MarcR wrote:The evidence suggests otherwise.Kenny4/4 wrote:all things equal a lower LDL equates to a lower CHD-CVD risk.
This 8-year study of 100,000+ people aged 50+ without preexisting diabetes or heart disease is the only high-powered study I have seen that focuses on the lipids of healthy older people. I am skeptical of the studies that support the high LDL -> disease link primarily because they include so many sick people. By excluding young people and those with preexisting diabetes, heart disease, or statin prescriptions, the study shows us a cross-section of people who navigated the contemporary nutritional minefield reasonably well to 1997. The subsequent experiences of this relatively insulin-sensitive population therefore seem more relevant to this question - how does LDL drive mortality when insulin is low?
It turns out that low LDL-C conforming to conventional recommendations correlates with greatly INCREASED mortality. LDL-C high enough to prompt many doctors to prescribe statins correlates with greatly REDUCED mortality. The effect is not small. As per Table III, here are the hazard ratios for LDL-C levels in mg/dL:
So if you're between the ages of 60 and 70, don't have diabetes and are not on a statin, having an LDL-C in excess of 154 mg/dL puts you in a group whose members are only 45% as likely to die as those with supposedly ideal LDL-C.
So, "all things equal", higher LDL-C = longer life in relatively healthy populations. If you want to parse it further, the two studies I cited in my previous post above show that LDL-C has no relationship with CVD event risk as long as one is insulin sensitive (low trigs/HDL ratio). The disappearance of the correlation in metabolically healthy people tells me that LDL-C is a marker of CVD risk in metabolically dysfunctional people, not a cause. And the huge reduction in all cause mortality as LDL-C rises suggests that plentiful LDL may offer benefits for overall health even though it has no effect on CVD risk.
They left out Statin users thereby confounding the population pool they sampled from. This results in a sampling bias as the high cholesterol portion that has high cardiovascular risk would be left out. This makes the high cholesterol population that is drawn from skewed in favor of robust individuals. Lower cholesterol high risk individuals would not be being treated with statins.
If you look at the historical data the pre statin era cholesterol studies show a u shaped CHD curve at a much lower nadir 160-200. I believe the all cause curve is lower as well. I will look them up and post them they are large sample size studies.
I agree that cholesterol is not the be all do all and that other lipid ratios have more meaningful significance.
Again the drawing population is sample biased in the statin era.