Osteocalcin and bone morphometric parameters in adults without bone disease.

Serum bone Gla-protein (s-BGP or osteocalcin) and other serum biochemical parameters were measured in 19 subjects (8 women and 11 men, aged 20-82 years) without any bone disease. Each subject simultaneously underwent an iliac crest biopsy; tetracycline double-labeling was performed in 11 subjects, allowing correlations between s-BGP and bone histomorphometric parameters. s-BGP was significantly correlated with static bone parameters: trabecular bone volume (r = 0.74; P less than 0.001), osteoid surfaces (r = 0.69; P less than 0.001), osteoblastic surfaces (r = 0.68; P less than 0.002); dynamic bone formation parameters: total labeled surfaces (r = 0.72; P less than 0.01); and the bone formation rate (r = 0.69; P less than 0.01). We conclude that s-BGP is a valuable marker for evaluating bone formation in healthy adult subjects.