Prediction of cardiovascular death and non-fatal cardiovascular events by the Kidney age–Chronological age Difference (KCD) score in men and women of different ages in a community-based cohort

OBJECTIVE: We examined the utility of the Kidney age–Chronological age Difference (KCD) score, an age-adapted measure of kidney function, to identify increased cardiovascular (CV) death or non-fatal CV event risk in participants of the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab), a community-based cohort aged 23–95 years. DESIGN: Cohort study. SETTING: Community. PARTICIPANTS: 11205 randomly selected participants from urban and nonurban areas across Australia. OUTCOME MEASURES: Mortality status and underlying and contributory causes of death obtained from the Australian National Death Index, and non-fatal CV events from adjudicated hospital records. The association of CV death or non-fatal CV event risk with KCD score was examined using penalised spline curve analysis. RESULTS: Of 11 180 participants with serum creatinine measurement at baseline and 5-year outcome data, there were 308 CV deaths or non-fatal CV events after 5 years. Penalised spline curve analysis showed similar progressive increase in CV death or non-fatal CV event risk with increasing KCD score in men and women, and participants aged <50 years to ≥80 years. Receiver operating characteristic curve analysis showed optimal discrimination at a KCD score ≥20 years (KCD20) for all participants. Among 148 participants aged<70 years with CV death or non-fatal CV event, KCD20 identified 24 (16%) participants, whereas estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) identified 8 (5%) participants (p=0.0001), with specificities of 95% and 99%, respectively (p<0.0001). CONCLUSION: KCD20 predicted CV death or non-fatal CV event risk similarly in men and women of different ages in this population-based cohort. The higher sensitivity for prediction of CV death or non-fatal CV event risk in participants aged <70 years by KCD20 than by eGFR <60 mL/min/1.73 m(2) offers opportunity for earlier renoprotective therapy in individuals with eGFR-associated increased CV death or non-fatal CV event risk.