Skeletal dynamics in man measured by nonradioactive strontium

Skeletal dynamics were calculated by usual dilution formulas, using stable strontium as a tracer, in 25 normal subjects, 14 athletes, 26 patients with postmenopausal osteoporosis, 28 with primary hyperparathyroidism, 3 with hyperadrenocorticism 8 with acromegaly, 7 with thyrotoxicosis, 11 with urclithiasis, 5 with Paget's disease of bone. and 1 with vitamin D poisoning. The technic requires that 10 mEq of strontium gluconate be injected intravenously and blood and urine concentrations be measured for 4 to 6 days. In normal subjects the rapidly miscible pool was equivalent to 42.7 + 1.1 L of serum, turning over at a rate of 13.5 plus or minus 0.6 L daily, of which 3.9 + 0.2 L was excreted by the kidney and 9.6 + 0.4 L went to bone. Since only approximately 2.5% of the pool is excreted in the feces daily, fecal excretion was not measured routinely. Good reproducibility was found in 21 duplicate studies. Intense muscular exercise (athletes) was found to expand the pool greatly and to accelerate the rate of deposition in bone. Kinetically, two divergent types of osteoporosis were differentiated. A small pool and low rate of bone deposition were found in postmenopausal osteoporosis and Cushing's disease of long duration. The large pool and rapid rate of bone deposition in thyrotoxicosis was confirmed and also found in acromegaly. In these two, excessive bone resorption is postulated. Urinary excretion rate was excessive in Cushing's disease, thyrotoxicosis, and acromegaly. In hyperparathyroidism with clinically evident osteitis, expanded pools, greatly increased turnover, urinary excretion, and bone deposition rates were confirmed. In patients with normal roentgenographic appearance and phosphatase, bone involvement was shown by slight increase in bone deposition rate and microscopic foci of resorption on iliac crest biopsy. In seven patients without histological foci of resorption, the bone deposition rate was not increased. (auth)