapy, patients underwent a euglycemichyperinsulinemic clamp combined with [6, H 2 ]glucose infusion. A total of 10 normal subjects underwent the same test as control subjects.RESULTS -In group 1, no changes in basal cGMP levels, systolic blood pressure, forearm blood flow, glucose disposal, and endogenous glucose production were observed throughout. In group 2, L-arginine normalized basal cGMP levels and significantly increased forearm blood flow by 36% and glucose disposal during the clamp by 34%, whereas it decreased systolic blood pressure and endogenous glucose production by 14 and 29%, respectively. However, compared with normal subjects, L-arginine treatment was not able to completely overcome the defect in glucose disposal.CONCLUSIONS -L-Arginine treatment significantly improves but does not completely normalize peripheral and hepatic insulin sensitivity in type 2 diabetic patients. Diabetes Care 24:875-880, 2001C ontradictory results have been found concerning the influence of insulin on nitric oxide (NO), a potent molecule with vasodilatory function. Baron et al. (1,2) showed that insulinmediated vasodilation is largely dependent on the action of insulin on NO release, whereas Petrie et al. (3) have shown that endothelial NO synthesis and insulin sensitivity are positively correlated in healthy individuals. In addition, in obese patients and patients with type 2 diabetes, the insulin-mediated vasodilatory response seems blunted (4). However, Yki-Jarvinen et al. (5) were unable to find any correlation between insulin action and increment in blood flow in normal and obese subjects, although all agree that methacoline-induced vasodilation is impaired in insulin-resistant subjects.L-Arginine is a precursor for NO, and both in vitro and in vivo studies have demonstrated that L-arginine can augment vascular dilation under certain conditions (6). Experimental studies in cholesterol-fed rabbits have shown that dietary supplementation with L-arginine causes attenuation of endothelial dysfunction with increased NO activity, resulting in reduced platelet activation (7), monocyte adhesion (8), and a marked reduction in aortic and coronary atherosclerosis (9). Moreover, in young hypercholesterolemic adults, the administr...
Background There is no information on acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) among invasively ventilated coronavirus disease 2019 (COVID-19) patients in Western healthcare systems. Objective To study the prevalence, characteristics, risk factors and outcome of AKI and CRRT among invasively ventilated COVID-19 patients. Methods Observational study in a tertiary care hospital in Milan, Italy. Results Among 99 patients, 72 (75.0%) developed AKI and 17 (17.7%) received CRRT. Most of the patients developed stage 1 AKI (33 [45.8%]), while 15 (20.8%) developed stage 2 AKI and 24 (33.4%) a stage 3 AKI. Patients who developed AKI or needed CRRT at latest follow-up were older, and among CRRT treated patients a greater proportion had preexisting CKD. Hospital mortality was 38.9% for AKI and 52.9% for CRRT patients. Conclusions Among invasively ventilated COVID-19 patients, AKI is very common and CRRT use is common. Both carry a high risk of in-hospital mortality.
There are concerns of a high barotrauma rate in coronavirus disease 2019 patients with acute respiratory distress syndrome receiving invasive mechanical ventilation. However, a few studies were published, and reported rates were highly variable. We performed a systematic literature review to identify rates of barotrauma, pneumothorax, and pneumomediastinum in coronavirus disease 2019 acute respiratory distress syndrome patients receiving invasive mechanical ventilation.DATA SOURCE: PubMed and Scopus were searched for studies reporting barotrauma event rate in adult coronavirus disease 2019 patients receiving invasive mechanical ventilation. STUDY SELECTION:We included all studies investigating adult patients with coronavirus disease 2019 acute respiratory distress syndrome requiring mechanical ventilation. Case reports, studies performed outside ICU setting, and pediatric studies were excluded. Two investigators independently screened and selected studies for inclusion. DATA EXTRACTION:Two investigators abstracted data on study characteristics, rate of pneumothorax, pneumomediastinum and overall barotrauma events, and mortality. When available, data from noncoronavirus disease 2019 acute respiratory distress syndrome patients were also collected. Pooled estimates for barotrauma, pneumothorax, and pneumomediastinum were calculated.DATA SYNTHESIS: A total of 13 studies with 1,814 invasively ventilated coronavirus disease 2019 patients and 493 noncoronavirus disease 2019 patients were included. A total of 266/1,814 patients (14.7%) had at least one barotrauma event (pooled estimates, 16.1% [95% CI,). Pneumothorax occurred in 132/1,435 patients (pooled estimates, 10.7%; 95% CI, 6.7-14.7%), whereas pneumomediastinum occurred in 162/1,432 patients (pooled estimates, 11.2%; 95% CI, 8.0-14.3%). Mortality in coronavirus disease 2019 patients who developed barotrauma was 111/198 patients (pooled estimates, 61.6%; 95% CI, 50.2-73.0%). In noncoronavirus disease 2019 acute respiratory distress syndrome patients, barotrauma occurred in 31/493 patients (6.3%; pooled estimates, 5.7%; 95% CI, −2.1% to 13.5%). CONCLUSIONS:Barotrauma occurs in one out of six coronavirus disease 2019 acute respiratory distress syndrome patients receiving invasive mechanical ventilation and is associated with a mortality rate of about 60%. Barotrauma rate may be higher than noncoronavirus disease 2019 controls.
