As for your numbers, LDL itself is not a very good predictor of CHD risk. Low LDL patients have heart attacks at nearly the same rate as high LDL ones. HDL/LDL ratio is a bit better as a predictor, but you have to bear in mind that this presumes that all LDL are the same. LDL particle size is an important predictor of CHD risk and particles tend to be larger and more difficult to oxidize in patients with high-fat diets, high saturated fat intake, low carbohydrate intake, and/or circulating ketones. As a result, you could have an LDL of 70 but have it all be Pattern B (small, dense) particles which oxidize easily and worm their way into your arterial lining or an LDL of 150 but have it mostly be the benign (and in many ways helpful) Pattern A type.