礦物質代謝、發炎與慢性腎臟病人預後之關係
The relationship between mineral metabolism, inflammation and
outcomes in chronic kidney disease patients
林港貴 1 洪啟智 1
蔡宜純 1 葉時孟 1 黃尚志 1,2 陳鴻鈞 1,2
Kang-Kuei Lin1, Chi-Chih Hung1, Yi-Chun Tsai1, Shih-Meng Yeh1, Shang-Jyh Hwang1,2,
Hung-Chun Chen1,2
高雄醫學大學附設醫院腎臟內科, 2 高雄醫學大學 腎臟照護學系
1
1
Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University
Hospital, 2Faculty of Renal Care, Kaohsiung Medical University
Background: Chronic inflammation, anemia and disorder of mineral metabolism are
associated with long term prognosis and mortality in chronic kidney disease (CKD).
C-reactive protein (CRP) is elevated in CKD and related to atherosclerosis and
malnutrition. The arm of our study is to investigate the relationships between CRP,
estimated glomerular filtration rate (eGFR), biomarkers of mineral metabolism and
outcomes in patients with CKD stage 1 to 5.
Methods: This study enrolled 1672 CKD stage 1 to 5 patients (61.5 ± 0.3 years, 45%
male). The average eGFR was 24.5 ± 0.6 mL/min/1.73 m2. Participants were recruited
from November 2002 to December 2008 in single hospital. All biochemical data were
the average from enrollment to endpoints. Primary endpoints were ESRD or all-cause
mortality followed up to December 2008. The eGFR was estimated from MDRD
equation. Clinical records and medication were ascertained from CKD care program
databases. Patients with clinical evidence of acute infection were excluded.
Associations between CRP level, eGFR and biomarkers of mineral metabolism were
examined by regression analysis.
Results: eGFR inversely correlated with CRP and ferritin levels (r=-0.16, p<0.0001),
respectively. Plasma phosphate (P) and Calcium (Ca) x P product (Ca x P) were
positively correlated with CRP and ferritin. Hyperuricemia was negatively associated
with eGFR (p <0.0001) and positively associated with CRP (p <0.0001). After
adjustment for age, sex, and eGFR, higher plasma phosphate and uric acid were
remained significantly associated with higher further dialysis rate but not all cause
mortality. Furthermore, higher ferritin is an independent risk factor for mortality in
CKD patients. There were no such associations with plasma calcium and Ca x P.
Conclusion: In subjects with reduced eGFR, CRP and ferritin levels are elevated.
Serum CRP and ferritin levels are associated with biomarkers of mineral metabolism,
including phosphate, Ca x P, and uric acid. Hyperferritinemia, but not elevated CRP, is
an independent risk factor for mortality in CKD.
Key words: inflammation, mineral metabolism, outcomes, chronic kidney disease