Cardiovascular disease

Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels (arteries and veins). While the term technically refers to any disease that affects the cardiovascular system (as used in MeSH C14), it is usually used to refer to those related to atherosclerosis (arterial disease). These conditions usually have similar causes, mechanisms, and treatments.

Most countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer. In recent years, cardiovascular risk in women has been increasing and has killed more women than breast cancer. A large histological study (PDAY) showed vascular injury accumulates from adolescence, making primary prevention efforts necessary from childhood.

By the time that heart problems are detected, the underlying cause (atherosclerosis) is usually quite advanced, having progressed for decades. There is therefore increased emphasis on preventing atherosclerosis by modifying risk factors, such as healthy eating, exercise, and avoidance of smoking.

Pathophysiology
Population based studies show that the precursors of heart disease start in adolescence. The process of atherosclerosis evolves over decades, and begins as early as childhood. The Pathobiological Determinants of Atherosclerosis in Youth Study demonstrated that intimal lesions appear in all the aortas and more than half of the right coronary arteries of youths aged 7–9 years. However, most adolescents are more concerned about other risks such as  HIV, accidents, and cancer than cardiovascular disease.

This is extremely important considering that 1 in 3 people will die from complications attributable to atherosclerosis. In order to stem the tide education and awareness that cardiovascular disease poses the greatest threat and measures to prevent or reverse this disease must be taken.

Obesity and diabetes mellitus are often linked to cardiovascular disease, as are a history of chronic kidney disease and hypercholesterolaemia . In fact, cardiovascular disease is the most life threatening of the diabetic complications and diabetics are two- to four-fold more likely to die of cardiovascular-related causes than nondiabetics.

Associated diagnostic markers

 * Low-density lipoprotein
 * Lipoprotein(a)
 * Apolipoprotein A1
 * Apolipoprotein Bho

Screening
Some biomarkers are thought to offer a more detailed risk of cardiovascular disease. However, the clinical value of these biomarkers is questionable. Currently, biomarkers which may reflect a higher risk of cardiovascular disease include:


 * Higher fibrinogen and PAI-1 blood concentrations
 * Elevated homocysteine, or even upper half of normal
 * Elevated blood levels of asymmetric dimethylarginine
 * Inflammation as measured by C-reactive protein
 * Elevated blood levels of brain natriuretic peptide (also known as B-type) (BNP)

Prevention
Evidence shows that the Mediterranean diet improves cardiovascular outcomes. As of 2010 however vitamins have not been found to be effective at preventing cardiovascular disease.

Other modifiable risk factors to improve or prevent atherosclerosis may include:
 * a low fat high fibre diet including whole grains and plenty of fresh fruit and vegetables (at least five portions a day) (though the advice continues to recommend you lower your saturated fat intake while eating some unsaturated fats, since this will help with cholesterol levels);
 * limit the amount of salt in your diet to no more than 6g (0.2 oz) a day;
 * tobacco cessation and avoidance of second-hand smoke;
 * limit alcohol consumption to the recommended daily limits;
 * lower blood pressures if elevated through the use of antihypertensive medications;
 * strict diabetes management;
 * decrease body fat (BMI) if overweight or obese;
 * increase daily activity to 30 minutes of vigorous exercise per day at least five times per week;
 * decrease emotional stress.
 * Consumption of 1-2 standard alcoholic drinks per day may reduce risk by 30%

The generally accepted viewpoint is that dietary saturated fat and cholesterol intake is associated with cardiovascular disease. However, this viewpoint has been disputed. While many studies have affirmed the link between consumption of saturated fats and heart disease, some studies have not found a statistically significant link or have been inconclusive. A study of rats suggests that the links between a diet high in sugar and saturated fat compared with a sugar-free, low fat diet lead to cardiac dysfunction despite modest levels of obesity, and a diet for humans that is low in sugar and rapidly absorbed starches and high in polyunsaturated fatty acids are associated with a reduced risk of coronary heart disease. Some experts suggest that the focus should reassess the recommendations to switch away from saturated fats and instead focus on carbohydrates, particularly switching refined carbohydrates (especially refined grains and sugar) to unsaturated fats and/or healthy sources of protein, a moved to whole grains and limiting sugar-sweetened beverage consumption. Though diets high in saturated fats or refined carbohydrates are not suitable for ischemic heart disease prevention, refined carbohydrates are likely to cause even greater metabolic damage than saturated fat in a predominantly sedentary and overweight population  Another study agrees with the approach and suggests this may be linked to the macronutrients associated with refined carbohydrates.

Management
Cardiovascular disease is treatable with initial treatment primarily focused on diet and lifestyle interventions. Medication may also be useful for prevention.

Epidemiology


The first studies on cardiovascular health were performed in 1949 by Jerry Morris using occupational health data and were published in 1958. The causes, prevention, and/or treatment of all forms of cardiovascular disease remain active fields of biomedical research, with hundreds of scientific studies being published on a weekly basis. A trend has emerged, particularly in the early 2000s, in which numerous studies have revealed a link between fast food and an increase in heart disease. These studies include those conducted by the Ryan Mackey Memorial Research Institute, Harvard University and the Sydney Center for Cardiovascular Health. Many major fast food chains, particularly McDonald's, have protested the methods used in these studies and have responded with healthier menu options.

A fairly recent emphasis is on the link between low-grade inflammation that hallmarks atherosclerosis and its possible interventions. C-reactive protein (CRP) is an common inflammatory marker that has been found to be present in increased levels in patients at risk for cardiovascular disease. Also osteoprotegerin which involved with regulation of a key inflammatory transcription factor called NF-κB has been found to be a risk factor of cardiovascular disease and mortality.

Some areas currently being researched include possible links between infection with Chlamydophila pneumoniae and coronary artery disease. The Chlamydia link has become less plausible with the absence of improvement after antibiotic use.