Cholesterol, the substance that collects inside blood vessels and increases the risk of coronary artery disease, was the subject of a study that looked at Americans' cholesterol levels over a 22-year period to determine what, if any, changes had taken place.
Trends in Lipids and Lipoproteins Study
Wednesday, The Journal of the American Medical Association published the study "Trends in Lipids and Lipoproteins in US Adults, 1988-2010" and its results. The study's objective was to examine blood lipid levels (types of cholesterol and triglycerides) to determine trends over the 22-year period that was accomplished by examining blood test and interview results from three U.S. cross-sectional studies, with each study having 9,000 or more participants.
Heartwire puts the study results into language a layperson can understand: "Total cholesterol fell by 10 mg/dL..., LDL fell by 13 mg/dL, and HDL levels rose by 2 mg/dL." Additionally, although triglyceride levels early in the study period showed an increase, overall change during the study period was a drop of 8 mg/dL.
These trends held true for adults not taking cholesterol-lowering medications as well as the 15 percent of adults who are now prescribed the medications. During the study period the use of statins and other cholesterol-lowering drugs increased from an initial 3 percent to the 15 percent in 2010.
Lead study author Margaret D. Carroll, MSPH, discusses the study and its results in a short video at The Journal of the American Medical Association.
Good, but not Great, News
Brian Kit, M.D., MPH, a study co-author, related to Heartwire that he was "very encouraged" to see the positive trends in the general population in regards to the slight lowering of LDL cholesterol and the slight increase in HDL cholesterol.
Dr. Goodarz Danaei of the Harvard School of Public Health was more reserved in his assessment of the study results when interviewed by Reuters . While Danaei stated the results were "important and significant," he also explained that a small change in diet was all that was necessary to achieve the changes and what will really be significant is how lipid levels change in the future.
Dr. Roger Blumenthal, commenting to Heartwire, puts the data into perspective. The mean LDL cholesterol figure of 116 mg/dL for adults, the figure at the study's end, is still above the optimal level for this "bad" cholesterol, which is 100 mg/dL.
Theories on Cholesterol Level Changes
No one can say for certain why there were overall improvements in the lipid levels of U.S. adults, particularly because rates of obesity and body mass index numbers rose during the same time period as the study. Health experts are theorizing that the increased use of cholesterol-lowering medications over the study period along with decreasing rates of tobacco smoking and the lowered exposure to trans fats in processed foods likely worked together to result in the improved numbers.
As you age, the effects of cholesterol on your blood vessels increases. You are more likely to have narrowing of the blood vessel lumens, arteriosclerosis, and the loss of elasticity to your blood vessels from the buildup of plaque in the vessels, atherosclerosis. These two conditions increase your likelihood of having a number of health issues, including high blood pressure and heart disease.
Baby boomers and seniors, you are the people most likely to incur health problems from runaway cholesterol levels. Use this bit of good news to your advantage and talk to your health care provider about how you can manage your cholesterol levels.