In a trial comparing 100 mg of aspirin with placebo in nearly 20,000 community-dwelling persons 70 years of age or older in Australia and the United States, aspirin use had no effect on the rate of ...survival free from dementia or physical disability.
In older persons without known cardiovascular disease, the use of low-dose aspirin resulted in a significantly higher risk of major hemorrhage and did not result in a significantly lower risk of ...cardiovascular disease than placebo.
There are no primary prevention trials of aspirin with relevant geriatric outcomes in elderly people. ASPirin in Reducing Events in the Elderly (ASPREE) is a placebo-controlled trial of low-dose ...aspirin that will determine whether 5 years of daily 100-mg enteric-coated aspirin extends disability-free and dementia-free life in a healthy elderly population and whether these benefits outweigh the risks.
Set in primary care, this randomized double-blind placebo-controlled trial has a composite primary endpoint of death, incident dementia or persistent physical disability. Participants aged 70+ years (non-minorities) or 65+ years (U.S. minorities) were free of cardiovascular disease, dementia, or physical disability and without a contraindication to, or indication for, aspirin. Baseline data include physical and lifestyle, personal and family medical history, hemoglobin, fasting glucose, creatinine, lipid panel, urinary albumin:creatinine ratio, cognition (3MS, HVLT-R, COWAT, SDMT), mood (CES-D-10), physical function (gait speed, grip strength), Katz activities of daily living and quality of life (SF-12).
Recruitment ended in December 2014 with 16,703 Australian and 2,411 U.S. participants, a median age of 74 (range 65-98) years and 56% women. Approximately 55% of the U.S. cohort were from minority groups; 9% of the total cohort. Proportions with hypertension, overweight, and chronic kidney disease were similar to age-matched populations from both countries although lower percentages had diabetes, dyslipidemia, and osteoarthritis.
Findings from ASPREE will be generalizable to a healthier older population in both countries and will assess whether the broad benefits of daily low-dose aspirin in prolonging independent life outweigh the risks.
Fire in the Earth System Bowman, David M.J.S; Balch, Jennifer K; Artaxo, Paulo ...
Science (American Association for the Advancement of Science),
04/2009, Letnik:
324, Številka:
5926
Journal Article
Recenzirano
Fire is a worldwide phenomenon that appears in the geological record soon after the appearance of terrestrial plants. Fire influences global ecosystem patterns and processes, including vegetation ...distribution and structure, the carbon cycle, and climate. Although humans and fire have always coexisted, our capacity to manage fire remains imperfect and may become more difficult in the future as climate change alters fire regimes. This risk is difficult to assess, however, because fires are still poorly represented in global models. Here, we discuss some of the most important issues involved in developing a better understanding of the role of fire in the Earth system.
Aims Angiotensin converting enzyme (ACE) 2 catalyses the cleavage of angiotensin (Ang) I to Ang 1‐9 and of Ang II to Ang 1‐7. ACE2 deficiency impairs cardiac contractility and upregulates ...hypoxia-induced genes, suggesting a link with myocardial ischaemia. We studied the expression of ACE2 after myocardial infarction (MI) in the rat as well as in human failing hearts. Methods and results Rats were killed at days 1, 3, and 28 after MI, or treated for 4 weeks with the ACE inhibitor ramipril (1 mg/kg). Cardiac gene and protein expression of ACE and ACE2 were assessed by quantitative real-time reverse transcriptase–polymerase chain reaction and immunohistochemistry/activity assays/in vitro autoradiography, respectively. Both ACE (P=0.022) and ACE2 (P=0.015) mRNA increased in the border/infarct area compared with the viable area at day 3 after MI. By day 28, increases in ACE (P=0.005) and ACE2 (P=0.006) mRNA were also seen in the viable myocardium of MI rats compared with myocardium of control rats. ACE2 protein localized to macrophages, vascular endothelium, smooth muscle, and myocytes. Ramipril attenuated cardiac hypertrophy and inhibited cardiac ACE. In contrast, ramipril had no effect on cardiac ACE2 mRNA, which remained elevated in all areas of the MI rat heart. Immunoreactivity of both ACE and ACE2 increased in failing human hearts. Conclusion The increase in ACE2 after MI suggests that it plays an important role in the negative modulation of the renin angiotensin system in the generation and degradation of angiotensin peptides after cardiac injury.
