International Journal of Cardiology
Letter to the Editor
The doubtful association between blood lipid changesand progression
Magle StoraKyrkogata 9, 22350 Lund, Sweden
|a r t i c l ei n f o
Received 20 August 2011
Recently Tenenbaum et al. reported that long-termchanges in serum cholesterol did not correlate with the progression ofcoronary calcium measured by computerized tomography (1). Theirfinding shows that the benefit of various cholesterol-loweringtreat-ments obtained in many angiographic trials must be caused by otherand un-known factors. The authors argued that one of the reasons to thelack of exposure/response may be that calcific plaques are resistant toundergoing changes in size in response to systemic anti-atherosclerotictherapy. However, other studies using different techniques and other kindsof outcome have also shown lack of exposure/response. In a pre-viousreview of the angiographic cholesterol-lowering trials I identifiedsixteen trials in which the authors had calculated exposure/responsebetween changes in low-density and/or total cholesterol, and degree ofathero-sclerotic progress measured either as change of minimum lumendiameter or percent stenosis (2). In these trials almost all kinds ofcholesterol lowering were used, including LDL-apheresis, multiple riskfactor reduction, low-fat diet and exercise, as well as drug treatmentwith chole-styramine, colestipol, niacin, fenofibrate, probucol, bezafibrate, lovastatin, prava-statin andsimvastatin. With one exception no expo-sure/response was recorded in anyof these trials. The exception was a trial where the only treatment usedwas physical exercise. In 12 of the trials exposure/response wasalsocalculated for HDL-cholesterol, in ten for tri-glycerides, in six for
|apolipoprotein B, in three forapolipoprotein A1, in three for VLDL-cholesterol andin one for small, dense LDL-cholesterol; in all of them the result was thesame: no exposure-response.
The findings of Tenenbaum et al. are in agree-mentwith the previous study by Hecht and Harman (3), who found no associationbetween the degree of LDL-cholesterol lowering and calcified plaqueprogression, using electron beam tomography. Exposure-response has alsobeen absent (4-6) and even inverse (7) in observationalangiographic studies.
Obviously the benefit achieved by the variouscholesterol-lowering treatments is caused by factors other than loweringof the blood lipids. Presence of exposure/response is not necessarilyproof of causa-lity, but its absence definitely disproves it. There-fore,the findings of Tenenbaum et al. cast doubt on the current view about thecausation of athero-sclerosis by plasma lipoproteins.References
 Tenenbaum A, Shemesh J, Koren-Morag, Fisman EZ,Adler Y, Goldenberg I, et al. Long-term changes in serum cholesterol leveldoes not influence the progression of coronary calci-fication. Int JCardiol 2011;150:130-4.
|Please cite this article as: Ravnskov U, The doubtful association betweenblood lipid changes and progression of atherosclerosis, Int J Cardiol(2011), doi:10.1016/j.ijcard.2011.08.
The doubtful association between blood lipid changes and progression
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