The American Heart Association and National Institutes of Health report that several landmark studies have been performed to demonstrate how reducing high blood cholesterol levels will decrease cardiovascular (heart-related) death. These studies include the Coronary Primary Prevention Trial, Oslo Study Diet and Antismoking Trial, Helsinki Heart Study, Coronary Drug Project, Stockholm Ischemic Heart Study and West of Scotland Prevention Study.
Coronary Primary Prevention Trial (CPPT)
This study provided the first definite evidence that reducing LDL cholesterol (also known as "bad" cholesterol) and total blood cholesterol can help decrease the rate of heart attacks and coronary heart disease in men at risk of these complications due to high cholesterol. The CPPT was conducted between 1973 and 1983 with 3,800 middle-aged men who had high cholesterol levels.
Oslo Study Diet and Antismoking Trial
This study was conducted with 1,200 middle-aged men who had high blood cholesterol levels. The study demonstrated a ten percent decline in cholesterol levels and a 47 percent drop in cholesterol-related mortality over a span of five years. The lower mortality rate continued even after the trial was completed.
Helsinki Heart Study
The Helsinki Heart Study was conducted with 4,081 middle-aged men who had high blood cholesterol levels. It showed that treating these men with gemfibrozil (an oral drug for cholesterol) lowered cholesterol by 10 percent total. Gemfibrozil decreased LDL cholesterol by 11 percent and increased HDL ("good" cholesterol) by 11 percent. This study also reduced cholesterol-related mortality more than was expected.
Coronary Drug Project
This study involved giving niacin (a drug containing vitamin B, which helps lower cholesterol) to 1,119 men who had survived heart attacks. These were men were compared with a larger control group. After six years, cholesterol levels were found to be 10 percent lower. Nine years later, total group mortality in the group that had received the drug remained 11 percent lower than mortality rates of the control group.
Stockholm Ischemic Heart Study
This five-year study involved heart attack survivors being divided into treatment and control groups. The treatment group had 26 percent less deaths and 36 percent fewer deaths due to heart disease compared to the control group.
West of Scotland Coronary Prevention Study (WOS)
This study was performed with 6,595 men between age 45 to 64 who had high LDL cholesterol levels but no previous heart attacks. It demonstrated that the risk of having a heart attack dropped 31 percent by taking a widely prescribed cholesterol drug called pravastatin sodium. This drug decreased the risk of death amongst these men by 22 percent.
