Nutrition-Related Cardiovascular Disease Risk Factors In Chronic Kidney Disease: Relationship With Clinical Outcome

Abstract

The significance of nutrition-related risk factors in early-stage chronic kidney disease (CKD) is largely unknown. Evidence in end-stage disease indicates a ‘risk-factor paradox’ with traditional cardiovascular (CV) risk factors associated with improved survival. This study aims to assess the relationship between nutrition-related risk factors and clinical outcome in early CKD. All patients with eGFR 15-60 ml/min commencing care at a large metropolitan hospital in 2008 and 2009 were assessed for a number of traditional (body mass index, waist circumference, lipids LDL, HDL, triglycerides) and renal-specific (serum phosphate (PO 4 ), 25(OH)Vitamin D, albumin and haemoglobin) risk markers. Serum creatinine, eGFR, PTH, calcium, comorbidities, age and gender were also collected from medical records. Clinical outcome was defined as reaching renal-end points (death, dialysis commencement and/or doubling serum creatinine) by June 30, 2011. Univariate analysis was undertaken by t-test and multivariate survival analysis by Cox time-dependant hazards model. 667 patients were investigated. During follow-up (median=18; range 1-40 months) 36% (n=239) were discharged from care or lost to follow-up. Of the 428 patients remaining 25% (n=106) a renal- end point of death(13%), dialysis (7%) or doubling creatinine (5%). In a univariate analysis, PO 4 (event 1.35; 95%CI 1.29-1.40 vs. no event 1.15; 1.13-1.17 mmol/L), Vitamin D (61.7; 54.0-69.4 vs 75.8; 72.8-78.8 ng/mL) and serum albumin (34.2; 32.8-35.6 vs 38.7; 38.3-39.1 g/L) were related to outcome renal-end point. In the survival analysis model, only PO 4 (HR 8.9; 95%CI 3.3-24.5) and Albumin (0.90; 0.87 – 0.93) were independently associated with outcome, after adjusting for a range of confounding factors. Traditional CV-risk factors in this CKD population were not associated with clinical outcome. Despite being within clinical reference range, serum phosphate and albumin were independently associated with clinical outcome. This may highlight a potential therapeutic target for risk management to delay or prevent renal end-points in CKD.