Alexander Janet, Stockman Jonathan, Atwal Jujhar, Butterwick Richard, Colyer Alison, Elliott Denise, Gilham Matthew, Morris Penelope, Staunton Ruth, Renfrew Helen, Elliott Jonathan, Watson Phillip
WALTHAM Centre for Pet Nutrition, Melton Mowbray, Leicestershire LE14 4RT, UK.
Royal Canin SAS, 650 Avenue de la Petite Camargue, 30470 Aimargues, France.
Br J Nutr. 2019 Feb 14;121(3):249-269. doi: 10.1017/S0007114518002751. Epub 2018 Dec 21.
Renal disease has a high incidence in cats, and some evidence implicates dietary P as well. To investigate this further, two studies in healthy adult cats were conducted. Study 1 (36 weeks) included forty-eight cats, stratified to control or test diets providing 1·2 or 4·8 g/1000 kcal (4184 kJ) P (0 or approximately 3·6 g/1000 kcal (4184 kJ) inorganic P, Ca:P 1·2, 0·6). Study 2 (29 weeks) included fifty cats, stratified to control or test diets, providing 1·3 or 3·6 g/1000 kcal (4184 kJ) P (0 or approximately 1·5 g/1000 kcal (4184 kJ) inorganic P, Ca:P 1·2, 0·9). Health markers, glomerular filtration rate (GFR) and mineral balance were measured regularly, with abdominal ultrasound. Study 1 was halted after 4 weeks as the test group GFR reduced by 0·4 (95 % CI 0·3, 0·5) ml/min per kg, and ultrasound revealed changes in renal echogenicity. In study 2, at week 28, no change in mean GFR was observed (P >0·05); however, altered renal echogenicity was detected in 36 % of test cats. In agreement with previous studies, feeding a diet with Ca:P <1·0, a high total and inorganic P inclusion resulted in loss of renal function and changes in echogenicity suggestive of renal pathology. Feeding a diet containing lower total and inorganic P with Ca:P close to 1·0 led to more subtle structural changes in a third of test cats; however, nephrolithiasis occurred in both diet groups, complicating data interpretation. We conclude that the no observed adverse effects level for total dietary P in adult cats is lower than 3·6 g/1000 kcal (4184 kJ), however the effect of inorganic P sources and Ca:P require further investigation.
肾脏疾病在猫中发病率很高，并且一些证据也表明饮食中的磷也有影响。为了进一步研究这一问题，对健康成年猫进行了两项研究。研究1（36周）包括48只猫，分为对照组或试验组，分别给予含1.2或4.8 g/1000千卡（4184千焦）磷的日粮（0或约3.6 g/1000千卡（4184千焦）无机磷，钙磷比1.2、0.6）。研究2（29周）包括50只猫，分为对照组或试验组，分别给予含1.3或3.6 g/1000千卡（4184千焦）磷的日粮（0或约1.5 g/1000千卡（4184千焦）无机磷，钙磷比1.2、0.9）。定期通过腹部超声测量健康指标、肾小球滤过率（GFR）和矿物质平衡。研究1在4周后停止，因为试验组的GFR每千克体重每分钟降低0.4（95%置信区间0.3，0.5）毫升，并且超声显示肾脏回声发生变化。在研究2中，在第28周时，未观察到平均GFR有变化（P>0.05）；然而，在36%的试验猫中检测到肾脏回声改变。与先前的研究一致，饲喂钙磷比<1.0、总磷和无机磷含量高的日粮会导致肾功能丧失和回声改变，提示存在肾脏病变。饲喂总磷和无机磷含量较低、钙磷比接近1.0的日粮会导致三分之一的试验猫出现更细微的结构变化；然而两个日粮组均出现肾结石，使数据解读变得复杂。我们得出结论，成年猫日粮中总磷的未观察到有害作用水平低于3.6 g/1000千卡（4184千焦）；然而，无机磷来源和钙磷比的影响需要进一步研究。
