Anthony Reshma M, Davidson Stephen, MacLeay Jennifer M, Brejda John, Werness Peter, Jewell Dennis E
Hill's Pet Nutrition, Inc., Topeka, KS, United States.
Alpha Statistical Consulting, Lincoln, NE, United States.
Front Vet Sci. 2023 Jun 2;10:1146945. doi: 10.3389/fvets.2023.1146945. eCollection 2023.
Relative supersaturation (RSS) values for urine crystals are a measure of the risk of urinary stone formation and have been shown to be lowered in foods shown to aid in the management of urolithiasis. In order to calculate RSS in pets, computer programs have been developed to calculate RSS and aid in the understanding of stone formation in veterinary medicine. However, some older programs have not been updated for use in animals, and the specific coefficients used are not publically available. One of the first RSS programs was developed in BASIC computer language and published in 1985 which was called EQUIL2. The EQUIL2 program was updated to a compiled version compatible with a PC platform. However, the formulas could not be read or altered.
This study evaluates a new program with known coefficients to the original EQUIL2 program. The RSS values of the two programs were compared through a -test, calculating the r from correlation analysis, Lin's concordance correlation coefficient, and by a Bland-Altman analysis of outputs from the two programs using urine samples from healthy dogs and cats.
Our results show that for both magnesium ammonium phosphate (struvite) and calcium oxalate, the RSS values of the original program could be calculated from the new programs RSS values. Although the actual RSS values were different (as might be expected through the use of the updated coefficients and different thermodynamic stability constants in the calculations) the results were highly correlated, finding elevations and reductions in RSS proportionally in the same urine samples. The current work creates a foundation for using the modernized program to calculate RSS and provides a shared method for understanding the risk of struvite and calcium oxalate stone formation.
尿结晶的相对过饱和度（RSS）值是尿路结石形成风险的一种度量，并且已表明在有助于尿路结石病管理的食物中该值会降低。为了计算宠物的RSS，已开发出计算机程序来计算RSS并有助于理解兽医学中的结石形成。然而，一些较旧的程序尚未更新以用于动物，并且所使用的特定系数并未公开。最早的RSS程序之一是用BASIC计算机语言开发的，并于1985年发布，称为EQUIL2。EQUIL2程序已更新为与PC平台兼容的编译版本。但是，公式无法读取或更改。
本研究评估了一个具有已知系数的新程序与原始EQUIL2程序。通过t检验比较了两个程序的RSS值，通过相关性分析计算r，计算了林氏一致性相关系数，并使用健康犬猫的尿液样本对两个程序的输出进行了Bland-Altman分析。
我们的结果表明，对于磷酸镁铵（鸟粪石）和草酸钙，原始程序的RSS值可以从新程序的RSS值计算得出。尽管实际的RSS值不同（通过在计算中使用更新的系数和不同的热力学稳定性常数可能会预期到），但结果高度相关，在相同的尿液样本中按比例发现RSS的升高和降低。当前的工作为使用现代化程序计算RSS奠定了基础，并提供了一种共同的方法来理解鸟粪石和草酸钙结石形成的风险。
