Modification of estimation of the urinary ion-activity products of calcium oxalate and calcium phosphate

Abstract

蓚酸カルシウム, 燐酸カルシウム, 酸性燐酸カルシウムのイオン活量積の簡易測定法としての諸指数は, 尿中のカルシウム, マグネシウム, 蓚酸, 燐酸, クエン酸, 尿量, pHなどの変数より求められる。それぞれの指数には採尿時間により異なる係数が与えられるが, それぞれの係数は採尿時間と相関する。従って, 係数をその計算式に組み込むことが可能となり, 24時間以内の如何なる採尿時間でせ計算式が利用できるようにした

Tiselius proposed simplified estimates of the ion-activity products of calcium oxalate, calcium phosphate, and brushite as the AP(CaOx) index, the AP(CaP) index, and the AP(Bru) index, respectively, which allowed assessment of the urinary saturation levels of these lithogenic substances. A number of urinary variables (calcium, magnesium, oxalate, phosphate, citrate, urine volume, and pH) are necessary to derive these indices. In addition, these three indices have correction factors corresponding to the urinary collection periods, although these periods were originally quite limited. In this study, the factors were shown to vary as a function of time. Therefore, they were incorporated into these indices after proper calculation so as to be usable for any collection period less than 24 hours. This means that the factors will now prove more useful in evaluating the urinary saturation levels after short-term collections.