. Triglycerides impair postischemic recovery in isolated hearts: roles of endothelin-1 and trimetazidine. Am J Physiol Heart Circ Physiol 281: H1122-H1130, 2001.-There is growing evidence that hypertriglyceridemia exacerbates ischemic injury. We tested the hypothesis that triglycerides impair myocardial recovery from low-flow ischemia in an ex vivo model and that such an effect is related to endothelin-1. Hyperglycemic (glucose concentration ϭ 12 mmol/l) and hyperinsulinemic (insulin concentration ϭ 1.2 mol/l) isolated rat hearts were perfused with Krebs-Henseleit buffer (PO 2 ϭ 670 mmHg, pH 7.4, 37°C) added with increasing triglycerides (0, 1,000, 2,000, and 4,000 mg/dl, n ϭ 6-9 rats/group). Hearts were exposed to 60 min of low-flow ischemia (10% of basal coronary flow), followed by 30 min of reperfusion. We found that increasing triglycerides impaired both the diastolic (P Ͻ 0.005) and systolic (P Ͻ 0.02) recovery. The release of endothelin-1 during reperfusion increased linearly with triglyceride concentration (P ϭ 0.0009). Elevated triglycerides also increased the release of nitrite and nitrate (NO x), the end products of nitric oxide, up to 6 mol/min. Trimetazidine (1 mol) further increased NO x release, blunted endothelin-1 release, and protected myocardial function during recovery. We conclude that high triglyceride levels impair myocardial recovery after low-flow ischemia in association with endothelin-1 release. The endothelium-mediated effect of triglycerides on both contractile recovery and endothelin-1 release is prevented by 1 M trimetazidine. nitric oxide ACCUMULATING EPIDEMIOLOGICAL EVIDENCE suggests that the situation characterized by elevated plasma triglycerides (TG) is associated with increased cardiovascular risk independent of factors such as hyperglycemia and elevated plasma cholesterol (3). Hypertriglyceridemia is also a critical risk factor for coronary heart disease (CHD) mortality in subjects with impaired glucose tolerance or diabetes (18). Furthermore, hypertriglyceridemia is a common finding in survivors of acute myocardial infarction (27). This epidemiological evidence suggests that TG influence myocardial performance after ischemia-reperfusion independently of atherosclerosis progression.Although its role in acute ischemia-reperfusion is controversial, endothelin-1 (ET-1) is known to exacerbate injury, likely via activation of ET type A receptors (9). Studies in isolated hearts showed that ET-1 release increases on early reperfusion after ischemia, thereby contributing to injury (7), and that ET-1 is a major factor that depresses cardiac function (6) and causes cell necrosis (8). These findings are consistent with other studies (21, 23, 30) demonstrating a relationship between ET-1 and the pathogenesis of myocardial ischemia. In humans, acute hypertriglyceridemia stimulates ET-1 release in normal subjects (36). In addition, hypertriglyceridemia is related with elevated plasma levels of ET-1 in glucose-intolerant and type II diabetic patients with insulin resistance syndrome (37). H...
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