Please select the eligibility criteria that correspond to the clinical trial below.
Title: CSP #453 - Homocysteinemia in Kidney and Endstage Renal Disease Study (HOST)
Brief Summary: The primary objective of this study is to test the hypothesis that administration of folate, pyridoxine (vitamin B6) and cyanocobalamin (vitamin B12) in high doses to patients with advanced chronic renal failure or end stage renal disease and abnormally high plasma homocysteine levels will lower the homocysteine levels and the death rate compared to patients who receive placebo. The secondary objective is to test the hypothesis that intake of the vitamins compared to placebo decreases the incidence of myocardial infarction, disabling stroke, and amputation of a lower extremity and, in hemodialysis patients, thrombosis of the vascular access.


Options:
A: Inclusion Criteria:

* age 50-75y

Exclusion Criteria:

* consumption of \< 3 slices of bread/day
* use of B-vitamins in the period three months prior to the study
* treatment with B12-injections in the last 5y
* illness or use of medication interfering with folate or vitamin B12 metabolism
B: Inclusion Criteria:

Patients will be screened by their plasma homocysteine concentration. They must have a level of at least 15 mM/L to be enrolled in the study.

Patients will be excluded by any of the following criteria: age less than 21 years, expected life span less than 6 months, pregnancy, metastatic cancer, end-stage liver disease, treatment with methotrexate, other anti-folate medication or anticonvulsants, unreliable or likely noncompliant, participation in another long-term trial, or unwilling or unable to give informed consent.

Exclusion Criteria:
C: Inclusion Criteria:

* Women and men 55 years of age or over with established CVD and at high risk for future fatal and nonfatal CV events, defined as:

  1. Documented coronary artery disease (CAD);
  2. Documented peripheral vascular disease (PVD);
  3. Documented cerebrovascular disease;
  4. Diabetes with one of the following; additional cardiovascular risk factors:

  i) hypertension (BP \>160 mmHg systolic or \>90 mmHg diastolic or on treatment); ii) total cholesterol \>5.2 mmol/L (\>200 mg/dl); iii) HDL cholesterol \<0.9 mmol/L (3.5 mg/dl); iv) current cigarette smoker; v) any evidence of previous vascular disease
* Provision of informed consent

Exclusion Criteria:

* Current use of any vitamin supplements containing folic acid \>200 micrograms/day. The patients taking such vitamin supplements can be asked if they agree to discontinue these supplements. If they agree, they can be randomized to the study following a one month wash-out period.
* Known previous adverse reactions to folic acid and/or vitamin B6 and/or B12.
* Planned cardiac, peripheral or cerebrovascular revascularization, defined as a decision taken by the patient and his or her physician(s) to perform surgical or percutaneous transluminal revascularization within the next 6 months.
* Hemodynamically significant primary valvular outflow tract obstruction (e.g. mitral stenosis, asymmetric septal hypertrophy, malfunctioning prosthetic valve).
* Constrictive pericarditis.
* Complex congenital heart disease.
* Syncopal episodes presumed to be due to uncontrolled life-threatening arrhythmias (asymptomatic arrhythmias including ventricular tachycardia are not exclusion criteria.
* Uncontrolled hypertension.
* Cor pulmonale.
* Heart transplant recipient.
* Other important non-cardiovascular disease(s) expected to limit compliance and/or impact on patient's ability to complete the study, such as: \*history of alcohol or drug abuse, \*psychiatric disorders, \*senility, \*severe physical disability, \*illnesses including terminal stage of cancer and other major systemic illnesses expected to limit the patient's ability to comply with the study protocol and to complete the study.
D: Inclusion Criteria:

1. One neoplastic polyp removed within three months of study entry or within 16 months of study entry if over 1 cm in size or if subject has had a lifetime history of at least two polyps, with the entire large bowel seen by colonoscopy to be free of further polyps within 3 months of entry.
2. An ability and willingness to follow the study protocol, as indicated by the subject's giving informed consent to participate.
3. Good general health, with no severely debilitating diseases or active malignancy that might compromise the patient's ability to complete the study.
4. Anticipated colonoscopic follow-up three years after the qualifying colonoscopy.
5. Age between 21 and 80 years at the time of the intake colonoscopy.
6. For women of childbearing potential, agreement to use effective birth control for the duration of the study.
7. Intent not to take aspirin or aspirin-containing products, NSAIDs or folic acid for the length of the study unless required by a physician.
8. Not randomized previously or currently in a chemoprevention trial, except for the: "Nutritional Prevention of Large Bowel Polyps" Study (Polyps Prevention Study I); and brief participation in the "VA Cooperative Study" with no continuing involvement.

Exclusion Criteria:

1. Invasive carcinoma in any colonic polyp removed.
2. Familial colonic polyposis syndromes.
3. Ulcerative colitis or Crohn's disease.
4. Malabsorption syndrome (e.g. pancreatic insufficiency).
5. Large bowel resection for any reason.
6. Diagnosed narcotic or alcohol dependence
7. Contraindication to aspirin use, including:

   1. documented peptic ulcer disease in the past 20 years
   2. aspirin sensitivity
   3. bleeding diathesis, including hemorrhagic stroke
8. Likelihood of NSAID use

   1. recurring arthritis or other musculo-skeletal problems
   2. frequent NSAID use in 5 years preceding
   3. history of stroke or TIAs
   4. history of angina or myocardial infarction
   5. desire to take aspirin for the prevention of cardiovascular disease
9. Required or contraindicated folic acid use pernicious anemia or folic acid deficiency
10. Pregnancy or lactation.

Answer: B