No abstract

High concentrations of nitrite present in saliva (derived from dietary nitrate) may, upon acidification, generate nitrogen oxides in the stomach in sufficient amounts to provide protection from swallowed pathogens. We now show that, in the rat, reduction of nitrate to nitrite is confined to a specialized area on the posterior surface of the tongue, which is heavily colonized by bacteria, and that nitrate reduction is absent in germ-free rats. We also show that in humans increased salivary nitrite production resulting from nitrate intake enhances oral nitric oxide production. We propose that the salivary generation of nitrite is accomplished by a symbiotic relationship involving nitrate-reducing bacteria on the tongue surface, which is designed to provide host defence against microbial pathogens in the mouth and lower gut. These results provide further evidence for beneficial effects of dietary nitrate.

A large number of drugs within the 3 currently classes of calcium antagonists are in common medical use for the treatment of hypertension and ischaemic heart disease. The reported adverse effect profile for each of these drugs varies, but tends to hold true to drug class and are typified by the adverse reactions reported for nifedipine and amlodipine (dihydropyridines), diltiazem (benzothiazepines) and verapamil (phenylalkylamines). Minor adverse effects such as flushing, headache, ankle oedema, palpitations and constipation are not uncommon and frequently require the cessation of treatment. Of greater concern affecting the wide and common first-line use of calcium antagonists is the as-yet unresolved issue of a reportedly greater risk of myocardial infarction and death following the use of short-acting nifedipine in patients with a history of hypertension, myocardial infarction or angina. Until this issue is fully resolved, it would seem prudent to limit the use of this agent in 'at-risk' patients and to await the results of further prospective studies before a final conclusion can be made.

Patients who had experienced an MI can be easily identified from a combination of a Read code for MI and a record of hospitalization for an MI giving 100% sensitivity and specificity with a yield of 1 in 1.11.

Background In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity. Methods and results CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009–2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure. Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest. Conclusion In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes. ClinicalTrials identifier ISRCTN43070564