Oral Paricalcitol in Stage 3 - 5 Chronic Kidney Disease

The purpose of this study is to test the hypothesis that selective vitamin D receptor activation reduces left ventricular hypertrophy and ameliorates inflammation and atherosclerosis in stage 3 -5 chronic kidney disease.

Cardiovascular disease is the leading cause of mortality and morbidity in patients with chronic kidney disease. According to a previous study, only 15.6% of the patients beginning dialysis therapy had a normal echocardiogram, with left ventricular hypertrophy, left ventricular dilatation and systolic dysfunction occurring in 40.7%, 28% and 15.6% of patients, respectively. In addition, these patients are at an accelerated risk of developing atherosclerosis. The Kidney Disease Outcome Quality Initiative guideline recently raised concerns of a high prevalence of vitamin D deficiency in chronic kidney disease patients not yet requiring dialysis treatment. In addition, very recent data suggested that vitamin D deficiency is an important predictor of mortality in end-stage renal disease patients. Furthermore, hemodialysis patients treated with paricalcitol, a selective vitamin D receptor activator, showed a significantly lower risk of cardiovascular death than those not receiving vitamin D therapy. A number of studies also showed positive benefit of vitamin D receptor activator treatment on regression of left ventricular hypertrophy in dialysis patients. However, there is so far no data in patients with stage 3 and 4 chronic kidney disease where a high prevalence of vitamin D deficiency and cardiac hypertrophy has been reported.

Eligibility Criteria:
Inclusion Criteria:

* Patient with stage 3 -5 chronic kidney disease (that is, eGFR \< 60 ml/min per 1.73m2) diagnosed for more than 2 months and not expected to start dialysis within the next 12 months, and
* Patient with screening echocardiography showing evidence of left ventricular hypertrophy
* Patient has not received vitamin D therapy in the previous 4 weeks
* For entry into the Treatment Phase, the subject must have:

  * screening iPTH \>= 55 pg/ml or 5.8pmol/L (determined by the Nichols second-generation assay or similar assay)
  * serum calcium \< 10.2 mg/dL (2.55 mmol/L)
  * serum phosphorus =\< 5.2mg/dL (1.68mmol/L)
  * Ca\*P product \< 54 mg2/dL2 (4.36mmol2/L2)
  * If female, subject is either not of childbearing potential, defined as postmenopausal for at least 1 year or surgically sterile (bilateral tubal ligation, bilateral oophorectomy, or hysterectomy), or is of childbearing potential and practicing birth control measures.
* Patients who provide informed consent for the study

Exclusion Criteria:

* Patient with a history of an allergic reaction or significant sensitivity to vitamin D or vitamin D related compounds.
* Patient with history of renal stones
* Patient with current malignancy
* Patients with clinically significant gastrointestinal disease or liver disease
* Patient with acute renal failure in the recent three months
* Patient with a history of drug or alcohol abuse within six months prior to the screening phase
* Patient is known to be human immunodeficiency virus (HIV) positive.
* Patient with evidence of poor compliance with diet and medication.
* Patient currently receiving medications that may affect calcium, phosphorus metabolism such as calcitonin, cinacalcet, bisphophonates or vitamin D compounds (other than study drug), or other drugs that may affect calcium or bone metabolism, other than females on stable estrogen and/or progestin therapy.
* Patients with active granulomatous disease
* Patient with pregnancy
* Patients currently receiving glucocorticoid steroid or other immunosuppressive treatment or had been administered glucocorticoid or other immunosuppressive treatment for more than 14 days within recent 6 months.
* Patients with contraindication for MRI examination