Conjugated linoleic acid does not improve insulin tolerance in mice.
OBJECTIVE
To determine if the addition or removal of dietary conjugated linoleic acid (CLA) would alter insulin tolerances in mice from two genetic lines.


METHODS
High metabolic rate (MH) and low metabolic rate (ML) mice were assigned to consume 1) a control diet ad libitum, 2) a control diet at a restricted intake, or 3) a diet containing 1% CLA ad libitum. After 9 weeks, an insulin tolerance test was conducted, and a portion of the mice were killed. All remaining mice consumed the control diet ad libitum. Insulin tolerance tests were conducted 11 and 32 days after the diet change, and mice were killed 3 days after each test. Body fatness, fat pad weights, and serum insulin concentrations of mice were determined at each time-point. Two follow-up experiments were also conducted.


RESULTS
Restricted mice had insulin sensitivities not different than control mice. CLA-fed MH mice in experiment 1 were resistant (p < 0.001) to insulin on each day measured. CLA-fed ML mice were slightly resistant (p = 0.08) to exogenous insulin on day 0 of recovery and not different from control mice on day 11 or 32. Glucose response to insulin in MH mice fed CLA in experiments 2 or 3 did not differ from control mice.


CONCLUSIONS
Mice fed CLA did not have improved insulin tolerances compared with control mice. In some cases, dietary CLA may cause insulin resistance. MH mice seem more sensitive to CLA than ML mice.
Hargrave
Kimberly M
KM
Department of Animal Science, University of Nebraska, Lincoln, Nebraska 68583-0908, USA.
Azain
Michael J
MJ
Kachman
Stephen D
SD
Miner
Jess L
JL
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology*; D005227:Fatty Acids / Q000032:analysis; D007328:Insulin / Q000378:metabolism*; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D051379:Mice; D011897:Random Allocation
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D044243:Linoleic Acids, Conjugated