Final answer:
An HDL level above 60 mg/dl and a total cholesterol to HDL ratio below 5:1 are protective against heart disease. High HDL levels are good because they help remove cholesterol from the arteries, while low LDL levels below 100 mg/dL are ideal.
Step-by-step explanation:
Having an HDL level above 60 mg/dl and a total cholesterol to HDL ratio below 5:1 is especially protective of cardiovascular disease. Values of HDL less than 40 mg/dL for men and 50 mg/dL for women are considered risk factors for heart disease. Higher HDL levels are beneficial as they transport excess cholesterol to the liver for recycling and thus prevent arterial plaque buildup. Conversely, having LDL levels of less than 100 mg/dL is ideal, while values above 160 mg/dL are high and increase the risk of heart disease.
To maintain a healthy cardiovascular system, individuals should aim for a low LDL:HDL ratio, as this is a better predictor of heart disease risk than overall serum cholesterol levels. Dietary modifications and increased physical activity are recommended to improve this ratio. Additionally, maintaining a total blood cholesterol under 200 mg/dL and keeping triglycerides at or below 150 mg/dL are other key factors in reducing cardiovascular risk.