The association between C-reactive protein levels and the risk for chronic kidney disease hospitalizations in adults of a remote Indigenous Australian community - A prospective cohort study.

BACKGROUND: Indigenous Australians are significantly burdened by chronic kidney disease (CKD). Elevated levels of C-reactive protein (CRP) have been associated with diabetes and cardiovascular incidence in previous studies. Elevated CRP has been associated with albuminuria and reduced eGFR in cross-sectional studies. This study investigated the long-term predictive association between CRP measured at a baseline exam and the incidence of a CKD-related hospitalization. METHODS: Health screening examinations were conducted in individuals of a remote indigenous Australian community between 1992 and 1998. The risk of subsequent CKD hospitalisations, documented through Northern Territory hospital records up to 2010, was estimated with Cox proportional hazard models in people aged over 18 years at the baseline screen and who had albumin-creatinine ratios (ACRs) less than 34g/mol. RESULTS: 546 participants were eligible for our study. Individuals in the highest CRP tertile at baseline had increased levels of traditional cardiovascular risk factors. They also had almost 4 times the risk of a CKD-related hospitalisation compared with participants in the lowest CRP tertile (HR=3.91, 95%CI 1.01-15.20, P=0.049) after adjustment for potential confounding factors. Participants with CRP concentrations greater than 3mg/L had almost 3 times the risk of CKD hospitalisations than those ≤3mg/L (HR=2.84, 95%CI 1.00-8.00, P=0.049). Furthermore, risk of CKD hospitalisations increased 34% per doubling of baseline CRP (HR=1.34, 95%CI 1.04-1.74, P=0.024). CONCLUSION: In individuals in this remote indigenous community without overt albuminuria at baseline the risk for incident CKD related hospitalisations was predicted by elevated C-reactive protein levels almost a decade earlier. Further research is needed to understand the roles that CRP and systemic inflammation play in CKD risk.