Predictive Value of Biomarkers for Normal and Pathological Ageing in a Rat Model

Sub-optimal diets are widely known to be associated with disease. This study investigated two questions: first, whether a Western affluent diet affects long-term health in the rat, and second, whether, and to what extent, early changes in blood biomarkers can predict specific pathologies. A rat model was used in which animals were fed from weaning either a control diet or a high fat, low protein, energy dense Western affluent diet. Rats were harvested at either 12 or 18 months, and at these time points blood samples were taken and various clinical biomarkers measured using a hospital analyser or by ELISA. Predictive biomarkers should show small changes at early time points and larger changes at later time-points, and be associated with disease(s). Tissues were examined for overt pathology, and data were mined to establish links between pathologies and specific blood markers that might be used predictively. Results showed that the Western affluent diet is associated with ill-health, with a relative risk of developing disease 4.5 times higher than for the control diet. Furthermore we conclude that triacylglycerol, HDL cholesterol, the ratio of total cholesterol to HDL cholesterol, creatinine and alanine aminotransferase were good predictors of disease as across the cohorts they showed altered levels before the clinical development of pathologies, in agreement with our hypothesis