Angiotensin-converting enzyme (ACE) is a zinc metalloproteinase and a key regulator of the renin–angiotensin system (RAS). ACE2 is a newly described enzyme identified in rodents and humans with a ...more restricted distribution than ACE, and is found mainly in heart and kidney. ACE2 cleaves a single residue from angiotensin I (Ang I) to generate Ang 1–9, and degrades Ang II, the main effector of the RAS, to the vasodilator Ang 1–7. The importance of ACE2 in normal physiology and pathophysiological states is largely unknown. ACE2 might act in a counter-regulatory manner to ACE, modulating the balance between vasoconstrictors and vasodilators within the heart and kidney, and playing a significant role in regulating cardiovascular and renal function.
Recent trials have suggested that inhibitors of the renin-angiotensin system (RAS), such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs), may reduce the ...incidence of new-onset diabetes in patients with or without hypertension and at high risk of developing diabetes. In this review, we critically evaluate the evidence from recent clinical trials for such a potential preventive effect of ACE inhibitors and ARBs, including a meta-analysis of these recent trials. The reduced incidence of diabetes in patients at high risk of developing diabetes by ACE inhibitors or ARBs has been explained by haemodynamic effects, such as improved delivery of insulin and glucose to the peripheral skeletal muscle, and non-haemodynamic effects, including direct effects on glucose transport and insulin signalling pathways, all of which decrease insulin resistance. There is now evidence that the pancreas may contain an in situ active RAS, which appears to be upregulated in an animal model of type 2 diabetes. Thus, ACE inhibitors and ARBs may act by attenuating the deleterious effect of angiotensin II on vasoconstriction, fibrosis, inflammation, apoptosis and beta-cell death in the pancreas, thereby protecting a critical beta-cell mass essential for insulin production. New evidence is presented that ACE inhibitors and ARBs may delay or prevent the development of insulin resistance and diabetes, for which novel mechanisms are suggested. The actions of agents that interrupt the RAS on insulin resistance, obesity and diabetes warrant further investigation in other animal models. Prospective clinical studies with the primary endpoint of the prevention of diabetes are now indicated to (i) further explore whether the inhibitors of the RAS are superior compared to other antihypertensive agents such as calcium channel blockers (CCBs) and (ii) to evaluate the potential beneficial effects of combination antihypertensive regimens on the development of diabetes.
ABSTRACT—ACE2, initially cloned from a human heart, is a recently described homologue of angiotensin-converting enzyme (ACE) but contains only a single enzymatic site that catalyzes the cleavage of ...angiotensin I to angiotensin 1–9 Ang(1–9) and is not inhibited by classic ACE inhibitors. It also converts angiotensin II to Ang(1–7). Although the role of ACE2 in the regulation of the renin-angiotensin system is not known, the renin-angiotensin system has been implicated in the pathogenesis of diabetic complications and in particular in diabetic nephropathy. Therefore, the aim of this study was to assess the possible involvement of this new enzyme in the kidney from diabetic Sprague-Dawley rats to compare and contrast it to ACE. ACE2 and ACE gene and protein expression were measured in the kidney after 24 weeks of streptozocin diabetes. ACE2 and ACE mRNA levels were decreased in diabetic renal tubules by ≈50% and were not influenced by ACE inhibitor treatment with ramipril. By immunostaining, both ACE2 and ACE protein were localized predominantly to renal tubules. In the diabetic kidney, there was reduced ACE2 protein expression that was prevented by ACE inhibitor therapy. The identification of ACE2 in the kidney, its modulation in diabetes, and the recent description that this enzyme plays a biological role in the generation and degradation of various angiotensin peptides provides a rationale to further explore the role of this enzyme in various pathophysiological states including diabetic complications.
This prospective, open-label, randomized study compared the outcomes in hypertensive subjects 65 to 84 years of age who received therapy with angiotensin-converting–enzyme (ACE) inhibitors or ...diuretic agents. The rate of cardiovascular events or death from any cause was lower among male subjects who received ACE inhibitors.
In older persons an ACE inhibitor may improve outcomes.
Placebo-controlled studies of the drug treatment of mild-to-moderate hypertension have demonstrated that the reduction of blood pressure is associated with a reduced risk of cardiovascular events and death.
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This benefit was first shown with diuretics, beta-blockers, or both as initial therapy.
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Since those studies were conducted, newer classes of antihypertensive agents, including angiotensin-converting–enzyme (ACE) inhibitors, calcium-channel antagonists, and angiotensin II antagonists, have become widely accepted into practice. When our study began, no data were available indicating whether therapy involving these newer agents would have the same benefit in persons with hypertension. However, evidence of a benefit of treatment . . .
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