Assessment of the influence of fatty acids on indices of insulin sensitivity and myocellular lipid content by use of magnetic resonance spectroscopy in cats.
OBJECTIVE
To determine whether dietary fatty acids affect indicators of insulin sensitivity, plasma insulin and lipid concentrations, and lipid accumulation in muscle cells in lean and obese cats.


METHODS
28 neutered adult cats.


METHODS
IV glucose tolerance tests and magnetic resonance imaging were performed before (lean phase) and after 21 weeks of ad libitum intake of either a diet high in omega-3 polyunsaturated fatty acids (3-PUFAs; n = 14) or high in saturated fatty acids (SFAs; 14).


RESULTS
Compared with the lean phase, ad libitum food intake resulted in increased weight, body mass index, girth, and percentage fat in both groups. Baseline plasma glucose or insulin concentrations and glucose area under the curve (AUC) were unaffected by diet. Insulin AUC values for obese and lean cats fed 3-PUFAs did not differ, but values were higher in obese cats fed SFAs, compared with values for lean cats fed SFAs and obese cats fed 3-PUFAs. Nineteen cats that became glucose intolerant when obese had altered insulin secretion and decreased glucose clearance when lean. Plasma cholesterol, triglyceride, and non-esterified fatty acid concentrations were unaffected by diet. Ad libitum intake of either diet resulted in an increase in both intra- and extramyocellular lipid. Obese cats fed SFAs had higher glycosylated hemoglobin concentration than obese cats fed 3-PUFAs.


CONCLUSIONS
In obese cats, a diet high in 3-PUFAs appeared to improve long-term glucose control and decrease plasma insulin concentration. Obesity resulted in intra- and extramyocellular lipid accumulations (regardless of diet) that likely modulate insulin sensitivity.
Wilkins
Caroline
C
Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Long
Robert C
RC
Waldron
Mark
M
Ferguson
Duncan C
DC
Hoenig
Margarethe
M
D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects; D002415:Cats / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism / Q000494:pharmacology*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000494:pharmacology*; D005951:Glucose Tolerance Test / Q000662:veterinary; D007328:Insulin / Q000097:blood*; D050356:Lipid Metabolism; D009682:Magnetic Resonance Spectroscopy; D032342:Muscle Cells / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
D001786:Blood Glucose; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D007328:Insulin