Am. Hackman et al., OBESE PIGS FED A HIGH CHOLESTEROL DIET FROM BIRTH TO 2 MONTHS ARE LESS SUSCEPTIBLE THAN LEAN PIGS TO ATHEROSCLEROSIS, The Journal of nutrition, 126(2), 1996, pp. 564-573
Dietary cholesterol in infancy may alter cholesterol metabolism and th
e propensity to develop atherosclerosis. This study examined the effec
ts of a 1% cholesterol diet (HC) vs. a no-cholesterol diet (NC) during
the first 2 mo of life on pigs selectively bred for leanness or obesi
ty. Three lean and three obese pigs received the no-cholesterol diet,
and four lean and four obese pigs received the 1% cholesterol diet fro
m d 1. Lean and obese pigs fed the no-cholesterol diet showed no incre
ase in serum lipid concentrations, nor did they develop atherosclerosi
s. Obese pigs fed the 1% cholesterol diet developed significantly high
er serum total cholesterol (TC) and high density lipoprotein cholester
ol (HDL-C) at 35 d than lean pigs fed the 1% cholesterol diet. By d 55
, only HDL-C remained significantly higher in the obese pigs, resultin
g in a higher (P < 0.1) TC/HDL-C ratio in the lean pigs. Atherosclerot
ic plaque formation in the aorta was more extensive in the lean pigs.
Cholesterol synthesis measured in vivo and at termination was equally
suppressed in lean and obese pigs fed the 1% cholesterol compared with
pigs fed the no-cholesterol diet. We conclude that genetic difference
s in the response of these lean and obese pigs to a high cholesterol d
iet render obese pigs less susceptible to atherosclerosis despite high
er serum TC concentrations. The persistent elevation of HDL-C in obese
pigs is the most likely mechanism of protection.