Estimation of bone turnover in climacteric women by the whole body retention of fluoride.

This paper reports the measurement of whole body retention using fluoride (WBRF) as an estimator of skeletal turnover in a group of climacteric women that received an oral dose of 700 mumol of sodium fluoride. WBRF is defined as 100(1-(urinary fluoride/fluoride load)). WBRF was significantly correlated with whole body retention of 99m-Tc-methylene-diphosphonate, the serum levels of the bone alkaline phosphatase and the urinary excretion of hydroxyproline. WBRF values ranged from 20% to 95% and were affected by calcium intake and the urinary calcium excretion. In normal subjects with high turnover, the measurement of serum alkaline phosphatase activity and/or urinary hydroxyproline excretion helps to distinguish these cases from patients with metabolic bone diseases due to metastases, Paget disease, etc. The fact that the fraction of fluoride not incorporated into bone is not further metabolized plus the accuracy, preciseness and rapidity of fluoride measurements in urine are the main advantages of this technique.