Please select the eligibility criteria that correspond to the clinical trial below.
Title: N/A
Brief Summary: This was a study to evaluate the efficacy and safety of HS219, chitosan-loaded chewing gum, when given three times a day for 3 weeks to the hemodialysis (HD) patients with hyperphosphatemia whose serum inorganic phosphorus was not well controlled with calcium carbonate or sevelamer hydrogen chloride.


Options:
A: Inclusion Criteria:

* Written informed consent given
* Able to comply with the study procedures and medication
* On a stable HD regimen (at least 3 x per week) for ≥ 3 months
* Subject receiving calcium carbonate or sevelamer hydrochloride as a phosphate binder at screening, must have been on a stable regimen (dose and medication) for at least 1 month
* A mean serum inorganic phosphorous in the previous 3 tests : \> 5.5 mg/dL and \< 9.0 mg/dL
* Removal rate of blood urea nitrogen (BUN) ≥ 60%
* Rate of salivary flow by Saxon test ≥ 1 g/2 min

Exclusion Criteria:

* Blood purification therapy other than HD
* Current clinically significant intestinal motility disorder
* Possible parathyroid intervention during the study period
* History of malignancy and severe cardiovascular disorders such as heart disease, angina, congested heart failure, valve stenosis, atrial fibrillation and arrhythmia
* History of allergy against active ingredient
* Receipt of any investigational drug within 30 days of informed consent
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:

* Men and women 18 years of age or greater and able to comply with the study protocol.
* eGFR within appropriate target ranges (15-40 ml/min/m² for late stage CKD stage 3 stage 4, and eGFR \> 60 ml/min/m² for normal subjects)
* Stable kidney function defined as an eGFR which remains within a 10ml/min range over a 3 to 6 month period prior to study enrollment. This will be determined from historical laboratory data.
* Willing to follow study protocol
* Have a level of understanding and willingness to cooperate with all visits and procedures as described by the study personnel
* Overall stable medical condition, defined as no malignancy, metabolic condition or gastrointestinal condition that would make it difficult to comply with the study protocol and complete both dietary study periods
* Able to read the consent form and provide informed consent.
* Serum calcium and phosphorus within the normal range off of vitamin D analogues, calcium supplements, and phosphate binders for 1 month.

Exclusion Criteria:

* 1. Age less than 18 years
* Are pregnant, plan on becoming pregnant during the study period, or breast-feeding, if female.
* Patient declines participation.
* GI malabsorption, short bowel syndrome, frequent vomiting, or gastroparesis.
* Subject receiving synthetic parathyroid hormone, glucocorticoids, calcitonin or bisphosphonates.
D: Inclusion Criteria:

* age \>18 years
* eGFR 20-45 by modified MDRD equation
* protein/creatinine ratio \<5
* blood pressure \<150/95
* not taking calcium binder or supplements, vitamin D, or phosphate binders
* normal serum phosphorus and calcium corrected for albumin and intact PTH \<100pg/ml
* medically stable
* able to give informed consent and come for all visits

Exclusion Criteria:

* history of significant liver disease or cirrhosis
* medically unstable
* unable to tolerate diets

Answer: A