Fluoride therapy for osteoporosis: characterization of the skeletal response by serial measurements of serum alkaline phosphatase activity.

Abstract Optimum use of fluoride therapy for osteoporosis requires a sensitive and convenient index of the skeletal response to fluoride. Since previous studies had shown that serum alkaline phosphatase activity (SALP) was increased in response to fluoride therapy, we examined serial measurmeents of SALP in 53 osteoporotics treated with 66 to 110 mg of sodium fluoride (NaF) for 12 to 91 months. SALP was increased in 87% of the subjects during therapy with fluoride. The increase in SALP was thought to reflect the osteogenic action of fluoride based on the findings that SALP (1) correlated with both trabecular bone area ( r = .81, P r = .67, P τ 1 2 for the SALP response (ie, time for 1 2 of the patients to show a significant response) was significantly less (1.2 ± 0.3 yr) than that for the pain response (1.6 ± 0.3 yr, P P r = .49, P r = .63, P