Chronic effects of dietary carbohydrate variation on [18F]-2-fluoro-2-deoxyglucose uptake in rodent heart.
OBJECTIVE
Measured cardiac [F]-2-fluoro-2-deoxyglucose (FDG) activity in human PET scans is variable despite efforts to standardize patient preparation. Heart uptake can obscure chest disease, and is of physiologic interest. Short-term carbohydrate (CHO) restriction can reduce FDG uptake, although unreliably, whereas long-term restriction of CHO has not been systematically studied. It would be valuable to understand FDG hearts' chronic dietary dependence.


METHODS
Fifteen Wistar rats (age 4 weeks) were randomized to three diet groups (n = 5) of low (0.1% of total energy), intermediate (52%), and high (78%) CHO content (LC, IC, and HC, respectively). After 4 weeks, blood for ketone bodies (KB), glucose, insulin, and glucagon was obtained, followed in 2 days by whole-body PET with 37 MBq FDG. Diet groups were switched every 4 weeks to control for the effects of dietary order. Heart maximal standardized uptake value was compared among animals.


RESULTS
Heart mean maximal standardized uptake value was dramatically reduced for LC (3.4+/-0.4; P<0.001) compared with either IC (10.9+/-0.7) or HC (11.0+/-0.7) (P=NS, IC vs. HC). KB (mumol/l) differed widely (P<0.001) in LC (718.6+/-40.0) versus IC (120.3+/-34.0) and HC (99.2+/-32.1) (P=NS, IC vs. HC), whereas glucose, insulin, and glucagon did not differ among the groups.


CONCLUSIONS
Sustained CHO-restriction results in marked, reproducibly reduced cardiac FDG uptake. Six-fold to seven-fold increased KB concentrations provide alternative substrate to glucose.
Fine
Eugene J
EJ
Department of Nuclear Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA. efine@aecom.yu.edu
Miao
Weibing
W
Koba
Wade
W
Volek
Jeff S
JS
Blaufox
M Donald
MD
D000818:Animals; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006321:Heart / Q000000981:diagnostic imaging* / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D049268:Positron-Emission Tomography; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D004040:Dietary Carbohydrates; D019788:Fluorodeoxyglucose F18