Does Body Mass Index affect survival and technique failure in patients undergoing peritoneal dialysis?

BACKGROUND: The aim of this study was to investigate the effect of Body Mass Index (BMI) on mortality and clinical outcomes in patients undergoing peritoneal dialysis (PD). METHODS: In this retrospective study, 367 consecutive patients undergoing PD from 2001 to 2014 were included. One-hundred and eight were excluded from the study. Remaining 259 patients' demographic and clinical data on initiation of PD and clinical events during the study period were collected. Patients were separated into two groups as normal BMI (18.5-24.9 kg/m²) and increased BMI (≥25 kg/m²). The increased BMI patients were categorized into two subgroups: obese, ≥30 kg/m²; overweight, 24-29.9 kg/m².The outcomes of interest were compared between the groups. Patient and technique survival were investigated. RESULTS: Normal weighted patients were 66% (N.=171), overweights were 24.3% (N.=63), and obese ones were 9.7% (N.=25) at commencement of PD therapy. Patients with increased BMI was older than the patients with normal BMI (P=0.001). There were no differences among other parameters (P>0.05). Mean patients' survival time was 64.8±4.4 months in normal weight patients. Survival rate was 91.5, 84.3, 76.6 and 58.2% at 1, 2, 3 and 5 years, respectively. Gender, administration way, pretreatment residual renal functions, incidence of catheter exit site/tunnel infection, pretreatment albumin levels and last systolic BP were the risk factors. Mean technique survival duration were 47.2±3.5 months. Technique survival rate was 86.5, 65.9, 53.7 and 29.9 % at 1, 2, 3 and 5 years, respectively. Age, Kt/V, incidence of peritonitis, catheter exit site/tunnel infection, pretreatment SBP and DBP were the risk factors. Mean patients' survival time was 63±5.2 months in increased BMI group. Survival rate was 81.3, 79.4, 75.1 and 53.6% at 1, 2, 3 and 5 years, respectively. Presences of HD history, incidence of peritonitis were the identified risk factors on patients' mortality. Mean technique survival duration were 57.1±4.8 months. Technique survival rate was 87.1, 76.1, 64.8 and 42% at 1, 2, 3 and 5 years, respectively. Pretreatment residual renal function, SBP and DBP were predictors of technique survival. There was no difference in patients and technique survival between groups (P>0.05). CONCLUSIONS: The PD patients with increased BMI at initiation of PD do have a similar survival when compared with patients with normal BMI.

Renal sarcoidosis with normal serum vitamin D and refractory hypercalcemia.

INTRODUCTION: Sarcoidosis is a multi-system disorder characterized by non-caseating epithelioid granulomas in multiple organs. Renal involvement may usually occur as granulomatous interstitial nephritis, but renal failure is uncommon. We report a case of renal-limited sarcoidosis diagnosed by renal biopsy, associated with abnormal calcium metabolism. CASE PRESENTATION: A 30-year-old Caucasian male presented with unexplained renal function impairment and hypercalcemia. The patient did not have any history of kidney disease, cough, skin rash, dysuria, hematuria or any other symptoms. Physical examination was unremarkable. Serum creatinine was 2.2 mg/dl and serum calcium was 11.5 mg/dl. Serum intact parathyroid hormone level (12 pg/mL) was decreased. Serum angiotensin-converting enzyme (ACE), 1,25-dihydroxyvitamin D (1,alpha-25 vit D) and pre-proparathyroid hormone (PTHrP) levels and urinary calcium excretion were all in normal range. The renal biopsy showed severe interstitial nephritis with non-caseating granuloma. The patient was treated with prednisone with starting dose of 1 mg/kg. After 2 months of prednisone therapy, serum creatinine decreased. However, because of continued of hypercalcemia unresponsive to low calcium diet and prednisone, chloroquine was prescribed. Six months after the onset, the patient's serum creatinine is stable at 1.30 mg/dl, serum calcium is 10.8 mg/dl, and serum ACE and 1,alpha-25 vit D levels are in normal range. He does not have any signs of extra-renal relapse. CONCLUSION: The mechanisms of abnormal calcium metabolism in this patient with renal-limited sarcoidosis are unclear.