Predicting Mortality with Biomarkers among Elderly Costa Ricans
Luis Rosero-Bixby, Universidad de Costa Rica
Melissa Rodriguez, Centro Centroamericano de Poblacion
William H. Dow, University of California, Berkeley
Biomarkers have increasingly been added to population surveys in recent years, but few studies document how well they relate to mortality outcomes. We considered 22 baseline biomarkers as three-year prospective death predictors in a nationally representative longitudinal sample from the Costa Rican Longevity and Healthy Aging Study (CRELES). The sample includes about 2,500 Costa Ricans born before 1945, of whom about 400 died. The strongest mortality predictors are markers of body functioning (hands, legs, lungs, and kidneys). C-reactive protein and HbA1c are also strong predictors. Low levels of DHEAS predict increased mortality only among men. Strikingly, traditional indicators of cardiovascular risk, such as high blood pressure and total cholesterol, unexpectedly predict lower mortality. Obesity increases the risk of dying but only among younger individuals. Results suggest the need for deeper understanding of the meaning of such biomarkers, particularly outside of the developed country settings where they have been primarily studied.