Effect of behavioral interventions on insulin sensitivity and atherosclerosis in the Watanabe heritable hyperlipidemic rabbit.
OBJECTIVE
A previous study suggested that insulin metabolic variables play a role in the progression of atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits. The present study sought to determine: 1) if young, individually caged WHHLs are insulin-resistant relative to New Zealand white (NZW) rabbits and 2) whether dietary or exercise interventions can improve insulin sensitivity and slow the development of atherosclerosis in these animals.


METHODS
Forty-two WHHLs were assigned to a dietary, exercise, or control condition, and 12 NZWs were used as a comparison control group. The intervention ran from 3 to 7 months of age, and all animals received an intravenous glucose tolerance test at the beginning and end of the intervention.


RESULTS
WHHLs were insulin-resistant relative to NZWs at 3 months of age. Whereas the dietary intervention was effective in controlling insulin resistance, WHHLs in the exercise group without dietary restriction and the control group exhibited significant increases in insulin resistance. No intervention significantly influenced the progression of atherosclerosis.


CONCLUSIONS
Young WHHLs are insulin-resistant during an early period when atherosclerosis is developing rapidly. Dietary restriction, but not exercise without weight control, is effective in controlling insulin metabolic variables in the WHHL model. Although dietary intervention can reduce cardiovascular risk factors such as insulin resistance, it is not effective in slowing the development of atherosclerosis in these genetically dyslipidemic animals. Similarly, exercise training, without dietary control, does not influence the progression of disease in WHHLs.
Gonzales
Julie A
JA
Department of Psychology, University of Miami, Coral Gables, FL 33124, USA.
Szeto
Angela
A
Mendez
Armando J
AJ
Zaias
Julia
J
Paredes
Jamespaul
J
Caperton
Caroline V
CV
Llabre
Maria M
MM
Levine
Jon E
JE
Goldberg
Ronald B
RB
Schneiderman
Neil
N
McCabe
Philip M
PM
D000367:Age Factors; D000818:Animals; D001011:Aorta / Q000473:pathology; D001018:Aortic Diseases / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D050197:Atherosclerosis / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D001522:Behavior, Animal / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D004032:Diet / Q000379:methods*; D004195:Disease Models, Animal; D018450:Disease Progression; D005247:Feeding Behavior / Q000502:physiology; D005951:Glucose Tolerance Test; D006949:Hyperlipidemias / Q000235:genetics* / Q000517:prevention & control; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000235:genetics / Q000502:physiology*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods*; D011817:Rabbits
D001786:Blood Glucose; D007328:Insulin