21-03-09, 13:52
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#15
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Banned
תאריך הצטרפות: Feb 2008
הודעות: 475
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עכשיו אתה עושה מעצמך צחוק. הקשר בין ldl לבין אתרוסקלרוזיס הוא ברור?
In 1997 Swedish researchers published a comparison of CHD
risk factors among men from Vilnius in Lithuania and Linkoping in
Sweden. These two groups were selected because the former had a
four-fold higher death rate from CHD than the latter. Very little
difference in traditional risk factors existed between the two
groups, except that the men from CHD-prone Vilnius had lower
total and LDL cholesterol levels.
According to common wisdom, the lower total and LDL
cholesterol of the Lithuanian men should have placed them at
reduced risk of heart disease. When the researchers probed further,
they discovered that the men from Vilnius had significantly higher
concentrations of oxidizeed LDL (Kristenson M, Zieden B, Kucinskiene Z, et al. Antioxidant state and mortality
from coronary heart disease in Lithuanian and Swedish men: concomitant
cross sectional study of men aged 50. BMJ 1997;314:629-633.)
In the large G  I-Prevenzione trial in Italy, the mortality
benefits of omega-3-rich fish oil appeared early on in the
study—as did an increase in LDL cholesterol levels. Mean LDL
levels in the subjects given fish oil rose from 136 mg/dL at base-
line to 150 mg/dL after 6 months, before gradually returning to
initial levels at 42 months. A similar pattern was observed in the
control group. This extended period of elevated LDL levels did not
prevent the fish-oil patients from experiencing significantly more
favorable cardiovascular and mortality outcomes :
Marchioli R, Barzi F, Bomba E, et al. Early protection against sudden death
by n-3 polyunsaturated fatty acids after myocardial infarction: time-course
analysis of the results of the Gruppo Italiano per lo Studio della
Sopravvivenza nell’Infarto Miocardico (G  I)-Prevenzione. Circulation
2002;105:1897-1903.
In the Scottish Aortic Stenosis and Lipid Lowering Trial,
patients with calcific aortic stenosis were randomly assigned to
receive either 80 mg of atorvastatin daily or placebo. After 25
months, serum LDL concentrations remained at an average 130
mg/dL in the placebo group but fell significantly to 63 mg mg/dL in
the atorvastatin group. Despite the fact that LDL levels were
reduced by more than half in the atorvastatin subjects, there was no
difference in aortic-jet velocity or progression in aortic-valve
calcification between the treatment or placebo groups. -
Cowell SJ, Newby DE, Prescott RJ, et al. A randomized trial of intensive
lipid-lowering therapy in calcific aortic stenosis. N Engl J Med
2005;352:2389-2397.
The lack of importance of total LDL levels was further
underscored by two recent trials that examined the impact of LDL-
lowering therapy on calcified coronary plaque progression. In the
first of these studies, patients given aggressive LDL cholesterol-
lowering treatment (statins plus niaicin) were compared with those
receiving less aggressive treatment (statins alone). Despite greater
LDL reductions in the former group, there were no differences in
calcified plaque progression as detected by electron beam
tomography. The authors concluded: “… with respect to LDL
cholesterol lowering, ‘lower is better’ is not supported by changes
in calcified plaque progression.”
- Hecht HS, Harman SM. Relation of aggressiveness of lipid-lowering
treatment to changes in calcified plaque burden by electron beam
tomography. Am J Cardiol 2003;92:334-336.
Von Shacky and coworkers, in a 2-year double-blind trial in
patients with CHD, found that daily fish-oil supplementation
increased the incidence of atherosclerotic regression, and
decreased the loss in minimal luminal diameter, as assessed by
quantitative coronary angiography. Fish-oil recipients also
experienced fewer cardiovascular events. LDL cholesterol levels
tended to be greater in the fish-oil group. - Von Schacky C, Angerer P Kothny W, et al. The effect of dietary omega-3
,
fatty acids on coronary atherosclerosis: A randomized, double-blind,
placebo-controlled trial. Ann Intern Med 1999;130:554-562.
זהו, אין לי כוח להביא לך עוד. אולי יותר מאוחר.
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