Is interleukin-6 the link between low LDL cholesterol and increased non-cardiovascular mortality in the elderly?

Abstract

A number of prospective studies, dating back to the 1980s, have found that lower levels of plasma cholesterol correlate with increased risk for cancer; in some of these studies, it was noted that this correlation was strongest for cancers diagnosed within a year of cholesterol measurement, suggesting the possibility of reverse causality.1–11 More recently, Ravnskov and colleagues conducted a systematic review of cohort studies enrolling subjects over 60 in which the association of low-density lipoprotein cholesterol (LDL-C) with all-cause mortality and/or cardiovascular mortality had been evaluated.12 In 14 of the 30 total cohorts involved, LDL-C was inversely and significantly associated with all-cause mortality; in the remaining 16, no association was found. With respect to cardiovascular mortality, which was determined in nine cohorts, the association of LDL-C was inverse and significant in two and null in seven. The failure to find a positive a correlation between LDL-C and cardiovascular mortality is consistent with the previous research reporting that the positive correlation of LDL cholesterol and cardiovascular mortality that is clearly seen among younger subjects is substantially blunted among the elderly.