Age associated change in biomarkers of bone metabolism in cats

Abstract

Age associated change in bone metabolism in cats was investigated by measuring biomarkers of bone metabolism in a cross sectional study. Serum and urine samples were collected from 96 healthy American domestic shorthair cats (29 males and 67 females) with ages ranging from 1.7 to 15.9 years old after they were fed a dry cat food for at least 3 weeks. Following biomarkers were measured: procollagen type II C‐propeptide (PIICP), C‐terminal cleavage products of type II collagen (C2C), C‐terminal telopeptide of type II collagen fragments (CTX II), Type IIA collagen N‐propeptide (PIIANP), N‐terminal cross‐linked telopeptide of type I collegen (NTx), keratan sulfate (KS), chondroitin sulfate epitope 846 (CS846), and bone specific alkaline phosphatase (BAP). Linear correlation coefficient between age and measured biomarkers was calculated.Serum BAP (r=−0.19, p=0.01) and urine CTX II (r=−0.47, p<0.01) were negatively and serum C2C (r=0.37, p<0.01) and KS (r=0.35, p<0.01) were positively associated with age. Both serum BAP and urine CTX II were significantly higher in cats < 2 years old, suggesting that bone metabolism does not attain maturity in cats until they are 2 years old. No association between age and other measured biomarkers was observed in cats > 1 year old.