Comparison of serum osteocalcin with total and bone specific alkaline phosphatase and urinary hydroxyproline:creatinine ratio in patients with Paget's disease of bone.

Osteocalcin or bone Gla protein (BGP) is secreted by osteoblasts, and its serum concentration is elevated in a number of conditions with high bone turnover. A comparison of serum osteocalcin with total (TALP) and bone specific alkaline phosphatase (BALP) and urinary hydroxyproline/creatinine (OHP/Cr ratio) was performed in 13 patients with active Paget's disease of bone. BGP did not correlate significantly with either BALP or TALP, but did show a significant correlation with OHP/Cr ratio (r = 0.76; P < 0.01). BGP does not appear to be as sensitive a marker as BALP or TALP in Paget's disease.