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© Dirk Biddle
i) C Reactive Protein (CRP - see also 2. Inflammation and Blood Proteins), sometimes called an “acute phase protein”, is a marker for inflammation. Traditionally it has been used to assess inflammation in response to infection, however CRP is also useful in predicting vascular disease, heart attack or stroke. The best treatment for a high C reactive protein level has not yet been defined, however statin drugs, niacin, weight loss, quitting smoking and exercise all appear to improve C Reactive Protein.
ii) Homocysteine is an amino acid that is normally found in small amounts in the blood. Higher levels are associated with increased risk of heart attack and other vascular diseases. Homocysteine levels may be high due to a deficiency of folic acid or Vitamin B12, due to heredity, older age, kidney disease, or certain medications. Men tend to have higher levels. You can reduce your homocysteine level by eating more green leafy vegetables and fortified grain products or cereals. The usual treatment is folic acid with or without Vitamin B-12.
iii) Elevated Apolipoprotein (a) (Lp[a]) concentrations are associated with premature coronary heart disease (CHD). The exact mechanism is not yet clear, but it appears that there is a strong genetic component to elevated Lp(a) levels that correlates with coronary disease. Persons with diabetes and a high Lp(a) level appear to be at increased risk of asymptomatic coronary disease. High levels of LP(a) are also associated with increased risk for atherosclerosis and its manifestations--myocardial infarction, stroke and restenosis. The plasma concentration of Lp(a) is strongly influenced by heritable factors and is refractory to most drug and dietary manipulation (1).
iv) BNP: A marker for congestive heart failure. Either BNP or NT-proBNP may be ordered to help diagnose heart failure and to grade the severity of that heart failure. There are various causes of heart failure. Currently, the condition is diagnosed by symptoms such as swelling in the legs (oedema), difficulty breathing, shortness of breath, and fatigue, in addition to chest X-rays and an ultrasound test called echocardiography. Despite this information, heart failure is still often confused with other conditions. BNP and NT-proBNP levels can help doctors differentiate between heart failure and other problems, such as lung disease. An accurate diagnosis is important because heart failure can be successfully managed with various medical treatments.
Another reason for using BNP and NT-proBNP is to evaluate risk in persons who present with chest pain. It has been found that high BNP predicts an increased risk of death or subsequent heart attack in patients with acute coronary syndromes.
Higher-than-normal results suggest that a person is in heart failure, and the level of BNP or NT-proBNP in the blood is related to the amount or severity of heart failure. Higher levels of BNP or NT-proBNP also may be associated with a worse outlook for the patient.
BNP and NT-proBNP levels decrease in most patients who have been taking drug therapies for heart failure, such as ACE inhibitors, beta-blockers, and diuretics. Levels of both BNP and NT-proBNP tend to increase with age. Levels of NT-proBNP and, to a lesser extent, BNP, are increased in persons with kidney disease.
While both BNP and NT-proBNP will rise with left ventricle dysfunction and either can be measured, they are not interchangeable and the results cannot be directly compared (2).
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1 http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=152200
2 http://www.labtestsonline.org/understanding/analytes/bnp/test.html