Which of the following is considered a negative risk factor?

The concept of negative risk factors refers to elements that can reduce the likelihood of adverse health outcomes, especially in relation to cardiovascular disease. In this context, having high levels of HDL (high-density lipoprotein) cholesterol is viewed as a protective factor. Specifically, an HDL level greater than 60 mg/dL is associated with a decreased risk of heart disease, hence why it is classified as a negative risk factor.

In contrast, the other options represent factors that do not contribute positively to reducing risk. For example, systolic blood pressure less than 120 mmHg is generally considered a normal reading, but it does not serve as a negative risk factor in the same way that high HDL does. Age above 65 years is known to increase the risk of various health issues, thus it is not a positive factor. Lastly, a BMI less than 25 is indicative of a healthy weight, which is beneficial, but it does not play the role of a negative risk factor in the same way as elevated HDL. High levels of HDL are commonly advocated as a protective measure, making it the distinguishing factor in this question.