Lipid lowering and ischaemic heart disease

Area of Science:

• Cardiology
• Biochemistry
• Preventive Medicine

Background:

• The relationship between serum cholesterol, LDL cholesterol, and ischemic heart disease (IHD) is complex and non-linear.
• Evidence supporting cholesterol reduction below 200-210 mg/dl for IHD prevention is limited.
• Regression of advanced atherosclerotic lesions in humans remains unproven, though animal studies show promise.

Purpose of the Study:

• To critically evaluate the evidence for cholesterol reduction in preventing and managing IHD.
• To assess the benefits and risks of lowering serum cholesterol, particularly concerning non-cardiovascular mortality.
• To provide recommendations for cholesterol management in different patient populations.

Main Methods:

• Review of primary prevention trials and epidemiological data on serum cholesterol and IHD.
• Analysis of studies investigating the regression of atheromatous lesions.
• Evaluation of mortality data, including cardiovascular and non-cardiovascular causes.

Main Results:

• Three major trials showed reduced non-fatal IHD mortality with cholesterol lowering, supporting the lipid hypothesis.
• These trials also indicated an increase in non-cardiovascular mortality.
• The benefit of reducing cholesterol in patients with established IHD is questionable due to other prognostic factors.

Conclusions:

• Doubts exist regarding the long-term safety of sustained cholesterol reduction, especially concerning aging cells.
• Aggressive treatment is recommended for familial hypercholesterolemia.
• General population advice includes reducing total fat intake to <30% and saturated fat to <1/3 of total fat calories.