82 Vitamin D Deficiency in a Large Urban Underserved Population in Southern California

NKF 2011 Spring Clinical Meetings Abstracts

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83 PERITONEAL DIALYSIS IN A CYSTIC FIBROSIS PATIENT Susmitha Dhanyamraju, Austine Mengnjo, Guillermo Carnero, William Difilippo Geisinger Medical Center, Danville, Pennsylvania Cystic fibrosis (CF) is an autosomal recessive disease caused by a mutation in the CFTR gene. While CF is primarily a pulmonary disease, renal disease is beginning to emerge as a cause of morbidity and mortality in this patient population. The spectrum of renal diseases commonly associated with CF includes nephronopthisis, nephrolithiasis, medullary cystic disease as well as aminoglycoside related renal toxicity and interstitial nephritis. Management of end stage renal disease (ESRD) in the CF patient is an area which is not well studied, with minimal data regarding dialysis modalities. This case discusses the successful use of peritoneal dialysis in a CF patient with ESRD. A 24 yo Caucasian female with a history of CF, gastric feeding tube, and underlying renal insufficiency due to MCD presented with worsening renal failure. Her renal insufficiency progressed as a result of multiple courses of aminoglycosides used to treat her CF exacerbations. Due to progression to ESRD by age 23, hemodialysis was initiated via a tunneled catheter. The concern of potential catheter related infection led to a change in dialysis modality to PD. Despite the existing gastric tube placement a PD catheter was placed laparoscopically. Low volume CCPD was used effectively in this patient achieving a Kt/v of 2.37. Literature review reveals only 2 other cases of peritoneal dialysis in patients with cystic fibrosis. In both of these cases the patient outcome was poor within the first month of treatment. Our patient is without PD complications for the last 4 months. We conclude PD should be considered a promising dialysis option for CF patients with ESRD.

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PREDISPOSITION FOR NEPHROLITHIASIS BASED ON WATER SOURCE Joseph Dreier, Jeannie Dreier, James E Hartle II Geisinger Medical Center, Danville, Pennsylvania, US The effect of water calcium content on the risk of nephrolithiasis remains uncertain. Earlier studies suggested that increased water calcium content had no association or an inverse association with the risk of renal stone formation, despite the fact that increased water calcium content can be associated with an increase in urinary calcium content by as much as 50%. A subsequent study showed that consumption of well water was associated with a 1.5 increased risk for renal stones, although no quantitation of urinary calcium was performed. We present a case of a 32 year-old female followed in the Nephrology Stone clinic for nephrolithiasis of uncertain type. In May 2007 urinary calcium was 420 mg/day, tested while using her home well water. In November 2007 and February 2009 urinary calcium dropped to 259 mg/day and 173 mg/day, respectively, while drinking bottled water. In December 2009 she went back to her own well water supply and her 24 hour urinary calcium was 409 mg/day. Again, the 24h urinary calcium dropped to 180 mg/day on her parents water supply in September 2010. Urinary oxalate remained low, with urinary citrate maintained greater than 300 mg/day, which was especially elevated when on her home water source. The urinary pH and volume did not vary significantly and under collection was ruled out by history. The disparity in 24 hour urinary calcium was associated with water source in this case, with episodes of significant hypercalciuria occurring on home well water. Hyperparathyroidism, vitamin D excess, and sarcoidosis were not present. Hypercalciuria has been shown to increase the risk of nephrolithiasis, but no association between water calcium content or water source has been found. Clearly supersaturation, oxalate, citrate, pH, and volume are involved in this multi-factorial problem, but urinary calcium itself was the most pronounced finding on the 24 hour collections in this case. Our case would suggest that well water may be independent risk factor for nephrolithiasis and deserves further investigation in individual cases.

84 VITAMIN D DEFICIENCY IN A LARGE URBAN UNDERSERVED POPULATION IN SOUTHERN CALIFORNIA Rahul Dhawan1, Andrea C. Sanchez1, David Endres1, John S. Kaptein2, Elaine M. Kaptein1, University of Southern California1 and Kaiser Permanente Medical Group2, Los Angeles, California, USA We assessed the characteristics of patients having 25(OH)D levels measured at LAC+USC Medical Center from January 1st to mid-August 2010. All serum 25(OH)D levels from in- and out-patients were retrieved and defined as deficient (30-100). Demographics, seasonal variation, and levels repeated more than 90 days after initial low values were assessed. As of mid-August 2010, 1950 patients had 25(OH)D levels measured. The majority were Hispanic, mean age was 52 years, with 30% males and 70% females. Of these, 38% had levels 30 ng/dL. A seasonal variation was observed with values 90 days of follow-up and to develop an intervention to ensure adequate detection, treatment and prevention of recurrence of vitamin D deficiency/insufficiency in our population.

Am J Kidney Dis. 2011;57(4):A1-A108

COMPARING MORTALITY RISK OF MINERALS, PTH AND ALKALINE PHOSPHATASE OVER 6 YEARS IN 12,422 CHRONIC PERITONEAL DIALYSIS (CPD) PATIENTS Uyen Duong, Rajnish Mehrotra, Csaba P Kovesdy, Lilia R Lukowski, Allen R Nissenson, Miklos Z Molnar, Kamyar Kalantar-Zadeh. Harold Simmons Center, Harbor-UCLA, Torrance, CA, DaVita, Lakewood, CO; Salem VA Salem, VA Osteodystrophy is a common complication of CKD and associated with disorders of mineral metabolism, changes in levels of PTH and alkaline phosphatase. We identified 12,422 CPD patients whose serum alkaline phosphatase (AP) was measured at baseline. They were 54±16 years old and included 47% women, 23% African Americans and 13% Hispanics. Each measure was dichotomized according to clinically meaningful cut-off levels: Serum calcium ≥ 10.2 mg/dl; phosphorus ≥ 5.5 mg/dl; PTH ≥300 pg/ml; and AP ≥120 U/L (vs. lower range as the reference). We found that higher levels of these measures were associated with higher death risk after adjusting for case-mix and malnutrition-inflammation-cachexia syndrome (MICS) (see Figure).

Alkaline Phos>120 U/L

intact PTH>300 pg/ml

Phosphorus>5.5 mg/dL case-mix case-mix + MICS

Calcium>10.2 mg/dL 0.5

1

1.5

2

All-Cause Mortality Hazard Ratio

In this large national cohort of CPD patients, higher levels of serum calcium (≥10.2 mg/dl), phosphorus (≥5.5 mg/dl), PTH (≥300 pg/m), and AP (≥120U/L) appeared associated with higher all-cause mortality.

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