EFFECTS OF A LIFESTYLE INTERVENTION ON TRIMETHYLAMINE N-OXIDE (TMAO) CONCENTRATIONS IN OVERWEIGHT AND OBESE ADULTS

Authors

EE Grammer
J McGee
T Brown
M Clunan
A Huff
B Osborne
L Matarese
W Pories
J Houmard
R Carels
DL Swift

Abstract

Emily E. Grammer¹, Joshua McGee², Taylor Brown², Marie Clunan², Anna Huff², Briceida Osborne², Laura Matarese², Walter Pories², Joseph Houmard², Robert Carels², Damon L. Swift¹. ¹University of Virginia, Charlottesville, VA. ²East Carolina University, Greenville, NC.

BACKGROUND: Trimethylamine N-Oxide (TMAO), a metabolite produced by gut microbiota and flavin-containing monooxygenase-3 (FMO3) of the liver, is found in foods high in carnitine, choline, and lecithin (e.g., egg yolks and full-fat dairy). The oxidation of choline that leads to betaine production may also contribute to increased TMAO levels. Epidemiological studies have linked elevated TMAO concentrations with obesity and cardiovascular disease, yet there are few data regarding the effects of combined diet and exercise interventions on TMAO. METHODS: Twenty-six sedentary overweight and obese adults (Age: 47.4 ± 10.7 yrs.; Weight: 95.1 ± 13.2 kg; BMI: 34.1 ± 3.2 kg/m²) completed a 10-week exercise and hypocaloric diet intervention to obtain clinically significant weight loss of ≥7%. Aerobic exercise volume began at 300 MET min per week and increased 50 MET min weekly until 700 MET min per week was reached. For 8 weeks, the OPTIFAST program included full meal replacement (~800 daily kcal). The last 2 weeks participants could replace 2 products with whole foods and increase intake (~1400 daily kcal). Weekly classes on behavior modification were also offered. Plasma blood samples were collected at baseline and follow-up and analyzed via nuclear magnetic resonance. RESULTS: At baseline, TMAO was correlated with body weight (r=0.40, p=0.046), waist circumference (r=0.40, p=0.044), and average RMR (r=0.50, p=0.009). After the intervention, waist circumference (-7.6 cm), BMI (-3.1 kg/m²), body weight (-8.5 kg, -9.0%), and total body fat percent (-1.7%) were reduced (all ps<0.001), while there were no changes in concentrations of TMAO (-0.3 µM, p=0.292) or betaine (0.3 µM, p=0.838). There were also decreases in 2-hr OGTT glucose (-12.8 mg/dL, p=0.032) and insulin (-43.7 mg/dL, p=0.002), HOMA-IR (-2.9, p<0.001), triglycerides (-31.7 mg/dL, p<0.001), and an increase in relative VO_2peak (2.4 ml/kg/min, p<0.001) following the intervention. Moreover, changes in TMAO were correlated with changes in waist circumference (r=0.50, p=0.010). Changes in betaine were correlated with average RMR changes (r=-0.42, p=0.037). CONCLUSIONS: Weight loss from a hypocaloric diet with aerobic exercise did not decrease TMAO levels, however, improvements in TMAO were associated with waist circumference reductions in overweight and obese adults. Future studies should evaluate predictors of TMAO alterations during weight maintenance.

Recommended Citation

Grammer, EE; McGee, J; Brown, T; Clunan, M; Huff, A; Osborne, B; Matarese, L; Pories, W; Houmard, J; Carels, R; and Swift, DL (2022) "EFFECTS OF A LIFESTYLE INTERVENTION ON TRIMETHYLAMINE N-OXIDE (TMAO) CONCENTRATIONS IN OVERWEIGHT AND OBESE ADULTS," International Journal of Exercise Science: Conference Proceedings: Vol. 16: Iss. 1, Article 57.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss1/57