124 - The Acute Effects of Supplementing a Meat-based Diet with a Combination of Creatine, Carnitine and Choline, Taurine or Methionine on Post-prandial Plasma Creatine and Creatinine Concentrations in Dogs

Abstract: Creatine is an essential nitrogenous compound for cellular energy homeostasis in vertebrates. It is synthesized from the methylation of guanidinoacetate, a metabolite of arginine and glycine. Creatine is found in animal protein, however, when heat-processed for pet food, the creatine content decreases dramatically and creatinine is formed. Previous data from this study have been presented, however, the current objective was to define the postprandial plasma creatine and creatinine response in dogs fed a commercial meat-based diet (CON), top-dressed with a combination of creatine, carnitine and choline (CCC) or other nutrients involved in methyl metabolism, methionine (MET) or taurine (TAU). The control diet contained 0.195 g/kg creatine and 0.563 g/kg creatinine on an as-fed basis. Eight adult Beagles were fed one of the four diets for 7 days in a Latin Square design. On day 7, dogs had cephalic catheters placed and a series of blood samples were collected at fasted and up to 6 hours post-meal. Creatine and creatinine were analyzed using HPLC and data analyzed using Proc Glimmix in SAS (Version 9.4). Plasma creatine concentrations were greater in dogs fed CCC (103±10 µmol/L) compared with MET (72±7 µmol/L) at fasted (P< 0.05) and greater compared with all other treatments from 15 to 360 minutes post-meal (P< 0.05), with a peak concentration of 735±74 µmol/L at 90 min. Plasma creatinine concentrations were greater in dogs fed CCC from 60 to 180 min post-meal compared to all other treatments (P< 0.05), with a peak concentration of 223±13 µmol/L at 90 min. Both peak concentrations were outside of established reference ranges in dogs. These data suggest that when creatine is top-dressed for 7 days, plasma creatine remains increased at fasted and up to 6 hours post-meal, while plasma creatinine remains increased up to 3 hours post-meal, which has implications for energy production and methyl metabolism.