TABLE 3.
Linear mixed model and generalized linear mixed model analyses examining the change in clinicopathological variables over time (first 200 days after the transition to a phosphate‐restricted diet) in CKD cats (n = 71)
| Variables | Group | Time | Group*Time |
|---|---|---|---|
| BCS a (“1‐3,” “4‐6,” “7‐9”) | .87 | .008 | .17 |
| MCS a (“0,” “1,” “2,” “3”) | .25 | .14 | .15 |
| Body weight a (kg) | .99 | .006 | .29 |
| Albumin (g/dL) | .41 | .006 | .04 |
| ALP (U/L) | .39 | .33 | .85 |
| ALT (U/L) | .67 | .84 | .22 |
| Chloride (mEq/L) | .18 | .86 | .4 |
| Creatinine (mg/dL) | .33 | .54 | .01 |
| ln[FGF23] (pg/mL) | .78 | .46 | .002 |
| Glucose (mg/dL) | .21 | .26 | .27 |
| Venous HCO3 − (mEq/L) | .57 | .64 | .13 |
| iCa (mg/dL) | .71 | .02 | .002 |
| PCV (%) | .12 | .009 | .91 |
| Venous pH | .59 | .62 | .28 |
| Phosphate (mg/dL) | .03 | .64 | .02 |
| Potassium (mEq/L) | .002 | .58 | .17 |
| ln[PTH] (pg/mL) | .95 | <.001 | .71 |
| SDMA (μg/dL) | .17 | .18 | .08 |
| SBP (mm Hg) | .75 | .49 | .2 |
| Sodium (mEq/L) | .03 | .07 | .11 |
| tCa (mg/dL) | .54 | .002 | <.001 |
| tMg (mg/dL) | .61 | .32 | .35 |
| Total protein (g/dL) | .24 | .09 | .48 |
| Urea (mmol/L) | .55 | .01 | .81 |
Note: Summary of P values for all variables included in the model. Group represents cats in “uptrend” or “nonuptrend” group based on the trend of plasma total calcium concentration. Outcome variables showing significant change over time and between groups (P < .05) are highlighted in bold. The unit used for time was month (30.4 days). A significant difference in the group column indicates a significant difference between the two groups at baseline for a given parameter (the start of the regression line at time 0). A significant difference in Group*Time indicates that the outcome variable differs significantly between groups (“uptrend” vs “nonuptrend”) over time. If Group*Time was not significant, a significant difference in Time indicates the overall rate of change of the outcome variable differs significantly from baseline over time, regardless of the trend of plasma calcium.
Abbreviations: ALP, alkaline phosphatase; ALT, alanine aminotransferase; BCS, body condition score; CKD, chronic kidney disease; HCO3 −, bicarbonate; iCa, ionized calcium; ln[FGF23], log‐transformed fibroblast growth factor 23; ln[PTH], log‐transformed parathyroid hormone; MCS, muscle condition score; SBP, systolic blood pressure; SDMA, symmetric dimethylarginine; tCa, total calcium; tMg, total magnesium.
Only the case number of each individual cat was included as random effect in the model.