What are HDL and LDL?
HDL and LDL are two different kinds of cholesterol that are measured as an index of a patient’s risk for cardiovascular disease. HDL stands for high-density lipoprotein and LDL stands for low-density lipoprotein. Total cholesterol measures the combination of HDL and LDL, along with several other factors. The levels of “fats” in the blood-total cholesterol, HDL (a subset called “good cholesterol”) and LDL (“bad cholesterol”) and triglycerides have been used for years to predict the risk of heart disease in men. Higher cholesterol, LDL, triglycerides, and/or low HDL all are associated with increased risk of heart diseases in men.
What do the numbers mean?
Many studies found that women with higher total cholesterol levels also had higher rates of a form of heart disease called coronary artery disease. That is where the arteries to the heart become clogged. This leads to heart attacks. For cholesterol, levels of about 200 or less are generally not associated with much increased heart disease. Women with total cholesterol levels of 265 or more have been found to have this disease two or three times as often as women with levels of about 200. Even mildly elevated levels, of about 235, had about 70% higher rates, than normal.
Men in the same situation are put on a diet and drugs to lower their cholesterol. The goal was to increase HDL, and lower LDL and total cholesterol. Little was done to lower elevated triglyceride levels. The men’s rates of disease dropped. A closer look at the problem in women found something different. Low HDL (“good cholesterol”) levels were the strongest predictor of heart disease in women. These are generally levels less than 50 (mg/dL). Low HDL and high cholesterol go hand in hand for many, which led to the confusion about what was important. Women with total cholesterol levels as low as 200 who also had low HDL levels still had high risks of heart disease. In fact, the best predictor for women, according to one study, was the ratio of cholesterol to HDL. If a woman’s total cholesterol is about 4 times or so of her HDL level, her risk of heart disease skyrockets to up to five times that of her normal counterpart. If her triglycerides are high, her risk goes up, too. Again, that happens even if she has a low total cholesterol level.
Unlike men, a high LDL (“bad cholesterol”) level is not as strong a predictor of future trouble, although there is still considerable debate on this. Some experts believe LDL is not to be worried about for most women, except for particular sub-groups of women who are affected. As one might expect, until we clarify the importance of LDL for women and factor in the additional significance HDL has for women, the HDL/LDL ratio’s significance is muddied.
The Bottom Line
Total cholesterol in and of itself does not matter so much. Look at the other factors and ratios: especially HDL, triglycerides, and the cholesterol to HDL ratio. The significance of LDL and ratios with it are uncertain. Most of all, keep checking for new research. This area is rapidly changing for women.