AUTHOR=Rankovic Alexandra , Verton-Shaw Shoshana , Shoveller Anna K. , Bakovic Marica , Kirby Gordon , Verbrugghe Adronie 

TITLE=Dietary choline, but not L-carnitine, increases circulating lipid and lipoprotein concentrations, without affecting body composition, energy expenditure or respiratory quotient in lean and obese male cats during weight maintenance

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1198175

DOI=10.3389/fvets.2023.1198175

ISSN=2297-1769

ABSTRACT=<sec><title>Introduction</title><p>Due to the involvement in one-carbon metabolism and lipid mobilization, choline and L-carnitine supplementation have been recommended to minimize hepatic lipid accumulation and support fat oxidation, respectively. This study investigated the lipotropic benefits of choline or L-carnitine supplementation in lean and obese cats maintaining body weight (BW).</p></sec><sec><title>Methods</title><p>Lean [<italic>n</italic> = 9; body condition score (BCS): 4–5/9] and obese (<italic>n</italic> = 9; BCS: 8–9/9) adult male neutered colony cats were used in a replicated 3 x 3 complete Latin square design. Treatments included choline (378 mg/kg BW<sup>0.67</sup>), L-carnitine (200 mg/kg BW) and control (no supplement). Treatments were supplemented to the food for 6 weeks each, with a 2-week washout between treatments. Cats were fed once daily to maintenance energy requirements, and BW and BCS were assessed weekly. Fasted blood collection, indirect calorimetry, and dual-energy X-ray absorptiometry occurred at the end of each treatment period. Serum was analyzed for cholesterol (CHOL), high-density lipoprotein CHOL (HDL-C), triglycerides (TAG), non-esterified fatty acids (NEFA), glucose, creatinine (CREAT), urea, alkaline phosphatase (ALP) and alanine aminotransferase (ALT). Very low-density lipoprotein CHOL (VLDL) and low-density lipoprotein CHOL (LDL-C) were calculated. Data were analyzed using proc GLIMMIX, with group and period as random effects, and treatment, body condition, and their interaction as fixed effects, followed by a Tukey's <italic>post-hoc</italic> test when significance occurred.</p></sec><sec><title>Results</title><p>Cats supplemented choline had lower food intake (<italic>P</italic> = 0.025). Treatment did not change BW, BCS and body composition (<italic>P</italic> &gt; 0.05). Obese cats had greater ALP, TAG, and VLDL, and lower HDL-C compared to lean cats (<italic>P</italic> &lt; 0.05). Choline resulted in greater CHOL, HDL-C, LDL-C and ALT (<italic>P</italic> &lt; 0.05). L-carnitine resulted in lower CREAT (<italic>P</italic> = 0.010). Following the <italic>post-hoc</italic> test, differences between treatment means were not present for ALP (<italic>P</italic> = 0.042). No differences were found for glucose, urea or NEFA (<italic>P</italic> &gt; 0.05). Obese cats had a lower fed respiratory quotient (RQ), regardless of treatment (<italic>P</italic> = 0.045). Treatment did not affect fed or fasted RQ and energy expenditure (<italic>P</italic> &gt; 0.05).</p></sec><sec><title>Discussion</title><p>Choline appeared to increase circulating lipid and lipoprotein concentrations regardless of body condition, likely through enhanced lipid mobilization and hepatic elimination. Neither dietary choline or L-carnitine altered body composition or energy metabolism in the lean or obese cats, as compared to control.</p></sec>