Summary
The availability of currently used methods of measuring. intestinal calcium absorption is limited by their expense and complexity. Since this measurement may be important in selecting appropriate therapies for patients with osteoporosis, a simpler procedure is required. This paper describes a test which measures the intestinal absorption of stable strontium. A comparison of this test with the single-isotope radio-calcium absorption test in the same group of patients showed a close correlation between the fractional absorption rates of the two elements (r=0.93,P<0.001). Subjects were correctly categorized as having normal or low absorption in 12 out of 13 cases (92%) and the value in the misclassified subject was at the borderline between normal and low calcium absorption. The convenience, low cost, and freedom from radioactivity of stable strontium make it suitable for routine clinical use and, if necessary, repeated testing. If these early results are confirmed, this test will make the assessment of calcium absorption much more widely available.
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References
Need AG, Horowitz M, Philcox JC, Nordin BEC (1985) 1,25-Dihydroxycholecalciferol and calcium therapy in osteoporosis with calcium malabsorption. Miner Electrolyte Metab 11:35–40
Nordin BEC, Need AG, Horowitz, M, Philcox JC, Hartley TF (1984) Treatment of osteoporosis with calcitriol and calcium alone and in combination. In: Christiansen C, Arnaud CD, Nordin BEC, Parfitt AM, Peck WA, Riggs BL (eds) Osteoporosis. Dept Clinical Chemistry, Glostrop Hospital, Denmark, p 769
Pybus J, Feldman FJ, Bowers NG Jr (1970) Measurement of total calcium in serum by atomic absorption spectrophotometry with use of a strontium internal reference. Clin Chem 16:998–1007.
Finlay JM, Nordin BEC, Fraser TRC (1956) A calcium-infusion test. Lancet 1:826–380
Samachson J, Lederer H (1958) Comparative ultrafiltration of calcium and strontium in serum. Proc Soc Exp Biol Med 98:867–870
Walser M (1961) Renal discrimination between alkaline earth cations. J Clin Invest 40:1087
Marshall DH, Nordin BEC (1969) Kinetic analysis of plasma radioactivity after oral ingestion of radiocalcium. Nature 222:797
Marshall DH (1976) Calcium and phosphate kinetics. In: Nordin BEC (ed) Calcium, phosphate and magnesium metabolism. Churchill Livingstone, Edinburgh, p 268
Marshall DH, Nordin BEC (1981) A comparison of radioactive calcium absorption tests with net calcium absorption. Clin Sci 61:477–481
Eisenberg E, Gordan GS (1961) Skeletal dynamics in man measured by nonradioactive strontium. J Clin Invest 40:1809–1825
Fraser R, Harrison M, Ibbertson K (1960) The rate of calcium turnover in bone. Q J Med 39:85–111
Eisenberg E (1966) Effects of androgens, estrogens and corticoids on strontium kinetics in man. J Clin Endocrinol 26:566–572
Papworth DG, Patrick G (1970) The kinetics of influx of calcium and strontium into rat intestine in vitro. J Physiol 210:999–1020
Wilkinson R (1976) Absorption of calcium, phosphorus and magnesium. In: Nordin BEC (ed) Calcium, phosphate and magnesium metabolism. Churchill Livingstone, Edinburg, p 49
Hendrix JZ, Alcock NW, Archibald RM (1963) Competition between calcium, strontium and magnesium for absorption in the isolated rat intestine. Clin Chem 9:734–744
Spencer H, Li M, Samachson J, Laszlo D (1960) Metabolism of strontium-85 and calcium-45 in man. Metabolism 9:916–925
Comar CL, Wasserman RH, Nold MM (1956) Strontium-calcium discrimination factors in the rat. Proc Soc Exp Biol 92:859–863
Tellez M, Reeve J, Royston JP, Veall N, Wootton R (1980) The reproducibility of double-isotope deconvolution measurements of intestinal calcium absorption. Clin Sci 59:169–172
Heaney RP, Recker RR (1985) Estimation of true calcium absorption. Ann Int Med 103:516–521