Please select the eligibility criteria that correspond to the clinical trial below.
Title: N/A
Brief Summary: The accumulation of p-cresol, a product of the metabolism of aromatic aminoacid operated by resident intestinal bacteria increases the cardiovascular risk of chronic kidney disease (CKD) patients. Therefore, therapeutic strategies to reduce plasma p-cresol levels are highly demanded. It has been reported that the phosphate binder sevelamer sequesters p-cresol in vitro, while in vivo studies on dialysis patients showed controversial results. Aim of our study was to evaluate the effect of sevelamer on p-cresol levels in CKD patients.


Options:
A: Inclusion Criteria:

* Eligible subjects will be male or female patients with end-stage renal disease on maintenance hemodialysis for less than 5 years, with elevated LDL cholesterol
* Currently treated with oral phosphate binders
* Coronary artery calcium scores of 30 to 5000 Agatston units measured by electron beam CT scanning
* Written informed consent
* Negative serum pregnancy test if appropriate
* Expect to comply with protocol procedures and schedule

Exclusion Criteria:

* Unstable angina pectoris
* Severe congestive heart failure
* Severe obstructive pulmonary disease requiring supplemental oxygen
* Severe liver dysfunction
* Severe malnutrition
* Severe hyperparathyroidism
* Known HIV
* Active malignancy for which the subject is receiving chemotherapy or radiation
* Planned renal transplant within the next year
* Clinical evidence of calciphylaxis or recent history of hypercalcemia
* History of obstructed bowels
* Hypersensitivity to any of the components of the study medication
* History of swallowing disorders
* Weight \> 300 pounds
* Any condition which makes patient participation not in the patient's best interest
B: Inclusion Criteria:

* We will include stage 3a, 3b and 4 CKD patients, aged 18 years or over with normal serum phosphate levels (≤ 4.6 mg/dl)

Exclusion Criteria:

* Patients with rapidly advancing renal failure who thus might develop hyperphosphatemia or end stage renal disease requiring initiation of dialysis during the study period
* Patients expected to require dialysis initiation within the follow up period
* Patients with hyperphosphatemia \> 4.6 mg/dl
* Patients with any previous or current treatment with phosphate binders or active vitamin D (doxercalciferol or calcitriol)
* Malnutrition, defined as a serum albumin \< 3.0 mg/dl
* Patients with liver disease (ALT or AST \> 100 U/L) or cholestasis (direct bilirubin \> 1.0 mg/dl) because this can limit their ability to absorb fat soluble vitamins such as vitamin D
* Anemia, defined as a hematocrit \< 27% at the screening visit
* Medical conditions impacting Pi metabolism-primary hyper- or hypoparathyroidism; Patients with previous subtotal parathyroidectomy; gastrointestinal malabsorption disorders such as Crohn's Disease, ulcerative colitis, celiac disease, or severe liver dysfunction;
* Patients with outpatient counseling by a renal nutritionist within the previous 6 months
* Hospitalization within the previous 4 weeks
* Pregnancy or breastfeeding mothers
* Patients unable to independently provide written informed consent - prisoners, mentally incompetent, minors
C: Inclusion Criteria:

* age \>18 years,
* CKD stage 3-5

Exclusion Criteria:

* Existing or previous treatment within the last 1 year with a phosphate binder;
* hyperphosphatemia (\>5.6 mg/dL);
* hypophosphatemia (\<2.5 mg/dL);
* malnutrition,
* malignant neoplasms,
* current history of gastrointestinal and/or endocrine diseases.
D: Inclusion Criteria:

1. Men or women \> 18 years of age;
2. The subject has voluntarily signed and dated the most recent informed consent form approved by an Institutional Review Board (IRB);
3. The subject will, in the opinion of the investigator, be compliant with prescribed therapy;
4. Subject must be able to communicate and be able to understand and comply with the requirements of the study;
5. For subjects with CKD not on dialysis- kidney function at any stage that in the opinion of the investigator is stable and not expected to initiate dialysis within 3 months;
6. For subjects with CKD not on dialysis- a screening serum phosphorus value greater than or equal to 4.5 mg/dL;
7. For subjects with ESRD - a screening serum phosphorus value greater than or equal to 4.6 mg/dL and less than or equal to 9.0 mg/dL and one of the two conditions: A mean historical value of the most recent 2 phosphorus measurements ≥ 4.6 and less than or equal to 9.0 mg/dL at the time of written informed consent or A second screening serum phosphorus value greater than or equal to 4.6 mg/dL and less than or equal to 9.0 mg/dL performed not less than 7 days from the date of the previous screening;
8. In the opinion of the investigator, subjects with ESRD must be prescribed a stable dialysis regimen (3x/week) for ≥ 4 weeks prior to baseline and must have a stable dialysis access;
9. Subjects with ESRD must have an historical URR ≥ 65% for at least 4 weeks prior to baseline;
10. All subjects must have NO change in prescribed dose or frequency of any of the following medications ≥ 14 days prior to baseline:

    1. Phosphate binding products including prescribed and over-the counter
    2. Oral or injectable active vitamin D
    3. Oral nutritional vitamin D
    4. Calcimimetics
    5. Calcium supplements
    6. Anti-osteoporotic medication (e.g. bisphosphonates)
11. Subject must be prescribed a diet appropriate for patients with their stage of kidney disease, and must be willing to avoid intentional changes in diet; and
12. Subjects must have a screening salivary flow rate by Saxon test ≥ 1 g/2 min.

Exclusion criteria:

1. Receiving or has received an investigational product (or is currently using an investigational device) within 28 days prior to baseline;
2. Known sensitivity to chitin or allergy to shellfish;
3. Clinical evidence of active malignancy and/or receiving systemic chemotherapy/radiotherapy with the exception of basal cell or squamous carcinoma of the skin;
4. Clinically significant infection requiring treatment with antibiotics (within 7 days prior to baseline);
5. Inpatient hospitalization within 14 days prior to baseline with the exception of hospitalizations related to vascular access procedures;
6. Planned surgical intervention for secondary hyperparathyroidism;
7. In the opinion of the investigator, inability to chew gum for 60 minutes;
8. Planned relocation to another area within the next 4 months;
9. Subject has a known history of immunodeficiency diseases, including a positive HIV (ELISA and Western blot) test result;
10. Active drug or alcohol dependence or abuse (excluding tobacco use) in the opinion of the principal investigator;
11. Unstable medical condition which in the opinion of the investigator would compromise successful completion of the study;
12. Known active liver disease with AST or ALT levels greater than 3X the upper limit of normal; and
13. Subject has had a major cardiovascular event within 90 days of screening. The investigator should be guided by evidence of any of the following;

    1. Acute myocardial infarction
    2. Acute cerebral vascular event
    3. Vascular surgical intervention
    4. Coronary Revascularization
    5. Decompensated congestive heart failure

Answer: C