Changes of Parathyroid Hormone and Vitamin D Metabolites According to Estimated Glomerular Filtration Rate in Chronic Kidney Disease Patients

Yu, Sukyong; Cho, Jinhee; Lim, Namkyu; Lee, Myounghee; Park, Jinsun; Park, Inwhee; Shin, Gyutae; Kim, Heungsoo

Abstract

PURPOSE: Disturbances of mineral metabolism are common during the course of chronic kidney disease (CKD) and may lead to serious and debilitating complications unless properly treated. The purpose of this study is to quantify the prevalence of secondary hyperparathyroidism and vitamin D deficiency in non-dialysed chronic kidney disease 3, 4, and 5 in Korea.
METHODS
This study included patients who had documented eGFR<60 mL/min/1.73m2 and non-dialysed and had not received any vitamin D compounds. eGFR was calculated by simplified MDRD (Modification of Diet in Renal Disease study) equation. Blood samples were collected for serum creatinine, calcium, phosphate, intact PTH and vitamin D metabolites between May 2006 and April 2007.
RESULTS
According to K/DOQI guideline, the prevalence of hyperparathyroidism was 46.9% (15/32) in stage 3 (iPTH>70 pg/mL),45.9% (17/37) in stage 4 (iPTH>110 pg/mL) and 20.5% (9/44) in stage 5 patients (iPTH>300 pg/mL). The prevalence of 25-hydroxyvitamin D deficiency (25(OH)D3<15 ng/mL) was 86.2% (25/29) in stage 3, 75.7% (28/37) in stage 4 and 88.4% (38/43) in stage 5. There was a negative correlation between eGFR and intact PTH (r=-0.531, p=0.000) and a positive correlation between eGFR and 1,25-dihydroxyvitamin D (r=0.587, p=0.000).
Conclusions
So far as non-dialysed CKD patients in Korea are concerned, quantification of the prevalence of abnormality of intact PTH and vitamin D deficiency has been described in this study. More research should be conducted in the future in a prospective, multi-center community cohort study, of which subjects include the early stages like CKD 1 and 2.